from galaxy.eggs import require
# Whoosh is compatible with Python 2.5+ Try to import Whoosh and set flag to indicate whether tool search is enabled.
try:
    require( "Whoosh" )

    from whoosh.filedb.filestore import RamStorage
    from whoosh.fields import Schema, STORED, ID, KEYWORD, TEXT
    from whoosh.index import Index
    from whoosh.qparser import QueryParser
    tool_search_enabled = True
    schema = Schema( id = STORED, title = TEXT, description = TEXT, help = TEXT )
except ImportError, e:
    tool_search_enabled = False
    schema = None

class ToolBoxSearch( object ):
    """
    Support searching tools in a toolbox. This implementation uses
    the "whoosh" search library.
    """
    
    def __init__( self, toolbox ):
        """
        Create a searcher for `toolbox`. 
        """
        self.toolbox = toolbox
        self.enabled = tool_search_enabled
        if tool_search_enabled:
            self.build_index()
        
    def build_index( self ):
        self.storage = RamStorage()
        self.index = self.storage.create_index( schema )
        writer = self.index.writer()
        ## TODO: would also be nice to search section headers.
        for id, tool in self.toolbox.tools_by_id.iteritems():
            def to_unicode( a_basestr ):
                if type( a_basestr ) is str:
                    return unicode( a_basestr, 'utf-8' )
                else:
                    return a_basestr

            writer.add_document( id=id, title=to_unicode(tool.name), description=to_unicode(tool.description), help=to_unicode(tool.help) )
        writer.commit()
        
    def search( self, query, return_attribute='id' ):
        if not tool_search_enabled:
            return []
        searcher = self.index.searcher()
        parser = QueryParser( "help", schema = schema )
        # Set query to search title, description, and help.
        query = "title:query OR description:query OR help:query".replace( "query", query ) 
        results = searcher.search( parser.parse( query ), minscore=1.5 )
        print results.scores
        return [ result[ return_attribute ] for result in results ]