package spm

import (
	"archive/tar"
	"compress/gzip"
	"fmt"
	"io"
	"math/rand"
	"os"
	"path/filepath"
)

func DecompressToTemp(filePath string) (string, error) {
	UpdateProgress(0, "Decompressing package")

	// 1) Base temp dir
	baseTempDir := GetTempDir()

	// 2) Create a unique subfolder inside the base temp dir
	subfolderName := fmt.Sprintf("spm_decompress_%d", rand.Intn(1000000))
	decompressDir := filepath.Join(baseTempDir, subfolderName)
	if err := os.MkdirAll(decompressDir, 0755); err != nil {
		return "", fmt.Errorf("failed to create decompress dir: %w", err)
	}

	// 3) Open the tar.gz file
	file, err := os.Open(filePath)
	if err != nil {
		return "", err
	}
	defer file.Close()

	gzr, err := gzip.NewReader(file)
	if err != nil {
		return "", err
	}
	defer gzr.Close()

	tarReader := tar.NewReader(gzr)

	// 4) Count total files
	var totalFiles, processedFiles int
	for {
		_, err := tarReader.Next()
		if err == io.EOF {
			break
		}
		if err != nil {
			return "", err
		}
		totalFiles++
	}

	// 5) Reset file position and tar reader
	if _, err := file.Seek(0, io.SeekStart); err != nil {
		return "", err
	}
	if err := gzr.Reset(file); err != nil {
		return "", err
	}
	tarReader = tar.NewReader(gzr)

	// 6) Extract into `decompressDir`
	for {
		header, err := tarReader.Next()
		if err == io.EOF {
			break
		}
		if err != nil {
			return "", err
		}

		targetPath := filepath.Join(decompressDir, header.Name)
		switch header.Typeflag {
		case tar.TypeDir:
			if err := os.MkdirAll(targetPath, os.FileMode(header.Mode)); err != nil {
				return "", err
			}
		case tar.TypeReg:
			outFile, err := os.Create(targetPath)
			if err != nil {
				return "", err
			}
			if _, err := io.Copy(outFile, tarReader); err != nil {
				outFile.Close()
				return "", err
			}
			outFile.Close()
		}

		processedFiles++
		UpdateProgress(int(float64(processedFiles)/float64(totalFiles)*100), "Decompressing package")
	}

	UpdateProgress(100, "Package decompressed")
	return decompressDir, nil
}

func MoveFilesToInstallDir(tempDir, installDir, pkgType string) error {
	// Ensure tempDir exists before processing
	if _, err := os.Stat(tempDir); os.IsNotExist(err) {
		return fmt.Errorf("tempDir does not exist: %s", tempDir)
	}

	// If the package type is "browser", set the subdirectory to "browser"
	if pkgType == "browser" {
		installDir = filepath.Join(installDir, "browser")
	}

	// Count total files to copy
	var totalFiles, copiedFiles int
	err := filepath.Walk(tempDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() {
			totalFiles++
		}
		return nil
	})
	if err != nil {
		return err
	}

	// Copy files and track progress
	err = filepath.Walk(tempDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

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

		targetPath := filepath.Join(installDir, relPath)
		if info.IsDir() {
			// Create directories in the install directory
			if err := os.MkdirAll(targetPath, os.ModePerm); err != nil {
				return err
			}
		} else {
			// Copy files to the install directory
			if err := copyFile(path, targetPath); err != nil {
				return err
			}
			copiedFiles++
			UpdateProgress(int(float64(copiedFiles)/float64(totalFiles)*100), "Copying files to install directory")
		}
		return nil
	})

	if err != nil {
		return err
	}

	// Clean up temporary directory
	UpdateProgress(100, "Cleaning up temporary files")
	return os.RemoveAll(tempDir)
}

// copyFile copies the contents of the source file to the destination file.
func copyFile(src, dst string) error {
	sourceFile, err := os.Open(src)
	if err != nil {
		return err
	}
	defer sourceFile.Close()

	// Create the destination file
	destinationFile, err := os.Create(dst)
	if err != nil {
		return err
	}
	defer destinationFile.Close()

	// Copy the file content
	if _, err := io.Copy(destinationFile, sourceFile); err != nil {
		return err
	}

	// Preserve file permissions
	info, err := sourceFile.Stat()
	if err != nil {
		return err
	}
	return os.Chmod(dst, info.Mode())
}

// FinalizeInstall finalizes the installation by updating installed.ini.
func FinalizeInstall(packageName, release, version, arch, osName string) error {
	installDir, err := GetDefaultInstallDir()
	if err != nil {
		return err
	}
	pkgInfo := AppIndexEntry{
		Name:    packageName,
		Version: version,
		Release: release,
		Arch:    arch,
		OS:      osName,
	}
	return UpdateInstalledPackage(installDir, pkgInfo)
}