// startup-panel.js — 6 階段啟動進度面板
// 對齊 Design Spec v2.1 startup-progress.md

import { t } from './i18n.js';

const TOTAL_STAGES = 6;

// 本地狀態：stages[1..6] = {status, startedAt, slow, manualHint, detail}
// detail: 從 startup:stage-detail event 來的 sub-step 提示，顯示在 stage-hint 欄位
const stages = {};
for (let i = 1; i <= TOTAL_STAGES; i++) {
    stages[i] = { status: 'pending', startedAt: 0, slow: false, manualHint: false, detail: null };
}

// 啟動流程旗標：stage 5 skipped → stage 6 進入「manual hint」模式
// 對齊 Design Spec §4.1「階段 6 Settings OFF 情境」
let manualMode = false;
// 觀察者：當進入 manual mode 時通知外層（app.js）加 pulse / enable primary CTA
const manualModeListeners = new Set();
export function onManualModeChange(fn) {
    manualModeListeners.add(fn);
    return () => manualModeListeners.delete(fn);
}
function emitManualMode(enabled) {
    manualModeListeners.forEach((fn) => {
        try { fn(enabled); } catch (e) { console.warn('manualMode listener error:', e); }
    });
}

// ---------- 渲染 stage 列 skeleton ----------
export function renderStages() {
    const container = document.getElementById('stages');
    if (!container) return;
    container.innerHTML = '';
    for (let i = 1; i <= TOTAL_STAGES; i++) {
        const row = document.createElement('div');
        row.className = 'stage-item';
        row.dataset.stage = String(i);
        row.dataset.state = stages[i].status;
        row.innerHTML = `
            <span class="stage-icon" aria-hidden="true"></span>
            <span class="stage-number">${i} ·</span>
            <div class="stage-label">
                <div class="stage-label-primary"></div>
                <div class="stage-label-secondary"></div>
            </div>
            <span class="stage-status"></span>
            <div class="stage-hint" hidden></div>
        `;
        container.appendChild(row);
        paintStageRow(i);
    }
    // 更新標題
    const titleEl = document.getElementById('startup-title');
    if (titleEl) titleEl.textContent = t('startup.panel.title');
    paintProgressBar();
}

function paintStageRow(stage) {
    const row = document.querySelector(`.stage-item[data-stage="${stage}"]`);
    if (!row) return;
    const st = stages[stage];
    row.dataset.state = st.slow && st.status === 'running' ? 'running-slow' : st.status;

    const iconEl = row.querySelector('.stage-icon');
    const labelPrimary = row.querySelector('.stage-label-primary');
    const labelSecondary = row.querySelector('.stage-label-secondary');
    const statusEl = row.querySelector('.stage-status');
    const hintEl = row.querySelector('.stage-hint');

    // icon
    let icon = '○';
    switch (st.status) {
        case 'pending':   icon = '○'; break;
        case 'running':   icon = '<span class="spinner-sm"></span>'; break;
        case 'completed':
        case 'done':      icon = '✓'; break;
        case 'failed':    icon = '✕'; break;
        case 'skipped':   icon = '⏭'; break;
    }
    iconEl.innerHTML = icon;

    // label
    labelPrimary.textContent = t(`startup.stage.${stage}.label`);
    // Stage 5 skipped → label secondary 顯示 skipped 原因
    // Stage 6 manual mode → description 改顯示 manual hint
    if (stage === 5 && st.status === 'skipped') {
        labelSecondary.textContent = t('startup.stage.5.skipped.label');
    } else if (stage === 6 && st.manualHint) {
        labelSecondary.textContent = t('startup.stage.6.manualHint');
    } else {
        labelSecondary.textContent = t(`startup.stage.${stage}.description`);
    }

    // status text
    const statusMap = {
        pending:   'startup.status.pending',
        running:   'startup.status.running',
        completed: 'startup.status.done',
        done:      'startup.status.done',
        failed:    'startup.status.failed',
        skipped:   'startup.status.skipped',
    };
    statusEl.textContent = t(statusMap[st.status] || 'startup.status.pending');

    // hint line：優先順序為 detail（細步進度）> slow hint > 隱藏
    // Design Spec §4.1：stage 6 manual mode 不套 20 秒 retry hint（等待人為動作）
    if (st.detail && st.status === 'running') {
        hintEl.textContent = st.detail;
        hintEl.removeAttribute('hidden');
    } else if (st.slow && st.status === 'running' && !st.manualHint) {
        hintEl.textContent = t('startup.timeout.message');
        hintEl.removeAttribute('hidden');
    } else {
        hintEl.setAttribute('hidden', '');
    }
}

