package main

import (
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"sync/atomic"
	"time"
)

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

	// os.ModeSymlink is a bitmask that identifies the symlink mode.
	// If the file mode & os.ModeSymlink is non-zero, the file is a symlink.
	return fileInfo.Mode()&os.ModeSymlink != 0, nil
}

func FileExists(path string) bool {
	_, err := os.Lstat(path)
	return err == nil
}

func NormalizePath(input, workdir string) string {
	input = filepath.Clean(input)
	input = filepath.ToSlash(input)
	input = strings.ReplaceAll(input, "\"", "")

	if !filepath.IsAbs(input) {
		log.Printf("Input '%s' is not absolute, prepending work dir '%s'", input, workdir)
		var err error
		input = filepath.Join(workdir, input)
		input, err = filepath.Abs(input)
		if err != nil {
			log.Printf("Failed to get absolute path for %s%s%s: %s%+v%s", SourceColor, input, DefaultColor, ErrorColor, err, DefaultColor)
			return input
		}
	}

	input = filepath.Clean(input)
	input = filepath.ToSlash(input)
	return input
}

func AreSame(lhs string, rhs string) bool {
	lhsinfo, err := os.Stat(lhs)
	if err != nil {
		return false
	}
	rhsinfo, err := os.Stat(rhs)
	if err != nil {
		return false
	}

	return os.SameFile(lhsinfo, rhsinfo)
}

func ConvertHome(input string) (string, error) {
	if strings.HasPrefix(input, "~/") {
		homedir, err := os.UserHomeDir()
		if err != nil {
			return input, fmt.Errorf("unable to convert ~ to user directory with error %+v", err)
		}

		return strings.Replace(input, "~", homedir, 1), nil
	}
	return input, nil
}

func GetSyncFilesRecursively(input string, output chan string, status chan error) {
	defer close(output)
	defer close(status)

	var filesProcessed int32
	var foldersProcessed int32
	var activeWorkers int32

	progressTicker := time.NewTicker(200 * time.Millisecond)
	defer progressTicker.Stop()

	done := make(chan struct{})
	defer close(done)

	directories := make(chan string, 100000)
	workerPool := make(chan struct{}, 4000)
	directories <- input

	go func() {
		for {
			select {
			case <-progressTicker.C:
				dirCount := len(directories)
				workers := atomic.LoadInt32(&activeWorkers)
				fmt.Printf("\rFiles processed: %d; Folders processed: %d; Active workers: %d; Directory queue: %d",
					atomic.LoadInt32(&filesProcessed),
					atomic.LoadInt32(&foldersProcessed),
					workers,
					dirCount)
			case <-done:
				// Final progress update
				fmt.Printf("\rFiles processed: %d; Folders processed: %d; Completed successfully\n",
					atomic.LoadInt32(&filesProcessed),
					atomic.LoadInt32(&foldersProcessed))
				return
			}
		}
	}()

	allDone := make(chan struct{})

	go func() {
		var wg sync.WaitGroup

		go func() {
			for {
				if atomic.LoadInt32(&activeWorkers) == 0 && len(directories) == 0 {
					time.Sleep(10 * time.Millisecond)
					if atomic.LoadInt32(&activeWorkers) == 0 && len(directories) == 0 {
						close(allDone)
						return
					}
				}
				time.Sleep(50 * time.Millisecond) 
			}
		}()

		for {
			select {
			case directory, ok := <-directories:
				if !ok {
					wg.Wait()
					return
				}

				atomic.AddInt32(&activeWorkers, 1)

				go func(dir string) {
					workerPool <- struct{}{}

					atomic.AddInt32(&foldersProcessed, 1)
					processDirectory(dir, directories, output, &filesProcessed)

					<-workerPool
					atomic.AddInt32(&activeWorkers, -1)
				}(directory)
			}
		}
	}()

	<-allDone

	log.Printf("Files processed: %d; Folders processed: %d",
		atomic.LoadInt32(&filesProcessed),
		atomic.LoadInt32(&foldersProcessed))
}

func processDirectory(directory string, directories chan<- string, output chan<- string, filesProcessed *int32) {
	files, err := os.ReadDir(directory)
	if err != nil {
		log.Printf("Error reading directory %s: %+v", directory, err)
		return
	}

	for _, file := range files {
		if file.IsDir() {
			directories <- filepath.Join(directory, file.Name())
		} else {
			if FileRegex.MatchString(file.Name()) || IsYAMLSyncFile(file.Name()) {
				output <- filepath.Join(directory, file.Name())
			}
			atomic.AddInt32(filesProcessed, 1)
		}
	}
}

func IsYAMLSyncFile(filename string) bool {
	return filename == "sync.yaml" || filename == "sync.yml"
}