package main

import (
  "embed"
  "fmt"
  "io/fs"
  "flag"
  "path/filepath"
  "text/template"
  "strings"
  "os"
)

//go:embed templates
var templates embed.FS

type Config struct {
  Name string
}

func WriteTemplate(config Config, from string, to string) error {
  source, err := templates.ReadFile(from)
  if err != nil { return err }

  t := template.Must(template.New(from).Parse(string(source)))

  out, err := os.Create(to)
  if err != nil { return err }

  err = t.Execute(out, config)
  if err != nil { panic(err) }

  return nil
}

func main() {
  var config Config

  flag.StringVar(&config.Name, "name", "", "name of the feature to generate")
  flag.Parse()

  if config.Name == "" {
    fmt.Println("USAGE: fgen -name name")
    return
  }

  feature_dir := filepath.Join("features", config.Name)
  view_dir := filepath.Join("views", config.Name)
  tests_dir := filepath.Join("tests", config.Name)

  err := os.MkdirAll(feature_dir, 0755)
  if err != nil { panic(err) }

  err = os.MkdirAll(view_dir, 0755)
  if err != nil { panic(err) }

  err = os.MkdirAll(tests_dir, 0755)
  if err != nil { panic(err) }

  err = fs.WalkDir(templates, "templates",
    func(path string, d fs.DirEntry, err error) error {
      if err != nil { return err }
      target := filepath.Base(path)

      if !d.IsDir() {
        switch {
        case strings.HasPrefix(path, "templates/views"):
          out_path := filepath.Join("views", config.Name, target)
          err := WriteTemplate(config, path, out_path) 
          if err != nil { panic(err) }
        case strings.HasPrefix(path, "templates/feature"):
          out_path := filepath.Join("features", config.Name, target)
          err := WriteTemplate(config, path, out_path) 
          if err != nil { panic(err) }
        case strings.HasPrefix(path, "templates/tests"):
          out_path := filepath.Join("tests", config.Name, target)
          err := WriteTemplate(config, path, out_path) 
          if err != nil { panic(err) }
        }
      }

      return nil
    })

  if err != nil { panic(err) }
}