import os
import time
from datetime import datetime

import psycopg2
from flask import Flask, jsonify, request

app = Flask(__name__)

DB_CONFIG = {
    "host": os.getenv("DB_HOST", "db"),
    "port": int(os.getenv("DB_PORT", "5432")),
    "dbname": os.getenv("DB_NAME", "guestbook"),
    "user": os.getenv("DB_USER", "guestbook_user"),
    "password": os.getenv("DB_PASSWORD", ""),

    "sslmode": os.getenv("DB_SSLMODE", "prefer"),
}

APP_PORT = int(os.getenv("APP_PORT", "5000"))


def get_connection():
    return psycopg2.connect(**DB_CONFIG)


def init_db(retries: int = 20, delay: int = 2) -> None:
    for attempt in range(1, retries + 1):
        try:
            with get_connection() as conn:
                with conn.cursor() as cur:
                    cur.execute(
                        """
                        CREATE TABLE IF NOT EXISTS messages (
                            id SERIAL PRIMARY KEY,
                            author VARCHAR(100) NOT NULL,
                            content TEXT NOT NULL,
                            created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
                        )
                        """
                    )
                    conn.commit()
            print("Database initialized.")
            return
        except Exception as exc:
            print(f"Database not ready yet (attempt {attempt}/{retries}): {exc}")
            time.sleep(delay)
    raise RuntimeError("Could not initialize the database.")


@app.route("/api/health", methods=["GET"])
def health():
    try:
        with get_connection() as conn:
            with conn.cursor() as cur:
                cur.execute("SELECT 1")
                cur.fetchone()
        return jsonify({"status": "ok", "database": "connected"}), 200
    except Exception as exc:
        return jsonify({"status": "error", "database": str(exc)}), 500


@app.route("/api/messages", methods=["GET"])
def get_messages():
    with get_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                SELECT id, author, content, created_at
                FROM messages
                ORDER BY created_at DESC, id DESC
                """
            )
            rows = cur.fetchall()

    data = [
        {
            "id": row[0],
            "author": row[1],
            "content": row[2],
            "created_at": row[3].isoformat(),
        }
        for row in rows
    ]
    return jsonify(data), 200


@app.route("/api/messages", methods=["POST"])
def add_message():
    payload = request.get_json(silent=True) or {}
    author = (payload.get("author") or "").strip()
    content = (payload.get("content") or "").strip()

    if not author or not content:
        return jsonify({"error": "Fields 'author' and 'content' are required."}), 400

    with get_connection() as conn:
        with conn.cursor() as cur:
            cur.execute(
                """
                INSERT INTO messages (author, content, created_at)
                VALUES (%s, %s, %s)
                RETURNING id, author, content, created_at
                """,
                (author, content, datetime.utcnow()),
            )
            row = cur.fetchone()
            conn.commit()

    return (
        jsonify(
            {
                "id": row[0],
                "author": row[1],
                "content": row[2],
                "created_at": row[3].isoformat(),
            }
        ),
        201,
    )


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