import type { Handle } from '@sveltejs/kit';
import { redirect } from '@sveltejs/kit';
import { verifyAccessToken } from '$lib/server/services/authService.js';
import * as authService from '$lib/server/services/authService.js';
import * as userService from '$lib/server/services/userService.js';
import * as apiTokenService from '$lib/server/services/apiTokenService.js';
import { extractBearerToken } from '$lib/server/middleware/authenticate.js';
import { isBoardGuestAccessible } from '$lib/server/middleware/guestAccess.js';
import { initBackupScheduler } from '$lib/server/jobs/backupScheduler.js';
import {
	clearSessionCookies,
	rotateSessionCookies,
	COOKIE_NAMES
} from '$lib/server/utils/sessionCookies.js';

// Initialize backup scheduler on server startup
initBackupScheduler();

const PUBLIC_PATHS = ['/login', '/register', '/auth/', '/api/health', '/api/onboarding', '/status'];

function isPublicPath(pathname: string): boolean {
	return PUBLIC_PATHS.some((path) => pathname === path || pathname.startsWith(path));
}

export const handle: Handle = async ({ event, resolve }) => {
	event.locals.user = null;
	event.locals.session = null;
	event.locals.apiTokenScope = null;

	const accessToken = event.cookies.get(COOKIE_NAMES.ACCESS_TOKEN);
	const refreshToken = event.cookies.get(COOKIE_NAMES.REFRESH_TOKEN);
	const sessionId = event.cookies.get(COOKIE_NAMES.SESSION_ID);

	if (accessToken) {
		try {
			const payload = verifyAccessToken(accessToken);
			const user = await userService.findById(payload.userId);
			event.locals.user = {
				id: user.id,
				email: user.email,
				displayName: user.displayName,
				role: user.role as 'admin' | 'user'
			};
			event.locals.session = {
				id: sessionId ?? payload.userId,
				expiresAt: new Date(Date.now() + 15 * 60 * 1000)
			};
		} catch {
			// Access token invalid/expired — try refresh below
		}
	}

	// If no valid session but refresh + session id exist, try to rotate.
	if (!event.locals.user && refreshToken && sessionId) {
		try {
			const session = await authService.validateSession(sessionId, refreshToken);
			if (session) {
				const user = await userService.findById(session.userId);
				await rotateSessionCookies(
					event.cookies,
					session.id,
					{ id: user.id, email: user.email, role: user.role },
					session.rememberMe
				);

				event.locals.user = {
					id: user.id,
					email: user.email,
					displayName: user.displayName,
					role: user.role as 'admin' | 'user'
				};
				event.locals.session = {
					id: session.id,
					expiresAt: new Date(Date.now() + 15 * 60 * 1000)
				};
			}
		} catch {
			clearSessionCookies(event.cookies);
		}
	}

	// Bearer API tokens (no session cookie).
	if (!event.locals.user) {
		const bearerToken = extractBearerToken(event);
		if (bearerToken) {
			try {
				const tokenResult = await apiTokenService.validateToken(bearerToken);
				if (tokenResult) {
					const user = await userService.findById(tokenResult.userId);
					event.locals.user = {
						id: user.id,
						email: user.email,
						displayName: user.displayName,
						role: user.role as 'admin' | 'user'
					};
					event.locals.session = {
						id: user.id,
						expiresAt: new Date(Date.now() + 15 * 60 * 1000)
					};
					event.locals.apiTokenScope = tokenResult.scope as 'read' | 'write' | 'admin';
				}
			} catch {
				// API token validation failed — continue as unauthenticated
			}
		}
	}

	const { pathname } = event.url;

	// API token scope enforcement
	if (event.locals.apiTokenScope) {
		const method = event.request.method;
		const scope = event.locals.apiTokenScope;
		const isWriteMethod =
			method === 'POST' || method === 'PATCH' || method === 'PUT' || method === 'DELETE';
		const isAdminPath = pathname.startsWith('/api/admin') || pathname.startsWith('/admin');

		if (scope === 'read' && isWriteMethod) {
			return new Response(
				JSON.stringify({
					success: false,
					data: null,
					error: 'API token scope "read" does not allow write operations'
				}),
				{ status: 403, headers: { 'Content-Type': 'application/json' } }
			);
		}
		if (scope !== 'admin' && isAdminPath) {
			return new Response(
				JSON.stringify({
					success: false,
					data: null,
					error: 'API token scope does not allow admin operations'
				}),
				{ status: 403, headers: { 'Content-Type': 'application/json' } }
			);
		}
	}

	if (!event.locals.user && !isPublicPath(pathname)) {
		const boardMatch = pathname.match(/^\/boards\/([^/]+)/);
		if (boardMatch) {
			const boardId = boardMatch[1];
			const isGuestAccessible = await isBoardGuestAccessible(boardId);
			if (isGuestAccessible) {
				return resolve(event);
			}
		}

		if (pathname === '/') {
			return resolve(event);
		}

		throw redirect(302, '/login');
	}

	return resolve(event);
};