import { Request, Response, NextFunction } from 'express'
import * as chalk from 'chalk'

import { ErrorResponse } from './ErrorResponse'

export class ErrorTreatment {

    private static instance: ErrorTreatment = new ErrorTreatment()

    private handlersMap: Map<string, Function> = new Map()

    private handlerDefault: Function

    logMissingConfigurationError = false

    private constructor() {
        this.handlerDefault = (err: Error, _: Request, res: Response) => {
            console.error(chalk.red(err.stack))
            const message = 'An unexpected error occurred during an execution'

            res.status(500).send(ErrorResponse(message))
        }
    }

    static getInstance() {
        return this.instance
    }

    static register(name: string, callBack: Function, defaultHandle = false) {
        if (defaultHandle) {
            this.instance.handlerDefault = callBack
        } else {
            this.instance.handlersMap.set(name, callBack)
        }
    }

    static getByName(handleName: string): Function | undefined {
        return this.instance.handlersMap.get(handleName)
    }

    static list() {
        return this.instance.handlersMap
    }

    static executeHandler(
        err: any,
        req: Request,
        res: Response,
        next: NextFunction
    ) {
        const callBack = this.instance.handlersMap.get(err.constructor.name)

        if (!callBack) {
            this.instance.handlerDefault(err, req, res, next)

            return
        }

        callBack(err, req, res, next)
    }

    static countRegister(): number {
        return this.instance.handlersMap.size
    }

}