import { db } from '$lib/db/schema';
import { upsertContext } from '$lib/db/repositories';
import type { AgendaContext } from '@ka-note/shared';

export interface MentionItem {
	context: AgendaContext;
	mentionName: string;
	icon: string;
	insertText: string;
}

export interface CreateOption {
	type: 'person' | 'project' | 'company';
	label: string;
	query: string;
}

export function extractMentionName(ctx: AgendaContext): string {
	return ctx.name.replace(/^(Person|Project|Firma)\s+/, '');
}

export function extractAbbreviation(ctx: AgendaContext): string | undefined {
	if (ctx.type !== 'person') return undefined;
	return (ctx.meta as { abbreviation?: string } | null)?.abbreviation || undefined;
}

export function quoteMention(prefix: string, name: string): string {
	return name.includes(' ') ? `${prefix}"${name}"` : `${prefix}${name}`;
}

function buildMentionItem(ctx: AgendaContext): MentionItem {
	const mentionName = extractMentionName(ctx);
	const icon = ctx.type === 'company' ? '\u{1F3E2}' : ctx.type === 'person' ? '\u{1F464}' : '\u{1F4C1}';
	const insertText = ctx.type === 'company'
		? quoteMention('@F:', mentionName)
		: ctx.type === 'person'
			? quoteMention('@', mentionName)
			: quoteMention('@P:', mentionName);
	return { context: ctx, mentionName, icon, insertText };
}

export async function fetchMentionItems(query: string, mode: '@' | '->' = '@'): Promise<{ items: MentionItem[]; createOptions: CreateOption[] }> {
	const all = await db.contexts
		.filter(c => !c.deletedAt && !c.archivedAt && (c.type === 'person' || c.type === 'project' || c.type === 'company'))
		.toArray();

	const q = query.replace(/_/g, ' ').toLowerCase();

	if (mode === '->') {
		// Arrow mode: only persons with an abbreviation, match against abbreviation OR full name
		const items = all
			.filter(c => c.type === 'person')
			.flatMap(c => {
				const abbr = extractAbbreviation(c);
				if (!abbr) return [];
				const fullName = extractMentionName(c).toLowerCase();
				if (!abbr.toLowerCase().includes(q) && !fullName.includes(q)) return [];
				return [{
					context: c,
					mentionName: `${abbr} – ${extractMentionName(c)}`,
					icon: '\u{1F464}',
					insertText: `-> ${abbr}`,
				} as MentionItem];
			})
			.slice(0, 8);
		return { items, createOptions: [] };
	}

	const items = all
		.map(buildMentionItem)
		.filter(m => m.mentionName.toLowerCase().includes(q))
		.slice(0, 8);

	const exactMatch = items.some(m => m.mentionName.toLowerCase() === q);
	const createOptions: CreateOption[] = [];
	if (query.length > 0 && !exactMatch) {
		const displayName = query.replace(/_/g, ' ');
		createOptions.push(
			{ type: 'person', label: `+ Person "${displayName}" anlegen`, query },
			{ type: 'project', label: `+ Projekt "${displayName}" anlegen`, query },
			{ type: 'company', label: `+ Firma "${displayName}" anlegen`, query }
		);
	}

	return { items, createOptions };
}

export async function createMentionContext(opt: CreateOption): Promise<string> {
	const name = opt.query.replace(/_/g, ' ');
	const slug = name.toLowerCase().replace(/\s+/g, '-');
	const id = opt.type === 'company' ? `f-${slug}` : opt.type === 'person' ? `u-${slug}` : `p-${slug}`;
	const contextName = opt.type === 'company' ? `Firma ${name}` : opt.type === 'person' ? `Person ${name}` : `Project ${name}`;

	const meta = opt.type === 'company'
		? { website: '', address: '' }
		: opt.type === 'person'
			? { fullName: '', email: '', phone: '', duSince: '' }
			: { status: '', owner: '', links: '' };

	await upsertContext({
		id,
		name: contextName,
		type: opt.type,
		sortOrder: 99,
		meta
	});

	return id;
}

export function renderDropdown(
	container: HTMLDivElement,
	items: MentionItem[],
	createOptions: CreateOption[],
	selectedIndex: number,
	onSelect: (index: number) => void,
	onHover: (index: number) => void
): void {
	container.innerHTML = '';

	items.forEach((item, i) => {
		const row = document.createElement('div');
		row.className = 'mention-item' + (i === selectedIndex ? ' mention-item-active' : '');
		row.textContent = `${item.icon} ${item.mentionName}`;
		row.classList.add(item.context.type === 'company' ? 'mention-company' : item.context.type === 'person' ? 'mention-person' : 'mention-project');
		row.addEventListener('pointerdown', (e) => {
			e.preventDefault();
			e.stopPropagation();
			console.log('[mention] pointerdown item', i, item.mentionName);
			onSelect(i);
		});
		row.addEventListener('mouseenter', () => onHover(i));
		container.appendChild(row);
	});

	createOptions.forEach((opt, i) => {
		const idx = items.length + i;
		const row = document.createElement('div');
		row.className = 'mention-item mention-create' + (idx === selectedIndex ? ' mention-item-active' : '');
		row.textContent = opt.label;
		row.addEventListener('pointerdown', (e) => {
			e.preventDefault();
			e.stopPropagation();
			console.log('[mention] pointerdown create', idx, opt.label);
			onSelect(idx);
		});
		row.addEventListener('mouseenter', () => onHover(idx));
		container.appendChild(row);
	});
}