package testutils

import (
	"bytes"
	"fmt"
	"log"
	"os"
	"path"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
	"text/template"
)

// GetHomeEnvVariableName Helper function to obtain the home directory on different systems.
// Based on os.UserHomeDir().
func GetHomeEnvVariableName() string {
	env := "HOME"
	switch runtime.GOOS {
	case "windows":
		env = "USERPROFILE"
	case "plan9":
		env = "home"
	}
	return env
}

// CreateTemporaryHome create temporary home and initialize the credentials file as well
func CreateTemporaryHome(createValidCredentialsFile bool, t *testing.T) string {
	// create a temporary file
	tempHome, err := os.MkdirTemp("", "tempHome")
	if err != nil {
		t.Fatalf("Failed to create temporary home directory: %v", err)
	}

	// create credentials file in temp directory
	stackitFolder := path.Join(tempHome, ".stackit")
	if err := os.Mkdir(stackitFolder, 0o750); err != nil {
		t.Fatalf("Failed to create stackit folder: %v", err)
	}

	filePath := path.Join(stackitFolder, "credentials.json")
	file, err := os.Create(filePath)
	if err != nil {
		t.Fatalf("Failed to create credentials file: %v", err)
	}
	defer func() {
		if err := file.Close(); err != nil {
			t.Fatalf("Error while closing the file: %v", err)
		}
	}()

	// Define content, default = invalid token
	token := "foo_token"
	if createValidCredentialsFile {
		token = GetTestProjectServiceAccountJson("")
	}
	if _, err = file.WriteString(token); err != nil {
		t.Fatalf("Error writing to file: %v", err)
	}

	return tempHome
}

// SetTemporaryHome Function to overwrite the home folder
func SetTemporaryHome(tempHomePath string) {
	env := GetHomeEnvVariableName()
	if err := os.Setenv(env, tempHomePath); err != nil {
		fmt.Printf("Error setting temporary home directory %v", err)
	}
}

// CleanupTemporaryHome cleanup the temporary home and reset the environment variable
func CleanupTemporaryHome(tempHomePath string, t *testing.T) {
	if err := os.RemoveAll(tempHomePath); err != nil {
		t.Fatalf("Error cleaning up temporary folder: %v", err)
	}
	originalHomeDir, err := os.UserHomeDir()
	if err != nil {
		t.Fatalf("Failed to restore home directory back to normal: %v", err)
	}
	// revert back to original home folder
	env := GetHomeEnvVariableName()
	if err := os.Setenv(env, originalHomeDir); err != nil {
		fmt.Printf("Error resetting temporary home directory %v", err)
	}
}

func ucFirst(s string) string {
	if s == "" {
		return ""
	}
	return strings.ToUpper(s[:1]) + s[1:]
}

func StringFromTemplateMust(tplFile string, data any) string {
	res, err := StringFromTemplate(tplFile, data)
	if err != nil {
		log.Fatalln(err)
	}
	return res
}

func StringFromTemplate(tplFile string, data any) (string, error) {
	fn := template.FuncMap{
		"ucfirst": ucFirst,
	}

	file := filepath.Base(tplFile)

	tmpl, err := template.New(file).Funcs(fn).ParseFiles(tplFile)
	if err != nil {
		return "", err
	}

	tplBuf := &bytes.Buffer{}

	err = tmpl.Execute(tplBuf, data)
	if err != nil {
		return "", err
	}

	return tplBuf.String(), nil
}

func ResStr(prefix, resource, name string) string {
	return fmt.Sprintf("%s_%s.%s", prefix, resource, name)
}