package build

import (
	"fmt"
	"io"
	"log/slog"
	"os"
	"os/exec"
	"strings"
	"text/template"
)

func FileExists(pathValue string) bool {
	_, err := os.Stat(pathValue)
	if os.IsNotExist(err) {
		return false
	}
	if err != nil {
		panic(err)
	}
	return true
}

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

func writeTemplateToFile(tplName, tplFile, outFile string, data *templateData) error {
	fn := template.FuncMap{
		"ucfirst": ucfirst,
	}

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

	var f *os.File
	f, err = os.Create(outFile)
	if err != nil {
		return err
	}

	err = tmpl.Execute(f, *data)
	if err != nil {
		return err
	}

	err = f.Close()
	if err != nil {
		return err
	}
	return nil
}

func deleteFiles(fNames ...string) error {
	for _, fName := range fNames {
		if _, err := os.Stat(fName); !os.IsNotExist(err) {
			err = os.Remove(fName)
			if err != nil {
				return err
			}
		}
	}
	return nil
}

func copyFile(src, dst string) (int64, error) {
	sourceFileStat, err := os.Stat(src)
	if err != nil {
		return 0, err
	}

	if !sourceFileStat.Mode().IsRegular() {
		return 0, fmt.Errorf("%s is not a regular file", src)
	}

	source, err := os.Open(src)
	if err != nil {
		return 0, err
	}
	defer func(source *os.File) {
		err := source.Close()
		if err != nil {
			slog.Error("copyFile", "err", err)
		}
	}(source)

	destination, err := os.Create(dst)
	if err != nil {
		return 0, err
	}
	defer func(destination *os.File) {
		err := destination.Close()
		if err != nil {
			slog.Error("copyFile", "err", err)
		}
	}(destination)
	nBytes, err := io.Copy(destination, source)
	return nBytes, err
}

func checkCommands(commands []string) error {
	for _, commandName := range commands {
		if !commandExists(commandName) {
			return fmt.Errorf("missing command %s", commandName)
		}
		slog.Info("        found", "command", commandName)
	}
	return nil
}

func commandExists(cmd string) bool {
	_, err := exec.LookPath(cmd)
	return err == nil
}