# Copyright (c) 2009 Volker Mische (http://vmx.cx/)
# Licensed under MIT.

import sys, os, time, warnings
from TileCache.Cache import Cache

from couchdbkit import Server, ResourceNotFound

class Couchdb(Cache):
    def __init__ (self, server = 'localhost:5984', db='tilecache', **kwargs):
        Cache.__init__(self, **kwargs)
        self.server = Server('http://' + server + '/')
        self.db = self.server.get_or_create_db(db)

    def getKey (self, tile):
        return "/".join(map(str, [tile.layer.name, tile.x, tile.y, tile.z]))

    def get (self, tile):
        key = self.getKey(tile)
        tile.data = self.db.fetch_attachment(key, key)
        return tile.data

    def set (self, tile, data):
        if self.readonly: return data
        key = self.getKey(tile)
        try:
            doc = self.db[key]
        except ResourceNotFound:
            doc = {}
            self.db[key] = doc
        self.db.put_attachment(doc, data, key, 'image/png')
        return data

    def delete (self, tile):
        key = self.getKey(tile)
        del self.db[key]
            
    def attemptLock (self, tile):
        pass 
    
    def unlock (self, tile):
        pass