(function () {
    'use strict';

    // ── Styles ──────────────────────────────────────────────────────────────
    const css = `
#pipeline-toasts {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    z-index: 9999;
    display: flex;
    flex-direction: column-reverse;
    gap: .5rem;
    max-width: 22rem;
    pointer-events: none;
}
.pipeline-toast {
    display: flex;
    align-items: flex-start;
    gap: .6rem;
    padding: .65rem .9rem;
    border-radius: .45rem;
    background: #1e293b;
    color: #f1f5f9;
    font-size: .82rem;
    line-height: 1.35;
    box-shadow: 0 4px 16px rgba(0,0,0,.35);
    pointer-events: all;
    opacity: 0;
    transform: translateX(110%);
    transition: opacity .25s ease, transform .25s ease;
}
.pipeline-toast.visible {
    opacity: 1;
    transform: translateX(0);
}
.pipeline-toast.hiding {
    opacity: 0;
    transform: translateX(110%);
}
.pipeline-toast .pt-icon {
    font-size: 1rem;
    flex-shrink: 0;
    margin-top: .05rem;
}
.pipeline-toast.status-queued     { border-left: 3px solid #60a5fa; }
.pipeline-toast.status-processing { border-left: 3px solid #f59e0b; }
.pipeline-toast.status-completed  { border-left: 3px solid #22c55e; }
.pipeline-toast.status-failed     { border-left: 3px solid #ef4444; background: #2d1a1a; }
.pipeline-toast.status-needs_review { border-left: 3px solid #f97316; }
`;

    const ICONS = {
        queued:       '🕐',
        processing:   '⚙️',
        completed:    '✅',
        failed:       '❌',
        needs_review: '⚠️',
    };

    const DISPLAY_SECONDS = {
        queued:       5,
        processing:   6,
        completed:    8,
        failed:       12,
        needs_review: 12,
    };

    // ── DOM setup ────────────────────────────────────────────────────────────
    function inject() {
        const style = document.createElement('style');
        style.textContent = css;
        document.head.appendChild(style);

        const container = document.createElement('div');
        container.id = 'pipeline-toasts';
        document.body.appendChild(container);
        return container;
    }

    function showToast(container, event) {
        const status = event.status ?? 'queued';
        const icon   = ICONS[status] ?? '🔔';
        const ttl    = (DISPLAY_SECONDS[status] ?? 6) * 1000;

        const toast = document.createElement('div');
        toast.className = `pipeline-toast status-${status}`;
        toast.innerHTML =
            `<span class="pt-icon">${icon}</span>` +
            `<span>${escapeHtml(event.message)}</span>`;

        container.appendChild(toast);

        // Animate in
        requestAnimationFrame(() => {
            requestAnimationFrame(() => toast.classList.add('visible'));
        });

        // Animate out and remove
        const hide = () => {
            toast.classList.add('hiding');
            toast.addEventListener('transitionend', () => toast.remove(), { once: true });
        };
        const timer = setTimeout(hide, ttl);
        toast.addEventListener('click', () => { clearTimeout(timer); hide(); });
    }

    function escapeHtml(str) {
        return str
            .replace(/&/g, '&amp;')
            .replace(/</g, '&lt;')
            .replace(/>/g, '&gt;')
            .replace(/"/g, '&quot;');
    }

    // ── SSE connection ───────────────────────────────────────────────────────
    function connect(container, lastEventId) {
        const url = lastEventId
            ? `/admin/pipeline/events?lastEventId=${encodeURIComponent(lastEventId)}`
            : '/admin/pipeline/events';

        const es = new EventSource(url);
        let storedLastId = lastEventId ?? null;

        es.onmessage = (e) => {
            if (e.lastEventId) storedLastId = e.lastEventId;
            try {
                const event = JSON.parse(e.data);
                if (event && event.message) showToast(container, event);
            } catch (_) { /* ignore malformed frames */ }
        };

        es.addEventListener('reconnect', () => {
            es.close();
            // Small delay so the server-side loop has fully exited
            setTimeout(() => connect(container, storedLastId), 500);
        });

        es.onerror = () => {
            es.close();
            // Browser will retry via EventSource built-in retry, but we also
            // reconnect manually to pass the last event ID properly.
            setTimeout(() => connect(container, storedLastId), 4000);
        };
    }

    // ── Boot ─────────────────────────────────────────────────────────────────
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', boot);
    } else {
        boot();
    }

    function boot() {
        const container = inject();
        connect(container, null);
    }
}());