#!/usr/bin/python3

import http.server
import os.path

import justserv

class StateStore:

    def __init__(self, dir = None):
        if dir is None:
            dir = "./__states__"

        if not os.path.isdir(dir):
            os.mkdir(dir)

        self.__dir = dir
        self.__cache = {}

    def getState(self, appname):
        sp = "{}/{}.state".format(self.__dir, appname)
        if not appname in self.__cache:
            if os.path.isfile(sp):
                with open(sp, "rb") as sf:
                    st = sf.read().decode("utf-8")
                    self.__cache[appname] = eval(st)
            else:
                self.__cache[appname] = {}

        return self.__cache[appname]

    def patchState(self, appname, newstate):
        state = self.getState(appname)
        justserv.patch.patch(state, newstate)
        self.setState(appname, state)

    def setState(self, appname, state):
        self.__cache[appname] = state

        sp = "{}/{}.state".format(self.__dir, appname)
        st = str(state)
        with open(sp, "wb") as sf:
            sf.write(st.encode("utf-8"))


class JSRequestHandler(http.server.BaseHTTPRequestHandler):
    _store = StateStore()

    def getAppname(self):
        if self.path == "" or self.path == "/":
            p = "__root__"
        else:
            p = self.path.split("/")[1]
        return p

    def do_GET(self):
        p = self.getAppname()

        s = self._store.getState(p)
        sb = str(s).encode("utf-8")

        self.send_response(200)
        self.send_header("content-length", len(sb))
        self.end_headers()

        self.wfile.write(sb)

    def do_PATCH(self):
        p = self.getAppname()

        bpatch = self.rfile.read(int(self.headers.get('content-length', 0)))
        ps = eval(bpatch.decode("utf-8"))
        self._store.patchState(p, ps)
        return self.do_GET()

if __name__ == '__main__':
    httpd = http.server.HTTPServer( ('', 8080 ), JSRequestHandler)
    httpd.serve_forever()