import os
import time
import psycopg2
from psycopg2.extras import RealDictCursor
from flask import Flask, request, jsonify

app = Flask(__name__)

DB_CONFIG = {
    "host": os.environ.get("DB_HOST", "db"),
    "database": os.environ.get("DB_NAME", "taskapp"),
    "user": os.environ.get("DB_USER", "taskapp"),
    "password": os.environ.get("DB_PASSWORD", "taskapp123"),
}


def get_db():
    return psycopg2.connect(**DB_CONFIG, cursor_factory=RealDictCursor)


def init_db():
    """Wait for PostgreSQL and create the tasks table if it doesn't exist."""
    for attempt in range(30):
        try:
            conn = get_db()
            cur = conn.cursor()
            cur.execute("""
                CREATE TABLE IF NOT EXISTS tasks (
                    id SERIAL PRIMARY KEY,
                    title VARCHAR(255) NOT NULL,
                    completed BOOLEAN NOT NULL DEFAULT FALSE,
                    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
                )
            """)
            conn.commit()
            cur.close()
            conn.close()
            print("Database initialized.")
            return
        except psycopg2.OperationalError:
            print(f"Waiting for database... (attempt {attempt + 1}/30)")
            time.sleep(2)
    raise RuntimeError("Could not connect to the database after 30 attempts.")


@app.route("/api/tasks", methods=["GET"])
def get_tasks():
    conn = get_db()
    cur = conn.cursor()
    cur.execute("SELECT * FROM tasks ORDER BY created_at DESC")
    tasks = cur.fetchall()
    cur.close()
    conn.close()
    return jsonify(tasks)


@app.route("/api/tasks", methods=["POST"])
def create_task():
    data = request.get_json()
    title = data.get("title", "").strip()
    if not title:
        return jsonify({"error": "Title is required"}), 400

    conn = get_db()
    cur = conn.cursor()
    cur.execute(
        "INSERT INTO tasks (title) VALUES (%s) RETURNING *",
        (title,),
    )
    task = cur.fetchone()
    conn.commit()
    cur.close()
    conn.close()
    return jsonify(task), 201


@app.route("/api/tasks/<int:task_id>", methods=["PUT"])
def update_task(task_id):
    conn = get_db()
    cur = conn.cursor()
    cur.execute(
        "UPDATE tasks SET completed = NOT completed WHERE id = %s RETURNING *",
        (task_id,),
    )
    task = cur.fetchone()
    conn.commit()
    cur.close()
    conn.close()
    if task is None:
        return jsonify({"error": "Task not found"}), 404
    return jsonify(task)


@app.route("/api/tasks/<int:task_id>", methods=["DELETE"])
def delete_task(task_id):
    conn = get_db()
    cur = conn.cursor()
    cur.execute("DELETE FROM tasks WHERE id = %s RETURNING id", (task_id,))
    deleted = cur.fetchone()
    conn.commit()
    cur.close()
    conn.close()
    if deleted is None:
        return jsonify({"error": "Task not found"}), 404
    return jsonify({"result": "ok"})


if __name__ == "__main__":
    init_db()
    app.run(host="0.0.0.0", port=5000)