import { useCallback, useEffect, useState } from 'react';
import { apiGet, apiDelete } from '../api.js';
import { Markdown } from '../markdown.jsx';
import Lightbox from '../components/Lightbox.jsx';
import { SkeletonCards } from '../components/Skeleton.jsx';

const dateFmt = new Intl.DateTimeFormat('de-DE', {
    weekday: 'short', day: '2-digit', month: '2-digit', year: 'numeric',
});
const monthFmt = new Intl.DateTimeFormat('de-DE', { month: 'long', year: 'numeric' });

/** Relative Angabe wie „vor 3 Tagen" für die Karten-Ecke */
function relative(iso) {
    const days = Math.floor((Date.now() - new Date(iso).getTime()) / 86400000);
    if (days <= 0) return 'heute';
    if (days === 1) return 'gestern';
    if (days < 30) return `vor ${days} Tagen`;
    const months = Math.floor(days / 30);
    return months === 1 ? 'vor 1 Monat' : `vor ${months} Monaten`;
}

/**
 * Devlog-Inhalt in Karten-Teile zerlegen:
 * - Embed-Titel („Devlog — Projekt") → Projekt-Chip statt Fließtext
 * - Abschließende Kursiv-Zeile („*X Commits heute …*") → abgesetzte Fußzeile
 */
export function splitContent(raw) {
    const blocks = raw.split(/\n{2,}/);
    let project = null;
    let footer = null;

    const title = blocks[0]?.match(/^Devlog\s*[—–-]\s*(.+)$/i);
    if (title) {
        project = title[1].trim();
        blocks.shift();
    }
    const last = blocks[blocks.length - 1];
    if (blocks.length > 1 && /^\*[^*]+\*$/s.test(last?.trim() ?? '')) {
        footer = last.trim().slice(1, -1);
        blocks.pop();
    }
    return { project, footer, body: blocks.join('\n\n') };
}

export default function Devlogs({ me }) {
    const [data, setData] = useState(null);
    const [page, setPage] = useState(1);
    const [error, setError] = useState(false);
    const [qInput, setQInput] = useState('');
    const [q, setQ] = useState('');
    const [lightbox, setLightbox] = useState(null); // { images, start }

    // Sucheingabe entprellen (300 ms), bei neuer Suche zurück auf Seite 1
    useEffect(() => {
        const t = setTimeout(() => {
            setQ(qInput.trim());
            setPage(1);
        }, 300);
        return () => clearTimeout(t);
    }, [qInput]);

    const load = useCallback(() => {
        setError(false);
        const search = q ? `&q=${encodeURIComponent(q)}` : '';
        apiGet(`/api/devlogs?page=${page}${search}`).then(setData).catch(() => setError(true));
    }, [page, q]);

    useEffect(() => {
        load();
        window.scrollTo(0, 0);
    }, [load]);

    // Admin: Devlog aus dem Archiv entfernen (löscht auch die lokalen Bilder)
    async function remove(id) {
        if (!window.confirm('Dieses Devlog aus dem Archiv löschen?')) return;
        try {
            await apiDelete(`/api/devlogs/${id}`);
            load();
        } catch {
            window.alert('Löschen fehlgeschlagen.');
        }
    }

    const pages = data ? Math.ceil(data.total / data.pageSize) : 0;

    // Monats-Trenner in der Timeline
    let lastMonth = null;

    return (
        <>
            <section className="page-header">
                <div className="page-bg-text">DEVLOG</div>
                <div className="page-header-grid" aria-hidden="true" />
                <div className="page-header-content">
                    <div className="page-tag">// Archiv</div>
                    <h1 className="page-title">Devlog</h1>
                    <p className="page-subtitle">
                        Entwicklungs-Updates, frisch aus dem Editor — automatisch archiviert.
                    </p>
                </div>
            </section>

            <section className="content">
                <div className="search">
                    <span className="search-icon">⌕</span>
                    <input
                        type="search"
                        placeholder="Devlogs durchsuchen …"
                        value={qInput}
                        onChange={(e) => setQInput(e.target.value)}
                    />
                    {q && data && <span className="search-count">{data.total} Treffer</span>}
                </div>

                {error && <p className="notice">Devlogs konnten nicht geladen werden.</p>}
                {!error && !data && <SkeletonCards n={3} />}
                {data?.total === 0 && (
                    <p className="notice">{q ? `Keine Treffer für „${q}".` : 'Noch keine Devlogs archiviert.'}</p>
                )}

                {data?.total > 0 && (
                    <div className="timeline">
                        {data.items.map((d) => {
                            const { project, footer, body } = splitContent(d.content);
                            const month = monthFmt.format(new Date(d.posted_at));
                            const showMonth = month !== lastMonth;
                            lastMonth = month;
                            return (
                                <div key={d.message_id}>
                                    {showMonth && <div className="month-sep">{month}</div>}
                                    <article className="card">
                                        <div className="card-meta">
                                            <span className="card-date">
                                                {dateFmt.format(new Date(d.posted_at))}
                                            </span>
                                            {project && <span className="card-project">{project}</span>}
                                            <span className="card-rel">{relative(d.posted_at)}</span>
                                            <a className="card-permalink" href={`/devlogs/${d.message_id}`} title="Direktlink zu diesem Devlog">🔗</a>
                                            {me?.admin && (
                                                <button
                                                    className="card-delete"
                                                    title="Aus dem Archiv löschen"
                                                    onClick={() => remove(d.message_id)}
                                                >
                                                    ✕
                                                </button>
                                            )}
                                        </div>
                                        <div className="card-body">
                                            <Markdown text={body} />
                                        </div>
                                        {d.images?.length > 0 && (
                                            <div className={`card-images n${Math.min(d.images.length, 4)}`}>
                                                {d.images.map((src, i) => (
                                                    <a
                                                        key={src} href={src}
                                                        onClick={(e) => {
                                                            e.preventDefault();
                                                            setLightbox({ images: d.images, start: i });
                                                        }}
                                                    >
                                                        <img src={src} alt="Devlog-Screenshot" loading="lazy" />
                                                    </a>
                                                ))}
                                            </div>
                                        )}
                                        {footer && (
                                            <div className="card-footer">
                                                <Markdown text={footer} />
                                            </div>
                                        )}
                                    </article>
                                </div>
                            );
                        })}
                    </div>
                )}

                {lightbox && (
                    <Lightbox
                        images={lightbox.images}
                        start={lightbox.start}
                        onClose={() => setLightbox(null)}
                    />
                )}

                {pages > 1 && (
                    <div className="pager">
                        <button className="btn" disabled={page <= 1} onClick={() => setPage(page - 1)}>
                            ← Neuere
                        </button>
                        <span className="pager-info">
                            {String(page).padStart(2, '0')} / {String(pages).padStart(2, '0')}
                        </span>
                        <button className="btn" disabled={page >= pages} onClick={() => setPage(page + 1)}>
                            Ältere →
                        </button>
                    </div>
                )}
            </section>
        </>
    );
}