// ============================================================
// Foreground: Currently-focused desktop process card (rendered at
// the top of the Display tab)
// ============================================================

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

let latestForeground = null;
let agoTickTimer = null;

function escapeHtml(s) {
    if (s === null || s === undefined) return '';
    return String(s)
        .replace(/&/g, '&')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;')
        .replace(/"/g, '&quot;')
        .replace(/'/g, '&#39;');
}

function formatAgo(epoch) {
    if (!epoch) return '';
    const now = Date.now() / 1000;
    const diff = Math.max(0, now - epoch);
    if (diff < 60) {
        return t('foreground.ago.seconds', { n: Math.floor(diff) });
    }
    if (diff < 3600) {
        return t('foreground.ago.minutes', { n: Math.floor(diff / 60) });
    }
    if (diff < 86400) {
        const h = Math.floor(diff / 3600);
        const m = Math.floor((diff % 3600) / 60);
        return t('foreground.ago.hours', { n: h, m: m });
    }
    return t('foreground.ago.days', { n: Math.floor(diff / 86400) });
}

function formatGeometry(g) {
    if (!g) return '—';
    const w = g.width ?? (g.right - g.left);
    const h = g.height ?? (g.bottom - g.top);
    return `${w}×${h} @ (${g.left}, ${g.top})`;
}

function truncatePath(p, max = 64) {
    if (!p) return '';
    if (p.length <= max) return p;
    // Keep the tail (filename) visible — that's the part the user cares about.
    return '…' + p.slice(-(max - 1));
}

function renderEmpty(message, errorMsg) {
    const stage = document.getElementById('foregroundStage');
    if (!stage) return;
    stage.innerHTML = `
        <div class="empty-state-illustration foreground-empty">
            <svg viewBox="0 0 64 64"><rect x="6" y="12" width="52" height="36" rx="3" fill="none" stroke="currentColor" stroke-width="2"/><line x1="6" y1="20" x2="58" y2="20" stroke="currentColor" stroke-width="2"/><circle cx="11" cy="16" r="1.4" fill="currentColor"/><circle cx="15" cy="16" r="1.4" fill="currentColor"/><circle cx="19" cy="16" r="1.4" fill="currentColor"/></svg>
            <p>${escapeHtml(message)}</p>
            ${errorMsg ? `<p class="foreground-empty-error">${escapeHtml(errorMsg)}</p>` : ''}
        </div>
    `;
}

function renderTile(data) {
    const stage = document.getElementById('foregroundStage');
    if (!stage) return;

    const procName = data.process_name || '—';
    const winTitle = data.window_title || '';
    const execPath = data.executable_path || '';
    const pid = data.pid ?? '—';
    const startedEpoch = data.started_at;
    const startedAgo = startedEpoch ? formatAgo(startedEpoch) : '—';
    const startedAbs = startedEpoch
        ? new Date(startedEpoch * 1000).toLocaleString()
        : '';
    const geom = formatGeometry(data.window_geometry);
    const platform = data.platform || '—';
    const monitorId = data.monitor_id;

    // Chips: only render ones that apply
    const chips = [];
    if (data.is_fullscreen) {
        chips.push(`<span class="fg-chip fg-chip-accent">${escapeHtml(t('foreground.fullscreen'))}</span>`);
    } else if (!data.is_minimized) {
        chips.push(`<span class="fg-chip">${escapeHtml(t('foreground.windowed'))}</span>`);
    }
    if (data.is_minimized) {
        chips.push(`<span class="fg-chip fg-chip-mute">${escapeHtml(t('foreground.minimized'))}</span>`);
    }
    if (monitorId !== null && monitorId !== undefined) {
        chips.push(`<span class="fg-chip">${escapeHtml(t('foreground.monitor', { n: monitorId + 1 }))}</span>`);
    }
    if (data.is_browser) {
        chips.push(`<span class="fg-chip fg-chip-mute">${escapeHtml(t('foreground.browser'))}</span>`);
    }

    // Optional browser-only detail rows (page title + URL when available)
    const browserRows = [];
    if (data.is_browser) {
        if (data.browser_page_title) {
            browserRows.push(`
                <div class="fg-row">
                    <dt>${escapeHtml(t('foreground.page_title'))}</dt>
                    <dd title="${escapeHtml(data.browser_page_title)}">${escapeHtml(data.browser_page_title)}</dd>
                </div>
            `);
        }
        if (data.browser_url) {
            browserRows.push(`
                <div class="fg-row">
                    <dt>${escapeHtml(t('foreground.url'))}</dt>
                    <dd title="${escapeHtml(data.browser_url)}"><span class="fg-mono">${escapeHtml(truncatePath(data.browser_url, 80))}</span></dd>
                </div>
            `);
        }
    }

    stage.innerHTML = `
        <article class="foreground-card" data-fullscreen="${data.is_fullscreen ? '1' : '0'}">
            <div class="fg-kicker">
                <span data-i18n="foreground.kicker">Foreground</span>
            </div>
            <h1 class="fg-process" title="${escapeHtml(procName)}">${escapeHtml(procName)}</h1>
            <div class="fg-window-title" title="${escapeHtml(winTitle)}">${escapeHtml(winTitle)}</div>

            <div class="fg-chips">${chips.join('')}</div>

            <dl class="fg-details">
                ${browserRows.join('')}
                <div class="fg-row">
                    <dt>${escapeHtml(t('foreground.executable'))}</dt>
                    <dd title="${escapeHtml(execPath)}"><span class="fg-mono">${escapeHtml(truncatePath(execPath))}</span></dd>
                </div>
                <div class="fg-row">
                    <dt>${escapeHtml(t('foreground.pid'))}</dt>
                    <dd><span class="fg-mono">${escapeHtml(String(pid))}</span></dd>
                </div>
                <div class="fg-row">
                    <dt>${escapeHtml(t('foreground.started'))}</dt>
                    <dd title="${escapeHtml(startedAbs)}"><span class="fg-ago" data-started="${startedEpoch ?? ''}">${escapeHtml(startedAgo)}</span></dd>
                </div>
                <div class="fg-row">
                    <dt>${escapeHtml(t('foreground.geometry'))}</dt>
                    <dd><span class="fg-mono">${escapeHtml(geom)}</span></dd>
                </div>
                <div class="fg-row">
                    <dt>${escapeHtml(t('foreground.platform'))}</dt>
                    <dd>${escapeHtml(platform)}</dd>
                </div>
            </dl>
        </article>
    `;
}

function startAgoTicker() {
    if (agoTickTimer) return;
    agoTickTimer = setInterval(() => {
        const el = document.querySelector('.fg-ago[data-started]');
        if (!el) return;
        const epoch = parseFloat(el.getAttribute('data-started'));
        if (!epoch) return;
        el.textContent = formatAgo(epoch);
    }, 15000);
}

export function updateForegroundUI(data) {
    latestForeground = data;

    if (!data || data.available === false) {
        const errMsg = data && data.error ? data.error : '';
        renderEmpty(t('foreground.unavailable'), errMsg);
    } else if (!data.process_name && !data.pid) {
        renderEmpty(t('foreground.no_process'), '');
    } else {
        renderTile(data);
        startAgoTicker();
    }
}

export function loadForegroundProcess() {
    // Push-only — just render the cached state. If nothing has arrived
    // yet, leave the loading placeholder visible.
    if (latestForeground !== null) {
        updateForegroundUI(latestForeground);
    }
}