from flask import Flask, jsonify, request
import auth
import re



HOSTS_PATH = "/app/hosts.d/izbi"
DB_PATH = "/app/sqlite.db"


app = Flask(__name__)

hosts = {}



def update_hosts(path: str, hosts: dict = {}) -> bool:
    try:
        hosts_str = ""
        for domain, ip in hosts.items():
            hosts_str += f"{ip}\t{domain}\n"
        with open(path, "w") as f:
            f.write(hosts_str)
        print(f"ddns - updated {path}", flush=True)
        return True
    except Exception as e:
        print(e, flush=True)
        return False



def validate_ip(ip: str) -> bool:
    exp = r"^((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])\.){3}(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])$"
    return re.search(exp, ip)



@app.route('/', methods=["GET"])
def health():
    return jsonify({"status": "healthy", "comment": ""})



@app.route('/update', methods=["GET"])
def update_addr():
    try:
        if 'domain' not in request.args:
            return jsonify({"status": "400", "code": "domain-error", "comment": "Missing or invalid domain"}), 400
        domain = request.args['domain']

        if 'ip' not in request.args:
            ip = request.remote_addr
        elif not validate_ip(request.args['ip']):
            return jsonify({"status": "400", "code": "ip-error", "comment": "Invalid IP"}), 400
        else:
            ip = request.args['ip']

        if 'token' not in request.args:
            return jsonify({"status": "400", "code": "token-error", "comment": "Missing or invalid token"}), 400
        token = request.args['token']

        if not auth.check_token_domain(DB_PATH, token, domain):
            print(f"ddns - unauthorized update attempt from {request.remote_addr} of {domain}", flush=True)
            return jsonify({"status": "401", "code": "unauthorized", "comment": "This token is not allowed to update this domain"}), 401

        success = True

        if domain not in hosts or ip != hosts[domain]:
            hosts[domain] = ip
            success = update_hosts(HOSTS_PATH, hosts)

        if not success:
            return jsonify({"status": "500", "code": "internal-server-error", "comment": "An error occurred while processing request"}), 500

        return jsonify({"status": "200", "code": "ok", "comment": "Updated successfully"})
    except:
        return jsonify({"status": "500", "code": "internal-server-error", "comment": "An error occurred while processing request"}), 500



if __name__ == '__main__':
    app.run(host="0.0.0.0", port=8080, debug=True)