/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#include <string>
#include <fstream>
#include <iostream>
#include <vector>
#include <list>

#include <stdlib.h>
#include <sys/stat.h>
#include <sstream>
#include "thrift/platform.h"
#include "thrift/version.h"
#include "thrift/generate/t_oop_generator.h"

using std::map;
using std::ostream;
using std::ostringstream;
using std::string;
using std::stringstream;
using std::vector;

static const string endl = "\n"; // avoid ostream << std::endl flushes

/**
 * PERL code generator.
 *
 */
class t_perl_generator : public t_oop_generator {
public:
  t_perl_generator(t_program* program,
                   const std::map<std::string, std::string>& parsed_options,
                   const std::string& option_string)
    : t_oop_generator(program), f_types_use_includes_emitted_(false) {
    (void)option_string;
    std::map<std::string, std::string>::const_iterator iter;

    /* no options yet */
    for( iter = parsed_options.begin(); iter != parsed_options.end(); ++iter) {
      throw "unknown option perl:" + iter->first;
    }

    out_dir_base_ = "gen-perl";
    escape_['$'] = "\\$";
    escape_['@'] = "\\@";
  }

  /**
   * Init and close methods
   */

  void init_generator() override;
  void close_generator() override;

  /**
   * Program-level generation functions
   */

  void generate_typedef(t_typedef* ttypedef) override;
  void generate_enum(t_enum* tenum) override;
  void generate_const(t_const* tconst) override;
  void generate_struct(t_struct* tstruct) override;
  void generate_xception(t_struct* txception) override;
  void generate_service(t_service* tservice) override;

  std::string render_const_value(t_type* type, t_const_value* value);

  /**
   * Structs!
   */

  void generate_perl_struct(t_struct* tstruct, bool is_exception);
  void generate_perl_struct_definition(std::ostream& out,
                                       t_struct* tstruct,
                                       bool is_xception = false);
  void generate_perl_struct_reader(std::ostream& out, t_struct* tstruct);
  void generate_perl_struct_writer(std::ostream& out, t_struct* tstruct);
  void generate_perl_function_helpers(t_function* tfunction);

  /**
   * Service-level generation functions
   */

  void generate_service_helpers(t_service* tservice);
  void generate_service_interface(t_service* tservice);
  void generate_service_rest(t_service* tservice);
  void generate_service_client(t_service* tservice);
  void generate_service_processor(t_service* tservice);
  void generate_process_function(t_service* tservice, t_function* tfunction);
  void generate_use_includes(std::ostream& os, bool& done, t_type *type, bool selfish);

  /**
   * Serialization constructs
   */

  void generate_deserialize_field(std::ostream& out,
                                  t_field* tfield,
                                  std::string prefix = "",
                                  bool inclass = false);

  void generate_deserialize_struct(std::ostream& out, t_struct* tstruct, std::string prefix = "");

  void generate_deserialize_container(std::ostream& out, t_type* ttype, std::string prefix = "");

  void generate_deserialize_set_element(std::ostream& out, t_set* tset, std::string prefix = "");

  void generate_deserialize_map_element(std::ostream& out, t_map* tmap, std::string prefix = "");

  void generate_deserialize_list_element(std::ostream& out,
                                         t_list* tlist,
                                         std::string prefix = "");

  void generate_serialize_field(std::ostream& out, t_field* tfield, std::string prefix = "");

  void generate_serialize_struct(std::ostream& out, t_struct* tstruct, std::string prefix = "");

  void generate_serialize_container(std::ostream& out, t_type* ttype, std::string prefix = "");

  void generate_serialize_map_element(std::ostream& out,
                                      t_map* tmap,
                                      std::string kiter,
                                      std::string viter);

  void generate_serialize_set_element(std::ostream& out, t_set* tmap, std::string iter);

  void generate_serialize_list_element(std::ostream& out, t_list* tlist, std::string iter);

  /**
   * Helper rendering functions
   */

  std::string perl_includes();
  std::string declare_field(t_field* tfield, bool init = false, bool obj = false);
  std::string function_signature(t_function* tfunction, std::string prefix = "");
  std::string argument_list(t_struct* tstruct);
  std::string type_to_enum(t_type* ttype);

  std::string autogen_comment() override {
    return std::string("#\n") + "# Autogenerated by Thrift Compiler (" + THRIFT_VERSION + ")\n"
           + "#\n" + "# DO NOT EDIT UNLESS YOU ARE SURE THAT YOU KNOW WHAT YOU ARE DOING\n" + "#\n";
  }

  void perl_namespace_dirs(t_program* p, std::list<std::string>& dirs) {
    std::string ns = p->get_namespace("perl");
    std::string::size_type loc;

    if (ns.size() > 0) {
      while ((loc = ns.find(".")) != std::string::npos) {
        dirs.push_back(ns.substr(0, loc));
        ns = ns.substr(loc + 1);
      }
    }

    if (ns.size() > 0) {
      dirs.push_back(ns);
    }
  }

  std::string perl_namespace(t_program* p) {
    std::string ns = p->get_namespace("perl");
    std::string result = "";
    std::string::size_type loc;

    if (ns.size() > 0) {
      while ((loc = ns.find(".")) != std::string::npos) {
        result += ns.substr(0, loc);
        result += "::";
        ns = ns.substr(loc + 1);
      }

      if (ns.size() > 0) {
        result += ns + "::";
      }
    }

    return result;
  }

  std::string get_namespace_out_dir() {
    std::string outdir = get_out_dir();
    std::list<std::string> dirs;
    perl_namespace_dirs(program_, dirs);
    std::list<std::string>::iterator it;
    for (it = dirs.begin(); it != dirs.end(); it++) {
      outdir += *it + "/";
    }
    return outdir;
  }

private:
  /**
   * File streams
   */
  ofstream_with_content_based_conditional_update f_types_;
  ofstream_with_content_based_conditional_update f_consts_;
  ofstream_with_content_based_conditional_update f_helpers_;
  ofstream_with_content_based_conditional_update f_service_;

  bool f_types_use_includes_emitted_;
};

/**
 * Prepares for file generation by opening up the necessary file output
 * streams.
 *
 * @param tprogram The program to generate
 */
void t_perl_generator::init_generator() {
  // Make output directory
  MKDIR(get_out_dir().c_str());

  string outdir = get_out_dir();
  std::list<std::string> dirs;
  perl_namespace_dirs(program_, dirs);
  std::list<std::string>::iterator it;
  for (it = dirs.begin(); it != dirs.end(); it++) {
    outdir += *it + "/";
    MKDIR(outdir.c_str());
  }

  // Make output file
  string f_types_name = outdir + "Types.pm";
  f_types_.open(f_types_name.c_str());
  string f_consts_name = outdir + "Constants.pm";
  f_consts_.open(f_consts_name.c_str());

  // Print header
  f_types_ << autogen_comment() << perl_includes();

  // Print header
  f_consts_ << autogen_comment() << "package " << perl_namespace(program_) << "Constants;" << endl
            << perl_includes() << endl;
}

