#! /usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright (c) 2008, PediaPress GmbH
# See README.txt for additional licensing information.

import os
import re
import shutil
import tempfile
import time
import urllib
import urllib2
import urlparse

import simplejson

from mwlib import uparser, utils
from mwlib.log import Log

log = Log("mwapidb")

try:
    from mwlib.licenses import lower2normal
except ImportError:
    log.warn('no licenses found')
    lower2normal = {}

# ==============================================================================


def fetch_url(url, ignore_errors=False):
    log.info("fetching %r" % (url,))
    opener = urllib2.build_opener()
    opener.addheaders = [('User-agent', 'mwlib')]
    try:
        data = opener.open(url).read()
    except urllib2.URLError, err:
        if ignore_errors:
            log.error("%s - while fetching %r" % (err, url))
            return None
        raise RuntimeError('Could not fetch %r: %s' % (url, err))
    log.info("got %r (%d Bytes)" % (url, len(data)))
    return data


# ==============================================================================


class APIHelper(object):
    def __init__(self, base_url):
        """
        @param base_url: base URL (or list of URLs) of a MediaWiki,
            i.e. URL path to php scripts,
            e.g. 'http://en.wikipedia.org/w/' for English Wikipedia.
        @type base_url: basestring or [basestring]
        """
        
        if isinstance(base_url, unicode):
            self.base_url = base_url.encode('utf-8')
        else:
            self.base_url = base_url
        if self.base_url[-1] != '/':
            self.base_url += '/'
    
    def query(self, **kwargs):
        args = {
            'action': 'query',
            'format': 'json',
        }
        args.update(**kwargs)
        for k, v in args.items():
            if isinstance(v, unicode):
                args[k] = v.encode('utf-8')
        data = fetch_url('%sapi.php?%s' % (self.base_url, urllib.urlencode(args)))
        if data is None:
            return None
        try:
            return simplejson.loads(unicode(data, 'utf-8'))['query']
        except KeyError:
            return None
        except:
            raise RuntimeError('api.php query failed. Are you sure you specified the correct baseurl?')
    
    def page_query(self, **kwargs):
        q = self.query(**kwargs)
        if q is None:
            return None
        try:
            page = q['pages'].values()[0]
        except (KeyError, IndexError):
            return None
        if 'missing' in page:
            return None
        return page
    

# ==============================================================================


class ImageDB(object):
    def __init__(self, base_url, shared_base_url=None):
        self.api_helpers = [APIHelper(base_url)]
        if shared_base_url is not None:
            self.api_helpers.append(APIHelper(shared_base_url))
        self.tmpdir = tempfile.mkdtemp()
    
    def clear(self):
        shutil.rmtree(self.tmpdir, ignore_errors=True)
    
    def getURL(self, name, size=None):
        """Return image URL for image with given name
        
        @param name: image name (without namespace, i.e. without 'Image:')
        @type name: unicode
        
        @returns: URL to original image
        @rtype: str
        """
        
        assert isinstance(name, unicode), 'name must be of type unicode'
        
        for api_helper in self.api_helpers:
            if size is None:
                result = api_helper.page_query(titles='Image:%s' % name, prop='imageinfo', iiprop='url')
            else:
                result = api_helper.page_query(titles='Image:%s' % name, prop='imageinfo', iiprop='url', iiurlwidth=str(size))
            if result is not None:
                break
        else:
            return None
        
        try:
            imageinfo = result['imageinfo'][0]
            if size is not None and 'thumburl' in imageinfo:
                url = imageinfo['thumburl']
            else:
                url = imageinfo['url']
            if url: # url can be False
                if url.startswith('/'):
                    url = urlparse.urljoin(self.api_helpers[0].base_url, url)
                return url
            return None
        except (KeyError, IndexError):
            return None
    
    def getDiskPath(self, name, size=None):
        """Return filename for image with given name and size
        
        @param name: image name (without namespace, i.e. without 'Image:')
        @type name: unicode
        
        @param size: if given, the image is converted to the given maximum width
        @type size: int or NoneType
        
        @returns: filename of image or None if image could not be found
        @rtype: basestring
        """
        
        assert isinstance(name, unicode), 'name must be of type unicode'
        
        url = self.getURL(name, size=size)
        if url is None:
            return None
        
        data = fetch_url(url, ignore_errors=True)
        if not data:
            return None
        
        ext = url.rsplit('.')[-1]
        if size is not None:
            ext = '%dpx.%s' % (size, ext)
        else:
            ext = '.%s' % ext
        filename = os.path.join(self.tmpdir, utils.fsescape(name + ext))
        f = open(filename, 'wb')
        f.write(data)
        f.close()
        return filename
    
    def getLicense(self, name):
        """Return license of image as stated on image description page
        
        @param name: image name without namespace (e.g. without "Image:")
        @type name: unicode
        
