package fileutil

import (
	"bufio"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"

	"github.com/alexmullins/zip"
)

func AppendFile(path string, line string) {
	file, _ := os.OpenFile(path, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
	defer file.Close()
	file.WriteString(line + "\n")
}

func Tree(path string, prefix string, isFirstDir ...bool) string {
	var sb strings.Builder

	files, _ := ioutil.ReadDir(path)
	for i, file := range files {
		isLast := i == len(files)-1
		var pointer string
		if isLast {
			pointer = prefix + "└── "
		} else {
			pointer = prefix + "├── "
		}
		if isFirstDir == nil {
			pointer = prefix
		}
		if file.IsDir() {
			fmt.Fprintf(&sb, "%s📂 - %s\n", pointer, file.Name())
			if isLast {
				sb.WriteString(Tree(filepath.Join(path, file.Name()), prefix+"    ", false))
			} else {
				sb.WriteString(Tree(filepath.Join(path, file.Name()), prefix+"│   ", false))
			}
		} else {
			fmt.Fprintf(&sb, "%s📄 - %s (%.2f kb)\n", pointer, file.Name(), float64(file.Size())/1024)
		}
	}

	tree := sb.String()
	if len(tree) > 4090 {
		tree = "Too many files to display"
	}
	return tree
}

func Zip(dirPath string, zipName string) error {
	zipFile, err := os.Create(zipName)
	if err != nil {
		return err
	}
	defer zipFile.Close()

	zipWriter := zip.NewWriter(zipFile)
	defer zipWriter.Close()

	err = filepath.Walk(dirPath, func(filePath string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		if info.IsDir() {
			return nil
		}

		relPath, err := filepath.Rel(dirPath, filePath)
		if err != nil {
			return err
		}

		zipEntry, err := zipWriter.Create(relPath)
		if err != nil {
			return err
		}

		file, err := os.Open(filePath)
		if err != nil {
			return err
		}
		defer file.Close()

		_, err = io.Copy(zipEntry, file)
		if err != nil {
			return err
		}

		return nil
	})

	if err != nil {
		return err
	}

	return nil
}

func ZipWithPassword(dirPath string, zipName string, password string) error {
	zipFile, err := os.Create(zipName)
	if err != nil {
		return err
	}
	defer zipFile.Close()

	zipWriter := zip.NewWriter(zipFile)
	defer zipWriter.Close()

	err = filepath.Walk(dirPath, func(filePath string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		if info.IsDir() {
			return nil
		}

		relPath, err := filepath.Rel(dirPath, filePath)
		if err != nil {
			return err
		}

		zipEntry, err := zipWriter.Encrypt(relPath, password)
		if err != nil {
			return err
		}

		file, err := os.Open(filePath)
		if err != nil {
			return err
		}
		defer file.Close()

		_, err = io.Copy(zipEntry, file)
		if err != nil {
			return err
		}

		return nil
	})

	if err != nil {
		return err
	}

	return nil
}

func Copy(src, dst string) (err error) {
	file, err := os.Stat(src)
	if err != nil {
		return err
	}

	if file.IsDir() {
		err = CopyDir(src, dst)
	} else {
		err = CopyFile(src, dst)
	}

	return
}

func CopyFile(src, dst string) (err error) {
	in, err := os.Open(src)
	if err != nil {
		return
	}
	defer in.Close()

	out, err := os.Create(dst)
	if err != nil {
		return
	}
	defer func() {
		if e := out.Close(); e != nil {
			err = e
		}
	}()

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

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

	si, err := os.Stat(src)
	if err != nil {
		return
	}
	err = os.Chmod(dst, si.Mode())
	if err != nil {
		return
	}

	return
}

func CopyDir(src string, dst string) (err error) {
	src = filepath.Clean(src)
	dst = filepath.Clean(dst)

	si, err := os.Stat(src)
	if err != nil {
		return err
	}
	if !si.IsDir() {
		return fmt.Errorf("source is not a directory")
	}

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

	err = os.MkdirAll(dst, si.Mode())
	if err != nil {
		return
	}

	entries, err := ioutil.ReadDir(src)
	if err != nil {
		return
	}

	for _, entry := range entries {
		srcPath := filepath.Join(src, entry.Name())
		dstPath := filepath.Join(dst, entry.Name())

		if entry.IsDir() {
			err = CopyDir(srcPath, dstPath)
			if err != nil {
				return
			}
		} else {
			if entry.Mode()&os.ModeSymlink != 0 {
				continue
			}

			err = CopyFile(srcPath, dstPath)
			if err != nil {
				return
			}
		}
	}

	return
}

func IsDir(path string) bool {
	fileInfo, err := os.Stat(path)
	if err != nil {
		return false
	}
	return fileInfo.IsDir()
}

func Exists(path string) bool {
	_, err := os.Stat(path)
	return !os.IsNotExist(err)
}

func ReadFile(path string) (string, error) {
	bytes, err := os.ReadFile(path)
	if err != nil {
		return "", err
	}
	return string(bytes), nil
}

func ReadLines(path string) ([]string, error) {
	f, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer f.Close()

	result := make([]string, 0)
	buf := bufio.NewReader(f)

	for {
		line, _, err := buf.ReadLine()
		l := string(line)
		if err == io.EOF {
			break
		}
		if err != nil {
			continue
		}
		result = append(result, l)
	}

	return result, nil
}