/**
 * Prints standard java imports
 */
string t_perl_generator::perl_includes() {
  string inc;

  inc  = "use 5.10.0;\n";
  inc += "use strict;\n";
  inc += "use warnings;\n";
  inc += "use Thrift::Exception;\n";
  inc += "use Thrift::MessageType;\n";
  inc += "use Thrift::Type;\n\n";

  return inc;
}

/**
 * Close up (or down) some filez.
 */
void t_perl_generator::close_generator() {
  // Close types file
  f_types_ << "1;" << endl;
  f_types_.close();

  f_consts_ << "1;" << endl;
  f_consts_.close();
}

/**
 * Generates a typedef. This is not done in PERL, types are all implicit.
 *
 * @param ttypedef The type definition
 */
void t_perl_generator::generate_typedef(t_typedef* ttypedef) {
  (void)ttypedef;
}

/**
 * Generates code for an enumerated type. Since define is expensive to lookup
 * in PERL, we use a global array for this.
 *
 * @param tenum The enumeration
 */
void t_perl_generator::generate_enum(t_enum* tenum) {
  f_types_ << "package " << perl_namespace(program_) << tenum->get_name() << ";" << endl;

  vector<t_enum_value*> constants = tenum->get_constants();
  vector<t_enum_value*>::iterator c_iter;
  for (c_iter = constants.begin(); c_iter != constants.end(); ++c_iter) {
    int value = (*c_iter)->get_value();
    f_types_ << "use constant " << (*c_iter)->get_name() << " => " << value << ";" << endl;
  }
}

/**
 * Generate a constant value
 */
void t_perl_generator::generate_const(t_const* tconst) {
  t_type* type = tconst->get_type();
  string name = tconst->get_name();
  t_const_value* value = tconst->get_value();

  f_consts_ << "use constant " << name << " => ";
  f_consts_ << render_const_value(type, value);
  f_consts_ << ";" << endl << endl;
}

/**
 * Prints the value of a constant with the given type. Note that type checking
 * is NOT performed in this function as it is always run beforehand using the
 * validate_types method in main.cc
 */
string t_perl_generator::render_const_value(t_type* type, t_const_value* value) {
  std::ostringstream out;

  type = get_true_type(type);

  if (type->is_base_type()) {
    t_base_type::t_base tbase = ((t_base_type*)type)->get_base();
    switch (tbase) {
    case t_base_type::TYPE_STRING:
      out << '"' << get_escaped_string(value) << '"';
      break;
    case t_base_type::TYPE_BOOL:
      out << (value->get_integer() > 0 ? "1" : "0");
      break;
    case t_base_type::TYPE_I8:
    case t_base_type::TYPE_I16:
    case t_base_type::TYPE_I32:
    case t_base_type::TYPE_I64:
      out << value->get_integer();
      break;
    case t_base_type::TYPE_DOUBLE:
      if (value->get_type() == t_const_value::CV_INTEGER) {
        out << value->get_integer();
      } else {
        out << value->get_double();
      }
      break;
    default:
      throw "compiler error: no const of base type " + t_base_type::t_base_name(tbase);
    }
  } else if (type->is_enum()) {
    out << value->get_integer();
  } else if (type->is_struct() || type->is_xception()) {
    out << perl_namespace(type->get_program()) << type->get_name() << "->new({" << endl;
    indent_up();

    const vector<t_field*>& fields = ((t_struct*)type)->get_members();
    vector<t_field*>::const_iterator f_iter;
    const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
    map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
    for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
      t_type* field_type = nullptr;
      for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
        if ((*f_iter)->get_name() == v_iter->first->get_string()) {
          field_type = (*f_iter)->get_type();
        }
      }
      if (field_type == nullptr) {
        throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
      }
      indent(out) << render_const_value(g_type_string, v_iter->first);
      out << " => ";
      out << render_const_value(field_type, v_iter->second);
      out << ",";
      out << endl;
    }
    indent_down();
    indent(out) << "})";
  } else if (type->is_map()) {
    t_type* ktype = ((t_map*)type)->get_key_type();
    t_type* vtype = ((t_map*)type)->get_val_type();
    out << "{" << endl;
    indent_up();

    const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
    map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
    for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
      indent(out) << render_const_value(ktype, v_iter->first);
      out << " => ";
      out << render_const_value(vtype, v_iter->second);
      out << "," << endl;
    }
    indent_down();
    indent(out) << "}";
  } else if (type->is_list() || type->is_set()) {
    t_type* etype;
    if (type->is_list()) {
      etype = ((t_list*)type)->get_elem_type();
    } else {
      etype = ((t_set*)type)->get_elem_type();
    }
    out << "[" << endl;
    indent_up();

    const vector<t_const_value*>& val = value->get_list();
    vector<t_const_value*>::const_iterator v_iter;
    for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {

      indent(out) << render_const_value(etype, *v_iter);
      if (type->is_set()) {
        out << " => 1";
      }
      out << "," << endl;
    }
    indent_down();
    indent(out) << "]";
  }
  return out.str();
}

/**
 * Make a struct
 */
void t_perl_generator::generate_struct(t_struct* tstruct) {
  generate_perl_struct(tstruct, false);
}

/**
 * Generates a struct definition for a thrift exception. Basically the same
 * as a struct but extends the Exception class.
 *
 * @param txception The struct definition
 */
void t_perl_generator::generate_xception(t_struct* txception) {
  generate_perl_struct(txception, true);
}

/**
 * Structs can be normal or exceptions.
 */
void t_perl_generator::generate_perl_struct(t_struct* tstruct, bool is_exception) {
  generate_use_includes(f_types_, f_types_use_includes_emitted_, tstruct, false);
  generate_perl_struct_definition(f_types_, tstruct, is_exception);
}

/**
 * Generates a struct definition for a thrift data type. This is nothing in PERL
 * where the objects are all just associative arrays (unless of course we
 * decide to start using objects for them...)
 *
 * @param tstruct The struct definition
 */
void t_perl_generator::generate_perl_struct_definition(ostream& out,
                                                       t_struct* tstruct,
                                                       bool is_exception) {
  const vector<t_field*>& members = tstruct->get_members();
  vector<t_field*>::const_iterator m_iter;

  out << "package " << perl_namespace(tstruct->get_program()) << tstruct->get_name() << ";\n";
  if (is_exception) {
    out << "use base qw(Thrift::TException);\n";
  }

  // Create simple acessor methods
  out << "use base qw(Class::Accessor);\n";

  if (members.size() > 0) {
    out << perl_namespace(tstruct->get_program()) << tstruct->get_name() << "->mk_accessors( qw( ";
    for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
      t_type* t = get_true_type((*m_iter)->get_type());
      if (!t->is_xception()) {
        out << (*m_iter)->get_name() << " ";
      }
    }

    out << ") );\n";
  }

  out << endl;

