# -*- coding: utf-8 -*-
# This file is part of Eigen, a lightweight C++ template library
# for linear algebra.
#
# Copyright (C) 2009 Benjamin Schindler <bschindler@inf.ethz.ch>
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

# Pretty printers for Eigen::Matrix
# This is still pretty basic as the python extension to gdb is still pretty basic.
# It cannot handle complex eigen types and it doesn't support any of the other eigen types
# Such as quaternion or some other type.
# This code supports fixed size as well as dynamic size matrices

# To use it:
#
# * Create a directory and put the file as well as an empty __init__.py in
#   that directory.
# * Create a ~/.gdbinit file, that contains the following:
#      python
#      import sys
#      sys.path.insert(0, '/path/to/eigen/printer/directory')
#      from printers import register_eigen_printers
#      register_eigen_printers (None)
#      end

import gdb
import re
import itertools


class EigenMatrixPrinter:
    "Print Eigen Matrix or Array of some kind"

    def __init__(self, variety, val):
        "Extract all the necessary information"

        # Save the variety (presumably "Matrix" or "Array") for later usage
        self.variety = variety

        # The gdb extension does not support value template arguments - need to extract them by hand
        type = val.type
        if type.code == gdb.TYPE_CODE_REF:
            type = type.target()
        self.type = type.unqualified().strip_typedefs()
        tag = self.type.tag
        regex = re.compile("\<.*\>")
        m = regex.findall(tag)[0][1:-1]
        template_params = m.split(",")
        template_params = [x.replace(" ", "") for x in template_params]

        if (
            template_params[1] == "-0x00000000000000001"
            or template_params[1] == "-0x000000001"
            or template_params[1] == "-1"
        ):
            self.rows = val["m_storage"]["m_rows"]
        else:
            self.rows = int(template_params[1])

        if (
            template_params[2] == "-0x00000000000000001"
            or template_params[2] == "-0x000000001"
            or template_params[2] == "-1"
        ):
            self.cols = val["m_storage"]["m_cols"]
        else:
            self.cols = int(template_params[2])

        self.options = 0  # default value
        if len(template_params) > 3:
            self.options = template_params[3]

        self.rowMajor = int(self.options) & 0x1

        self.innerType = self.type.template_argument(0)

        self.val = val

        # Fixed size matrices have a struct as their storage, so we need to walk through this
        self.data = self.val["m_storage"]["m_data"]
        if self.data.type.code == gdb.TYPE_CODE_STRUCT:
            self.data = self.data["array"]
            self.data = self.data.cast(self.innerType.pointer())

    class _iterator:
        def __init__(self, rows, cols, dataPtr, rowMajor):
            self.rows = rows
            self.cols = cols
            self.dataPtr = dataPtr
            self.currentRow = 0
            self.currentCol = 0
            self.rowMajor = rowMajor

        def __iter__(self):
            return self

        def next(self):
            return self.__next__()  # Python 2.x compatibility

        def __next__(self):

            row = self.currentRow
            col = self.currentCol
            if self.rowMajor == 0:
                if self.currentCol >= self.cols:
                    raise StopIteration

                self.currentRow = self.currentRow + 1
                if self.currentRow >= self.rows:
                    self.currentRow = 0
                    self.currentCol = self.currentCol + 1
            else:
                if self.currentRow >= self.rows:
                    raise StopIteration

                self.currentCol = self.currentCol + 1
                if self.currentCol >= self.cols:
                    self.currentCol = 0
                    self.currentRow = self.currentRow + 1

            item = self.dataPtr.dereference()
            self.dataPtr = self.dataPtr + 1
            if self.cols == 1:  # if it's a column vector
                return ("[%d]" % (row,), item)
            elif self.rows == 1:  # if it's a row vector
                return ("[%d]" % (col,), item)
            return ("[%d,%d]" % (row, col), item)

    def children(self):

        return self._iterator(self.rows, self.cols, self.data, self.rowMajor)

    def to_string(self):
        return "Eigen::%s<%s,%d,%d,%s> (data ptr: %s)" % (
            self.variety,
            self.innerType,
            self.rows,
            self.cols,
            "RowMajor" if self.rowMajor else "ColMajor",
            self.data,
        )


class EigenQuaternionPrinter:
    "Print an Eigen Quaternion"

    def __init__(self, val):
        "Extract all the necessary information"
        # The gdb extension does not support value template arguments - need to extract them by hand
        type = val.type
        if type.code == gdb.TYPE_CODE_REF:
            type = type.target()
        self.type = type.unqualified().strip_typedefs()
        self.innerType = self.type.template_argument(0)
        self.val = val

        # Quaternions have a struct as their storage, so we need to walk through this
        self.data = self.val["m_coeffs"]["m_storage"]["m_data"]["array"]
        self.data = self.data.cast(self.innerType.pointer())

    class _iterator:
        def __init__(self, dataPtr):
            self.dataPtr = dataPtr
            self.currentElement = 0
            self.elementNames = ["x", "y", "z", "w"]

        def __iter__(self):
            return self

        def next(self):
            return self.__next__()  # Python 2.x compatibility

        def __next__(self):
            element = self.currentElement

            if self.currentElement >= 4:  # there are 4 elements in a quanternion
                raise StopIteration

            self.currentElement = self.currentElement + 1

            item = self.dataPtr.dereference()
            self.dataPtr = self.dataPtr + 1
            return ("[%s]" % (self.elementNames[element],), item)

    def children(self):

        return self._iterator(self.data)

    def to_string(self):
        return "Eigen::Quaternion<%s> (data ptr: %s)" % (self.innerType, self.data)


def build_eigen_dictionary():
    pretty_printers_dict[
        re.compile("^Eigen::Quaternion<.*>$")
    ] = lambda val: EigenQuaternionPrinter(val)
    pretty_printers_dict[
        re.compile("^Eigen::Matrix<.*>$")
    ] = lambda val: EigenMatrixPrinter("Matrix", val)
    pretty_printers_dict[
        re.compile("^Eigen::Array<.*>$")
    ] = lambda val: EigenMatrixPrinter("Array", val)


def register_eigen_printers(obj):
    "Register eigen pretty-printers with objfile Obj"

    if obj == None:
        obj = gdb
    obj.pretty_printers.append(lookup_function)


def lookup_function(val):
    "Look-up and return a pretty-printer that can print va."

    type = val.type

    if type.code == gdb.TYPE_CODE_REF:
        type = type.target()

    type = type.unqualified().strip_typedefs()

    typename = type.tag
    if typename == None:
        return None

    for function in pretty_printers_dict:
        if function.search(typename):
            return pretty_printers_dict[function](val)

    return None


pretty_printers_dict = {}

build_eigen_dictionary()
