import { getDatabaseRouter } from 'koa-mongo-router'
import { IDatabaseRouterOptions } from 'koa-mongo-router/lib/database-router-options'

const databaseRouterOptions: IDatabaseRouterOptions = {
    permissionCheck: async (
        ctx: Koa.Context,
        next: () => Promise<any>,
        database: string,
        collection: string
    ) => {
        // Assumes you have middleware that already adds a user
        if (ctx.state.user == undefined) {
            ctx.status = 401
            return
        }

        // Example of validating if a user has read or write permissions
        switch (ctx.Method) {
            case "GET":
                if (!ctx.state.user.canRead(database, collection)) {
                    ctx.status = 403
                    return
                }
                break

            case "PUT":
            case "POST":
            case "PATCH":
            case "DELETE":
                if (!ctx.state.user.canWrite(database, collection)) {
                    ctx.status = 403
                    return
                }
                break
        }

        // If user haas permission for method, then continue on
        await next()
    }
};

const mongoRouter = getDatabaseRouter(databaseRouterOptions)

const app = new Koa()
    .use(mongoRouter.routes())
    .use(mongoRouter.allowedMethods())