  // new()
  indent_up();
  out << "sub new {" << endl << indent() << "my $classname = shift;" << endl << indent()
      << "my $self      = {};" << endl << indent() << "my $vals      = shift || {};" << endl;

  for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
    string dval = "undef";
    t_type* t = get_true_type((*m_iter)->get_type());
    if ((*m_iter)->get_value() != nullptr && !(t->is_struct() || t->is_xception())) {
      dval = render_const_value((*m_iter)->get_type(), (*m_iter)->get_value());
    }
    out << indent() << "$self->{" << (*m_iter)->get_name() << "} = " << dval << ";" << endl;
  }

  // Generate constructor from array
  if (members.size() > 0) {

    for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
      t_type* t = get_true_type((*m_iter)->get_type());
      if ((*m_iter)->get_value() != nullptr && (t->is_struct() || t->is_xception())) {
        indent(out) << "$self->{" << (*m_iter)->get_name()
                    << "} = " << render_const_value(t, (*m_iter)->get_value()) << ";" << endl;
      }
    }

    out << indent() << "if (UNIVERSAL::isa($vals,'HASH')) {" << endl;
    indent_up();
    for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
      out << indent() << "if (defined $vals->{" << (*m_iter)->get_name() << "}) {" << endl
          << indent() << "  $self->{" << (*m_iter)->get_name() << "} = $vals->{"
          << (*m_iter)->get_name() << "};" << endl << indent() << "}" << endl;
    }
    indent_down();
    out << indent() << "}" << endl;
  }

  out << indent() << "return bless ($self, $classname);" << endl;
  indent_down();
  out << "}\n\n";

  out << "sub getName {" << endl << indent() << "  return '" << tstruct->get_name() << "';" << endl
      << indent() << "}" << endl << endl;

  generate_perl_struct_reader(out, tstruct);
  generate_perl_struct_writer(out, tstruct);
}

/**
 * Generates the read() method for a struct
 */
void t_perl_generator::generate_perl_struct_reader(ostream& out, t_struct* tstruct) {
  const vector<t_field*>& fields = tstruct->get_members();
  vector<t_field*>::const_iterator f_iter;

  out << "sub read {" << endl;

  indent_up();

  out << indent() << "my ($self, $input) = @_;" << endl << indent() << "my $xfer  = 0;" << endl
      << indent() << "my $fname;" << endl << indent() << "my $ftype = 0;" << endl << indent()
      << "my $fid   = 0;" << endl;

  indent(out) << "$xfer += $input->readStructBegin(\\$fname);" << endl;

  // Loop over reading in fields
  indent(out) << "while (1)" << endl;

  scope_up(out);

  indent(out) << "$xfer += $input->readFieldBegin(\\$fname, \\$ftype, \\$fid);" << endl;

  // Check for field STOP marker and break
  indent(out) << "if ($ftype == Thrift::TType::STOP) {" << endl;
  indent_up();
  indent(out) << "last;" << endl;
  indent_down();
  indent(out) << "}" << endl;

  // Switch statement on the field we are reading
  indent(out) << "SWITCH: for($fid)" << endl;

  scope_up(out);

  // Generate deserialization code for known cases
  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {

    indent(out) << "/^" << (*f_iter)->get_key() << "$/ && do{";
    indent(out) << "if ($ftype == " << type_to_enum((*f_iter)->get_type()) << ") {" << endl;

    indent_up();
    generate_deserialize_field(out, *f_iter, "self->");
    indent_down();

    indent(out) << "} else {" << endl;

    indent(out) << "  $xfer += $input->skip($ftype);" << endl;

    out << indent() << "}" << endl << indent() << "last; };" << endl;
  }
  // In the default case we skip the field

  indent(out) << "  $xfer += $input->skip($ftype);" << endl;

  scope_down(out);

  indent(out) << "$xfer += $input->readFieldEnd();" << endl;

  scope_down(out);

  indent(out) << "$xfer += $input->readStructEnd();" << endl;

  indent(out) << "return $xfer;" << endl;

  indent_down();
  out << indent() << "}" << endl << endl;
}

/**
 * Generates the write() method for a struct
 */
void t_perl_generator::generate_perl_struct_writer(ostream& out, t_struct* tstruct) {
  string name = tstruct->get_name();
  const vector<t_field*>& fields = tstruct->get_sorted_members();
  vector<t_field*>::const_iterator f_iter;

  out << "sub write {" << endl;

  indent_up();
  indent(out) << "my ($self, $output) = @_;" << endl;
  indent(out) << "my $xfer   = 0;" << endl;

  indent(out) << "$xfer += $output->writeStructBegin('" << name << "');" << endl;

  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
    out << indent() << "if (defined $self->{" << (*f_iter)->get_name() << "}) {" << endl;
    indent_up();

    indent(out) << "$xfer += $output->writeFieldBegin("
                << "'" << (*f_iter)->get_name() << "', " << type_to_enum((*f_iter)->get_type())
                << ", " << (*f_iter)->get_key() << ");" << endl;

    // Write field contents
    generate_serialize_field(out, *f_iter, "self->");

    indent(out) << "$xfer += $output->writeFieldEnd();" << endl;

    indent_down();
    indent(out) << "}" << endl;
  }

  out << indent() << "$xfer += $output->writeFieldStop();" << endl << indent()
      << "$xfer += $output->writeStructEnd();" << endl;

  out << indent() << "return $xfer;" << endl;

  indent_down();
  out << indent() << "}" << endl << endl;
}

/**
 * Generates use clauses for included entities
 *
 * @param  os       The output stream
 * @param  done     A flag reference to debounce the action
 * @param  type     The type being processed
 * @param  selfish  Flag to indicate if the current namespace types should be "use"d as well.
 */
void t_perl_generator::generate_use_includes(std::ostream& os, bool& done, t_type *type, bool selfish) {
  t_program *current = type->get_program();
  if (current && !done) {
    std::vector<t_program*>& currInc = current->get_includes();
    std::vector<t_program*>::size_type numInc = currInc.size();
    if (selfish) {
      os << "use " << perl_namespace(current) << "Types;" << endl;
    }
    for (std::vector<t_program*>::size_type i = 0; i < numInc; ++i) {
      t_program* incProgram = currInc.at(i);
      os << "use " << perl_namespace(incProgram) << "Types;" << endl;
    }
    os << endl;
    done = true;
  }
}

/**
 * Generates a thrift service.
 *
 * @param tservice The service definition
 */
void t_perl_generator::generate_service(t_service* tservice) {
  string f_service_name = get_namespace_out_dir() + service_name_ + ".pm";
  f_service_.open(f_service_name.c_str());

  f_service_ << autogen_comment() << perl_includes();

  bool done = false;
  generate_use_includes(f_service_, done, tservice, true);

  t_service* extends_s = tservice->get_extends();
  if (extends_s != nullptr) {
    f_service_ << "use " << perl_namespace(extends_s->get_program()) << extends_s->get_name() << ";"
               << endl;
  }

  f_service_ << endl;

  // Generate the three main parts of the service (well, two for now in PERL)
  generate_service_helpers(tservice);
  generate_service_interface(tservice);
  generate_service_rest(tservice);
  generate_service_client(tservice);
  generate_service_processor(tservice);

