{% extends "portal/base.html" %}
{% block title %}{{ location.name }}{% endblock %}
{% block head %}
<script src="https://cdn.jsdelivr.net/npm/chart.js@4"></script>
{% endblock %}
{% block content %}
<a href="/portal" class="text-sm text-gray-400 hover:text-gray-200">&larr; All locations</a>
<h1 class="text-2xl font-semibold mt-1">{{ location.name }}</h1>
<div class="flex items-center gap-2 text-sm mt-1 mb-6">
    <span id="p-badge" class="hidden px-2 py-0.5 text-xs font-medium rounded-full"></span>
    <span id="p-fresh" class="text-gray-400"></span>
</div>

{% if not has_device %}
<div class="rounded-xl border border-slate-700 bg-slate-800/50 p-8 text-center text-gray-400">
    No device is currently assigned to this location.
</div>
{% else %}
<div class="grid grid-cols-2 sm:grid-cols-5 gap-3 mb-6">
    <div class="rounded-lg bg-slate-800/60 border border-slate-700 p-3">
        <div class="text-xs text-gray-400">Lp (Instant)</div>
        <div id="p-lp" class="text-2xl font-bold text-blue-400">--</div><div class="text-xs text-gray-500">dB</div>
    </div>
    <div class="rounded-lg bg-slate-800/60 border border-slate-700 p-3">
        <div class="text-xs text-gray-400">Leq (Average)</div>
        <div id="p-leq" class="text-2xl font-bold text-green-400">--</div><div class="text-xs text-gray-500">dB</div>
    </div>
    <div class="rounded-lg bg-slate-800/60 border border-slate-700 p-3">
        <div class="text-xs text-gray-400">Lmax (Max)</div>
        <div id="p-lmax" class="text-2xl font-bold text-red-400">--</div><div class="text-xs text-gray-500">dB</div>
    </div>
    <div class="rounded-lg bg-slate-800/60 border border-slate-700 p-3">
        <div class="text-xs text-gray-400">L1</div>
        <div id="p-ln1" class="text-2xl font-bold text-purple-400">--</div><div class="text-xs text-gray-500">dB</div>
    </div>
    <div class="rounded-lg bg-slate-800/60 border border-slate-700 p-3">
        <div class="text-xs text-gray-400">L10</div>
        <div id="p-ln2" class="text-2xl font-bold text-orange-400">--</div><div class="text-xs text-gray-500">dB</div>
    </div>
</div>

<div class="relative rounded-xl border border-slate-700 bg-slate-800/50 p-4" style="min-height: 360px;">
    <canvas id="p-chart"></canvas>
    <div id="p-paused" class="hidden absolute inset-0 flex items-center justify-center bg-slate-900/70 rounded-xl">
        <button onclick="resumeStream()"
                class="px-4 py-2 rounded-lg bg-seismo-orange/20 text-seismo-orange border border-seismo-orange/40 hover:bg-seismo-orange/30 text-sm font-medium">
            &#9208; Live paused — click to resume
        </button>
    </div>
</div>
{% endif %}
{% endblock %}

{% block scripts %}
{% if has_device %}
<script>
const LOC_ID = "{{ location.id }}";
const cd = { t: [], lp: [], leq: [], ln1: [], ln2: [] };
let chart;
const numOrNull = v => { const f = parseFloat(v); return isNaN(f) ? null : f; };

function ds(label, color) {
    return { label, data: [], borderColor: color, backgroundColor: color,
             borderWidth: 2, pointRadius: 0, tension: 0.3, spanGaps: true };
}
function initChart() {
    const ctx = document.getElementById('p-chart').getContext('2d');
    chart = new Chart(ctx, {
        type: 'line',
        data: { labels: [], datasets: [
            ds('Lp', 'rgb(96,165,250)'), ds('Leq', 'rgb(74,222,128)'),
            ds('L1', 'rgb(192,132,252)'), ds('L10', 'rgb(251,146,60)') ] },
        options: {
            responsive: true, maintainAspectRatio: false, animation: false,
            interaction: { intersect: false, mode: 'index' },
            scales: {
                y: { min: 30, max: 130, title: { display: true, text: 'dB', color: '#94a3b8' },
                     ticks: { color: '#94a3b8' }, grid: { color: 'rgba(148,163,184,0.12)' } },
                x: { ticks: { color: '#94a3b8', maxTicksLimit: 8 }, grid: { color: 'rgba(148,163,184,0.12)' } }
            },
            plugins: { legend: { labels: { color: '#cbd5e1' } } }
        }
    });
}

function setCard(id, v) { document.getElementById(id).textContent = (v == null || v === '') ? '--' : v; }
function setBadge(measuring, lastSeen) {
    const b = document.getElementById('p-badge'), f = document.getElementById('p-fresh');
    if (measuring === null) { b.className = 'hidden px-2 py-0.5 text-xs font-medium rounded-full'; b.textContent = ''; }
    else if (measuring) { b.className = 'px-2 py-0.5 text-xs font-medium rounded-full bg-green-900/40 text-green-300'; b.textContent = '● Live'; }
    else { b.className = 'px-2 py-0.5 text-xs font-medium rounded-full bg-slate-700 text-gray-300'; b.textContent = '■ Stopped'; }
    f.innerHTML = fmtFreshness(lastSeen);
}
function fmtFreshness(iso) {
    if (!iso) return '<span class="text-gray-500">no recent reading</span>';
    const t = new Date(iso.endsWith('Z') ? iso : iso + 'Z');
    const s = Math.max(0, Math.round((Date.now() - t.getTime()) / 1000));
    let ago, stale = false;
    if (s < 10) ago = 'just now';
    else if (s < 60) ago = s + 's ago';
    else if (s < 3600) { ago = Math.round(s / 60) + 'm ago'; stale = s >= 300; }
    else { ago = Math.round(s / 3600) + 'h ago'; stale = true; }
    const cls = stale ? 'text-amber-400' : 'text-gray-400';
    return `as of ${t.toLocaleTimeString()} <span class="${cls}">(${ago}${stale ? ' · cached' : ''})</span>`;
}

