#!/usr/bin/env python
# vim: set ts=4 sw=4 et: coding=UTF-8
#
# Copyright (c) 2010, Novell, Inc.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
# USA.
#
# Authors: Vincent Untz <vuntz@gnome.org>

import os
import sys

import optparse

try:
    from lxml import etree as ET
except ImportError:
    try:
        from xml.etree import cElementTree as ET
    except ImportError:
        import cElementTree as ET


GSETTINGS_SIMPLE_SCHEMA_INDENT = '  '


######################################


class GSettingsSchemaConvertException(Exception):
    pass


######################################


class GSettingsSchemaRoot:

    def __init__(self):
        self.schemas = []

    def simplify(self):
        for schema in self.schemas:
            schema.simplify()

    def get_simple_string(self):
        need_empty_line = False
        result = ''

        for schema in self.schemas:
            if need_empty_line:
                result += '\n'
            result += schema.get_simple_string()
            if result:
                need_empty_line = True

        return result

    def get_xml_node(self):
        schemalist_node = ET.Element('schemalist')
        for schema in self.schemas:
            schema_node = schema.get_xml_node()
            if schema_node is not None:
                schemalist_node.append(schema_node)
        return schemalist_node


######################################


# Note: defined before GSettingsSchema because GSettingsSchema is a subclass.
# But from a schema point of view, GSettingsSchema is a parent of
# GSettingsSchemaDir.
class GSettingsSchemaDir:

    def __init__(self):
        self.name = None
        self.dirs = []
        self.keys = []

    def get_simple_string(self, current_indent):
        content = self._get_simple_string_for_content(current_indent)
        if not content:
            return ''

        result = ''
        result += '%schild %s:\n' % (current_indent, self.name)
        result += content
        return result

    def _get_simple_string_for_content(self, current_indent):
        need_empty_line = False
        result = ''

        for key in self.keys:
            result += key.get_simple_string(current_indent + GSETTINGS_SIMPLE_SCHEMA_INDENT)
            need_empty_line = True

        for dir in self.dirs:
            if need_empty_line:
                result += '\n'
            result += dir.get_simple_string(current_indent + GSETTINGS_SIMPLE_SCHEMA_INDENT)
            if result:
                need_empty_line = True

        return result

    def get_xml_node(self):
        node = self._get_xml_node_for_content()
        if node is not None:
            node.set('id', self.name)
        return node

    def _get_xml_node_for_content(self):
        if not self.keys and not self.dirs:
            return None

        schema_node = ET.Element('schema')
        for key in self.keys:
            key_node = key.get_xml_node()
            schema_node.append(key_node)
        for dir in self.dirs:
            dir_node = dir.get_xml_node()
            schema_node.append(dir_node)

        return schema_node


######################################


class GSettingsSchema(GSettingsSchemaDir):

    def __init__(self):
        self.id = None
        self.path = None
        self.dirs = []
        self.keys = []

    def simplify(self):
        while len(self.dirs) == 1 and not self.keys:
            dir = self.dirs[0]
            self.dirs = dir.dirs
            self.keys = dir.keys
            if self.path:
                self.path += dir.name + '/'

    def get_simple_string(self):
        if not self.dirs and not self.keys:
            return ''

        result = ''
        result += 'schema %s:\n' % self.id
        if self.path:
            result += '%spath %s\n' % (GSETTINGS_SIMPLE_SCHEMA_INDENT, self.path)
        result += '\n'
        result += self._get_simple_string_for_content('')

        return result

    def get_xml_node(self):
        if not self.dirs and not self.keys:
            return None

        node = self._get_xml_node_for_content()
        node.set('id', self.id)
        if self.path:
            node.set('path', self.path)

        return node


######################################


class GSettingsSchemaKey:

    def __init__(self):
        self.name = None
        self.type = None
        self.default = None
        self.typed_default = None
        self.localized = None
        self.summary = None
        self.description = None

    def fill(self, name, type, default, typed_default, localized, summary, description):
        self.name = name
        self.type = type
        self.default = default
        self.typed_default = typed_default
        self.localized = localized
        self.summary = summary
        self.description = description

    def get_simple_string(self, current_indent):
        result = ''
        result += '%skey %s = %s\n' % (current_indent, self.name, self.typed_default or self.default)
        current_indent += GSETTINGS_SIMPLE_SCHEMA_INDENT
        if self.summary:
            result += '%sSummary: %s\n' % (current_indent, self.summary)
        if self.description:
            result += '%sDescription: %s\n' % (current_indent, self.description)
        return result

    def get_xml_node(self):
        key_node = ET.Element('key')
        key_node.set('name', self.name)
        key_node.set('type', self.type)
        default_node = ET.SubElement(key_node, 'default')
        default_node.text = self.default
        if self.summary:
            summary_node = ET.SubElement(key_node, 'summary')
            summary_node.text = self.summary
        if self.description:
            description_node = ET.SubElement(key_node, 'description')
            description_node.text = self.description
        return key_node