  // Close service file
  f_service_ << "1;" << endl;
  f_service_.close();
}

/**
 * Generates a service server definition.
 *
 * @param tservice The service to generate a server for.
 */
void t_perl_generator::generate_service_processor(t_service* tservice) {
  // Generate the dispatch methods
  vector<t_function*> functions = tservice->get_functions();
  vector<t_function*>::iterator f_iter;

  string extends = "";
  string extends_processor = "";
  t_service* extends_s = tservice->get_extends();
  if (extends_s != nullptr) {
    extends = perl_namespace(extends_s->get_program()) + extends_s->get_name();
    extends_processor = "use base qw(" + extends + "Processor);";
  }

  indent_up();

  // Generate the header portion
  f_service_ << "package " << perl_namespace(program_) << service_name_ << "Processor;" << endl
             << endl << "use strict;" << endl << extends_processor << endl << endl;

  if (extends.empty()) {
    f_service_ << "sub new {" << endl;

    indent_up();

    f_service_ << indent() << "my ($classname, $handler) = @_;" << endl << indent()
               << "my $self      = {};" << endl;

    f_service_ << indent() << "$self->{handler} = $handler;" << endl;

    f_service_ << indent() << "return bless ($self, $classname);" << endl;

    indent_down();

    f_service_ << "}" << endl << endl;
  }

  // Generate the server implementation
  f_service_ << "sub process {" << endl;
  indent_up();

  f_service_ << indent() << "my ($self, $input, $output) = @_;" << endl;

  f_service_ << indent() << "my $rseqid = 0;" << endl << indent() << "my $fname  = undef;" << endl
             << indent() << "my $mtype  = 0;" << endl << endl;

  f_service_ << indent() << "$input->readMessageBegin(\\$fname, \\$mtype, \\$rseqid);" << endl;

  // HOT: check for method implementation
  f_service_ << indent() << "my $methodname = 'process_'.$fname;" << endl << indent()
             << "if (!$self->can($methodname)) {" << endl;
  indent_up();

  f_service_ << indent() << "$input->skip(Thrift::TType::STRUCT);" << endl << indent()
             << "$input->readMessageEnd();" << endl << indent()
             << "my $x = Thrift::TApplicationException->new('Function '.$fname.' not implemented.', "
                "Thrift::TApplicationException::UNKNOWN_METHOD);" << endl << indent()
             << "$output->writeMessageBegin($fname, Thrift::TMessageType::EXCEPTION, $rseqid);" << endl
             << indent() << "$x->write($output);" << endl << indent()
             << "$output->writeMessageEnd();" << endl << indent()
             << "$output->getTransport()->flush();" << endl << indent() << "return;" << endl;

  indent_down();
  f_service_ << indent() << "}" << endl << indent()
             << "$self->$methodname($rseqid, $input, $output);" << endl << indent() << "return 1;"
             << endl;

  indent_down();

  f_service_ << "}" << endl << endl;

  // Generate the process subfunctions
  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    generate_process_function(tservice, *f_iter);
  }
}

/**
 * Generates a process function definition.
 *
 * @param tfunction The function to write a dispatcher for
 */
void t_perl_generator::generate_process_function(t_service* tservice, t_function* tfunction) {
  // Open function
  f_service_ << "sub process_" << tfunction->get_name() << " {" << endl;

  indent_up();

  f_service_ << indent() << "my ($self, $seqid, $input, $output) = @_;" << endl;

  string argsname = perl_namespace(tservice->get_program()) + service_name_ + "_"
                    + tfunction->get_name() + "_args";
  string resultname = perl_namespace(tservice->get_program()) + service_name_ + "_"
                      + tfunction->get_name() + "_result";

  f_service_ << indent() << "my $args = " << argsname << "->new();" << endl << indent()
             << "$args->read($input);" << endl;

  f_service_ << indent() << "$input->readMessageEnd();" << endl;

  t_struct* xs = tfunction->get_xceptions();
  const std::vector<t_field*>& xceptions = xs->get_members();
  vector<t_field*>::const_iterator x_iter;

  // Declare result for non oneway function
  if (!tfunction->is_oneway()) {
    f_service_ << indent() << "my $result = " << resultname << "->new();" << endl;
  }

  // Try block for a function with exceptions
  if (xceptions.size() > 0) {
    f_service_ << indent() << "eval {" << endl;
    indent_up();
  }

  // Generate the function call
  t_struct* arg_struct = tfunction->get_arglist();
  const std::vector<t_field*>& fields = arg_struct->get_members();
  vector<t_field*>::const_iterator f_iter;

  f_service_ << indent();
  if (!tfunction->is_oneway() && !tfunction->get_returntype()->is_void()) {
    f_service_ << "$result->{success} = ";
  }
  f_service_ << "$self->{handler}->" << tfunction->get_name() << "(";
  bool first = true;
  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
    if (first) {
      first = false;
    } else {
      f_service_ << ", ";
    }
    f_service_ << "$args->" << (*f_iter)->get_name();
  }
  f_service_ << ");" << endl;

  if (!tfunction->is_oneway() && xceptions.size() > 0) {
    indent_down();
    for (x_iter = xceptions.begin(); x_iter != xceptions.end(); ++x_iter) {
      f_service_ << indent() << "}; if( UNIVERSAL::isa($@,'"
                 << perl_namespace((*x_iter)->get_type()->get_program())
                 << (*x_iter)->get_type()->get_name() << "') ){ " << endl;

      indent_up();
      f_service_ << indent() << "$result->{" << (*x_iter)->get_name() << "} = $@;" << endl;
      f_service_ << indent() << "$@ = undef;" << endl;
      indent_down();
      f_service_ << indent();
    }
    f_service_ << "}" << endl;

    // catch-all for unexpected exceptions (THRIFT-3191)
    f_service_ << indent() << "if ($@) {" << endl;
    indent_up();
    f_service_ << indent() << "$@ =~ s/^\\s+|\\s+$//g;" << endl
               << indent() << "my $err = Thrift::TApplicationException->new(\"Unexpected Exception: \" . $@, Thrift::TApplicationException::INTERNAL_ERROR);" << endl
               << indent() << "$output->writeMessageBegin('" << tfunction->get_name() << "', Thrift::TMessageType::EXCEPTION, $seqid);" << endl
               << indent() << "$err->write($output);" << endl
               << indent() << "$output->writeMessageEnd();" << endl
               << indent() << "$output->getTransport()->flush();" << endl
               << indent() << "$@ = undef;" << endl
               << indent() << "return;" << endl;
    indent_down();
    f_service_ << indent() << "}" << endl;
  }

  // Shortcut out here for oneway functions
  if (tfunction->is_oneway()) {
    f_service_ << indent() << "return;" << endl;
    indent_down();
    f_service_ << "}" << endl;
    return;
  }

