import json
import os
from datetime import datetime, timezone
from pathlib import Path

import yaml
from flask import Flask, Response, jsonify, request


CONFIG_FILE = Path(__file__).with_name("config.yaml")
with CONFIG_FILE.open(encoding="utf-8") as stream:
    CONFIG = yaml.safe_load(stream) or {}

LOG_FILE = Path(CONFIG["HOME_CONTROL_LOG"])
if not LOG_FILE.is_absolute():
    LOG_FILE = CONFIG_FILE.parent / LOG_FILE
IP_ADDRESS = str(CONFIG.get("ip_address", "127.0.0.1"))
PORT = int(CONFIG.get("port", 5000))
URL_PREFIX = "/" + str(CONFIG.get("url_prefix", "")).strip("/")
if URL_PREFIX == "/":
    URL_PREFIX = ""

app = Flask(__name__)


def _tail(path: Path, line_count: int = 50) -> str:
    try:
        with path.open("rb") as logfile:
            logfile.seek(0, os.SEEK_END)
            end = logfile.tell()
            data = b""

            while end > 0 and data.count(b"\n") <= line_count:
                size = min(4096, end)
                end -= size
                logfile.seek(end)
                data = logfile.read(size) + data

        return b"\n".join(data.splitlines()[-line_count:]).decode("utf-8", "replace")
    except FileNotFoundError:
        return ""


@app.route(f"{URL_PREFIX}/event", methods=["GET", "POST"])
def add_event():
    data = request.get_json(silent=True)
    if data is None:
        data = request.values.to_dict(flat=False)
    if not data:
        data = request.get_data(as_text=True)

    entry = {
        "timestamp": datetime.now(timezone.utc).isoformat(),
        "remote_addr": request.remote_addr,
        "event": data,
    }
    LOG_FILE.parent.mkdir(parents=True, exist_ok=True)
    with LOG_FILE.open("a", encoding="utf-8") as logfile:
        logfile.write(json.dumps(entry, ensure_ascii=False, separators=(",", ":")) + "\n")

    return jsonify(ok=True), 201


@app.get(URL_PREFIX or "/", strict_slashes=False)
def show_log():
    return Response(_tail(LOG_FILE), mimetype="text/plain")


if __name__ == "__main__":
    app.run(host=IP_ADDRESS, port=PORT)