import psycopg2
from psycopg2.extras import RealDictCursor

# Подключение к БД (укажи свои параметры)
conn = psycopg2.connect(
    dbname="parsed_url",
    user="postgres",
    password="qwertyqwerty123123",
    # host="45.129.78.228",
    host="127.0.0.1"
)
conn.autocommit = True

def create_table():
    with conn.cursor() as cur:
        cur.execute("""
            CREATE TABLE IF NOT EXISTS work_parser (
                id SERIAL PRIMARY KEY,
                status VARCHAR(20) NOT NULL CHECK (status IN ('queued', 'in_progress', 'completed', 'failed')),
                created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
                started_at TIMESTAMPTZ,
                finished_at TIMESTAMPTZ,
                source_url TEXT,
                error_message TEXT,
                attempts INTEGER DEFAULT 0,
                priority INTEGER DEFAULT 0
            );
        """)
    print("Таблица work_parser создана или уже существует")

def insert_task(status, source_url=None, source_id=None, priority=0):
    with conn.cursor() as cur:
        cur.execute("""
            INSERT INTO work_parser (status, source_url, priority)
            VALUES (%s, %s, %s)
            RETURNING id;
        """, (status, source_url, priority))
        task_id = cur.fetchone()[0]
        return task_id


def get_tasks_offset(limit, offset):
    with conn.cursor(cursor_factory=RealDictCursor) as cur:
        cur.execute("""
            SELECT * FROM work_parser
            ORDER BY created_at DESC
            LIMIT %s OFFSET %s
            """, (limit, offset))
        tasks = cur.fetchall()
        return tasks

def delete_task(task_id: int):
    with conn.cursor(cursor_factory=RealDictCursor) as cur:
        cur.execute("DELETE FROM work_parser WHERE id = %s RETURNING *;", (task_id,))
        deleted_task = cur.fetchone()
        if deleted_task:
            return {"message": f"Задача {task_id} удалена", "deleted_task": dict(deleted_task)}
        else:
            return {"message": f"Задача с id {task_id} не найдена"}

def update_task(task_id, **fields):
    # dynamic update query generator
    allowed_fields = ['status', 'started_at', 'finished_at', 'source_url', 'error_message', 'attempts', 'priority']
    set_parts = []
    values = []
    for key, value in fields.items():
        if key in allowed_fields:
            set_parts.append(f"{key} = %s")
            values.append(value)
    if not set_parts:
        return False
    values.append(task_id)
    set_sql = ", ".join(set_parts)
    with conn.cursor() as cur:
        cur.execute(f"UPDATE work_parser SET {set_sql} WHERE id = %s;", values)
    return True

# Пример использования
# if __name__ == "__main__":
#     create_table()

#     task_id = insert_task(status='queued', source_url='http://example.com', priority=5)
#     print("Создана задача с id:", task_id)

#     task = get_task(task_id)
#     print("Получена задача:", task)

#     update_task(task_id, status='in_progress', started_at=datetime.utcnow(), attempts=1)
#     task = get_task(task_id)
#     print("Обновленная задача:", task)