import sys
from asyncio import wait_for, TimeoutError
from base64 import b64encode
from sanic import Sanic
from sanic.response import file, redirect, empty

from InputController import InputController
from MessageParser import MessageParser


app = Sanic(
    "capybara",
    env_prefix="CAPYBARA_"
)
input_controller = InputController()
control_message_parser = MessageParser()

# auth packet
control_message_parser.add_handler("0", {
    "auth_string": "str"
})

app.static("app", "frontend/dist/", resource_type="dir")

@app.get("/")
async def home(req):
    return redirect("/app/app.html")

@app.get("/app")
async def app_route(req):
    return redirect("/app/app.html")

@app.websocket("/gateway")
async def gateway(req, ws):
    # Before the client is able to send any data, we must await an authorization packet
    try:
        auth_payload = await wait_for(ws.recv(), timeout=5)
    except TimeoutError:
        await ws.close(code=4001, reason="Invalid auth packet")
        return

    code, args = control_message_parser.parse(auth_payload)
    if (
        not code or
        code != "0" or
        args["auth_string"] != app.ctx.EXPECTED_AUTH_STRING
    ): # 0 is the code for the initial auth packet
        await ws.close(code=4001, reason="Invalid auth packet")
        return

    await ws.send("1") # send a single `1` to let the client know the server is accepting input packets

    while True:
        input_controller.process_message(await ws.recv())


def main():
    if not app.config.get("AUTH_PASSWORD"):
        print(
            "capybara: FATAL ERROR: Capybara is expecting the `CAPYBARA_AUTH_PASSWORD` environment variable to be set (to a password of your choice).\nYour users will use this password to authenticate to your server.\nEXITING...",
            file=sys.stderr
        )
        exit(1)
        return

    app.ctx.EXPECTED_AUTH_STRING = "%auth%" + str(b64encode(app.config.AUTH_PASSWORD.encode("utf-8")), "utf-8")
    app.run(host='0.0.0.0', port=4003, access_log=False)

if __name__ == "__main__":
    main()