  // Serialize the reply
  f_service_ << indent() << "$output->writeMessageBegin('" << tfunction->get_name() << "', Thrift::TMessageType::REPLY, $seqid);" << endl
             << indent() << "$result->write($output);" << endl
             << indent() << "$output->writeMessageEnd();" << endl
             << indent() << "$output->getTransport()->flush();" << endl;

  // Close function
  indent_down();
  f_service_ << "}" << endl << endl;
}

/**
 * Generates helper functions for a service.
 *
 * @param tservice The service to generate a header definition for
 */
void t_perl_generator::generate_service_helpers(t_service* tservice) {
  vector<t_function*> functions = tservice->get_functions();
  vector<t_function*>::iterator f_iter;

  f_service_ << "# HELPER FUNCTIONS AND STRUCTURES" << endl << endl;

  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    t_struct* ts = (*f_iter)->get_arglist();
    string name = ts->get_name();
    ts->set_name(service_name_ + "_" + name);
    generate_perl_struct_definition(f_service_, ts, false);
    generate_perl_function_helpers(*f_iter);
    ts->set_name(name);
  }
}

/**
 * Generates a struct and helpers for a function.
 *
 * @param tfunction The function
 */
void t_perl_generator::generate_perl_function_helpers(t_function* tfunction) {
  t_struct result(program_, service_name_ + "_" + tfunction->get_name() + "_result");
  t_field success(tfunction->get_returntype(), "success", 0);
  if (!tfunction->get_returntype()->is_void()) {
    result.append(&success);
  }

  t_struct* xs = tfunction->get_xceptions();
  const vector<t_field*>& fields = xs->get_members();
  vector<t_field*>::const_iterator f_iter;
  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
    result.append(*f_iter);
  }

  generate_perl_struct_definition(f_service_, &result, false);
}

/**
 * Generates a service interface definition.
 *
 * @param tservice The service to generate a header definition for
 */
void t_perl_generator::generate_service_interface(t_service* tservice) {
  string extends_if = "";
  t_service* extends_s = tservice->get_extends();
  if (extends_s != nullptr) {
    extends_if = "use base qw(" + perl_namespace(extends_s->get_program()) + extends_s->get_name()
                 + "If);";
  }

  f_service_ << "package " << perl_namespace(program_) << service_name_ << "If;" << endl << endl
             << "use strict;" << endl << extends_if << endl << endl;

  indent_up();
  vector<t_function*> functions = tservice->get_functions();
  vector<t_function*>::iterator f_iter;
  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    f_service_ << "sub " << function_signature(*f_iter) << endl << "  die 'implement interface';\n}"
               << endl << endl;
  }
  indent_down();
}

/**
 * Generates a REST interface
 */
void t_perl_generator::generate_service_rest(t_service* tservice) {
  string extends = "";
  string extends_if = "";
  t_service* extends_s = tservice->get_extends();
  if (extends_s != nullptr) {
    extends = extends_s->get_name();
    extends_if = "use base qw(" + perl_namespace(extends_s->get_program()) + extends_s->get_name()
                 + "Rest);";
  }
  f_service_ << "package " << perl_namespace(program_) << service_name_ << "Rest;" << endl << endl
             << "use strict;" << endl << extends_if << endl << endl;

  if (extends.empty()) {
    f_service_ << "sub new {" << endl;

    indent_up();

    f_service_ << indent() << "my ($classname, $impl) = @_;" << endl << indent()
               << "my $self     ={ impl => $impl };" << endl << endl << indent()
               << "return bless($self,$classname);" << endl;

    indent_down();

    f_service_ << "}" << endl << endl;
  }

  vector<t_function*> functions = tservice->get_functions();
  vector<t_function*>::iterator f_iter;
  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    f_service_ << "sub " << (*f_iter)->get_name() << "{" << endl;

    indent_up();

    f_service_ << indent() << "my ($self, $request) = @_;" << endl << endl;

    const vector<t_field*>& args = (*f_iter)->get_arglist()->get_members();
    vector<t_field*>::const_iterator a_iter;
    for (a_iter = args.begin(); a_iter != args.end(); ++a_iter) {
      t_type* atype = get_true_type((*a_iter)->get_type());
      string req = "$request->{'" + (*a_iter)->get_name() + "'}";
      f_service_ << indent() << "my $" << (*a_iter)->get_name() << " = (" << req << ") ? " << req
                 << " : undef;" << endl;
      if (atype->is_string() && ((t_base_type*)atype)->is_string_list()) {
        f_service_ << indent() << "my @" << (*a_iter)->get_name() << " = split(/,/, $"
                   << (*a_iter)->get_name() << ");" << endl << indent() << "$"
                   << (*a_iter)->get_name() << " = \\@" << (*a_iter)->get_name() << endl;
      }
    }
    f_service_ << indent() << "return $self->{impl}->" << (*f_iter)->get_name() << "("
               << argument_list((*f_iter)->get_arglist()) << ");" << endl;
    indent_down();
    indent(f_service_) << "}" << endl << endl;
  }
}

/**
 * Generates a service client definition.
 *
 * @param tservice The service to generate a server for.
 */
void t_perl_generator::generate_service_client(t_service* tservice) {
  string extends = "";
  string extends_client = "";
  t_service* extends_s = tservice->get_extends();
  if (extends_s != nullptr) {
    extends = perl_namespace(extends_s->get_program()) + extends_s->get_name();
    extends_client = "use base qw(" + extends + "Client);";
  }

  f_service_ << "package " << perl_namespace(program_) << service_name_ << "Client;" << endl << endl
             << extends_client << endl << "use base qw(" << perl_namespace(program_)
             << service_name_ << "If);" << endl;

  // Constructor function
  f_service_ << "sub new {" << endl;

  indent_up();

  f_service_ << indent() << "my ($classname, $input, $output) = @_;" << endl << indent()
             << "my $self      = {};" << endl;

  if (!extends.empty()) {
    f_service_ << indent() << "$self = $classname->SUPER::new($input, $output);" << endl;
  } else {
    f_service_ << indent() << "$self->{input}  = $input;" << endl << indent()
               << "$self->{output} = defined $output ? $output : $input;" << endl << indent()
               << "$self->{seqid}  = 0;" << endl;
  }

  f_service_ << indent() << "return bless($self,$classname);" << endl;

  indent_down();

  f_service_ << "}" << endl << endl;

  // Generate client method implementations
  vector<t_function*> functions = tservice->get_functions();
  vector<t_function*>::const_iterator f_iter;
  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    t_struct* arg_struct = (*f_iter)->get_arglist();
    const vector<t_field*>& fields = arg_struct->get_members();
    vector<t_field*>::const_iterator fld_iter;
    string funname = (*f_iter)->get_name();

