// 首页登录交互入口，负责验证码刷新、房间提示、性别选中态和 AJAX 登录。

let homeLoginControlsBound = false;

/**
 * 读取 CSRF 令牌，供登录请求使用。
 *
 * @returns {string}
 */
function getCsrfToken() {
    return document.querySelector('meta[name="csrf-token"]')?.getAttribute("content") ?? "";
}

/**
 * 刷新验证码图片，避免浏览器缓存旧图。
 *
 * @param {HTMLImageElement} captchaImage
 * @returns {void}
 */
function refreshCaptcha(captchaImage) {
    const refreshUrl = captchaImage.getAttribute("data-captcha-refresh-url") ?? "/captcha/default";
    captchaImage.src = `${refreshUrl}?${Math.random()}`;
}

/**
 * 同步性别单选项的选中视觉状态。
 *
 * @returns {void}
 */
function syncSelectedState() {
    document.querySelectorAll(".gender-option").forEach((option) => {
        const input = option.querySelector('input[type="radio"]');
        option.classList.toggle("selected", Boolean(input?.checked));
    });
}

/**
 * 根据当前房间选择更新提示文案。
 *
 * @returns {void}
 */
function updateRoomHint() {
    const roomSelect = document.getElementById("room_id");
    const hint = document.getElementById("room-hint");

    if (!roomSelect || !hint || roomSelect.selectedIndex < 0) {
        return;
    }

    const selectedOption = roomSelect.options[roomSelect.selectedIndex];
    const roomName = selectedOption.getAttribute("data-room-name") || selectedOption.text;
    const roomOwner = selectedOption.getAttribute("data-room-owner") || "未设置";

    hint.textContent = `当前房间：${roomName} / 房主：${roomOwner}`;
}

/**
 * 展示或隐藏登录提示框。
 *
 * @param {string} message
 * @param {string} type
 * @param {boolean} visible
 * @returns {void}
 */
function showAlert(message, type, visible) {
    const alertBox = document.getElementById("alert-box");
    if (!alertBox) {
        return;
    }

    alertBox.textContent = message;
    alertBox.className = type === "success" ? "alert-success" : "alert-error";
    alertBox.id = "alert-box";
    alertBox.style.display = visible ? "block" : "none";
}

/**
 * 打开聊天室窗口，并尽量铺满当前可用屏幕。
 *
 * @param {string} url
 * @returns {void}
 */
function openChatRoomWindow(url) {
    const chatWindow = window.open(
        url,
        "chatroom",
        "toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes",
    );

    if (!chatWindow) {
        return;
    }

    chatWindow.moveTo(0, 0);
    chatWindow.resizeTo(window.screen.availWidth, window.screen.availHeight);
    chatWindow.focus();
}

/**
 * 处理登录表单提交。
 *
 * @param {SubmitEvent} event
 * @returns {Promise<void>}
 */
async function submitLogin(event) {
    event.preventDefault();

    const form = event.target;
    if (!(form instanceof HTMLFormElement)) {
        return;
    }

    const button = document.getElementById("submit-btn");
    const captchaInput = document.getElementById("captcha");
    const captchaImage = document.getElementById("captcha-img");
    const loginUrl = form.getAttribute("data-login-url") ?? form.action;
    const roomsUrl = form.getAttribute("data-rooms-url") ?? "/rooms";
    const roomUrlTemplate = form.getAttribute("data-room-url-template") ?? "/room/:id";
    const formData = new FormData(form);
    const data = Object.fromEntries(formData.entries());
    const roomId = data.room_id || "1";

    if (button instanceof HTMLButtonElement) {
        button.disabled = true;
        button.innerText = "正在进入...";
    }

    showAlert("", "error", false);

    try {
        const response = await fetch(loginUrl, {
            method: "POST",
            credentials: "same-origin",
            headers: {
                "Content-Type": "application/json",
                "X-CSRF-TOKEN": getCsrfToken(),
                Accept: "application/json",
            },
            body: JSON.stringify(data),
        });
        const body = await response.json();

        if (response.status === 419 || body?.message === "CSRF token mismatch.") {
            showAlert("安全令牌已过期，正在刷新页面...", "error", true);
            window.setTimeout(() => {
                window.location.reload();
            }, 1500);
            return;
        }

        if (response.status === 200 && body.status === "success") {
            showAlert(body.message, "success", true);
            openChatRoomWindow(roomUrlTemplate.replace(":id", roomId));
            window.setTimeout(() => {
                window.location.href = roomsUrl;
            }, 1500);
            return;
        }

        const errorMessage = body.message || (body.errors ? Object.values(body.errors)[0][0] : "登录失败，请稍后再试。");
        showAlert(errorMessage, "error", true);

        if (captchaImage instanceof HTMLImageElement) {
            refreshCaptcha(captchaImage);
        }
        if (captchaInput instanceof HTMLInputElement) {
            captchaInput.value = "";
        }
        if (button instanceof HTMLButtonElement) {
            button.disabled = false;
            button.innerText = "进入和平聊吧";
        }
    } catch {
        showAlert("网络或服务器异常，请稍后再试。", "error", true);
        if (captchaImage instanceof HTMLImageElement) {
            refreshCaptcha(captchaImage);
        }
        if (button instanceof HTMLButtonElement) {
            button.disabled = false;
            button.innerText = "进入和平聊吧";
        }
    }
}

/**
 * 绑定首页登录页交互。
 *
 * @returns {void}
 */
function bindHomeLoginControls() {
    if (homeLoginControlsBound || typeof document === "undefined") {
        return;
    }

    homeLoginControlsBound = true;

    document.addEventListener("click", (event) => {
        if (!(event.target instanceof HTMLImageElement)) {
            return;
        }

        if (event.target.hasAttribute("data-captcha-refresh-url")) {
            refreshCaptcha(event.target);
        }
    });

    document.querySelectorAll('.gender-option input[type="radio"]').forEach((input) => {
        input.addEventListener("change", syncSelectedState);
    });

    document.getElementById("room_id")?.addEventListener("change", updateRoomHint);
    document.getElementById("login-form")?.addEventListener("submit", (event) => {
        void submitLogin(event);
    });

    syncSelectedState();
    updateRoomHint();
}

bindHomeLoginControls();