package command

import (
	"io"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"strings"
	"text/template"

	"github.com/manifoldco/promptui"

	rice "github.com/GeertJohan/go.rice"
	"github.com/Masterminds/sprig"
	"github.com/pkg/errors"
	"github.com/urfave/cli/v2"
)

func newProjectCommand() *cli.Command {
	return &cli.Command{
		Name:    "new",
		Aliases: []string{"n"},
		Flags: []cli.Flag{
			&cli.StringFlag{
				Name:     "directory",
				Aliases:  []string{"d"},
				Value:    "./",
				Usage:    "project base directory",
				Required: false,
			},
			&cli.StringFlag{
				Name:     "name",
				Aliases:  []string{"n"},
				Value:    "",
				Usage:    "project name",
				Required: false,
			},
			&cli.StringFlag{
				Name:     "namespace",
				Aliases:  []string{"ns"},
				Value:    "",
				Usage:    "project module namespace",
				Required: false,
			},
			&cli.StringFlag{
				Name:     "type",
				Aliases:  []string{"t"},
				Value:    "",
				Usage:    "project type",
				Required: false,
			},
		},
		Usage:  "generate a new project",
		Action: newProjectAction,
	}
}

func newProjectAction(c *cli.Context) error {
	projectLayoutBox, err := rice.FindBox("../.project-layout")
	if err != nil {
		return err
	}

	destDir := c.String("directory")

	projectName := c.String("name")
	if projectName == "" {
		projectName, err = promptForProjectName()
		if err != nil {
			return err
		}
	}

	projectNamespace := c.String("namespace")
	if projectNamespace == "" {
		projectNamespace, err = promptForProjectNamespace()
		if err != nil {
			return err
		}
	}

	projectType := c.String("type")
	if projectType == "" {
		projectType, err = promptForProjectType()
		if err != nil {
			return err
		}
	}

	data := map[string]interface{}{
		"ProjectName":      projectName,
		"ProjectType":      projectType,
		"ProjectNamespace": projectNamespace,
	}

	return copyTemplateDir(projectLayoutBox, projectType, destDir, data, ".gotpl")
}

func promptForProjectName() (string, error) {
	validate := func(input string) error {
		if input == "" {
			return errors.New("Project name cannot be empty")
		}

		return nil
	}

	prompt := promptui.Prompt{
		Label:    "Project Name",
		Validate: validate,
	}

	return prompt.Run()
}

func promptForProjectNamespace() (string, error) {
	validate := func(input string) error {
		if input == "" {
			return errors.New("Project namespace cannot be empty")
		}

		return nil
	}

	prompt := promptui.Prompt{
		Label:    "Project namespace",
		Validate: validate,
	}

	return prompt.Run()
}

func promptForProjectType() (string, error) {
	prompt := promptui.Select{
		Label: "Project Type",
		Items: []string{"web"},
	}

	_, result, err := prompt.Run()

	return result, err
}

func copyFile(box *rice.Box, src, dst string) (err error) {
	log.Printf("copying file '%s' to '%s'", src, dst)

	in, err := box.Open(src)
	if err != nil {
		return err
	}
	defer in.Close()

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

	defer func() {
		if e := out.Close(); e != nil {
			err = e
		}
	}()

	_, err = io.Copy(out, in)
	if err != nil {
		return err
	}

	err = out.Sync()
	if err != nil {
		return err
	}

	return nil
}

func copyTemplateFile(box *rice.Box, src, dst string, data map[string]interface{}, templateExt string) (err error) {
	if !strings.HasSuffix(src, templateExt) {
		return copyFile(box, src, dst)
	}

	in, err := box.Open(src)
	if err != nil {
		return err
	}
	defer in.Close()

	templateData, err := ioutil.ReadAll(in)
	if err != nil {
		return err
	}

	tmpl, err := template.New(filepath.Base(src)).Funcs(sprig.TxtFuncMap()).Parse(string(templateData))
	if err != nil {
		return err
	}

	dst = strings.TrimSuffix(dst, templateExt)

	log.Printf("templating file from '%s' to '%s'", src, dst)

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

	defer func() {
		if e := out.Close(); e != nil {
			err = e
		}
	}()

	data["SourceFile"] = src
	data["DestFile"] = dst

	if err := tmpl.Execute(out, data); err != nil {
		return err
	}

	return nil

}

func copyTemplateDir(box *rice.Box, baseDir string, dst string, data map[string]interface{}, templateExt string) error {
	baseDir = filepath.Clean(baseDir)
	dst = filepath.Clean(dst)

	_, err := os.Stat(dst)
	if err != nil && !os.IsNotExist(err) {
		return err
	}

	if err := os.MkdirAll(dst, 0755); err != nil {
		return errors.Wrapf(err, "could not create directory '%s'", dst)
	}

	err = box.Walk(baseDir, func(srcPath string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		if srcPath == baseDir {
			return nil
		}

		relSrcPath, err := filepath.Rel(baseDir, srcPath)
		if err != nil {
			return err
		}

		dstPath := filepath.Join(dst, relSrcPath)

		if info.IsDir() {
			log.Printf("creating dir '%s'", dstPath)
			if err := os.MkdirAll(dstPath, 0755); err != nil {
				return errors.Wrapf(err, "could not create directory '%s'", dstPath)
			}

			return nil
		}

		err = copyTemplateFile(box, srcPath, dstPath, data, templateExt)
		if err != nil {
			return errors.Wrapf(err, "could not copy file '%s'", srcPath)
		}

		return nil
	})

	if err != nil {
		return errors.Wrapf(err, "could not walk source directory '%s'", baseDir)
	}

	return nil
}