function paintProgressBar() {
    const bar = document.getElementById('progress-bar');
    const textEl = document.getElementById('progress-text');
    if (!bar || !textEl) return;
    bar.innerHTML = '';
    let completed = 0;
    let current = 0;
    for (let i = 1; i <= TOTAL_STAGES; i++) {
        const cell = document.createElement('span');
        cell.className = 'progress-cell state-' + stages[i].status;
        bar.appendChild(cell);
        if (stages[i].status === 'completed' || stages[i].status === 'done' || stages[i].status === 'skipped') completed++;
        if (stages[i].status === 'running') current = i;
    }
    const progressNum = current || completed;
    // 不顯示已等待秒數 — pause 機制讓 elapsed 計算失準（pause 期間 wall clock
    // 仍走但 startedAt 沒重設，會顯示明顯比真實還久的數字），且使用者覺得
    // 沒必要看秒數。直接顯示 progress N/M 即可，slow hint 改由 stage-hint
    // 文案傳達。
    textEl.textContent = t('startup.progressLabel', { current: progressNum, max: TOTAL_STAGES });

    // aria
    const panel = document.getElementById('startup-panel');
    if (panel) panel.setAttribute('aria-valuenow', String(progressNum));
}

// ---------- Panel 顯示 / 收合 / 隱藏 / 重置 ----------
export function showStartupPanel() {
    const panel = document.getElementById('startup-panel');
    if (!panel) return;
    panel.removeAttribute('hidden');
    panel.removeAttribute('data-collapsed');
    // Error mode 預設隱藏
    document.getElementById('startup-error').setAttribute('hidden', '');
}

// collapseStartupPanel 在啟動完成後呼叫：保留 panel 在 DOM 但縮成一行
// summary（Stage 都標 ✓，可點擊重新展開）。比 hide 友善——使用者想回顧
// 啟動歷程時點一下就能看到。Restart / Retry 時應呼叫 expandStartupPanel
// 把它打開。
export function collapseStartupPanel() {
    const panel = document.getElementById('startup-panel');
    if (!panel) return;
    panel.removeAttribute('hidden');
    panel.setAttribute('data-collapsed', 'true');
    panel.setAttribute('data-collapse-hint', t('startup.collapsed.hint'));
    // 標題改為「啟動完成」精簡字樣
    const titleEl = document.getElementById('startup-title');
    if (titleEl) titleEl.textContent = t('startup.collapsed.title');
    // 確保 error block 是隱藏的（成功路徑）
    const err = document.getElementById('startup-error');
    if (err) err.setAttribute('hidden', '');
}

// expandStartupPanel 由「點 collapsed bar」觸發（純展開檢視歷史）
// 不重置內部狀態 / 不改 title，使用者展開後仍是「啟動完成」標題。
export function expandStartupPanel() {
    const panel = document.getElementById('startup-panel');
    if (!panel) return;
    panel.removeAttribute('hidden');
    panel.removeAttribute('data-collapsed');
}

// resetStartupPanel：重置內部狀態 + DOM render（給 Restart 用）
// 注意：不要呼叫 hide，因為使用者按 Restart 是想看新一輪啟動進度。
export function resetStartupPanel() {
    for (let i = 1; i <= TOTAL_STAGES; i++) {
        stages[i] = { status: 'pending', startedAt: 0, slow: false, manualHint: false, detail: null };
    }
    if (manualMode) {
        manualMode = false;
        emitManualMode(false);
    }
    renderStages();
    expandStartupPanel();
}

// hideStartupPanel 保留為 legacy，目前已被 collapseStartupPanel 取代於成功路徑
export function hideStartupPanel() {
    const panel = document.getElementById('startup-panel');
    if (!panel) return;
    panel.setAttribute('hidden', '');
    panel.removeAttribute('data-collapsed');
    for (let i = 1; i <= TOTAL_STAGES; i++) {
        stages[i] = { status: 'pending', startedAt: 0, slow: false, manualHint: false, detail: null };
    }
    if (manualMode) {
        manualMode = false;
        emitManualMode(false);
    }
    renderStages();
}

// 階段狀態優先級：愈大愈「前進」。回填 snapshot 時用來避免倒退覆蓋
// 已收到的事件（race window 解法的一部分）。
const STAGE_STATUS_RANK = {
    pending: 0,
    running: 1,
    skipped: 2,
    failed: 2,
    completed: 3,
    done: 3,
};
function statusRank(s) {
    return STAGE_STATUS_RANK[s] ?? 0;
}

// ---------- 更新階段（收到 startup:progress）----------
// monotonic = true 時不會用較舊的狀態覆蓋較新的（snapshot 補漏用）
export function updateStage(ev, opts = {}) {
    if (!ev || !ev.stage) return;
    const n = ev.stage;
    if (n < 1 || n > TOTAL_STAGES) return;
    const newStatus = ev.status || 'pending';
    if (opts.monotonic && statusRank(newStatus) < statusRank(stages[n].status)) {
        // snapshot 帶來的狀態比 event 流的狀態還舊，忽略
        return;
    }
    stages[n].status = newStatus;
    if (ev.startedAt) stages[n].startedAt = ev.startedAt;
    if (stages[n].status !== 'running') {
        stages[n].slow = false;
        stages[n].detail = null;
    }

