package app

import (
	"context"
	"errors"
	"fmt"
)

type Runner struct {
	Name string
	Run  func(context.Context) error
}

type runnerResult struct {
	name string
	err  error
}

func RunConcurrent(ctx context.Context, runners ...Runner) error {
	if len(runners) == 0 {
		return nil
	}

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()
	results := make(chan runnerResult, len(runners))
	for _, runner := range runners {
		runner := runner
		go func() {
			results <- runnerResult{name: runner.Name, err: runner.Run(ctx)}
		}()
	}

	var resultErr error
	for range runners {
		result := <-results
		if result.err != nil {
			resultErr = errors.Join(resultErr, fmt.Errorf("%s flow: %w", result.name, result.err))
			cancel()
		}
	}
	return resultErr
}