// Admin → System → App — per-container deep-dive page.
//
// Mounted at /admin/config/system/app/<name>. Lists every container in the
// compose project (or single-container "app") and renders a rich card per
// container:
//
//   - Status badge + uptime + restart count
//   - Live cpu/mem/network/blkio (polled every 2s from /api/system/containers/<id>/stats)
//   - Memory-limit gauge if a limit is set; otherwise text "unlimited"
//   - CPU quota / shares summary
//   - Health-check state + last log entries (if a healthcheck is configured)
//   - Image, image digest (short), created/started timestamps
//   - Networks (name, IP, MAC, gateway) and published ports
//   - Mounts (volumes + binds), with type/mode badges
//   - Recent log tail (collapsible, last 200 lines, refresh button)
//
// One backend hit at mount: GET /api/system/containers (list). Per-card
// detail (limits, mounts, networks) comes from GET /api/system/containers/:id.
// Live numbers come from GET /api/system/containers/:id/stats every 2s.
// Stats endpoint is cached server-side, so multiple tabs share the cost.

class SystemAppPage {
    constructor(rootId = 'config-section') {
        this.rootId = rootId;
        this.appName = null;
        this.members = [];          // [{ id, name, ... }] from /containers
        this.details = new Map();   // id -> /containers/:id detail
        this.stats = new Map();     // id -> latest /containers/:id/stats sample
        this._timer = null;
        this._onClick = this._onClick.bind(this);
    }

    root() { return document.getElementById(this.rootId); }

    async mount(name) {
        this.appName = name;
        await this._loadList();
        this._renderShell();
        // Kick off detail + stats fetches for each member in parallel.
        await Promise.all(this.members.map(m => this._loadDetail(m.id)));
        await Promise.all(this.members.map(m => this._loadStats(m.id)));
        this._renderCards();
        this._bind();
        // Poll live stats every 2s. Containers refresh list every 15s.
        this._timer = setInterval(() => {
            if (!document.querySelector('.sys-app-page')) {
                clearInterval(this._timer); this._timer = null;
                return;
            }
            this._tickStats();
        }, 2000);
        this._slowTimer = setInterval(() => {
            if (!document.querySelector('.sys-app-page')) {
                clearInterval(this._slowTimer); this._slowTimer = null;
                return;
            }
            this._loadList().then(() => this._renderHeader());
        }, 15000);
    }

    dispose() {
        if (this._timer) { clearInterval(this._timer); this._timer = null; }
        if (this._slowTimer) { clearInterval(this._slowTimer); this._slowTimer = null; }
        const r = this.root();
        if (r) r.removeEventListener('click', this._onClick);
    }

    async _loadList() {
        try {
            const r = await fetch('/api/system/containers');
            const j = await r.json().catch(() => ({}));
            const apps = Array.isArray(j?.apps) ? j.apps : [];
            const me = apps.find(a => a.app === this.appName);
            this.members = me && Array.isArray(me.members) ? me.members : [];
        } catch (_) {
            this.members = [];
        }
    }

    async _loadDetail(id) {
        try {
            const r = await fetch(`/api/system/containers/${encodeURIComponent(id)}`);
            if (!r.ok) return;
            const d = await r.json();
            this.details.set(id, d);
        } catch (_) { /* leave missing */ }
    }

    async _loadStats(id) {
        try {
            const r = await fetch(`/api/system/containers/${encodeURIComponent(id)}/stats`);
            if (!r.ok) return;
            this.stats.set(id, await r.json());
        } catch (_) { /* leave missing */ }
    }

    async _tickStats() {
        // Only stat running containers — stats for stopped containers return
        // zeros and waste a daemon roundtrip.
        const running = this.members.filter(m => m.state === 'running').map(m => m.id);
        await Promise.all(running.map(id => this._loadStats(id)));
        for (const id of running) this._renderLive(id);
    }

    _bind() {
        const r = this.root();
        if (r) r.addEventListener('click', this._onClick);
    }