######################################


def map_gconf_type_to_variant_type(gconftype, gconfsubtype):
    typemap = { 'string': 's', 'int': 'i', 'float': 'f', 'bool': 'b', 'list': 'a' }
    result = typemap[gconftype]
    if gconftype == 'list':
        result = result + typemap[gconfsubtype]
    return result


class GConfSchema:

    def __init__(self, node):
        locale_node = node.find('locale')

        self.key = node.find('key').text
        self.type = node.find('type').text
        if self.type == 'list':
            self.list_type = node.find('list_type').text
        else:
            self.list_type = None
        self.varianttype = map_gconf_type_to_variant_type(self.type, self.list_type)

        applyto_node = node.find('applyto')
        if applyto_node is not None:
            self.applyto = node.find('applyto').text
            self.applyto.strip()
            self.keyname = self.applyto[self.applyto.rfind('/')+1:]
            self.prefix = self.applyto[:self.applyto.rfind('/')+1]
        else:
            self.applyto = None
            self.key.strip()
            self.keyname = self.key[self.key.rfind('/')+1:]
            self.prefix = self.key[:self.key.rfind('/')+1]
        self.prefix = os.path.normpath(self.prefix)

        try:
            self.default = locale_node.find('default').text
            self.localized = True
        except:
            self.default = node.find('default').text
            self.localized = False
        self.typed_default = None

        self.short = self._get_value_with_locale(node, locale_node, 'short')
        self.long = self._get_value_with_locale(node, locale_node, 'long')

        self.short = self._oneline(self.short)
        self.long = self._oneline(self.long)

        # Fix the default to be parsable by GVariant
        if self.type == 'string':
            if not self.default:
                self.default = '\'\''
            else:
                self.default.replace('\'', '\\\'')
                self.default = '\'%s\'' % self.default
        elif self.type == 'bool':
            self.default = self.default.lower()
        elif self.type == 'list':
            l = self.default.strip()
            if not (l[0] == '[' and l[-1] == ']'):
                raise GSettingsSchemaConvertException('Cannot parse default value for list: %s' % self.default)
            values = l[1:-1].strip()
            if not values:
                self.typed_default = '@%s []' % self.varianttype
            elif self.list_type == 'string':
                items = [ item.strip() for item in values.split(',') ]
                items = [ item.replace('\'', '\\\'') for item in items ]
                values = ', '.join([ '\'%s\'' % item for item in items ])
                self.default = '[ %s ]' % values

        # FIXME: kill this when we'll have python bindings for GVariant. Right
        # now, every simple format schema we'll generate has to have an
        # explicit type since we can't guess the type later on when converting
        # to XML.
        if not self.typed_default:
            self.typed_default = '@%s %s' % (self.varianttype, self.default)

    def _get_value_with_locale(self, node, locale_node, element):
        element_node = None
        if locale_node is not None:
            element_node = locale_node.find(element)
        if element_node is None:
            element_node = node.find(element)
        if element_node is not None:
            return element_node.text
        else:
            return None

    def _oneline(self, s):
        lines = s.splitlines()
        result = ''
        for line in lines:
            result += ' ' + line.lstrip()
        return result.strip()

    def get_gsettings_schema_key(self):
        key = GSettingsSchemaKey()
        key.fill(self.keyname, self.varianttype, self.default, self.typed_default, self.localized, self.short, self.long)
        return key


