const fs = require("fs");
const Database = require("better-sqlite3");
const path = require("path");
const { open } = require('sqlite');
const filepath = "./data/minzbot.db";

async function createDbConnection() {
    const dir = path.dirname(filepath);
    if (!fs.existsSync(dir)) {
        fs.mkdirSync(dir, { recursive: true });
    }

    const db = new Database(filepath, { verbose: console.log });

    initDB(db);

    console.log("[DATABASE] Connection with better-sqlite3 established");
    return db;
}

async function initDB(db) {
    await db.exec(`
        CREATE TABLE IF NOT EXISTS anniversaries (
            ID INTEGER PRIMARY KEY AUTOINCREMENT,
            name   VARCHAR(50) NOT NULL,
            guild_id TEXT NOT NULL,
            discord_id   VARCHAR(50) NOT NULL,
            last_anniversary_notification TEXT
        );
    `);
    await db.exec(`
        CREATE TABLE IF NOT EXISTS lastfm (
            discord_id TEXT PRIMARY KEY NOT NULL,
            lastfm_name TEXT
        );
    `);
    await db.exec(`
        CREATE TABLE IF NOT EXISTS bot_config (
            id INTEGER PRIMARY KEY CHECK (id = 1),
            weekly_budget REAL DEFAULT 0,
            last_date_msg_receipts DATE NOT NULL DEFAULT CURRENT_TIMESTAMP
        );
    `);
    await db.exec(`
        CREATE TABLE IF NOT EXISTS grocery_spendings (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            discord_id VARCHAR(50) NOT NULL,
            message_id VARCHAR(50) NOT NULL,
            message_raw TEXT DEFAULT "-",
            amount DECIMAL(10, 2) NOT NULL,
            created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
            
            budget_id INTEGER,
            FOREIGN KEY (budget_id) REFERENCES weekly_budgets(id)
        );
    `);
    await db.exec(`
        CREATE TABLE IF NOT EXISTS weekly_budgets (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            start_date DATE NOT NULL,
            end_date DATE NOT NULL,
            budget_amount DECIMAL(10, 2) NOT NULL,
            exchange_rate DECIMAL(10, 6) NOT NULL,
            created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
            CONSTRAINT date_check CHECK (end_date > start_date)
        );
        CREATE INDEX IF NOT EXISTS idx_budget_dates ON weekly_budgets (start_date, end_date);
    `);
    

    await db.exec(`
        INSERT OR IGNORE INTO bot_config (id, weekly_budget) 
        VALUES (1, 10);
    `);
    console.log('[DATABASE] Created new DB table');
}

module.exports = createDbConnection;