# (Be in -*- python -*- mode.)
#
# ====================================================================
# Copyright (c) 2000-2008 CollabNet.  All rights reserved.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution.  The terms
# are also available at http://subversion.tigris.org/license-1.html.
# If newer versions of this license are posted there, you may use a
# newer version instead, at your option.
#
# This software consists of voluntary contributions made by many
# individuals.  For exact contribution history, see the revision
# history and logs, available at http://cvs2svn.tigris.org/.
# ====================================================================

"""Access the CVS repository via CVS's 'cvs' command."""


from cvs2hg_lib.common import FatalError
from cvs2hg_lib.common import canonicalize_eol
from cvs2hg_lib.process import check_command_runs
from cvs2hg_lib.process import get_command_output
from cvs2hg_lib.process import CommandFailedException
from cvs2hg_lib.context import Ctx
from cvs2hg_lib.revision_manager import RevisionReader
from cvs2hg_lib.apple_single_filter import get_maybe_apple_single


class CVSRevisionReader(RevisionReader):
    """A RevisionReader that reads the contents via CVS."""

    # Different versions of CVS support different global options.  Here
    # are the global options that we try to use, in order of decreasing
    # preference:
    _possible_global_options = [
        ['-Q', '-R', '-f'],
        ['-Q', '-R'],
        ['-Q', '-f'],
        ['-Q'],
        ['-q', '-R', '-f'],
        ['-q', '-R'],
        ['-q', '-f'],
        ['-q'],
        ]

    def __init__(self, cvs_executable, global_options=None):
        """Initialize a CVSRevisionReader.

        CVS_EXECUTABLE is the CVS command (possibly including the full
        path to the executable; otherwise it is sought in the $PATH).
        GLOBAL_ARGUMENTS, if specified, should be a list of global options
        that are passed to the CVS command before the subcommand.  If
        GLOBAL_ARGUMENTS is not specified, then each of the possibilities
        listed in _possible_global_options is checked in order until one
        is found that runs successfully and without any output to stderr."""

        self.cvs_executable = cvs_executable

        if global_options is None:
            for global_options in self._possible_global_options:
                try:
                    self._check_cvs_runs(global_options)
                except CommandFailedException as e:
                    pass
                else:
                    break
            else:
                raise FatalError(
                    '%s\n'
                    'Please check that cvs is installed and in your PATH.' % (e,)
                    )
        else:
            try:
                self._check_cvs_runs(global_options)
            except CommandFailedException as e:
                raise FatalError(
                    '%s\n'
                    'Please check that cvs is installed and in your PATH and that\n'
                    'the global options that you specified (%r) are correct.'
                    % (e, global_options,)
                    )

        # The global options were OK; use them for all CVS invocations.
        self.global_options = global_options

    def _check_cvs_runs(self, global_options):
        """Check that CVS can be started.

        Try running 'cvs --version' with the current setting for
        self.cvs_executable and the specified global_options.  If not
        successful, raise a CommandFailedException."""

        check_command_runs(
            [self.cvs_executable] + global_options + ['--version'],
            self.cvs_executable,
            )

    def get_content(self, cvs_rev):
        project = cvs_rev.cvs_file.project
        pipe_cmd = [
            self.cvs_executable
            ] + self.global_options + [
            '-d', ':local:' + project.cvs_repository_root,
            'co',
            '-r' + cvs_rev.rev,
            '-p'
            ]
        if cvs_rev.get_property('_keyword_handling') == 'collapsed':
            pipe_cmd.append('-kk')
        pipe_cmd.append(project.cvs_module + cvs_rev.cvs_path)
        data = get_command_output(pipe_cmd)

        if Ctx().decode_apple_single:
            # Insert a filter to decode any files that are in AppleSingle
            # format:
            data = get_maybe_apple_single(data)

        eol_fix = cvs_rev.get_property('_eol_fix')
        if eol_fix:
            data = canonicalize_eol(data, eol_fix)

        return data