    // Open function
    f_service_ << "sub " << function_signature(*f_iter) << endl;

    indent_up();

    indent(f_service_) << indent() << "$self->send_" << funname << "(";

    bool first = true;
    for (fld_iter = fields.begin(); fld_iter != fields.end(); ++fld_iter) {
      if (first) {
        first = false;
      } else {
        f_service_ << ", ";
      }
      f_service_ << "$" << (*fld_iter)->get_name();
    }
    f_service_ << ");" << endl;

    if (!(*f_iter)->is_oneway()) {
      f_service_ << indent();
      if (!(*f_iter)->get_returntype()->is_void()) {
        f_service_ << "return ";
      }
      f_service_ << "$self->recv_" << funname << "();" << endl;
    }

    indent_down();

    f_service_ << "}" << endl << endl;

    f_service_ << "sub send_" << function_signature(*f_iter) << endl;

    indent_up();

    std::string argsname = perl_namespace(tservice->get_program()) + service_name_ + "_"
                           + (*f_iter)->get_name() + "_args";

    // Serialize the request header
    f_service_ << indent() << "$self->{output}->writeMessageBegin('" << (*f_iter)->get_name()
               << "', " << ((*f_iter)->is_oneway() ? "Thrift::TMessageType::ONEWAY" : "Thrift::TMessageType::CALL")
               << ", $self->{seqid});" << endl;

    f_service_ << indent() << "my $args = " << argsname << "->new();" << endl;

    for (fld_iter = fields.begin(); fld_iter != fields.end(); ++fld_iter) {
      f_service_ << indent() << "$args->{" << (*fld_iter)->get_name() << "} = $"
                 << (*fld_iter)->get_name() << ";" << endl;
    }

    // Write to the stream
    f_service_ << indent() << "$args->write($self->{output});" << endl << indent()
               << "$self->{output}->writeMessageEnd();" << endl << indent()
               << "$self->{output}->getTransport()->flush();" << endl;

    indent_down();

    f_service_ << "}" << endl;

    if (!(*f_iter)->is_oneway()) {
      std::string resultname = perl_namespace(tservice->get_program()) + service_name_ + "_"
                               + (*f_iter)->get_name() + "_result";
      t_struct noargs(program_);

      t_function recv_function((*f_iter)->get_returntype(),
                               string("recv_") + (*f_iter)->get_name(),
                               &noargs);
      // Open function
      f_service_ << endl << "sub " << function_signature(&recv_function) << endl;

      indent_up();

      f_service_ << indent() << "my $rseqid = 0;" << endl << indent() << "my $fname;" << endl
                 << indent() << "my $mtype = 0;" << endl << endl;

      f_service_ << indent() << "$self->{input}->readMessageBegin(\\$fname, \\$mtype, \\$rseqid);"
                 << endl << indent() << "if ($mtype == Thrift::TMessageType::EXCEPTION) {" << endl
                 << indent() << "  my $x = Thrift::TApplicationException->new();" << endl << indent()
                 << "  $x->read($self->{input});" << endl << indent()
                 << "  $self->{input}->readMessageEnd();" << endl << indent() << "  die $x;" << endl
                 << indent() << "}" << endl;

      f_service_ << indent() << "my $result = " << resultname << "->new();" << endl << indent()
                 << "$result->read($self->{input});" << endl;

      f_service_ << indent() << "$self->{input}->readMessageEnd();" << endl << endl;

      // Careful, only return result if not a void function
      if (!(*f_iter)->get_returntype()->is_void()) {
        f_service_ << indent() << "if (defined $result->{success} ) {" << endl << indent()
                   << "  return $result->{success};" << endl << indent() << "}" << endl;
      }

      t_struct* xs = (*f_iter)->get_xceptions();
      const std::vector<t_field*>& xceptions = xs->get_members();
      vector<t_field*>::const_iterator x_iter;
      for (x_iter = xceptions.begin(); x_iter != xceptions.end(); ++x_iter) {
        f_service_ << indent() << "if (defined $result->{" << (*x_iter)->get_name() << "}) {"
                   << endl << indent() << "  die $result->{" << (*x_iter)->get_name() << "};"
                   << endl << indent() << "}" << endl;
      }

      // Careful, only return _result if not a void function
      if ((*f_iter)->get_returntype()->is_void()) {
        indent(f_service_) << "return;" << endl;
      } else {
        f_service_ << indent() << "die \"" << (*f_iter)->get_name() << " failed: unknown result\";"
                   << endl;
      }

      // Close function
      indent_down();
      f_service_ << "}" << endl;
    }
  }
}

/**
 * Deserializes a field of any type.
 */
void t_perl_generator::generate_deserialize_field(ostream& out,
                                                  t_field* tfield,
                                                  string prefix,
                                                  bool inclass) {
  (void)inclass;
  t_type* type = get_true_type(tfield->get_type());

  if (type->is_void()) {
    throw "CANNOT GENERATE DESERIALIZE CODE FOR void TYPE: " + prefix + tfield->get_name();
  }

  string name = tfield->get_name();

  // Hack for when prefix is defined (always a hash ref)
  if (!prefix.empty()) {
    name = prefix + "{" + tfield->get_name() + "}";
  }

  if (type->is_struct() || type->is_xception()) {
    generate_deserialize_struct(out, (t_struct*)type, name);
  } else if (type->is_container()) {
    generate_deserialize_container(out, type, name);
  } else if (type->is_base_type() || type->is_enum()) {
    indent(out) << "$xfer += $input->";

    if (type->is_base_type()) {
      t_base_type::t_base tbase = ((t_base_type*)type)->get_base();
      switch (tbase) {
      case t_base_type::TYPE_VOID:
        throw "compiler error: cannot serialize void field in a struct: " + name;
        break;
      case t_base_type::TYPE_STRING:
        out << "readString(\\$" << name << ");";
        break;
      case t_base_type::TYPE_BOOL:
        out << "readBool(\\$" << name << ");";
        break;
      case t_base_type::TYPE_I8:
        out << "readByte(\\$" << name << ");";
        break;
      case t_base_type::TYPE_I16:
        out << "readI16(\\$" << name << ");";
        break;
      case t_base_type::TYPE_I32:
        out << "readI32(\\$" << name << ");";
        break;
      case t_base_type::TYPE_I64:
        out << "readI64(\\$" << name << ");";
        break;
      case t_base_type::TYPE_DOUBLE:
        out << "readDouble(\\$" << name << ");";
        break;
      default:
        throw "compiler error: no PERL name for base type " + t_base_type::t_base_name(tbase);
      }
    } else if (type->is_enum()) {
      out << "readI32(\\$" << name << ");";
    }
    out << endl;

  } else {
    printf("DO NOT KNOW HOW TO DESERIALIZE FIELD '%s' TYPE '%s'\n",
           tfield->get_name().c_str(),
           type->get_name().c_str());
  }
}

