import { get_session, get_user, PRECHECK_TABLE, require_user } from '../../../../utils/prechecks.ts';
import { PASSWORD_ENTRIES, PASSWORD_ENTRY } from '../../../../models/password_entry.ts';
import { SESSIONS } from '../../../../models/session.ts';
import { USER, USERS } from '../../../../models/user.ts';
import parse_body from '../../../../utils/bodyparser.ts';
import * as CANNED_RESPONSES from '../../../../utils/canned_responses.ts';

export const PRECHECKS: PRECHECK_TABLE = {};

// GET /api/users/:id - Get single user
PRECHECKS.GET = [get_session, get_user, require_user, (_req: Request, meta: Record<string, any>): Response | undefined => {
	const user_is_self = !!meta.user && !!meta.params && meta.user.id === meta.params.user_id;
	const can_read_self = meta.user?.permissions.includes('self.read');
	const can_read_others = meta.user?.permissions?.includes('users.read');

	const has_permission = can_read_others || (can_read_self && user_is_self);
	if (!has_permission) {
		return CANNED_RESPONSES.permission_denied();
	}
}];
export async function GET(_req: Request, meta: Record<string, any>): Promise<Response> {
	const user_id: string = meta.params?.user_id?.toLowerCase().trim() ?? '';
	const user: USER | null = user_id.length === 49 ? await USERS.get(user_id) : null; // lurid is 49 chars as we use them, eg: "also-play-flow-want-form-wide-thus-work-burn-same"

	if (!user) {
		return Response.json({
			error: {
				message: `Could not locate a user with id: "${user_id}"`,
				cause: 'unknown_user'
			}
		}, {
			status: 404
		});
	}

	return Response.json(user, {
		status: 200
	});
}

// PUT /api/users/:id - Update user
PRECHECKS.PUT = [get_session, get_user, require_user, (req: Request, meta: Record<string, any>): Response | undefined => {
	const user_is_self = !!meta.user && !!meta.params && meta.user.id === meta.params.user_id;
	const can_write_self = meta.user?.permissions.includes('self.write');
	const can_write_others = meta.user?.permissions?.includes('users.write');
	const is_a_test_override = Deno.env.get('DENO_ENV') === 'test' && !!req.headers.get('x-test-override');

	const has_permission = is_a_test_override || can_write_others || (can_write_self && user_is_self);
	if (!has_permission) {
		return CANNED_RESPONSES.permission_denied();
	}
}];
export async function PUT(req: Request, meta: Record<string, any>): Promise<Response> {
	const now = new Date().toISOString();
	const id: string = meta.params.user_id ?? '';
	const existing = await USERS.get(id);

	if (!existing) {
		return Response.json({
			error: {
				message: 'User not found',
				cause: 'unknown_user'
			}
		}, {
			status: 404
		});
	}

	try {
		const body = await parse_body(req);
		const updated: USER = {
			...existing,
			...body,
			timestamps: {
				created: existing.timestamps.created,
				updated: now
			}
		};

		if (Array.isArray(body.permissions) && body.permissions.join(':') !== existing.permissions.join(':')) {
			const user_can_write_others = meta.user.permissions.includes('users.write');
			const is_a_test_override = Deno.env.get('DENO_ENV') === 'test' && req.headers.get('x-test-override');
			const is_allowed = user_can_write_others || is_a_test_override;

			if (!is_allowed) {
				return CANNED_RESPONSES.permission_denied();
			}
		}

		await USERS.update(updated);
		return Response.json(updated, {
			status: 200
		});
	} catch (err) {
		return Response.json({
			error: {
				message: (err as Error)?.message ?? 'Unknown error due to invalid user data.',
				cause: (err as Error)?.cause ?? 'invalid_user_data'
			}
		}, {
			status: 400
		});
	}
}

// DELETE /api/users/:id - Delete user
PRECHECKS.DELETE = [get_session, get_user, require_user, (_req: Request, meta: Record<string, any>): Response | undefined => {
	const user_is_self = !!meta.user && !!meta.params && meta.user.id === meta.params.user_id;
	const can_write_self = meta.user?.permissions.includes('self.write');
	const can_write_others = meta.user?.permissions?.includes('users.write');

	const has_permission = can_write_others || (can_write_self && user_is_self);
	if (!has_permission) {
		return CANNED_RESPONSES.permission_denied();
	}
}];
export async function DELETE(_req: Request, meta: Record<string, any>): Promise<Response> {
	const user_id: string = meta.params.user_id ?? '';

	const user: USER | null = await USERS.get(user_id);
	if (!user) {
		return Response.json({
			error: {
				message: 'Error deleting user.',
				cause: 'unknown_user'
			}
		}, {
			status: 404
		});
	}

	const password_entry: PASSWORD_ENTRY | null = await PASSWORD_ENTRIES.get(user_id);
	if (password_entry) {
		await PASSWORD_ENTRIES.delete(password_entry);
	}

	const sessions = await SESSIONS.find({
		user_id
	});
	for (const session of sessions) {
		await SESSIONS.delete(session);
	}

	await USERS.delete(user);

	return Response.json({
		deleted: true
	}, {
		status: 200
	});
}