package main

import "fmt"
import "time"

// Goroutines Error Handling
// Example with same channel for Return and Error

type ResultError struct {
	res Result
	err error
}

type Result struct {
	ErrorName          string
	NumberOfOccurances int64
}

func runFunc(outputChannel chan ResultError, errorId string) {
	errors  := map[string]Result {
		"1001": {"a is undefined", 245},
		"2001": {"Cannot read property 'data' of undefined", 10352},
	}
	
	time.Sleep(time.Second)
	if r, ok := errors[errorId]; ok {
		outputChannel <- ResultError{res: r, err: nil}
	} else {
		outputChannel <- ResultError{res: Result{}, err: fmt.Errorf("getErrorName: %s errorId not found", errorId)}
	}
}

func getError(errorId string) (r ResultError) {
	outputChannel := make (chan ResultError)
	go runFunc(outputChannel, errorId)
	return <- outputChannel
}

func main() {
	fmt.Println("Using separate channels for error and result")
	errorIds := []string{
		"1001",
		"2001",
		"3001",
	}
	for _, e := range errorIds {
		r := getError(e)
		if r.err != nil {
			fmt.Printf("Failed: %s\n", r.err.Error())
			continue
		}
		fmt.Printf("Name: \"%s\" has occurred \"%d\" times\n", r.res.ErrorName, r.res.NumberOfOccurances)
	}
}