import type { Transaction } from '@/types/transaction';
import Dexie, { type EntityTable } from 'dexie';

export interface SyncMetadata {
    key: string;
    value: string;
}

type WhisperMoneyDB = Dexie & {
    transactions: EntityTable<Transaction, 'id'>;
    sync_metadata: EntityTable<SyncMetadata, 'key'>;
};

let dbInstance: WhisperMoneyDB | null = null;

function initializeDatabase(): WhisperMoneyDB {
    const database = new Dexie('whisper_money') as WhisperMoneyDB;

    database.version(5).stores({
        transactions: 'id, user_id, account_id, updated_at',
        accounts: 'id, user_id, bank_id, updated_at',
        categories: 'id, user_id, updated_at',
        banks: 'id, user_id, updated_at',
        automation_rules: 'id, user_id, priority, updated_at',
        account_balances: 'id, account_id, balance_date, updated_at',
        sync_metadata: 'key',
        pending_changes: '++id, store, timestamp',
    });

    database.version(6).stores({
        transactions: 'id, user_id, account_id, updated_at',
        accounts: 'id, user_id, bank_id, updated_at',
        categories: 'id, user_id, updated_at',
        labels: 'id, user_id, updated_at',
        banks: 'id, user_id, updated_at',
        automation_rules: 'id, user_id, priority, updated_at',
        account_balances: 'id, account_id, balance_date, updated_at',
        sync_metadata: 'key',
        pending_changes: '++id, store, timestamp',
    });

    // Version 7: Remove all tables except transactions and sync_metadata
    database.version(7).stores({
        transactions: 'id, user_id, account_id, updated_at',
        sync_metadata: 'key',
        // Delete removed tables
        accounts: null,
        categories: null,
        labels: null,
        banks: null,
        automation_rules: null,
        account_balances: null,
        pending_changes: null,
    });

    // Version 8: Ensure clean state (no schema changes, just trigger upgrade)
    database.version(8).stores({
        transactions: 'id, user_id, account_id, updated_at',
        sync_metadata: 'key',
    });

    return database;
}

export const db = new Proxy({} as WhisperMoneyDB, {
    get(_target, prop) {
        if (!dbInstance) {
            dbInstance = initializeDatabase();
        }
        return dbInstance[prop as keyof WhisperMoneyDB];
    },
});