/**
 * Auth Modes: 
 * 0 - Login 
 * 1 - Register
 * 2 - Reset Password
 */
let authMode = 0;

const getEl = (id) => document.getElementById(id);

const updateUI = () => {
    const title = getEl('authTitle');
    const sub = getEl('authSub');
    const submitBtnSpan = getEl('authSubmitBtn')?.querySelector('span');
    const switchBtn = getEl('authSwitchBtn');
    const forgotBtn = getEl('forgotPwdBtn');
    const smsGroup = getEl('smsGroup');
    const captchaGroup = getEl('captchaGroup');
    const inviteGroup = getEl('inviteGroup');

    if (!title || !sub || !submitBtnSpan || !switchBtn || !forgotBtn || !smsGroup || !captchaGroup) return;

    if (authMode === 1) { // Register
        title.innerText = "加入视界 AI";
        sub.innerText = "注册并开启创作";
        submitBtnSpan.innerText = "立即注册";
        switchBtn.innerText = "已有账号？返回登录";
        forgotBtn.classList.add('hidden');
        smsGroup.classList.remove('hidden');
        captchaGroup.classList.remove('hidden'); // 注册模式默认显示图形验证码防止刷短信
        if (inviteGroup) inviteGroup.classList.remove('hidden');
    } else if (authMode === 2) { // Reset Password
        title.innerText = "重置密码";
        sub.innerText = "验证短信以设置新密码";
        submitBtnSpan.innerText = "确认重置";
        switchBtn.innerText = "我想起来了，返回登录";
        forgotBtn.classList.add('hidden');
        smsGroup.classList.remove('hidden');
        captchaGroup.classList.remove('hidden'); // 重置模式默认显示
        if (inviteGroup) inviteGroup.classList.add('hidden');
    } else { // Login
        title.innerText = "欢迎回来";
        sub.innerText = "请登录以开启 AI 创作之旅";
        submitBtnSpan.innerText = "立即登录";
        switchBtn.innerText = "没有账号？立即注册";
        forgotBtn.classList.remove('hidden');
        smsGroup.classList.add('hidden');
        captchaGroup.classList.add('hidden'); // 登录默认隐藏，除非高频失败
        if (inviteGroup) inviteGroup.classList.add('hidden');
    }
};

const refreshCaptcha = () => {
    const phone = getEl('authPhone')?.value;
    const captchaImg = getEl('captchaImg');
    if (!captchaImg) return;

    if (!phone) {
        // 如果没有手机号，不加载，或者显示占位（此处保持空，等待用户输入）
        return;
    }

    // 简单的手机号长度检查，避免无效请求
    if (phone.length < 11) return;

    captchaImg.src = `/api/auth/captcha?phone=${phone}&t=${Date.now()}`;
};

const handleAuth = async () => {
    const phone = getEl('authPhone')?.value;
    const password = getEl('authPass')?.value;

    if (!phone || !password) {
        return showToast('请输入手机号和密码', 'warning');
    }

    let url = '';
    let body = { phone, password };

    if (authMode === 1) {
        url = '/api/auth/register';
        body.code = getEl('authCode')?.value;
        body.invite_code = getEl('authInvite')?.value; // 获取邀请码
    } else if (authMode === 0) {
        url = '/api/auth/login';
        if (!getEl('captchaGroup')?.classList.contains('hidden')) {
            body.code = getEl('authCaptcha')?.value;
        }
    } else if (authMode === 2) {
        url = '/api/auth/reset_password';
        body.code = getEl('authCode')?.value;
        if (!body.code) return showToast('请输入短信验证码', 'warning');
    }

    try {
        const btn = getEl('authSubmitBtn');
        if (btn) btn.disabled = true;

        const r = await fetch(url, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify(body)
        });
        const d = await r.json();

        if (r.status === 403 && d.require_captcha) {
            showToast(d.error, 'warning');
            getEl('captchaGroup')?.classList.remove('hidden');
            refreshCaptcha();
            if (btn) btn.disabled = false;
            return;
        }

