import { Request, Response, NextFunction } from 'express';
import { z } from 'zod';
import { db } from '@server/db';
import { sites, orgs, exitNodes, userSites, roleSites } from '@server/db/schema';
import response from "@server/utils/response";
import HttpCode from '@server/types/HttpCode';
import createHttpError from 'http-errors';
import { sql, eq, and, or, inArray } from 'drizzle-orm';
import { ActionsEnum, checkUserActionPermission } from '@server/auth/actions';
import logger from '@server/logger';

const listSitesParamsSchema = z.object({
    orgId: z.string().optional().transform(Number).pipe(z.number().int().positive()),
});

const listSitesSchema = z.object({
    limit: z.string().optional().transform(Number).pipe(z.number().int().positive().default(10)),
    offset: z.string().optional().transform(Number).pipe(z.number().int().nonnegative().default(0)),
});

export async function listSites(req: Request, res: Response, next: NextFunction): Promise<any> {
    try {
        const parsedQuery = listSitesSchema.safeParse(req.query);
        if (!parsedQuery.success) {
            return next(createHttpError(HttpCode.BAD_REQUEST, parsedQuery.error.errors.map(e => e.message).join(', ')));
        }
        const { limit, offset } = parsedQuery.data;


        const parsedParams = listSitesParamsSchema.safeParse(req.params);
        if (!parsedParams.success) {
            return next(createHttpError(HttpCode.BAD_REQUEST, parsedParams.error.errors.map(e => e.message).join(', ')));
        }
        const { orgId } = parsedParams.data;

        // Check if the user has permission to list sites
        const hasPermission = await checkUserActionPermission(ActionsEnum.listSites, req);
        if (!hasPermission) {
            return next(createHttpError(HttpCode.FORBIDDEN, 'User does not have permission to list sites'));
        }

        if (orgId && orgId !== req.userOrgId) {
            return next(createHttpError(HttpCode.FORBIDDEN, 'User does not have access to this organization'));
        }

        const accessibleSites = await db
            .select({ siteId: sql<number>`COALESCE(${userSites.siteId}, ${roleSites.siteId})` })
            .from(userSites)
            .fullJoin(roleSites, eq(userSites.siteId, roleSites.siteId))
            .where(
                or(
                    eq(userSites.userId, req.user!.id),
                    eq(roleSites.roleId, req.userOrgRoleId!)
                )
            );

        const accessibleSiteIds = accessibleSites.map(site => site.siteId);

        let baseQuery: any = db
            .select({
                siteId: sites.siteId,
                name: sites.name,
                subdomain: sites.subdomain,
                pubKey: sites.pubKey,
                subnet: sites.subnet,
                megabytesIn: sites.megabytesIn,
                megabytesOut: sites.megabytesOut,
                orgName: orgs.name,
                exitNodeName: exitNodes.name,
            })
            .from(sites)
            .leftJoin(orgs, eq(sites.orgId, orgs.orgId))
            .where(inArray(sites.siteId, accessibleSiteIds));

        let countQuery: any = db
            .select({ count: sql<number>`cast(count(*) as integer)` })
            .from(sites)
            .where(inArray(sites.siteId, accessibleSiteIds));

        if (orgId) {
            baseQuery = baseQuery.where(eq(sites.orgId, orgId));
            countQuery = countQuery.where(eq(sites.orgId, orgId));
        }

        const sitesList = await baseQuery.limit(limit).offset(offset);
        const totalCountResult = await countQuery;
        const totalCount = totalCountResult[0].count;

        return response(res, {
            data: {
                sites: sitesList,
                pagination: {
                    total: totalCount,
                    limit,
                    offset,
                },
            },
            success: true,
            error: false,
            message: "Sites retrieved successfully",
            status: HttpCode.OK,
        });
    } catch (error) {
        logger.error(error);
        return next(createHttpError(HttpCode.INTERNAL_SERVER_ERROR, "An error occurred..."));
    }
}