import { WalletType } from 'rnwalletman';
import AsyncStorage from '@react-native-async-storage/async-storage';

export interface WalletItem {
    id: string;
    walletType: string;
    upi?: string;
    phone?: string;
    status?: string;
}

const DEFAULT_DOMAIN = 'aa.pfgame.org';
const STORAGE_KEY = 'server_domain';
const HTTPS_KEY = 'server_https';

let _domain = DEFAULT_DOMAIN;
let _useHttps = true;

export async function loadServerDomain(): Promise<string> {
    const saved = await AsyncStorage.getItem(STORAGE_KEY);
    if (saved) _domain = saved;
    const https = await AsyncStorage.getItem(HTTPS_KEY);
    if (https !== null) _useHttps = https === 'true';
    console.log('loadServerDomain', _domain, 'https:', _useHttps);
    return _domain;
}

export async function saveServerDomain(domain: string, useHttps: boolean): Promise<void> {
    _domain = domain;
    _useHttps = useHttps;
    await AsyncStorage.setItem(STORAGE_KEY, domain);
    await AsyncStorage.setItem(HTTPS_KEY, String(useHttps));
}

export function getServerDomain(): string {
    return _domain;
}

export function getUseHttps(): boolean {
    return _useHttps;
}

class Api {
    public static get BASE_URL() { 
        const domain = getServerDomain();
        const scheme = getUseHttps() ? 'https' : 'http';
        return `${scheme}://${domain}`; 
    }
    public static get WS_URL() { 
        const domain = getServerDomain();
        const scheme = getUseHttps() ? 'wss' : 'ws';
        return `${scheme}://${domain}/ws`; 
    }

    private static _instance: Api | null = null;
    private userId: number = 0;

    private constructor() {}

    public setUserId(userId: number) {
        this.userId = userId;
    }

    public getUserId(): number {
        return this.userId;
    }

    public static get instance() {
        if (Api._instance === null) {
            Api._instance = new Api();
        }
        return Api._instance;
    }

    private headers(): Record<string, string> {
        const h: Record<string, string> = { 'Content-Type': 'application/json' };
        if (this.userId > 0) {
            h['X-User-ID'] = String(this.userId);
        }
        return h;
    }

    public async login(username: string, password: string): Promise<number> {
        console.log('login', Api.BASE_URL);
        const res = await fetch(`${Api.BASE_URL}/login`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ username, password }),
        });
        const data = await res.json();
        if (!data.success) throw new Error(data.message);
        this.userId = data.data.userId;
        return this.userId;
    }

    public async register(walletType: WalletType, params: any) {
        const res = await fetch(`${Api.BASE_URL}/register`, {
            method: 'POST',
            headers: this.headers(),
            body: JSON.stringify({ walletType, params }),
        });
        const data = await res.json();
        if (!data.success) throw new Error(data.message);
        return data;
    }

    public async requestOTP(walletType: WalletType, mobile: string, params: any = {}) {
        const res = await fetch(`${Api.BASE_URL}/request-otp`, {
            method: 'POST',
            headers: this.headers(),
            body: JSON.stringify({ walletType, mobile, params }),
        });
        const data = await res.json();
        if (!data.success) throw new Error(data.message);
        return data;
    }

    public async verifyOTP(walletType: WalletType, mobile: string, otp: string, params: any = {}) {
        const res = await fetch(`${Api.BASE_URL}/verify-otp`, {
            method: 'POST',
            headers: this.headers(),
            body: JSON.stringify({ walletType, mobile, otp, params }),
        });
        const data = await res.json();
        if (!data.success) throw new Error(data.message);
        return data;
    }

    public async listWallets(): Promise<WalletItem[]> {
        const res = await fetch(`${Api.BASE_URL}/wallets`, { headers: this.headers() });
        const data = await res.json();
        if (!data.success) throw new Error(data.message);
        return data.data?.wallets ?? [];
    }

    public async getWalletVpas(walletId: string): Promise<string[]> {
        const res = await fetch(`${Api.BASE_URL}/wallet/vpas?walletId=${encodeURIComponent(walletId)}`, {
            headers: this.headers(),
        });
        const data = await res.json();
        if (!data.success) throw new Error(data.message);
        return data.data?.vpas ?? [];
    }

    public async setCurrentVpa(walletId: string, vpaIndex: number): Promise<string> {
        const res = await fetch(`${Api.BASE_URL}/wallet/set-vpa`, {
            method: 'POST',
            headers: this.headers(),
            body: JSON.stringify({ walletId, vpaIndex }),
        });
        const data = await res.json();
        if (!data.success) throw new Error(data.message);
        return data.data?.vpa ?? '';
    }

    public async generateLink(walletId: string, amount: string): Promise<{ link: string; orderId: string }> {
        const res = await fetch(`${Api.BASE_URL}/generate-link`, {
            method: 'POST',
            headers: this.headers(),
            body: JSON.stringify({ walletId, amount }),
        });
        const data = await res.json();
        if (!data.success) throw new Error(data.message);
        return { link: data.data?.link, orderId: data.data?.orderId };
    }
}

export default Api;