#!/usr/bin/env python
# encoding: utf-8
# whoosh indexer daemon for hg-app
# Copyright (C) 2009-2010 Marcin Kuzminski <marcin@python-works.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; version 2
# of the License or (at your opinion) any later version of the license.
# 
# 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 General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA  02110-1301, USA.
"""
Created on Jan 26, 2010

@author: marcink
A deamon will read from task table and run tasks
"""
import sys
import os
from pidlock import LockHeld, DaemonLock
import traceback

from os.path import dirname as dn
from os.path import join as jn

#to get the pylons_app import
sys.path.append(dn(dn(dn(os.path.realpath(__file__)))))

from pylons_app.config.environment import load_environment
from pylons_app.model.hg_model import HgModel
from whoosh.index import create_in, open_dir
from shutil import rmtree
from pylons_app.lib.indexers import ANALYZER, EXCLUDE_EXTENSIONS, IDX_LOCATION, SCHEMA, IDX_NAME
import logging
log = logging.getLogger(__name__)


location = '/home/marcink/python_workspace_dirty/*'

def scan_paths(root_location):
    return HgModel.repo_scan('/', root_location, None, True)

class WhooshIndexingDaemon(object):
    """Deamon for atomic jobs"""

    def __init__(self, indexname='HG_INDEX'):
        self.indexname = indexname
        
    
    def get_paths(self, root_dir):
        """recursive walk in root dir and return a set of all path in that dir
        excluding files in .hg dir"""
        index_paths_ = set()
        for path, dirs, files in os.walk(root_dir):
            if path.find('.hg') == -1:
                for f in files:
                    index_paths_.add(jn(path, f))
    
        return index_paths_
    
    def add_doc(self, writer, path, repo):
        """Adding doc to writer"""
        
        #we don't won't to read excluded file extensions just index them
        if path.split('/')[-1].split('.')[-1].lower() not in EXCLUDE_EXTENSIONS:
            fobj = open(path, 'rb')
            content = fobj.read()
            fobj.close()
            try:
                u_content = unicode(content)
            except UnicodeDecodeError:
                #incase we have a decode error just represent as byte string
                u_content = unicode(str(content).encode('string_escape'))
        else:
            u_content = u''    
        writer.add_document(owner=unicode(repo.contact),
                            repository=u"%s" % repo.name,
                            path=u"%s" % path,
                            content=u_content,
                            modtime=os.path.getmtime(path)) 
    
    def build_index(self):
        if os.path.exists(IDX_LOCATION):
            rmtree(IDX_LOCATION)
            
        if not os.path.exists(IDX_LOCATION):
            os.mkdir(IDX_LOCATION)
        
        idx = create_in(IDX_LOCATION, SCHEMA, indexname=IDX_NAME)
        writer = idx.writer()
        
        for cnt, repo in enumerate(scan_paths(location).values()):
            log.debug('building index @ %s' % repo.path)
        
            for idx_path in self.get_paths(repo.path):
                log.debug('    >> %s' % idx_path)
                self.add_doc(writer, idx_path, repo)
        writer.commit(merge=True)
                
        log.debug('>>> FINISHED BUILDING INDEX <<<')
            
    
    def update_index(self):
        log.debug('STARTING INCREMENTAL INDEXING UPDATE')
            
        idx = open_dir(IDX_LOCATION, indexname=self.indexname)
        # The set of all paths in the index
        indexed_paths = set()
        # The set of all paths we need to re-index
        to_index = set()
        
        reader = idx.reader()
        writer = idx.writer()
    
        # Loop over the stored fields in the index
        for fields in reader.all_stored_fields():
            indexed_path = fields['path']
            indexed_paths.add(indexed_path)
    
            if not os.path.exists(indexed_path):
                # This file was deleted since it was indexed
                log.debug('removing from index %s' % indexed_path)
                writer.delete_by_term('path', indexed_path)
    
            else:
                # Check if this file was changed since it
                # was indexed
                indexed_time = fields['modtime']
                
                mtime = os.path.getmtime(indexed_path)
    
                if mtime > indexed_time:
    
                    # The file has changed, delete it and add it to the list of
                    # files to reindex
                    log.debug('adding to reindex list %s' % indexed_path)
                    writer.delete_by_term('path', indexed_path)
                    to_index.add(indexed_path)
                    #writer.commit()
    
        # Loop over the files in the filesystem
        # Assume we have a function that gathers the filenames of the
        # documents to be indexed
        for repo in scan_paths(location).values():
            for path in self.get_paths(repo.path):
                if path in to_index or path not in indexed_paths:
                    # This is either a file that's changed, or a new file
                    # that wasn't indexed before. So index it!
                    self.add_doc(writer, path, repo)
                    log.debug('reindexing %s' % path)
    
        writer.commit(merge=True)
        #idx.optimize()
        log.debug('>>> FINISHED <<<')
        
    def run(self, full_index=False):
        """Run daemon"""
        if full_index:
            self.build_index()
        else:
            self.update_index()
        
if __name__ == "__main__":
    
    #config = load_environment()
    #print config
    try:
        l = DaemonLock()
        WhooshIndexingDaemon().run(full_index=True)
        l.release()
    except LockHeld:
        sys.exit(1)