    // Design Spec §4.1：stage 5 skipped → 立即推 stage 6 進入 manual hint mode
    // （此時 Go 層也會送 stage 6 running，但這裡先行設定 manualHint 旗標，
    // 以便收到後續 stage 6 progress 時仍能維持 hint 文案。）
    if (n === 5 && stages[5].status === 'skipped') {
        enterManualMode();
    }

    // stage 6 收到 done → 離開 manual mode（使用者已成功點擊並建立連線）
    if (n === 6 && (stages[6].status === 'completed' || stages[6].status === 'done')) {
        if (manualMode) {
            manualMode = false;
            stages[6].manualHint = false;
            emitManualMode(false);
        }
    }

    // running 狀態下，把其他仍 pending 的顯示維持
    paintStageRow(n);
    paintProgressBar();

    // 無障礙 live region
    const live = document.getElementById('startup-live');
    if (live) {
        const statusKey = {
            pending:   'startup.status.pending',
            running:   'startup.status.running',
            completed: 'startup.status.done',
            failed:    'startup.status.failed',
            skipped:   'startup.status.skipped',
        }[stages[n].status] || 'startup.status.pending';
        live.textContent = `${n} · ${t(`startup.stage.${n}.label`)} · ${t(statusKey)}`;
    }
}

// ---------- 進入 Manual Hint 模式（stage 5 skipped → stage 6 等待人為動作）----------
// 對齊 Design Spec §4.1「階段 6 Settings OFF 情境」
function enterManualMode() {
    if (manualMode) return;
    manualMode = true;
    // 把 stage 6 標成 running + manualHint（若 Go 層還沒送 stage 6 running，這裡主動 paint）
    if (stages[6].status === 'pending') {
        stages[6].status = 'running';
        stages[6].startedAt = Date.now();
    }
    stages[6].manualHint = true;
    // 不套 soft timeout（因為是等人為動作）
    stages[6].slow = false;
    paintStageRow(6);
    paintProgressBar();
    emitManualMode(true);
}

// 外部呼叫：查詢是否處於 manual mode
export function isManualMode() {
    return manualMode;
}

// ---------- 階段細步 detail（收到 startup:stage-detail）----------
// Go 端 EmitStageDetail 送來，payload {stage, detailKey, elapsedSeconds}
// 把 i18n key 解析為文案存到 stages[n].detail，paintStageRow 顯示在 stage-hint 欄位。
export function updateStageDetail(ev) {
    if (!ev || !ev.stage || !ev.detailKey) return;
    const n = ev.stage;
    if (!stages[n]) return;
    const elapsed = ev.elapsedSeconds || 0;
    // 用 i18n 模板（{elapsed} 會被 t() 帶入）
    stages[n].detail = t(ev.detailKey, { elapsed });
    paintStageRow(n);
}

// ---------- 階段 soft timeout ----------
export function markStageTimeout(ev) {
    if (!ev || !ev.stage) return;
    const n = ev.stage;
    if (!stages[n]) return;
    // Design Spec §4.1：stage 6 manual mode 不套 20 秒 retry hint
    if (n === 6 && stages[6].manualHint) return;
    stages[n].slow = true;
    if (!stages[n].startedAt) stages[n].startedAt = Date.now();
    paintStageRow(n);
    paintProgressBar();
}

// ---------- Error mode ----------
export function showStartupError(ev) {
    const errorBlock = document.getElementById('startup-error');
    const descEl = document.getElementById('error-desc');
    const stageEl = document.getElementById('error-stage');
    if (!errorBlock) return;

    const cause = ev && ev.cause || 'stage-failure';
    const failedStage = ev && ev.stage || 0;

    if (cause === 'total-timeout') {
        descEl.textContent = t('startup.error.description.timeout');
    } else {
        const stageLabel = failedStage ? t(`startup.stage.${failedStage}.label`) : '';
        descEl.textContent = t('startup.error.description.stageFailed', { stageLabel });
    }

    if (failedStage) {
        stageEl.textContent = t('startup.error.failedStage', {
            n: failedStage,
            label: t(`startup.stage.${failedStage}.label`),
        });
        // 標記該階段為 failed
        stages[failedStage].status = 'failed';
        paintStageRow(failedStage);
        paintProgressBar();
    }

    errorBlock.removeAttribute('hidden');
    // 確保 panel 顯示
    const panel = document.getElementById('startup-panel');
    if (panel) panel.removeAttribute('hidden');
}