async function prefill() {
    try {
        const j = await (await fetch(`/portal/api/location/${encodeURIComponent(LOC_ID)}/live`)).json();
        const d = j.data;
        if (!d) {
            setBadge(null, null);
            document.getElementById('p-fresh').textContent =
                j.reason === 'no_device' ? 'No device assigned' : 'Currently unreachable';
            return;
        }
        setCard('p-lp', d.lp); setCard('p-leq', d.leq); setCard('p-lmax', d.lmax);
        setCard('p-ln1', d.ln1); setCard('p-ln2', d.ln2);
        const measuring = d.measurement_state === 'Start' || d.measurement_state === 'Measure';
        setBadge(measuring, d.last_seen);
    } catch (e) { /* keep last values */ }
}
async function backfill() {
    try {
        const j = await (await fetch(`/portal/api/location/${encodeURIComponent(LOC_ID)}/history?hours=2`)).json();
        for (const row of (j.readings || [])) {
            cd.t.push(row.timestamp ? new Date(row.timestamp + 'Z').toLocaleTimeString() : '');
            cd.lp.push(numOrNull(row.lp)); cd.leq.push(numOrNull(row.leq));
            cd.ln1.push(numOrNull(row.ln1)); cd.ln2.push(numOrNull(row.ln2));
        }
        chart.data.labels = cd.t;
        chart.data.datasets[0].data = cd.lp; chart.data.datasets[1].data = cd.leq;
        chart.data.datasets[2].data = cd.ln1; chart.data.datasets[3].data = cd.ln2;
        chart.update('none');
    } catch (e) { /* leave chart empty */ }
}

// ---- live stream (upgrades the cache prefill to a real ~1Hz feed) --------
let ws = null, hardCap = null, paused = false;
const IDLE_CAP_MS = 15 * 60 * 1000;  // auto-close after 15 min so an abandoned
                                     // tab doesn't pin the device at 1Hz polling

function pushPoint(d) {
    cd.t.push(new Date().toLocaleTimeString());
    cd.lp.push(numOrNull(d.lp)); cd.leq.push(numOrNull(d.leq));
    cd.ln1.push(numOrNull(d.ln1)); cd.ln2.push(numOrNull(d.ln2));
    if (cd.t.length > 600) { cd.t.shift(); cd.lp.shift(); cd.leq.shift(); cd.ln1.shift(); cd.ln2.shift(); }
    chart.data.labels = cd.t;
    chart.data.datasets[0].data = cd.lp; chart.data.datasets[1].data = cd.leq;
    chart.data.datasets[2].data = cd.ln1; chart.data.datasets[3].data = cd.ln2;
    chart.update('none');
}

function openStream() {
    if (paused || ws) return;
    const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
    ws = new WebSocket(`${proto}//${location.host}/portal/api/location/${encodeURIComponent(LOC_ID)}/stream`);
    ws.onmessage = (e) => {
        let d; try { d = JSON.parse(e.data); } catch (_) { return; }
        if (d.feed_status === 'no_device') {
            setBadge(null, null);
            document.getElementById('p-fresh').textContent = 'No device assigned';
            return;
        }
        if (d.heartbeat) return;
        if (d.feed_status === 'unreachable') {
            document.getElementById('p-fresh').innerHTML = '<span class="text-amber-400">device unreachable</span>';
            return;
        }
        setCard('p-lp', d.lp); setCard('p-leq', d.leq); setCard('p-lmax', d.lmax);
        setCard('p-ln1', d.ln1); setCard('p-ln2', d.ln2);
        const measuring = d.measurement_state === 'Start' || d.measurement_state === 'Measure';
        setBadge(measuring, d.timestamp || new Date().toISOString());
        pushPoint(d);
    };
    ws.onclose = () => { ws = null; };
    ws.onerror = () => {};
    clearTimeout(hardCap);
    hardCap = setTimeout(() => { paused = true; closeStream(); showPaused(true); }, IDLE_CAP_MS);
}

function closeStream() {
    clearTimeout(hardCap);
    if (ws) { try { ws.close(); } catch (_) {} ws = null; }
}

function showPaused(on) {
    const el = document.getElementById('p-paused');
    if (el) el.classList.toggle('hidden', !on);
}
function resumeStream() {
    paused = false; showPaused(false);
    prefill();        // refresh cards instantly on resume
    openStream();
}

// Stop streaming when the tab is hidden (client switched away / locked phone) and
// resume when it's visible again — the main cost guard, so the device relaxes back
// to its idle poll rate the moment nobody is actually looking.
document.addEventListener('visibilitychange', () => {
    if (document.hidden) closeStream();
    else if (!paused) openStream();
});
window.addEventListener('beforeunload', closeStream);

initChart();
prefill();      // instant first paint from cache
backfill();     // seed the chart trail
openStream();   // then upgrade to the live feed
</script>
{% endif %}
{% endblock %}
