/**
 * <folk-tasks-activity> — Recent task activity widget for rTasks canvas.
 *
 * Derives a lightweight activity feed from task updated_at timestamps until
 * the server activity endpoint is populated. Each entry shows what changed
 * most recently (task title + relative time).
 *
 * Attribute: space — space slug
 */

interface TaskRow {
	id: string;
	title: string;
	status: string;
	priority: string | null;
	updated_at: string;
	created_at: string;
}

class FolkTasksActivity extends HTMLElement {
	private shadow: ShadowRoot;
	private space = '';
	private tasks: TaskRow[] = [];
	private loading = true;
	private error = '';

	constructor() {
		super();
		this.shadow = this.attachShadow({ mode: 'open' });
	}

	connectedCallback() {
		this.space = this.getAttribute('space') || 'demo';
		this.render();
		this.load();
	}

	static get observedAttributes() { return ['space']; }
	attributeChangedCallback(name: string, _old: string, val: string) {
		if (name === 'space' && val !== this.space) {
			this.space = val;
			this.load();
		}
	}

	private getApiBase(): string {
		const path = window.location.pathname;
		const match = path.match(/^(\/[^/]+)?\/rtasks/);
		return match ? match[0] : '/rtasks';
	}

	private async load() {
		this.loading = true;
		this.error = '';
		this.render();
		try {
			const res = await fetch(`${this.getApiBase()}/api/spaces/${encodeURIComponent(this.space)}/tasks`);
			if (!res.ok) throw new Error(`HTTP ${res.status}`);
			this.tasks = await res.json();
		} catch (e) {
			this.error = e instanceof Error ? e.message : String(e);
		}
		this.loading = false;
		this.render();
	}

	private recent(): TaskRow[] {
		return [...this.tasks]
			.sort((a, b) => Date.parse(b.updated_at) - Date.parse(a.updated_at))
			.slice(0, 20);
	}

	private relTime(iso: string): string {
		const delta = Date.now() - Date.parse(iso);
		const m = Math.floor(delta / 60000);
		if (m < 1) return 'just now';
		if (m < 60) return `${m}m ago`;
		const h = Math.floor(m / 60);
		if (h < 24) return `${h}h ago`;
		const d = Math.floor(h / 24);
		if (d < 7) return `${d}d ago`;
		return new Date(iso).toLocaleDateString(undefined, { month: 'short', day: 'numeric' });
	}

	private render() {
		const items = this.recent();
		this.shadow.innerHTML = `
		<style>${this.getStyles()}</style>
		<div class="activity">
			<div class="list">
				${this.loading ? '<div class="state">Loading…</div>' :
				  this.error ? `<div class="state err">${this.esc(this.error)}</div>` :
				  items.length === 0 ? '<div class="state">No activity yet.</div>' :
				  items.map(t => this.renderEntry(t)).join('')}
			</div>
		</div>`;
		this.bindEvents();
	}

	private renderEntry(t: TaskRow): string {
		const isNew = t.created_at === t.updated_at;
		const verb = isNew ? 'created' : 'updated';
		const rel = this.relTime(t.updated_at);
		const statusCls = `status-${t.status.toLowerCase().replace(/_/g, '-')}`;
		return `<div class="entry" data-task-id="${this.esc(t.id)}">
			<div class="entry-main">
				<span class="verb">${verb}</span>
				<span class="title">${this.esc(t.title)}</span>
			</div>
			<div class="entry-meta">
				<span class="status ${statusCls}">${this.esc(t.status)}</span>
				<span class="rel">${this.esc(rel)}</span>
			</div>
		</div>`;
	}

	private bindEvents() {
		this.shadow.querySelectorAll('.entry').forEach(el => {
			el.addEventListener('click', () => {
				const id = (el as HTMLElement).dataset.taskId;
				if (!id) return;
				this.dispatchEvent(new CustomEvent('task-selected', { bubbles: true, composed: true, detail: { taskId: id } }));
			});
		});
	}

	private getStyles(): string {
		return `
			:host { display: block; height: 100%; }
			.activity { display: flex; flex-direction: column; height: 100%; min-height: 0; }
			.list { flex: 1; overflow-y: auto; min-height: 0; }
			.state { text-align: center; padding: 1.5rem 1rem; color: var(--rs-text-secondary); font-size: 0.875rem; }
			.state.err { color: #f87171; }
			.entry {
				padding: 0.5rem 0.75rem;
				border-bottom: 1px solid var(--rs-border);
				cursor: pointer;
			}
			.entry:hover { background: var(--rs-bg-hover); }
			.entry-main { display: flex; gap: 0.375rem; align-items: baseline; }
			.verb { font-size: 0.75rem; color: var(--rs-text-secondary); font-weight: 500; }
			.title { font-size: 0.8125rem; color: var(--rs-text-primary); flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
			.entry-meta { display: flex; gap: 0.5rem; align-items: center; margin-top: 0.25rem; }
			.status {
				font-size: 0.65rem; font-weight: 600;
				padding: 0.0625rem 0.375rem; border-radius: 4px;
				background: var(--rs-bg-hover); color: var(--rs-text-secondary);
				text-transform: uppercase; letter-spacing: 0.03em;
			}
			.status-done { background: rgba(34,197,94,0.15); color: #16a34a; }
			.status-in-progress { background: rgba(59,130,246,0.15); color: #2563eb; }
			.status-review { background: rgba(168,85,247,0.15); color: #9333ea; }
			.rel { font-size: 0.7rem; color: var(--rs-text-muted); }
		`;
	}

	private esc(s: string): string {
		const d = document.createElement('div');
		d.textContent = s;
		return d.innerHTML;
	}
}

if (!customElements.get('folk-tasks-activity')) customElements.define('folk-tasks-activity', FolkTasksActivity);

export {};