/**
 * Login page.
 *
 * Username + password form, plus "Sign in with passkey" button.
 * On success: stores tokens and navigates to dashboard.
 */

import {
    h,
    definePage,
    html,
    apiFetch,
    toast,
    doLogin,
    webauthnSupported,
    startAuthentication,
    esc,
} from '/static/hoover/index.js';

function LoginPage() {
    const hasWebAuthn = webauthnSupported();

    return html`
        <div class="login-page">
            <div class="login-card">
                <h2 class="login-title">Vacuum Wall</h2>
                <p class="login-subtitle">Sign in to continue</p>
                <form id="loginForm" class="login-form">
                    <div class="form-group">
                        <input
                            type="text"
                            id="loginUsername"
                            autocomplete="username"
                            placeholder="Username"
                            required
                        />
                    </div>
                    <div id="loginPasswordGroup" class="form-group">
                        <input
                            type="password"
                            id="loginPassword"
                            autocomplete="current-password"
                            placeholder="Password"
                            required
                        />
                    </div>
                    <div id="loginError" class="login-error"></div>
                    <button type="submit" class="btn btn-primary btn-login" id="loginBtn">Sign in</button>
                </form>
                ${hasWebAuthn ? html`
                    <div class="login-divider">or</div>
                    <button type="button" class="btn btn-outline btn-passkey" id="passkeyBtn">
                        Sign in with passkey
                    </button>
                ` : ''}
            </div>
        </div>
    `;
}

function handleLogin() {
    const form = document.getElementById('loginForm');
    if (!form) return;

    form.removeEventListener('submit', loginFormHandler);
    form.addEventListener('submit', loginFormHandler);
}

const loginFormHandler = async (e) => {
    e.preventDefault();
    await doPasswordLogin();
};

async function doPasswordLogin() {
    const username = document.getElementById('loginUsername').value.trim();
    const password = document.getElementById('loginPassword').value;
    const errEl = document.getElementById('loginError');
    if (!username || !password) {
        errEl.textContent = 'Username and password are required';
        return;
    }
    errEl.textContent = '';

    const res = await apiFetch('/api/auth/login', {
        method: 'POST',
        body: { username, password },
    });

    if (res.ok) {
        doLogin(res.data);
        toast('Welcome, ' + esc(username), 'success');
    } else {
        errEl.textContent = res.error || 'Login failed';
    }
}

function setupPasskeyButton() {
    const passkeyBtn = document.getElementById('passkeyBtn');
    if (!passkeyBtn) return;

    passkeyBtnRef.btn = passkeyBtn;
    passkeyBtnRef.usernameInput = document.getElementById('loginUsername');
    passkeyBtnRef.passwordGroup = document.getElementById('loginPasswordGroup');
    passkeyBtnRef.errEl = document.getElementById('loginError');

    passkeyBtn.removeEventListener('click', passkeyClickHandler);
    passkeyBtn.addEventListener('click', passkeyClickHandler);

    passkeyBtn.removeEventListener('mouseenter', passkeyMouseEnterHandler);
    passkeyBtn.removeEventListener('mouseleave', passkeyMouseLeaveHandler);
    passkeyBtn.addEventListener('mouseenter', passkeyMouseEnterHandler);
    passkeyBtn.addEventListener('mouseleave', passkeyMouseLeaveHandler);
}

const passkeyBtnRef = {
    btn: null,
    usernameInput: null,
    passwordGroup: null,
    errEl: null,
};

const passkeyClickHandler = async () => {
    const { btn, usernameInput, passwordGroup, errEl } = passkeyBtnRef;
    if (!btn) return;

    errEl.textContent = '';
    const username = usernameInput.value.trim();
    if (!username) {
        errEl.textContent = 'Enter your username first';
        usernameInput.focus();
        return;
    }

    btn.disabled = true;
    btn.textContent = 'Checking...';

    try {
        const beginRes = await apiFetch('/api/auth/webauthn/authenticate-begin', {
            method: 'POST',
            body: { username },
        });

        if (!beginRes.ok) {
            errEl.textContent = beginRes.error || 'Failed to start authentication';
            btn.disabled = false;
            btn.textContent = 'Sign in with passkey';
            return;
        }

        if (beginRes.data && beginRes.data.no_webauthn) {
            errEl.textContent = 'No passkey registered for this account';
            btn.disabled = false;
            btn.textContent = 'Sign in with passkey';
            return;
        }

        const authOptions = beginRes.data;
        btn.textContent = 'Waiting for authenticator...';

        const assertionResponse = await startAuthentication(authOptions);

        btn.textContent = 'Verifying...';

        const finishRes = await apiFetch('/api/auth/webauthn/authenticate-finish', {
            method: 'POST',
            body: {
                username,
                assertion_response: assertionResponse,
                auth_options: authOptions,
            },
        });

        if (finishRes.ok) {
            doLogin(finishRes.data);
            toast('Welcome, ' + esc(username), 'success');
        } else {
            errEl.textContent = finishRes.error || 'Passkey authentication failed';
        }
    } catch (err) {
        if (err.message && err.message.toLowerCase().includes('user cancelled')) {
            errEl.textContent = 'Authentication cancelled';
        } else {
            errEl.textContent = err.message || 'Passkey authentication failed';
        }
    } finally {
        if (btn) {
            btn.disabled = false;
            btn.textContent = 'Sign in with passkey';
        }
    }
};

const passkeyMouseEnterHandler = () => {
    const { passwordGroup } = passkeyBtnRef;
    if (passwordGroup) {
        passwordGroup.style.display = 'none';
    }
};

const passkeyMouseLeaveHandler = () => {
    const { passwordGroup } = passkeyBtnRef;
    if (passwordGroup) {
        passwordGroup.style.display = '';
    }
};

const Page = definePage({
    init() {
        document.title = 'Login — Vacuum Wall';
    },

    load() {
        handleLogin();
        setupPasskeyButton();
    },

    render() {
        return h('div', null, LoginPage());
    },
});

export default Page;