import sqlite3
from typing import Iterable
from app.config import DB_NAME

def get_connection() -> sqlite3.Connection:
    connection = sqlite3.connect(DB_NAME)
    connection.row_factory = sqlite3.Row
    connection.execute("PRAGMA foreign_keys = ON")
    return connection

DEFAULT_CATEGORIES: Iterable[tuple[str, str]] = [
    ("Продукты", "Расход"),
    ("Транспорт", "Расход"),
    ("Кафе", "Расход"),
    ("Жильё", "Расход"),
    ("Здоровье", "Расход"),
    ("Развлечения", "Расход"),
    ("Одежда", "Расход"),
    ("Образование", "Расход"),
    ("Зарплата", "Доход"),
    ("Фриланс", "Доход"),
    ("Подарки", "Доход"),
    ("Возврат", "Доход"),
]

def init_database() -> None:
    with get_connection() as connection:
        cursor = connection.cursor()
        cursor.executescript(
            """
            CREATE TABLE IF NOT EXISTS accounts (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                name TEXT NOT NULL,
                account_type TEXT NOT NULL,
                balance REAL NOT NULL DEFAULT 0
            );

            CREATE TABLE IF NOT EXISTS categories (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                name TEXT NOT NULL,
                category_type TEXT NOT NULL,
                UNIQUE(name, category_type)
            );

            CREATE TABLE IF NOT EXISTS transactions (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                title TEXT NOT NULL,
                amount REAL NOT NULL,
                transaction_type TEXT NOT NULL,
                account_id INTEGER NOT NULL,
                category_id INTEGER NOT NULL,
                created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (account_id) REFERENCES accounts(id) ON DELETE RESTRICT,
                FOREIGN KEY (category_id) REFERENCES categories(id) ON DELETE RESTRICT
            );

            CREATE TABLE IF NOT EXISTS subscriptions (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                name TEXT NOT NULL,
                amount REAL NOT NULL,
                billing_day INTEGER NOT NULL,
                period TEXT NOT NULL,
                status TEXT NOT NULL DEFAULT 'Активна'
            );

            CREATE TABLE IF NOT EXISTS budgets (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                category_id INTEGER NOT NULL UNIQUE,
                limit_amount REAL NOT NULL,
                FOREIGN KEY (category_id) REFERENCES categories(id) ON DELETE RESTRICT
            );
            """
        )
        cursor.executemany(
            """
            INSERT OR IGNORE INTO categories (name, category_type)
            VALUES (?, ?)
            """,
            DEFAULT_CATEGORIES,
        )
        connection.commit()