    _onClick(e) {
        const lt = e.target.closest('[data-logs-toggle]');
        if (lt) {
            const id = lt.dataset.logsToggle;
            const body = this.root().querySelector(`[data-logs-body="${id}"]`);
            if (body) {
                const open = !body.hidden;
                body.hidden = open;
                lt.textContent = open ? 'Show logs' : 'Hide logs';
                if (!open && !body.dataset.loaded) {
                    this._loadLogs(id, body);
                }
            }
            return;
        }
        const lr = e.target.closest('[data-logs-refresh]');
        if (lr) {
            const id = lr.dataset.logsRefresh;
            const body = this.root().querySelector(`[data-logs-body="${id}"]`);
            if (body) { body.dataset.loaded = ''; this._loadLogs(id, body); }
            return;
        }
        const back = e.target.closest('[data-back]');
        if (back && window.navigateToRoute) {
            window.navigateToRoute('/admin/config/system');
        }
    }

    async _loadLogs(id, bodyEl) {
        bodyEl.innerHTML = '<div class="sys-app-logs-loading">Loading…</div>';
        try {
            const r = await fetch(`/api/system/containers/${encodeURIComponent(id)}/logs?tail=200`);
            const text = await r.text();
            bodyEl.dataset.loaded = '1';
            // Render as a pre-block; strip ANSI just in case (rare in our
            // containers but cheap to do).
            const clean = text.replace(/\x1b\[[0-9;]*[A-Za-z]/g, '');
            bodyEl.innerHTML = `<pre class="sys-app-logs-pre">${(window.SystemFmt?.escape || ((s)=>s))(clean) || '<em>empty</em>'}</pre>`;
            const pre = bodyEl.querySelector('pre');
            if (pre) pre.scrollTop = pre.scrollHeight;
        } catch (err) {
            bodyEl.innerHTML = `<div class="sys-app-logs-err">Failed to load logs: ${(err && err.message) || err}</div>`;
        }
    }

    _renderShell() {
        const r = this.root();
        if (!r) return;
        const fmt = window.SystemFmt;
        const totalRunning = this.members.filter(m => m.state === 'running').length;
        const header = `
            <div class="page-header config-page-header">
                <div class="page-header-title">
                    <div class="admin-breadcrumb">
                        <a href="/admin/config/system" data-back>Admin · System</a>
                    </div>
                    <h1>${fmt.escape(this.appName)}</h1>
                    <p class="sys-app-sub" data-app-sub>${this.members.length} container${this.members.length === 1 ? '' : 's'} · ${totalRunning} running</p>
                </div>
            </div>`;
        if (!this.members.length) {
            r.innerHTML = `
                <div class="admin-page sys-app-page">
                    ${header}
                    <div class="sys-app-empty">
                        No containers found for "<strong>${fmt.escape(this.appName)}</strong>".
                        It may not be installed, or its compose project label differs from the app name.
                    </div>
                </div>`;
            return;
        }
        r.innerHTML = `
            <div class="admin-page sys-app-page">
                ${header}
                <div class="sys-app-grid" data-app-grid>
                    ${this.members.map(m => this._cardSkeleton(m)).join('')}
                </div>
            </div>`;
    }

    _renderHeader() {
        const r = this.root();
        if (!r) return;
        const sub = r.querySelector('[data-app-sub]');
        if (!sub) return;
        const totalRunning = this.members.filter(m => m.state === 'running').length;
        sub.textContent = `${this.members.length} container${this.members.length === 1 ? '' : 's'} · ${totalRunning} running`;
    }

    _cardSkeleton(member) {
        const fmt = window.SystemFmt;
        const statusCls = member.state === 'running' ? 'ok' : (member.state === 'restarting' ? 'warn' : 'none');
        const service = member.service ? `<span class="sys-app-card-svc">${fmt.escape(member.service)}</span>` : '';
        return `
            <article class="sys-app-card" data-cid="${fmt.escape(member.id)}">
                <header class="sys-app-card-head">
                    <div>
                        <div class="sys-app-card-status">
                            <span class="admin-status-dot ${statusCls}"></span>
                            <span class="sys-app-card-state">${fmt.escape(member.state || 'unknown')}</span>
                            ${service}
                        </div>
                        <h2 class="sys-app-card-name">${fmt.escape(member.name)}</h2>
                        <div class="sys-app-card-meta">
                            <span title="${fmt.escape(member.image_id || '')}">${fmt.escape(member.image || '—')}</span>
                            <span class="sys-app-card-sep">·</span>
                            <span>${fmt.escape(member.short || '')}</span>
                        </div>
                    </div>
                    <div class="sys-app-card-status-line">${fmt.escape(member.status || '')}</div>
                </header>

