#
# Copyright (C) 2008 The Android Open Source Project
#
# Licensed 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.


import os
import re
import sys
import subprocess
import tempfile

from error import EditorError


class Editor(object):
    """Manages the user's preferred text editor."""

    _editor = None
    globalConfig = None

    @classmethod
    def _GetEditor(cls):
        if cls._editor is None:
            cls._editor = cls._SelectEditor()
        return cls._editor

    @classmethod
    def _SelectEditor(cls):
        e = os.getenv('GIT_EDITOR')
        if e:
            return e

        if cls.globalConfig:
            e = cls.globalConfig.GetString('core.editor')
            if e:
                return e

        e = os.getenv('VISUAL')
        if e:
            return e

        e = os.getenv('EDITOR')
        if e:
            return e

        if os.getenv('TERM') == 'dumb':
            print(
                """No editor specified in GIT_EDITOR, core.editor, VISUAL or EDITOR.
                Tried to fall back to vi but terminal is dumb.  Please configure at
                least one of these before using this command.""", file=sys.stderr)
            sys.exit(1)

        return 'vi'

    @classmethod
    def EditString(cls, data):
        """Opens an editor to edit the given content.

           Args:
             data        : the text to edit

          Returns:
            new value of edited text; None if editing did not succeed
        """
        editor = cls._GetEditor()
        if editor == ':':
            return data

        fd, path = tempfile.mkstemp()
        try:
            os.write(fd, data)
            os.close(fd)
            fd = None

            if re.compile("^.*[$ \t'].*$").match(editor):
                editor = re.sub('["\']', '', editor)  ## Removes " or ' from windows path like "C:/Program Files (x86)/GitExtensions/GitExtensions.exe" so they don't go into the Popen list.
                args = editor.rsplit()                ## supports multiple spaces in windows path, and editor arguments like "C:/Program Files (x86)/GitExtensions/GitExtensions.exe fileeditor".
                shell = False
            else:
                args = [editor]
                shell = False
            args.append(path)

            try:
                rc = subprocess.Popen(args, shell=shell).wait()
            except OSError as e:
                raise EditorError('editor failed, %s: %s %s'
                                  % (str(e), editor, path))
            if rc != 0:
                raise EditorError('editor failed with exit status %d: %s %s'
                                  % (rc, editor, path))

            fd2 = open(path)
            try:
                return fd2.read()
            finally:
                fd2.close()
        finally:
            if fd:
                os.close(fd)
            os.remove(path)