        if (d.error) {
            showToast(d.error, 'error');
            if (getEl('captchaGroup') && !getEl('captchaGroup').classList.contains('hidden')) {
                refreshCaptcha();
            }
            if (btn) btn.disabled = false;
        } else {
            showToast(d.message, 'success');
            if (authMode === 1 || authMode === 2) {
                authMode = 0;
                updateUI();
                if (btn) btn.disabled = false;
            } else {
                const urlParams = new URLSearchParams(window.location.search);
                const nextUrl = urlParams.get('next') || '/';
                window.location.href = nextUrl;
            }
        }
    } catch (e) {
        showToast('网络连接失败', 'error');
        const btn = getEl('authSubmitBtn');
        if (btn) btn.disabled = false;
    }
};

// 初始化
document.addEventListener('DOMContentLoaded', () => {
    updateUI();

    getEl('authSwitchBtn').onclick = () => {
        authMode = (authMode === 0) ? 1 : 0;
        updateUI();
        if (authMode === 1 || authMode === 2) refreshCaptcha();
    };

    getEl('forgotPwdBtn').onclick = () => {
        authMode = 2;
        updateUI();
        refreshCaptcha();
    };

    getEl('captchaImg').onclick = refreshCaptcha;

    getEl('authSubmitBtn').onclick = handleAuth;

    // 回车登录支持
    ['authPhone', 'authPass', 'authCode', 'authCaptcha'].forEach(id => {
        getEl(id)?.addEventListener('keydown', (e) => {
            if (e.key === 'Enter') handleAuth();
        });
    });

    // 监听手机号输入，自动刷新验证码
    const phoneInput = getEl('authPhone');
    if (phoneInput) {
        phoneInput.addEventListener('blur', refreshCaptcha);
        phoneInput.addEventListener('input', (e) => {
            if (e.target.value.length === 11) refreshCaptcha();
        });
    }

    getEl('sendSmsBtn').onclick = async () => {
        const phone = getEl('authPhone')?.value;
        const captcha = getEl('authCaptcha')?.value;
        const btn = getEl('sendSmsBtn');

        if (!phone) return showToast('请输入手机号', 'warning');
        if (!captcha) {
            getEl('captchaGroup')?.classList.remove('hidden');
            refreshCaptcha();
            return showToast('请先输入图形验证码以发送短信', 'warning');
        }

        btn.disabled = true;
        const originalText = btn.innerText;

        try {
            const r = await fetch('/api/auth/send_code', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ phone, captcha })
            });
            const d = await r.json();

            if (d.error) {
                showToast(d.error, 'error');
                btn.disabled = false;
                if (d.show_captcha || d.refresh_captcha) {
                    getEl('captchaGroup')?.classList.remove('hidden');
                    refreshCaptcha();
                }
            } else {
                showToast(d.message, 'success');
                // 发送成功后也要刷新图形验证码，防止被再次利用
                refreshCaptcha();
                let countdown = 60;
                const timer = setInterval(() => {
                    btn.innerText = `${countdown}秒后重试`;
                    countdown--;
                    if (countdown < 0) {
                        clearInterval(timer);
                        btn.innerText = originalText;
                        btn.disabled = false;
                    }
                }, 1000);
            }
        } catch (e) {
            showToast('短信发送失败', 'error');
            btn.disabled = false;
        }
    };

    // 处理邀请链接逻辑
    const urlParams = new URLSearchParams(window.location.search);
    const inviteCode = urlParams.get('invite_code');
    if (inviteCode) {
        authMode = 1; // 切换到注册模式
        updateUI();
        refreshCaptcha(); // 注册需验证码
        const inviteInput = getEl('authInvite');
        if (inviteInput) {
            inviteInput.value = inviteCode;
            inviteInput.disabled = true; // 锁定邀请码
            inviteInput.classList.add('bg-indigo-50', 'text-indigo-600', 'font-bold');
            showToast('已自动填入邀请码', 'success');
        }
    }
});