                <div class="sys-app-card-stats" data-live="${fmt.escape(member.id)}">
                    <div class="sys-app-stat"><span class="sys-app-stat-k">CPU</span><strong class="sys-app-stat-v" data-live-k="cpu">—</strong></div>
                    <div class="sys-app-stat"><span class="sys-app-stat-k">Memory</span><strong class="sys-app-stat-v" data-live-k="mem">—</strong></div>
                    <div class="sys-app-stat"><span class="sys-app-stat-k">↓ rx</span><strong class="sys-app-stat-v" data-live-k="rx">—</strong></div>
                    <div class="sys-app-stat"><span class="sys-app-stat-k">↑ tx</span><strong class="sys-app-stat-v" data-live-k="tx">—</strong></div>
                    <div class="sys-app-stat"><span class="sys-app-stat-k">Block r/w</span><strong class="sys-app-stat-v" data-live-k="blk">—</strong></div>
                    <div class="sys-app-stat"><span class="sys-app-stat-k">PIDs</span><strong class="sys-app-stat-v" data-live-k="pids">—</strong></div>
                </div>

                <div class="sys-app-card-body" data-body="${fmt.escape(member.id)}">
                    <div class="sys-app-card-loading">Loading container detail…</div>
                </div>

                <div class="sys-app-card-logs">
                    <div class="sys-app-card-logs-head">
                        <button type="button" class="sys-app-logs-toggle" data-logs-toggle="${fmt.escape(member.id)}">Show logs</button>
                        <button type="button" class="sys-app-logs-refresh" data-logs-refresh="${fmt.escape(member.id)}" title="Refresh">↻</button>
                    </div>
                    <div class="sys-app-card-logs-body" data-logs-body="${fmt.escape(member.id)}" hidden></div>
                </div>
            </article>`;
    }

    _renderCards() {
        for (const m of this.members) this._renderDetail(m.id);
        for (const m of this.members) this._renderLive(m.id);
    }

    _renderDetail(id) {
        const r = this.root();
        if (!r) return;
        const body = r.querySelector(`[data-body="${id}"]`);
        if (!body) return;
        const d = this.details.get(id);
        if (!d) {
            body.innerHTML = `<div class="sys-app-card-err">Couldn't load container detail.</div>`;
            return;
        }
        const fmt = window.SystemFmt;
        const lim = d.limits || {};
        const memLimit = lim.memory;
        const cpuLimit = lim.nano_cpus
            ? `${(lim.nano_cpus / 1e9).toFixed(2)} CPU${(lim.nano_cpus / 1e9) === 1 ? '' : 's'}`
            : (lim.cpu_quota && lim.cpu_period
                ? `${(lim.cpu_quota / lim.cpu_period).toFixed(2)} CPU equiv`
                : 'unlimited');
        const limitsRow = `
            <div class="sys-app-card-limits">
                <div class="sys-app-limit">
                    <span class="sys-app-limit-k">Memory limit</span>
                    <strong class="sys-app-limit-v">${memLimit ? fmt.bytes(memLimit) : 'unlimited'}</strong>
                </div>
                <div class="sys-app-limit">
                    <span class="sys-app-limit-k">CPU limit</span>
                    <strong class="sys-app-limit-v">${fmt.escape(cpuLimit)}</strong>
                </div>
                <div class="sys-app-limit">
                    <span class="sys-app-limit-k">PIDs limit</span>
                    <strong class="sys-app-limit-v">${lim.pids ? lim.pids : 'unlimited'}</strong>
                </div>
                <div class="sys-app-limit">
                    <span class="sys-app-limit-k">Restart policy</span>
                    <strong class="sys-app-limit-v">${fmt.escape(lim.restart_policy || 'no')}${lim.restart_max ? ` (max ${lim.restart_max})` : ''}</strong>
                </div>
                <div class="sys-app-limit">
                    <span class="sys-app-limit-k">Restart count</span>
                    <strong class="sys-app-limit-v">${d.state?.restart_count ?? 0}</strong>
                </div>
                <div class="sys-app-limit">
                    <span class="sys-app-limit-k">Started</span>
                    <strong class="sys-app-limit-v">${d.state?.started_at ? fmt.timeAgoIso(d.state.started_at) : '—'}</strong>
                </div>
            </div>`;

