# -*- coding: utf-8 -*-
#
# Copyright (C) 2003-2009 Edgewall Software
# Copyright (C) 2003-2005 Jonas Borgström <jonas@edgewall.com>
# Copyright (C) 2005 Christopher Lenz <cmlenz@gmx.de>
# 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://trac.edgewall.org/wiki/TracLicense.
#
# This software consists of voluntary contributions made by many
# individuals. For the exact contribution history, see the revision
# history and logs, available at http://trac.edgewall.org/log/.
#
# Author: Jonas Borgström <jonas@edgewall.com>
#         Christopher Lenz <cmlenz@gmx.de>

from __future__ import with_statement

from datetime import datetime

from trac.core import *
from trac.resource import Resource
from trac.util.datefmt import from_utimestamp, to_utimestamp, utc
from trac.util.translation import _
from trac.wiki.api import WikiSystem, validate_page_name


class WikiPage(object):
    """Represents a wiki page (new or existing)."""

    realm = 'wiki'

    def __init__(self, env, name=None, version=None, db=None):
        self.env = env
        if isinstance(name, Resource):
            self.resource = name
            name = self.resource.id
        else:
            if version:
                version = int(version) # must be a number or None
            self.resource = Resource('wiki', name, version)
        self.name = name
        if name:
            self._fetch(name, version, db)
        else:
            self.version = 0
            self.text = self.comment = self.author = ''
            self.time = None
            self.readonly = 0
        self.old_text = self.text
        self.old_readonly = self.readonly

    def _fetch(self, name, version=None, db=None):
        if version is not None:
            sql = """SELECT version, time, author, text, comment, readonly 
                     FROM wiki WHERE name=%s AND version=%s"""
            args = (name, int(version))
        else:
            sql = """SELECT version, time, author, text, comment, readonly 
                     FROM wiki WHERE name=%s ORDER BY version DESC LIMIT 1"""
            args = (name,)
        for version, time, author, text, comment, readonly in \
                self.env.db_query(sql, args):
            self.version = int(version)
            self.author = author
            self.time = from_utimestamp(time)
            self.text = text
            self.comment = comment
            self.readonly = int(readonly) if readonly else 0
            break
        else:
            self.version = 0
            self.text = self.comment = self.author = ''
            self.time = None
            self.readonly = 0
            
    exists = property(lambda self: self.version > 0)

    def delete(self, version=None, db=None):
        """Delete one or all versions of a page.

        :since 1.0: the `db` parameter is no longer needed and will be removed
        in version 0.14
        """
        assert self.exists, "Cannot delete non-existent page"
        
        with self.env.db_transaction as db:
            if version is None:
                # Delete a wiki page completely
                db("DELETE FROM wiki WHERE name=%s", (self.name,))
                self.env.log.info("Deleted page %s", self.name)
            else:
                # Delete only a specific page version
                db("DELETE FROM wiki WHERE name=%s and version=%s",
                   (self.name, version))
                self.env.log.info("Deleted version %d of page %s", version,
                                  self.name)

            if version is None or version == self.version:
                self._fetch(self.name, None)

            if not self.exists:
                # Invalidate page name cache
                del WikiSystem(self.env).pages
                # Delete orphaned attachments
                from trac.attachment import Attachment
                Attachment.delete_all(self.env, 'wiki', self.name)

        # Let change listeners know about the deletion
        if not self.exists:
            for listener in WikiSystem(self.env).change_listeners:
                listener.wiki_page_deleted(self)
        else:
            for listener in WikiSystem(self.env).change_listeners:
                if hasattr(listener, 'wiki_page_version_deleted'):
                    listener.wiki_page_version_deleted(self)

    def save(self, author, comment, remote_addr, t=None, db=None):
        """Save a new version of a page.

        :since 1.0: the `db` parameter is no longer needed and will be removed
        in version 0.14
        """
        if not validate_page_name(self.name):
            raise TracError(_("Invalid Wiki page name '%(name)s'",
                              name=self.name))

        new_text = self.text != self.old_text
        if not new_text and self.readonly == self.old_readonly:
            raise TracError(_("Page not modified"))
        t = t or datetime.now(utc)

        with self.env.db_transaction as db:
            if new_text:
                db("""INSERT INTO wiki (name, version, time, author, ipnr,
                                        text, comment, readonly)
                      VALUES (%s,%s,%s,%s,%s,%s,%s,%s)
                      """, (self.name, self.version + 1, to_utimestamp(t),
                            author, remote_addr, self.text, comment,
                            self.readonly))
                self.version += 1
                self.resource = self.resource(version=self.version)
            else:
                db("UPDATE wiki SET readonly=%s WHERE name=%s",
                   (self.readonly, self.name))
            if self.version == 1:
                # Invalidate page name cache
                del WikiSystem(self.env).pages
        
        self.author = author
        self.comment = comment
        self.time = t

        for listener in WikiSystem(self.env).change_listeners:
            if self.version == 1:
                listener.wiki_page_added(self)
            else:
                listener.wiki_page_changed(self, self.version, t, comment,
                                           author, remote_addr)

        self.old_readonly = self.readonly
        self.old_text = self.text

    def rename(self, new_name):
        """Rename wiki page in-place, keeping the history intact.
        Renaming a page this way will eventually leave dangling references
        to the old page - which litterally doesn't exist anymore.
        """
        assert self.exists, "Cannot rename non-existent page"

        if not validate_page_name(new_name):
            raise TracError(_("Invalid Wiki page name '%(name)s'",
                              name=new_name))
        old_name = self.name
        
        with self.env.db_transaction as db:
            new_page = WikiPage(self.env, new_name)
            if new_page.exists:
                raise TracError(_("Can't rename to existing %(name)s page.",
                                  name=new_name))

            db("UPDATE wiki SET name=%s WHERE name=%s", (new_name, old_name))
            # Invalidate page name cache
            del WikiSystem(self.env).pages
            # Reparent attachments
            from trac.attachment import Attachment
            Attachment.reparent_all(self.env, 'wiki', old_name, 'wiki',
                                    new_name)

        self.name = new_name
        self.env.log.info('Renamed page %s to %s', old_name, new_name)
        
        for listener in WikiSystem(self.env).change_listeners:
            if hasattr(listener, 'wiki_page_renamed'):
                listener.wiki_page_renamed(self, old_name)

    def get_history(self, db=None):
        """Retrieve the edit history of a wiki page.

        :since 1.0: the `db` parameter is no longer needed and will be removed
        in version 0.14
        """
        for version, ts, author, comment, ipnr in self.env.db_query("""
                SELECT version, time, author, comment, ipnr FROM wiki
                WHERE name=%s AND version<=%s ORDER BY version DESC
                """, (self.name, self.version)):
            yield version, from_utimestamp(ts), author, comment, ipnr
