import wx
from cStringIO import StringIO
from tiledownloader import DownloadRequest, TileDownloader
from tilecache import TileCoord, TileCache

class GoogleTileCache(TileCache):
    downloader = None
    tilesize = (256,256)
    
    def validateCoords(self, coords):
        if coords.x < 0 or coords.y < 0:
            return False
        
        if coords.zoom < 0 or coords.zoom > 17:
            return False
        
        divs = 2 ** coords.zoom
        
        if coords.x >= divs or coords.y >= divs:
            return False
        
        return True
    
    def loadTile(self, coords, block):
        if not self.downloader:
            self.downloader = TileDownloader(["mt0.google.com", "mt1.google.com", "mt2.google.com", "mt3.google.com"])
        
        path = "/mt?x=%d&y=%d&zoom=%d" % (coords.x, coords.y, 17 - coords.zoom)
        request = DownloadRequest(path)
        
        if self.validateCoords(coords):
            request = self.downloader.download(request, block)
        
        if not request:
            return None
        
        if not request.data:
            self.addTile(coords, self.emptytile)
            return self.emptytile
        
        buf = StringIO(request.data)
        image = wx.ImageFromStream(buf)
        
        self.addTile(coords, image)
        return image

if __name__ == "__main__":
    import time
    
    tilecache = GoogleTileCache()
    image = False
    while not image:
        image = tilecache.getTile(TileCoord(1,1,16))
        print image
        time.sleep(0.01)