(function () {
    const statusLabels = {
        pending: "排队中",
        running: "执行中",
        cancel_requested: "停止中",
        completed: "已完成",
        stopped: "已停止",
        failed: "失败",
        idle: "未启动"
    };

    function renderLogLine(log) {
        const line = document.createElement("div");
        const level = (log.level || "INFO").toLowerCase();
        line.className = `log-line level-${level}`;

        const meta = document.createElement("span");
        meta.className = "log-meta";
        const owner = log.student_id || "system";
        meta.textContent = `${log.created_at} · ${owner} · ${log.scope} · ${log.level}`;

        const message = document.createElement("span");
        message.textContent = log.message || "";

        line.append(meta, message);
        return line;
    }

    function bindLogStream() {
        const shell = document.querySelector("[data-log-stream-url]");
        const consoleNode = document.getElementById("log-console");
        if (!shell || !consoleNode || !window.EventSource) {
            return;
        }

        const streamUrl = shell.getAttribute("data-log-stream-url");
        const eventSource = new EventSource(streamUrl);

        eventSource.onmessage = function (event) {
            try {
                const payload = JSON.parse(event.data);
                if (consoleNode.querySelector(".muted")) {
                    consoleNode.innerHTML = "";
                }
                consoleNode.appendChild(renderLogLine(payload));
                while (consoleNode.children.length > 360) {
                    consoleNode.removeChild(consoleNode.firstChild);
                }
                consoleNode.scrollTop = consoleNode.scrollHeight;
            } catch (_error) {
                // Ignore malformed frames and keep the stream alive.
            }
        };
    }

    function updateUserStatus(data) {
        const taskText = document.getElementById("task-status-text");
        const taskPill = document.getElementById("task-status-pill");
        const courseCount = document.getElementById("course-count");
        const status = (data.task && data.task.status) || "idle";
        if (taskText) {
            taskText.textContent = statusLabels[status] || status;
        }
        if (taskPill) {
            taskPill.className = `status-pill status-${status}`;
            taskPill.textContent = statusLabels[status] || status;
        }
        if (courseCount && Array.isArray(data.courses)) {
            courseCount.textContent = String(data.courses.length);
        }
    }

    function updateAdminStatus(data) {
        const users = document.getElementById("stat-users");
        const running = document.getElementById("stat-running");
        const pending = document.getElementById("stat-pending");
        const parallel = document.getElementById("parallel-limit-input");
        if (users) {
            users.textContent = String(data.stats.users_count || 0);
        }
        if (running) {
            running.textContent = String(data.stats.running_count || 0);
        }
        if (pending) {
            pending.textContent = String(data.stats.pending_count || 0);
        }
        if (parallel) {
            parallel.value = String(data.parallel_limit || parallel.value);
        }
    }

    function bindStatusPolling() {
        const shell = document.querySelector("[data-status-url]");
        if (!shell) {
            return;
        }

        const statusUrl = shell.getAttribute("data-status-url");
        const isAdmin = shell.classList.contains("admin-dashboard");

        async function refresh() {
            try {
                const response = await fetch(statusUrl, { headers: { "X-Requested-With": "fetch" } });
                if (!response.ok) {
                    return;
                }
                const payload = await response.json();
                if (!payload.ok) {
                    return;
                }
                if (isAdmin) {
                    updateAdminStatus(payload);
                } else {
                    updateUserStatus(payload);
                }
            } catch (_error) {
                // Leave the current UI state as-is if polling fails.
            }
        }

        refresh();
        window.setInterval(refresh, 7000);
    }

    bindLogStream();
    bindStatusPolling();
})();