/**
 * Generates an unserializer for a variable. This makes two key assumptions,
 * first that there is a const char* variable named data that points to the
 * buffer for deserialization, and that there is a variable protocol which
 * is a reference to a TProtocol serialization object.
 */
void t_perl_generator::generate_deserialize_struct(ostream& out,
                                                   t_struct* tstruct,
                                                   string prefix) {
  out << indent() << "$" << prefix << " = " << perl_namespace(tstruct->get_program())
      << tstruct->get_name() << "->new();" << endl << indent() << "$xfer += $" << prefix
      << "->read($input);" << endl;
}

void t_perl_generator::generate_deserialize_container(ostream& out, t_type* ttype, string prefix) {
  scope_up(out);

  string size = tmp("_size");
  string ktype = tmp("_ktype");
  string vtype = tmp("_vtype");
  string etype = tmp("_etype");

  t_field fsize(g_type_i32, size);
  t_field fktype(g_type_i8, ktype);
  t_field fvtype(g_type_i8, vtype);
  t_field fetype(g_type_i8, etype);

  out << indent() << "my $" << size << " = 0;" << endl;

  // Declare variables, read header
  if (ttype->is_map()) {
    out << indent() << "$" << prefix << " = {};" << endl << indent() << "my $" << ktype << " = 0;"
        << endl << indent() << "my $" << vtype << " = 0;" << endl;

    out << indent() << "$xfer += $input->readMapBegin("
        << "\\$" << ktype << ", \\$" << vtype << ", \\$" << size << ");" << endl;

  } else if (ttype->is_set()) {

    out << indent() << "$" << prefix << " = {};" << endl << indent() << "my $" << etype << " = 0;"
        << endl << indent() << "$xfer += $input->readSetBegin("
        << "\\$" << etype << ", \\$" << size << ");" << endl;

  } else if (ttype->is_list()) {

    out << indent() << "$" << prefix << " = [];" << endl << indent() << "my $" << etype << " = 0;"
        << endl << indent() << "$xfer += $input->readListBegin("
        << "\\$" << etype << ", \\$" << size << ");" << endl;
  }

  // For loop iterates over elements
  string i = tmp("_i");
  indent(out) << "for (my $" << i << " = 0; $" << i << " < $" << size << "; ++$" << i << ")"
              << endl;

  scope_up(out);

  if (ttype->is_map()) {
    generate_deserialize_map_element(out, (t_map*)ttype, prefix);
  } else if (ttype->is_set()) {
    generate_deserialize_set_element(out, (t_set*)ttype, prefix);
  } else if (ttype->is_list()) {
    generate_deserialize_list_element(out, (t_list*)ttype, prefix);
  }

  scope_down(out);

  // Read container end
  if (ttype->is_map()) {
    indent(out) << "$xfer += $input->readMapEnd();" << endl;
  } else if (ttype->is_set()) {
    indent(out) << "$xfer += $input->readSetEnd();" << endl;
  } else if (ttype->is_list()) {
    indent(out) << "$xfer += $input->readListEnd();" << endl;
  }

  scope_down(out);
}

/**
 * Generates code to deserialize a map
 */
void t_perl_generator::generate_deserialize_map_element(ostream& out, t_map* tmap, string prefix) {
  string key = tmp("key");
  string val = tmp("val");
  t_field fkey(tmap->get_key_type(), key);
  t_field fval(tmap->get_val_type(), val);

  indent(out) << declare_field(&fkey, true, true) << endl;
  indent(out) << declare_field(&fval, true, true) << endl;

  generate_deserialize_field(out, &fkey);
  generate_deserialize_field(out, &fval);

  indent(out) << "$" << prefix << "->{$" << key << "} = $" << val << ";" << endl;
}

void t_perl_generator::generate_deserialize_set_element(ostream& out, t_set* tset, string prefix) {
  string elem = tmp("elem");
  t_field felem(tset->get_elem_type(), elem);

  indent(out) << "my $" << elem << " = undef;" << endl;

  generate_deserialize_field(out, &felem);

  indent(out) << "$" << prefix << "->{$" << elem << "} = 1;" << endl;
}

void t_perl_generator::generate_deserialize_list_element(ostream& out,
                                                         t_list* tlist,
                                                         string prefix) {
  string elem = tmp("elem");
  t_field felem(tlist->get_elem_type(), elem);

  indent(out) << "my $" << elem << " = undef;" << endl;

  generate_deserialize_field(out, &felem);

  indent(out) << "push(@{$" << prefix << "},$" << elem << ");" << endl;
}

/**
 * Serializes a field of any type.
 *
 * @param tfield The field to serialize
 * @param prefix Name to prepend to field name
 */
void t_perl_generator::generate_serialize_field(ostream& out, t_field* tfield, string prefix) {
  t_type* type = get_true_type(tfield->get_type());

  // Do nothing for void types
  if (type->is_void()) {
    throw "CANNOT GENERATE SERIALIZE CODE FOR void TYPE: " + prefix + tfield->get_name();
  }

  if (type->is_struct() || type->is_xception()) {
    generate_serialize_struct(out, (t_struct*)type, prefix + "{" + tfield->get_name() + "}");
  } else if (type->is_container()) {
    generate_serialize_container(out, type, prefix + "{" + tfield->get_name() + "}");
  } else if (type->is_base_type() || type->is_enum()) {

    string name = tfield->get_name();

    // Hack for when prefix is defined (always a hash ref)
    if (!prefix.empty())
      name = prefix + "{" + tfield->get_name() + "}";

    indent(out) << "$xfer += $output->";

    if (type->is_base_type()) {
      t_base_type::t_base tbase = ((t_base_type*)type)->get_base();
      switch (tbase) {
      case t_base_type::TYPE_VOID:
        throw "compiler error: cannot serialize void field in a struct: " + name;
        break;
      case t_base_type::TYPE_STRING:
        out << "writeString($" << name << ");";
        break;
      case t_base_type::TYPE_BOOL:
        out << "writeBool($" << name << ");";
        break;
      case t_base_type::TYPE_I8:
        out << "writeByte($" << name << ");";
        break;
      case t_base_type::TYPE_I16:
        out << "writeI16($" << name << ");";
        break;
      case t_base_type::TYPE_I32:
        out << "writeI32($" << name << ");";
        break;
      case t_base_type::TYPE_I64:
        out << "writeI64($" << name << ");";
        break;
      case t_base_type::TYPE_DOUBLE:
        out << "writeDouble($" << name << ");";
        break;
      default:
        throw "compiler error: no PERL name for base type " + t_base_type::t_base_name(tbase);
      }
    } else if (type->is_enum()) {
      out << "writeI32($" << name << ");";
    }
    out << endl;

  } else {
    printf("DO NOT KNOW HOW TO SERIALIZE FIELD '%s%s' TYPE '%s'\n",
           prefix.c_str(),
           tfield->get_name().c_str(),
           type->get_name().c_str());
  }
}

/**
 * Serializes all the members of a struct.
 *
 * @param tstruct The struct to serialize
 * @param prefix  String prefix to attach to all fields
 */
void t_perl_generator::generate_serialize_struct(ostream& out, t_struct* tstruct, string prefix) {
  (void)tstruct;
  indent(out) << "$xfer += $" << prefix << "->write($output);" << endl;
}

