package util

import (
	"os"
	"os/exec"

	"github.com/skratchdot/open-golang/open"
)

// OpenBrowser opens the URL in a browser, respecting the BROWSER environment variable.
func OpenBrowser(url string) error {
	if browser := os.Getenv("BROWSER"); browser != "" {
		return exec.Command(browser, url).Start()
	}
	return open.Run(url)
}

// SliceDiff returns the elements in slice `x` that are not in slice `y`
func SliceDiff(x, y []string) []string {
	mapY := make(map[string]struct{}, len(y))
	for _, val := range y {
		mapY[val] = struct{}{}
	}
	var diff []string
	for _, val := range x {
		if _, found := mapY[val]; !found {
			diff = append(diff, val)
		}
	}
	return diff
}

// FileExists returns true if specified file exists
func FileExists(path string) bool {
	_, err := os.Stat(path)
	return err == nil
}

/// Bool helpers

// True returns a *bool whose underlying value is true.
func True() *bool {
	t := true
	return &t
}

// False returns a *bool whose underlying value is false.
func False() *bool {
	t := false
	return &t
}

// Return bool representation if the bool pointer is non-nil, otherwise returns false
func ReturnBoolWithDefaultFalse(b *bool) bool {
	if b != nil {
		return *b
	} else {
		return false
	}

}

// Return bool representation if the bool pointer is non-nil, otherwise returns true
func ReturnBoolWithDefaultTrue(b *bool) bool {
	if b != nil {
		return *b
	} else {
		return true
	}

}