######################################

allowed_tokens = {
  ''            : [ 'schema' ],
  'schema'      : [ 'path', 'child', 'key' ],
  'path'        : [ ],
  'child'       : [ 'child', 'key' ],
  'key'         : [ 'summary', 'description' ],
  'summary'     : [ ],
  'description' : [ ]
}

def _eat_indent(line, indent_stack):
    i = 0
    buf = ''
    previous_max_index = len(indent_stack) - 1
    index = -1

    while i < len(line) - 1 and line[i].isspace():
        buf += line[i]
        i += 1
        if previous_max_index > index:
            if buf == indent_stack[index + 1]:
                buf = ''
                index += 1
                continue
            elif indent_stack[index + 1].startswith(buf):
                continue
            else:
                raise GSettingsSchemaConvertException('Indentation not consistent.')
        else:
            continue

    if buf and previous_max_index <= index:
        indent_stack.append(buf)
    elif previous_max_index > index:
        indent_stack = indent_stack[:index + 1]

    return (indent_stack, line[i:])

def _eat_word(line):
    i = 0
    while i < len(line) - 1 and not line[i].isspace():
        i += 1
    return (line[:i], line[i:])

def _word_to_token(word):
    if word == 'schema':
        return 'schema'
    if word == 'path':
        return 'path'
    if word == 'child':
        return 'child'
    if word == 'key':
        return 'key'
    if word == 'Summary:':
        return 'summary'
    if word == 'Description:':
        return 'description'
    raise GSettingsSchemaConvertException('\'%s\' is not a valid token.' % word)

def _get_name_without_colon(line):
    if line[-1] != ':':
        raise GSettingsSchemaConvertException('\'%s\' has no trailing colon.' % line)
    line = line[:-1].strip()
    # FIXME: we could check there's no space
    return line

def _parse_key(line):
    items = line.split('=')
    if len(items) != 2:
        raise GSettingsSchemaConvertException('Cannot parse key \'%s\'.' % line)
    name = items[0].strip()
    type = ''
    value = items[1].strip()
    if value[0] == '@':
        i = 1
        while not value[i].isspace():
            i += 1
        type = value[1:i]
        value = value[i:].strip()
        if not value:
            raise GSettingsSchemaConvertException('No value specified for key \'%s\'.' % line)
    return (name, type, value)

def read_simple_schema(simple_schema_file):
    root = GSettingsSchemaRoot()

    f = open(simple_schema_file, 'r')
    lines = f.readlines()
    f.close()
    lines = [ line[:-1] for line in lines ]

    leading_indent = None
    indent_stack = []
    token_stack = []
    object_stack = [ root ]

    for line in lines:
        # make sure that lines with only spaces are ignored and considered as
        # empty lines
        line = line.rstrip()

        # ignore empty line
        if not line:
            continue

        # look at the indentation to know where we should be
        (indent_stack, line) = _eat_indent(line, indent_stack)
        if leading_indent is None:
            leading_indent = len(indent_stack)

        # ignore comments
        if line[0] == '#':
            continue

        (word, line) = _eat_word(line)
        token = _word_to_token(word)
        line = line.lstrip()

        new_level = len(indent_stack) - leading_indent
        old_level = len(token_stack)

        if new_level > old_level + 1:
            raise GSettingsSchemaConvertException('Internal error: stacks not in sync.')
        elif new_level <= old_level:
            token_stack = token_stack[:new_level]
            # we always have the root
            object_stack = object_stack[:new_level + 1]

        if new_level == 0:
            parent_token = ''
        else:
            parent_token = token_stack[-1]

        if not token in allowed_tokens[parent_token]:
            raise GSettingsSchemaConvertException('Token \'%s\' not allowed after token \'%s\'.' % (token, parent_token))

        current_object = object_stack[-1]

        new_object = None
        if token == 'schema':
            name = _get_name_without_colon(line)
            new_object = GSettingsSchema()
            new_object.id = name
            current_object.schemas.append(new_object)
        elif token == 'path':
            current_object.path = line
        elif token == 'child':
            name = _get_name_without_colon(line)
            new_object = GSettingsSchemaDir()
            new_object.name = name
            current_object.dirs.append(new_object)
        elif token == 'key':
            new_object = GSettingsSchemaKey()
            (name, type, value) = _parse_key(line)
            new_object.name = name
            new_object.type = type
            new_object.default = value
            current_object.keys.append(new_object)
        elif token == 'summary':
            current_object.summary = line
        elif token == 'description':
            current_object.description = line

        if new_object:
            token_stack.append(token)
            object_stack.append(new_object)

    return root


######################################


def read_gconf_schema(gconf_schema_file):
    gsettings_schema_root = GSettingsSchemaRoot()

    gconfschemafile_node = ET.parse(gconf_schema_file).getroot()
    for schemalist_node in gconfschemafile_node.findall('schemalist'):
        for schema_node in schemalist_node.findall('schema'):
            gconf_schema = GConfSchema(schema_node)

            schemas_only = (gconf_schema.applyto is not None)

            dirpath = gconf_schema.prefix
            # remove leading slash because there's none in gsettings, and trailing
            # slash because we'll split the string
            if dirpath[0] == '/':
                dirpath = dirpath[1:]
            if dirpath[-1] == '/':
                dirpath = dirpath[:-1]
            # remove leading 'schemas/' for schemas-only keys
            if schemas_only and dirpath.startswith('schemas/'):
                dirpath = dirpath[len('schemas/'):]

            if not dirpath:
                raise GSettingsSchemaConvertException('Toplevel keys are not accepted: %s' % gconf_schema.applyto)

            hierarchy = dirpath.split('/')