/**
 * Writes out a container
 */
void t_perl_generator::generate_serialize_container(ostream& out, t_type* ttype, string prefix) {
  scope_up(out);

  if (ttype->is_map()) {
    indent(out) << "$xfer += $output->writeMapBegin("
                << type_to_enum(((t_map*)ttype)->get_key_type()) << ", "
                << type_to_enum(((t_map*)ttype)->get_val_type()) << ", "
                << "scalar(keys %{$" << prefix << "}));" << endl;
  } else if (ttype->is_set()) {
    indent(out) << "$xfer += $output->writeSetBegin("
                << type_to_enum(((t_set*)ttype)->get_elem_type()) << ", "
                << "scalar(@{$" << prefix << "}));" << endl;

  } else if (ttype->is_list()) {

    indent(out) << "$xfer += $output->writeListBegin("
                << type_to_enum(((t_list*)ttype)->get_elem_type()) << ", "
                << "scalar(@{$" << prefix << "}));" << endl;
  }

  scope_up(out);

  if (ttype->is_map()) {
    string kiter = tmp("kiter");
    string viter = tmp("viter");
    indent(out) << "while( my ($" << kiter << ",$" << viter << ") = each %{$" << prefix << "}) "
                << endl;

    scope_up(out);
    generate_serialize_map_element(out, (t_map*)ttype, kiter, viter);
    scope_down(out);

  } else if (ttype->is_set()) {
    string iter = tmp("iter");
    indent(out) << "foreach my $" << iter << " (@{$" << prefix << "})" << endl;
    scope_up(out);
    generate_serialize_set_element(out, (t_set*)ttype, iter);
    scope_down(out);

  } else if (ttype->is_list()) {
    string iter = tmp("iter");
    indent(out) << "foreach my $" << iter << " (@{$" << prefix << "}) " << endl;
    scope_up(out);
    generate_serialize_list_element(out, (t_list*)ttype, iter);
    scope_down(out);
  }

  scope_down(out);

  if (ttype->is_map()) {
    indent(out) << "$xfer += $output->writeMapEnd();" << endl;
  } else if (ttype->is_set()) {
    indent(out) << "$xfer += $output->writeSetEnd();" << endl;
  } else if (ttype->is_list()) {
    indent(out) << "$xfer += $output->writeListEnd();" << endl;
  }

  scope_down(out);
}

/**
 * Serializes the members of a map.
 *
 */
void t_perl_generator::generate_serialize_map_element(ostream& out,
                                                      t_map* tmap,
                                                      string kiter,
                                                      string viter) {
  t_field kfield(tmap->get_key_type(), kiter);
  generate_serialize_field(out, &kfield);

  t_field vfield(tmap->get_val_type(), viter);
  generate_serialize_field(out, &vfield);
}

/**
 * Serializes the members of a set.
 */
void t_perl_generator::generate_serialize_set_element(ostream& out, t_set* tset, string iter) {
  t_field efield(tset->get_elem_type(), iter);
  generate_serialize_field(out, &efield);
}

/**
 * Serializes the members of a list.
 */
void t_perl_generator::generate_serialize_list_element(ostream& out, t_list* tlist, string iter) {
  t_field efield(tlist->get_elem_type(), iter);
  generate_serialize_field(out, &efield);
}

/**
 * Declares a field, which may include initialization as necessary.
 *
 * @param ttype The type
 */
string t_perl_generator::declare_field(t_field* tfield, bool init, bool obj) {
  string result = "my $" + tfield->get_name();
  if (init) {
    t_type* type = get_true_type(tfield->get_type());
    if (type->is_base_type()) {
      t_base_type::t_base tbase = ((t_base_type*)type)->get_base();
      switch (tbase) {
      case t_base_type::TYPE_VOID:
        break;
      case t_base_type::TYPE_STRING:
        result += " = ''";
        break;
      case t_base_type::TYPE_BOOL:
        result += " = 0";
        break;
      case t_base_type::TYPE_I8:
      case t_base_type::TYPE_I16:
      case t_base_type::TYPE_I32:
      case t_base_type::TYPE_I64:
        result += " = 0";
        break;
      case t_base_type::TYPE_DOUBLE:
        result += " = 0.0";
        break;
      default:
        throw "compiler error: no PERL initializer for base type "
            + t_base_type::t_base_name(tbase);
      }
    } else if (type->is_enum()) {
      result += " = 0";
    } else if (type->is_container()) {
      result += " = []";
    } else if (type->is_struct() || type->is_xception()) {
      if (obj) {
        result += " = " + perl_namespace(type->get_program()) + type->get_name() + "->new()";
      } else {
        result += " = undef";
      }
    }
  }
  return result + ";";
}

/**
 * Renders a function signature of the form 'type name(args)'
 *
 * @param tfunction Function definition
 * @return String of rendered function definition
 */
string t_perl_generator::function_signature(t_function* tfunction, string prefix) {

  string str;

  str = prefix + tfunction->get_name() + "{\n";
  str += "  my $self = shift;\n";

  // Need to create perl function arg inputs
  const vector<t_field*>& fields = tfunction->get_arglist()->get_members();
  vector<t_field*>::const_iterator f_iter;

  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
    str += "  my $" + (*f_iter)->get_name() + " = shift;\n";
  }

  return str;
}

/**
 * Renders a field list
 */
string t_perl_generator::argument_list(t_struct* tstruct) {
  string result = "";

  const vector<t_field*>& fields = tstruct->get_members();
  vector<t_field*>::const_iterator f_iter;
  bool first = true;
  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
    if (first) {
      first = false;
    } else {
      result += ", ";
    }
    result += "$" + (*f_iter)->get_name();
  }
  return result;
}

/**
 * Converts the parse type to a C++ enum string for the given type.
 */
string t_perl_generator::type_to_enum(t_type* type) {
  type = get_true_type(type);

  if (type->is_base_type()) {
    t_base_type::t_base tbase = ((t_base_type*)type)->get_base();
    switch (tbase) {
    case t_base_type::TYPE_VOID:
      throw "NO T_VOID CONSTRUCT";
    case t_base_type::TYPE_STRING:
      return "Thrift::TType::STRING";
    case t_base_type::TYPE_BOOL:
      return "Thrift::TType::BOOL";
    case t_base_type::TYPE_I8:
      return "Thrift::TType::BYTE";
    case t_base_type::TYPE_I16:
      return "Thrift::TType::I16";
    case t_base_type::TYPE_I32:
      return "Thrift::TType::I32";
    case t_base_type::TYPE_I64:
      return "Thrift::TType::I64";
    case t_base_type::TYPE_DOUBLE:
      return "Thrift::TType::DOUBLE";
    }
  } else if (type->is_enum()) {
    return "Thrift::TType::I32";
  } else if (type->is_struct() || type->is_xception()) {
    return "Thrift::TType::STRUCT";
  } else if (type->is_map()) {
    return "Thrift::TType::MAP";
  } else if (type->is_set()) {
    return "Thrift::TType::SET";
  } else if (type->is_list()) {
    return "Thrift::TType::LIST";
  }

  throw "INVALID TYPE IN type_to_enum: " + type->get_name();
}

THRIFT_REGISTER_GENERATOR(perl, "Perl", "")
