import { NextFunction, Request, Response } from 'express'
import Joi from 'joi'
import { CustomError, NotFoundError } from './error'
import { pick } from './utilities'

export const errorHandler = async (
    err: any,
    _req: Request,
    res: Response,
    // eslint-disable-next-line
    _next: NextFunction
) => {
    if ('statusCode' in err) {
        return res.status(err.statusCode).json({
            message: err.message,
            error: true,
            data: null,
        })
    }
    return res.status(500).json({
        message: err.message,
        error: true,
        data: null,
        error_stack:
            process.env.NODE_ENV === 'production' ? undefined : err.stack,
    })
}

export const notFoundHandler = async (
    _req: Request,
    _res: Response,
    next: NextFunction
) => {
    return next(new NotFoundError())
}

export const validate =
    (schema: any) => (req: Request, _res: Response, next: NextFunction) => {
        // Request body should be JSON, if present
        if (Object.keys(req.body).length !== 0 && !req.is('application/json')) {
            return next(new Error('Supports JSON request body only'))
        }

        // cherry-pick from the input schema ["params", "query", "body"] fields
        const validSchema = pick(schema, ['params', 'query', 'body'])

        // cherry-pick from the request object ["params", "query", "body"] fields
        const object = pick(req, Object.keys(validSchema))

        // Compile schema to Joi schema object and validate the request object
        const { value, error } = Joi.compile(validSchema)
            .prefs({ errors: { label: 'key' } })
            .validate(object)

        // If validation fails throw 400 Bad Request error
        if (error) {
            const errorMessage = error.details
                .map((details) => details.message)
                .join(', ')
            return next(
                new CustomError({
                    message: errorMessage,
                    statusCode: 400,
                })
            )
        }

        // Update validated fields in request with returned value
        Object.assign(req, value)

        return next()
    }