#!/usr/bin/env python3

import pickle
import atexit
import datetime

from flask import Flask, Blueprint, jsonify, request, abort
from flask_cors import CORS

DB_FILE = "vacation.db"

last_update = datetime.datetime.now()
since_backup = 0

try:
    with open(DB_FILE, "rb") as infile:
        db = pickle.load(infile)
except FileNotFoundError:
    db = {}


@atexit.register
def save_db(prefix=""):
    with open(prefix + DB_FILE, "wb") as outfile:
        pickle.dump(db, outfile)


def backup_db():
    save_db(f"backup-{datetime.datetime.now().isoformat()}-")


bp = Blueprint("vacation", __name__)


@bp.route("/")
def health():
    return jsonify({"status": "healthy"})


@bp.route("/availability", methods=["GET", "POST"])
def status():
    global last_update, since_backup
    
    if request.method == "POST":
        body = request.get_json()
        if body is None:
            abort(400)
        name = body.get("name", None)
        availability = body.get("availability", None)
        if not isinstance(name, str) or not isinstance(availability, list):
            abort(400)
        
        transaction = []
        for a in availability:
            month = a.get("month", None)
            day = a.get("day", None)
            status = a.get("status", None)
            if (month, day) not in db or status not in ("yes", "no", "maybe", "unknown"):
                abort(400)
            transaction.append((month, day, status))
        
        last_update = datetime.datetime.now()
        for (month, day, status) in transaction:
            db[(month, day)][name] = status

        since_backup += 1
        if since_backup > 50:
            backup_db()

    return jsonify({
        "lastUpdated": last_update.isoformat(),
        "availability": [
            {
                "month": month,
                "day": day,
                "availability": [{
                    "name": name,
                    "status": status,
                } for (name, status) in avail.items()],
            } for (month, day), avail in db.items()
        ],
    })


app = Flask(__name__)
CORS(app)
app.register_blueprint(bp, url_prefix="/vacation-planner/api")
app.url_map.strict_slashes = False


if __name__ == "__main__":
    app.run("0.0.0.0", 5000, debug=False, threaded=True)