        const health = d.state?.health
            ? `<div class="sys-app-section">
                    <h3>Healthcheck</h3>
                    <div class="sys-app-health">
                        <span class="sys-app-health-pill sys-app-health-${fmt.escape(d.state.health.status || 'unknown')}">${fmt.escape(d.state.health.status || 'unknown')}</span>
                        ${d.state.health.failing_streak ? `<span class="sys-app-health-fail">${d.state.health.failing_streak} failing in a row</span>` : ''}
                    </div>
                    ${(d.state.health.log || []).slice(-3).reverse().map(l =>
                        `<details class="sys-app-health-log"><summary>${fmt.escape(l.end || l.start || '')} · exit ${l.exit_code ?? '?'}</summary><pre>${fmt.escape(l.output || '')}</pre></details>`
                    ).join('')}
                </div>` : '';

        const nets = (d.networks || []).length
            ? `<div class="sys-app-section">
                    <h3>Networks</h3>
                    <table class="sys-app-table">
                        <thead><tr><th>Name</th><th>IP</th><th>Gateway</th><th>MAC</th></tr></thead>
                        <tbody>${d.networks.map(n => `
                            <tr><td>${fmt.escape(n.name)}</td><td>${fmt.escape(n.ip || '—')}</td><td>${fmt.escape(n.gateway || '—')}</td><td>${fmt.escape(n.mac || '—')}</td></tr>
                        `).join('')}</tbody>
                    </table>
                </div>` : '';

        const ports = (d.ports || []).filter(p => p.host).length
            ? `<div class="sys-app-section">
                    <h3>Published ports</h3>
                    <ul class="sys-app-ports">${(d.ports || []).filter(p => p.host).map(p =>
                        `<li><strong>${p.host}</strong> → ${p.container}/${fmt.escape(p.proto || '')}</li>`
                    ).join('')}</ul>
                </div>` : '';

        const mounts = (d.mounts || []).length
            ? `<div class="sys-app-section">
                    <h3>Mounts</h3>
                    <table class="sys-app-table">
                        <thead><tr><th>Type</th><th>Source</th><th>Target</th><th>Mode</th></tr></thead>
                        <tbody>${d.mounts.map(m => `
                            <tr><td><span class="sys-app-mount-type sys-app-mount-${fmt.escape(m.type || '')}">${fmt.escape(m.type || '')}</span></td>
                                <td class="sys-app-mount-path">${fmt.escape(m.source || '')}</td>
                                <td class="sys-app-mount-path">${fmt.escape(m.target || '')}</td>
                                <td>${fmt.escape(m.mode || '')}${m.rw === false ? ' (ro)' : ''}</td></tr>
                        `).join('')}</tbody>
                    </table>
                </div>` : '';

        body.innerHTML = `${limitsRow}${health}${nets}${ports}${mounts}`;
    }

    _renderLive(id) {
        const r = this.root();
        if (!r) return;
        const card = r.querySelector(`[data-live="${id}"]`);
        if (!card) return;
        const s = this.stats.get(id);
        const d = this.details.get(id);
        const memLimit = d?.limits?.memory || 0;
        const fmt = window.SystemFmt;
        if (!s) {
            // Container stopped or stats not loaded — clear the row.
            for (const v of card.querySelectorAll('.sys-app-stat-v')) v.textContent = '—';
            return;
        }
        const cpu = s.cpu_percent ?? 0;
        const memUsed = s.memory?.used ?? 0;
        const memPct = memLimit > 0 ? (memUsed / memLimit) * 100 : (s.memory?.percent ?? 0);
        const rx = s.network?.rx_total ?? 0;
        const tx = s.network?.tx_total ?? 0;
        const br = s.blkio?.read ?? 0;
        const bw = s.blkio?.write ?? 0;
        const pids = s.pids?.current ?? 0;
        const set = (k, v) => { const el = card.querySelector(`[data-live-k="${k}"]`); if (el) el.textContent = v; };
        set('cpu',  `${cpu.toFixed(1)}%`);
        set('mem',  memLimit > 0 ? `${fmt.bytes(memUsed)} (${memPct.toFixed(0)}%)` : fmt.bytes(memUsed));
        set('rx',   fmt.bytes(rx));
        set('tx',   fmt.bytes(tx));
        set('blk',  `${fmt.bytes(br)} / ${fmt.bytes(bw)}`);
        set('pids', pids ? String(pids) : '—');
        // Memory limit headroom — colour the cell when above 80%.
        const memEl = card.querySelector('[data-live-k="mem"]');
        if (memEl) {
            memEl.classList.toggle('warn', memLimit > 0 && memPct >= 80);
            memEl.classList.toggle('danger', memLimit > 0 && memPct >= 95);
        }
    }
}

window.SystemAppPage = SystemAppPage;