        @returns: license of image of None, if no valid license could be found
        @rtype: unicode
        """
        
        assert isinstance(name, unicode), 'name must be of type unicode'
        
        for api_helper in self.api_helpers:
            result = api_helper.page_query(titles='Image:%s' % name, prop='templates')
            if result is not None:
                break
        else:
            return None
        
        try:
            templates = [t['title'] for t in result['templates']]
        except KeyError:
            return None
        
        for t in templates:
            try:
                return lower2normal[t.split(':', 1)[-1].lower()]
            except KeyError:
                pass
        
        return None
    

# ==============================================================================

    
class WikiDB(object):
    print_template = u'Template:Print%s'
    
    ip_rex = re.compile(r'^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$')
    bot_rex = re.compile(r'\bbot\b', re.IGNORECASE)
    
    def __init__(self, base_url, license, template_blacklist=None):
        """
        @param base_url: base URL of a MediaWiki,
            e.g. 'http://en.wikipedia.org/w/'
        @type base_url: basestring
        
        @param license: title of an article containing full license text
        @type license: unicode
        
        @param template_blacklist: title of an article containing blacklisted
            templates (optional)
        @type template_blacklist: unicode
        """
        
        self.base_url = base_url
        self.license = license
        self.api_helper = APIHelper(self.base_url)
        self.template_cache = {}
        self.template_blacklist = []
        if template_blacklist is not None:
            raw = self.getRawArticle(template_blacklist)
            if raw is None:
                log.error('Could not get template blacklist article %r' % template_blacklist)
            else:
                self.template_blacklist = [template.lower().strip() 
                                           for template in re.findall('\* *\[\[.*?:(.*?)\]\]', raw)]
    
    def getURL(self, title, revision=None):
        name = urllib.quote(title.replace(" ", "_").encode('utf-8'))
        if revision is None:
            return '%sindex.php?title=%s' % (self.base_url, name)
        else:
            return '%sindex.php?title=%s&oldid=%s' % (self.base_url, name, revision)
    
    def getAuthors(self, title, revision=None, max_num_authors=10):
        """Return at most max_num_authors names of non-bot, non-anon users for
        non-minor changes of given article (before given revsion).
        
        @returns: list of principal authors
        @rtype: [unicode]
        """
        
        result = self.api_helper.page_query(
            titles=title,
            redirects=1,
            prop='revisions',
            rvprop='user|ids|flags|comment',
            rvlimit=500,
        )
        if result is None:
            return None
        
        try:
            revs = result['revisions']
        except KeyError:
            return None

        if revision is not None:
            revision = int(revision)
            revs = [r for r in revs if r['revid'] < revision]
        
        authors = [r['user'] for r in revs
                   if not r.get('anon')
                   and not self.ip_rex.match(r['user'])
                   and not r.get('minor')
                   and not self.bot_rex.search(r.get('comment', ''))
                   and not self.bot_rex.search(r['user'])
                   ]
        author2count = {}
        for a in authors:
            try:
                author2count[a] += 1
            except KeyError:
                author2count[a] = 1
        author2count = author2count.items()
        author2count.sort(key=lambda a: -a[1])
        return [a[0] for a in author2count[:max_num_authors]]
    
    def getTemplate(self, name, followRedirects=True):
        """
        Note: *Not* following redirects is unsupported!
        """
        
        try:
            return self.template_cache[name]
        except KeyError:
            pass
        
        if ":" in name:
            name = name.split(':', 1)[1]
        
        if name.lower() in self.template_blacklist:
            log.info("ignoring blacklisted template:" , repr(name))
            return None
        
        for title in (self.print_template % name, 'Template:%s' % name):
            log.info("Trying template %r" % (title,))
            c = self.getRawArticle(title)
            if c is not None:
                self.template_cache[name] = c
                return c
        
        return None
    
    def getRawArticle(self, title, revision=None):
        if revision is None:
            page = self.api_helper.page_query(titles=title, redirects=1, prop='revisions', rvprop='content')
        else:
            page = self.api_helper.page_query(revids=revision, prop='revisions', rvprop='content')
            if page['title'] != title: # given revision could point to another article!
                return None
        if page is None:
            return None
        try:
            return page['revisions'][0].values()[0]
        except KeyError:
            return None
    
    def getMetaData(self):
        result = self.api_helper.query(meta='siteinfo')
        try:
            g = result['general']
            return {
                'license': {
                    'name': g['rights'],
                    'wikitext': self.getRawArticle(self.license),
                },
                'url': g['base'],
                'name': '%s (%s)' % (g['sitename'], g['lang']),
            }
        except KeyError:
            return None
    
    def getParsedArticle(self, title, revision=None):
        raw = self.getRawArticle(title, revision=revision)
        if raw is None:
            return None
        a = uparser.parseString(title=title, raw=raw, wikidb=self)
        return a
    

class Overlay(WikiDB):
    def __init__(self, wikidb, templates):
        self.__dict__.update(wikidb.__dict__)
        self.overlay_templates = templates
        
    def getTemplate(self, name, followRedirects=False):
        try:
            return self.overlay_templates[name]
        except KeyError:
            pass
        
        return super(Overlay, self).getTemplate(name, followRedirects=followRedirects)