import rsgdnd.utils as utils
import rsgdnd.server as server
import threading
import importlib
import time
import json
import sys
import os

services = {}
service_defs = {}
services_mtime = 0
services_running = False
services_lock = threading.Lock()

def get_callback(self, in_path, response):
    global services_lock
    in_path = in_path.replace("\\", "/")
    utils.log("==================")
    utils.log(f"server: in coming path '{in_path}'")
    utils.log("==================")
    # pass through
    handled = []
    with services_lock:
        for k, service in services.items():
            callback = "get_callback"
            callback = service[callback] if callback in service else None
            if callback and callback(self, in_path, response):
                handled.append(k)

        if len(handled) > 1:
            utils.log(f"server: {in_path} handled by multiple services, is that intended? "+",".join(handled))

    return len(handled) != 0
    
def post_callback(self, in_path, data, response):
    global services_lock
    in_path = in_path.replace("\\", "/")
    utils.log("==================")
    utils.log(f"server: in coming path '{in_path}'")
    utils.log("==================")
    # pass through
    handled = []
    with services_lock:
        for k, service in services.items():
            callback = "post_callback"
            callback = service[callback] if callback in service else None
            if callback and callback(self, in_path, data, response):
                handled.append(k)

        if len(handled) > 1:
            utils.log(f"server: {in_path} handled by multiple services, is that intended? "+",".join(handled))

    return len(handled) != 0

def service_update():
    global services
    global service_defs
    global services_mtime
    global services_running
    
    services_running = True

    while services_running:
        # check if service defs have updated
        if services_mtime != os.stat("services.json").st_mtime:
            services_mtime = os.stat("services.json").st_mtime
            do_update = False
            with open("services.json") as serv_json:
                try: 
                    service_defs = json.loads(serv_json.read())
                    do_update = True
                except Exception as error:
                    utils.log("Failed trying to open parse services.json")
                    utils.log(error)
        
            if do_update:
                with services_lock:
                    # stop any services that shouldn't be running anymore
                    removals = []
                    for k, v in services.items():
                        try: 
                            if k not in service_defs:
                                if "stop" in v and callable(v["stop"]):
                                    utils.log(f"server: stopping '{k}'")
                                    v["stop"]()
                                removals.append(k)
                        except Exception as error:
                            utils.log("Failed trying to stop services")
                            utils.log(error)

                    for k in removals:
                        utils.log(f"server: removing '{k}' from the service list")
                        del services[k]
                    
                    # start services
                    for k, v in service_defs.items():
                        if k not in services:
                            try:
                                if k in sys.modules:
                                    importlib.reload(sys.modules[k])
                                new_service = importlib.import_module(k)
                                services[k] = { "module": new_service }
                                for id in v:
                                    if hasattr(new_service, v[id]):
                                        services[k][id] = getattr(new_service, v[id])
                                    else:
                                        services[k][id] = None

                                if not any([id in services[k] for id in ["get_callback", "post_callback", "start", "stop"]]):
                                    raise ValueError(k+" doesn't define any of the service interfaces.")

                                for func in [services[k][id] for id in ["get_callback", "post_callback", "start", "stop"] if id in services[k]]:
                                    if not callable(func):
                                        raise ValueError(k+" '"+func.__name__+"' is not callable")

                                utils.log(f"server: added '{k}' to the service list")

                                if "start" in services[k] and callable(services[k]["start"]):
                                    utils.log(f"server: starting '{k}'")
                                    services[k]["start"]()

                            except Exception as error:
                                utils.log("Failed trying to start services")
                                utils.log(error)
                                if k in services:
                                    del services[k]
        time.sleep(1)


@utils.trywrap()
def main():
    global services_running
    update = threading.Thread(target=service_update)
    update.start()
    server.run_whitelist(get_callback=get_callback, post_callback=post_callback)
    services_running = False
    update.join()

    pass

if __name__ == "__main__":
    main()