import typing as t
import hmac
import hashlib
import json
from collections import defaultdict
from flask import Flask, request, abort
from .conf import Configuration

config = Configuration()
app = Flask(__name__)


def webhook_receiver(hook_type):
    if hook_type not in config.raw:
        raise Exception(f"Badly configured route: no conf of type {hook_type}")

    relevant_hooks = config.raw[hook_type]

    def inner(func):
        def wrapped(hook_name: str):
            if request.content_length is None or request.content_length > 32000:
                abort(400)
            if request.content_type != "application/json":
                return "Expected json", 415

            if hook_name not in relevant_hooks:
                abort(404)
            hook_conf = relevant_hooks[hook_name]

            raw_payload: bytes = request.get_data(cache=False)
            provided_sig: str = request.headers["X-Gitea-Signature"]
            computed_sig = hmac.new(
                hook_conf["secret"].encode("utf-8"), raw_payload, hashlib.sha256
            ).hexdigest()
            if not hmac.compare_digest(provided_sig, computed_sig):
                abort(403)

            try:
                payload = json.loads(raw_payload)
            except json.JSONDecodeError:
                return "Bad JSON", 400

            return func(payload, hook_name, hook_conf)

        return wrapped

    return inner


@app.route("/")
def root() -> t.Tuple[str, int]:
    """Root web handler -- pointless in this case"""
    return "Not supported.", 400


@app.route("/fifo/<string:hook_name>", methods=["POST"])
@webhook_receiver("fifo_hooks")
def fifo_hooks(payload, hook_name, hook_conf):
    """Fifo web handler -- write 1 to a unix fifo"""
    try:
        with open(hook_conf["fifo_path"], "w") as fifo:
            fifo.write("1")
    except FileNotFoundError:
        return "No such fifo", 500
    except PermissionError:
        return "Permission denied on FIFO", 500

    return "OK", 200