import urllib2, os, threading, time, sys

URL = "http://img.4chan.org/b/imgboard.html" #"http://img.4chan.org/b/res/53264202.html"
imgdir = "_4chan"
I = 0
Y = 0
T = 0
recurse = False

def log(msg):
    print "[%s]: %s" % (time.strftime("%I:%M"),msg)

if "-r" in sys.argv or "-recurse" in sys.argv or "-watch" in sys.argv:
    log( "recursing enabled" )
    recurse = True
else:
    log( "recursing disabled" )

def threadurl(thread):
    nurl = "http://img.4chan.org/b/res/%s" % thread
    #log( "threadurl: %s" % nurl )
    return nurl

class FetchThread(threading.Thread):
    def __init__(self, topic):
        self.topic = topic
        threading.Thread.__init__(self)
    def run(self):
        global I
        log( "fetching topic %s" % self.topic )
        s=urllib2.urlopen(self.topic);html=s.read();s.close()
        g = html.split("File :<a href=\"")
        
        for split in g:
            sp = split.split("\"")[0]
            if sp[0:4] == "http":
                I += 1
                bname = os.path.basename(sp)
                localfile = os.path.join(imgdir,bname)
                if not os.path.exists(localfile):
                    log( "fetching %s to %s (%i of %i)" % (bname,localfile,I,len(g)) )
                    try:
                        st = urllib2.urlopen(sp);f = open(localfile,'wb')
                        f.write(st.read());f.close();st.close()
                    except Exception, e:
                        log( "exception in FetchThread: %s (url: %s)" % (e,sp) )
                    
class MainGET(threading.Thread):
    def run(self):
        global T
        log( "got main page" )
        FetchThread(URL).start()
        try:
            if recurse: s=urllib2.urlopen(URL);html=s.read();s.close()
        except Exception, e:
            log("MainGET: exception: %s (url: %s)" % (e,url))
            return
        
        if recurse:
            g = html.split("<a href=\"res/")
            for split in g:
                sp = split.split("#")[0]
                if sp[len(sp)-4:len(sp)] == "html":
                    T += 1
                    #log( "MainGET: res ends with html, getting topic. (%i)" % T)
                    FetchThread(threadurl(sp)).start()
                #log("end MainGET")
            
        

class MainWatcher(threading.Thread):
    def run(self):
        global Y
        while True:
            Y += 1
            MainGET().start()
            log( "updating main page: %i" % Y )
            time.sleep(30)

def main():
    MainWatcher().start()

if __name__ == '__main__': main()