import { error } from '@sveltejs/kit';
import type { RequestHandler } from './$types.js';
import { withTenant } from '$lib/server/rls.js';
import { requireAuth } from '$lib/server/guards.js';
import { canViewBoard } from '$lib/server/permissions.js';
import { readFile, unlink } from 'fs/promises';
import { json } from '@sveltejs/kit';
import { broadcast } from '$lib/server/realtime.js';
import { logActivity } from '$lib/server/activity.js';

export const GET: RequestHandler = async ({ params, locals }) => {
	const tenant = locals.tenant;
	if (!tenant) throw error(400, 'Unknown tenant');

	const attachment = await withTenant(tenant.id, async (tx) => {
		const att = await tx.attachment.findFirst({
			where: { id: params.attachmentId },
			include: {
				card: {
					include: {
						column: {
							include: {
								board: {
									select: { tenantId: true, visibility: true, members: true }
								}
							}
						}
					}
				}
			}
		});
		if (!att) throw error(404, 'Attachment not found');
		if (att.card.column.board.tenantId !== tenant.id) throw error(404, 'Attachment not found');

		if (!canViewBoard(locals.user, att.card.column.board.visibility, att.card.column.board.members)) {
			if (!locals.user) throw error(401, 'Not authenticated');
			throw error(403, 'Access denied');
		}

		return att;
	});

	const buffer = await readFile(attachment.filepath);
	return new Response(buffer, {
		headers: {
			'Content-Type': attachment.mimetype,
			'Content-Disposition': `attachment; filename="${attachment.filename}"`,
			'Content-Length': String(attachment.size)
		}
	});
};

export const DELETE: RequestHandler = async ({ params, request, locals }) => {
	const tenant = locals.tenant;
	if (!tenant) throw error(400, 'Unknown tenant');
	requireAuth(locals.user);

	const deleted = await withTenant(tenant.id, async (tx) => {
		const att = await tx.attachment.findFirst({
			where: { id: params.attachmentId },
			include: {
				card: {
					include: {
						column: {
							include: {
								board: { select: { id: true, tenantId: true, members: true } }
							}
						}
					}
				}
			}
		});
		if (!att) throw error(404, 'Attachment not found');
		if (att.card.column.board.tenantId !== tenant.id) throw error(404, 'Attachment not found');

		// Check board editor permission
		const { canEditBoard } = await import('$lib/server/permissions.js');
		if (!canEditBoard(locals.user, att.card.column.board.members)) {
			throw error(403, 'Access denied');
		}

		await logActivity(tx, {
			boardId: att.card.column.board.id,
			userId: locals.user!.id,
			action: 'attachment.deleted',
			cardId: att.cardId,
			metadata: { filename: att.filename }
		});

		await tx.attachment.delete({ where: { id: params.attachmentId } });

		try {
			await unlink(att.filepath);
		} catch {
			// File may already be gone
		}

		return { boardId: att.card.column.board.id, cardId: att.cardId, columnId: att.card.columnId };
	});

	const socketId = request.headers.get('X-Socket-ID');
	broadcast(deleted.boardId, 'card:updated', { cardId: deleted.cardId, columnId: deleted.columnId, socketId });
	broadcast(deleted.boardId, 'activity:new', { boardId: deleted.boardId, cardId: deleted.cardId, socketId });

	return json({ ok: true });
};