            # we don't want to put apps/ and desktop/ keys in the same schema,
            # so we have a first step where we make sure to create a new schema
            # to avoid this case if necessary
            gsettings_schema = None
            for schema in gsettings_schema_root.schemas:
                if schemas_only:
                    schema_path = schema.path
                else:
                    schema_path = schema._hacky_path
                if dirpath.startswith(schema_path):
                    gsettings_schema = schema
                    break
            if not gsettings_schema:
                gsettings_schema = GSettingsSchema()
                gsettings_schema.id = 'FIXME'
                if schemas_only:
                    gsettings_schema.path = hierarchy[0] + '/'
                else:
                    gsettings_schema._hacky_path = hierarchy[0] + '/'
                gsettings_schema_root.schemas.append(gsettings_schema)

            # we create all the subdirs that lead to this key
            gsettings_dir = gsettings_schema
            for item in hierarchy[1:]:
                subdir = None
                for dir in gsettings_dir.dirs:
                    if dir.name == item:
                        subdir = dir
                        break
                if not subdir:
                    subdir = GSettingsSchemaDir()
                    subdir.name = item
                    gsettings_dir.dirs.append(subdir)
                gsettings_dir = subdir

            # we have the final directory, so we can put the key there
            gsettings_dir.keys.append(gconf_schema.get_gsettings_schema_key())

    gsettings_schema_root.simplify()

    return gsettings_schema_root


######################################


def main(args):
    parser = optparse.OptionParser()

    parser.add_option("-o", "--output", dest="output",
                      help="output file")
    parser.add_option("-g", "--gconf", action="store_true", dest="gconf",
                      default=False, help="convert a gconf schema file")
    parser.add_option("-s", "--simple", action="store_true", dest="simple",
                      default=False, help="use the simple schema format as output (only for gconf schema conversion)")
    parser.add_option("-x", "--xml", action="store_true", dest="xml",
                      default=False, help="use the xml schema format as output")
    parser.add_option("-f", "--force", action="store_true", dest="force",
                      default=False, help="overwrite output file if already existing")

    (options, args) = parser.parse_args()

    if len(args) < 1:
        print >> sys.stderr, 'Need a filename to work on.'
        return 1
    elif len(args) > 1:
        print >> sys.stderr, 'Too many arguments.'
        return 1

    if options.simple and options.xml:
        print >> sys.stderr, 'Too many output formats requested.'
        return 1
    if not options.simple and not options.xml:
        if options.gconf:
            options.simple = True
        else:
            options.xml = True

    argfile = os.path.expanduser(args[0])
    if not os.path.exists(argfile):
        print >> sys.stderr, '%s does not exist.' % argfile
        return 1

    if options.output:
        options.output = os.path.expanduser(options.output)

    try:
        if options.output and not options.force and os.path.exists(options.output):
            raise GSettingsSchemaConvertException('%s already exists.' % options.output)

        if options.gconf:
            try:
                schema_root = read_gconf_schema(argfile)
            except SyntaxError, e:
                raise GSettingsSchemaConvertException('%s does not look like a gconf schema file: %s' % (argfile, e))
        else:
            schema_root = read_simple_schema(argfile)

        if options.xml:
            node = schema_root.get_xml_node()
            tree = ET.ElementTree(node)
            try:
                output = ET.tostring(tree, pretty_print = True)
            except TypeError:
                # pretty_print only works with lxml
                output = ET.tostring(tree)
        else:
            output = schema_root.get_simple_string()

        if not options.output:
            sys.stdout.write(output)
        else:
            try:
                fout = open(options.output, 'w')
                fout.write(output)
                fout.close()
            except GSettingsSchemaConvertException, e:
                fout.close()
                if os.path.exists(options.output):
                    os.unlink(options.output)
                raise e

    except GSettingsSchemaConvertException, e:
        print >> sys.stderr, '%s' % e
        return 1

    return 0


if __name__ == '__main__':
    try:
        res = main(sys.argv)
        sys.exit(res)
    except KeyboardInterrupt:
        pass