package installer

import (
	"context"
	"fmt"
	"io"
	"path/filepath"
)

// DownloadAndExtract downloads a file and extracts it to the target directory
// This is a common pattern used across Windows and macOS installers.
// The downloaded archive is verified against expectedHash (BLAKE3) after
// download; a missing hash and a mismatch are both hard failures.
func DownloadAndExtract(installer *Installer, cr *CommandRunner, url, targetDir, archiveName, expectedHash string) error {
	if url == "" {
		return fmt.Errorf("release manifest unavailable or missing a download URL - check your internet connection and use Retry, then try again")
	}

	if cr != nil {
		if err := installer.EnsureDirWithOutput(cr, targetDir); err != nil {
			return err
		}
	} else {
		if err := installer.EnsureDir(targetDir); err != nil {
			return err
		}
	}

	archivePath := filepath.Join(targetDir, archiveName)

	if cr != nil {
		if err := installer.DownloadFileWithProgressToChannel(cr, url, archivePath); err != nil {
			return fmt.Errorf("download failed: %w", err)
		}
		if err := installer.verifyDownload(cr, archivePath, expectedHash); err != nil {
			return fmt.Errorf("checksum verification failed: %w", err)
		}
		if err := installer.ExtractArchiveWithOutput(cr, archivePath, targetDir); err != nil {
			return fmt.Errorf("extraction failed: %w", err)
		}
	} else {
		if err := installer.DownloadFile(url, archivePath); err != nil {
			return fmt.Errorf("download failed: %w", err)
		}
		if err := installer.verifyDownload(nil, archivePath, expectedHash); err != nil {
			return fmt.Errorf("checksum verification failed: %w", err)
		}
		if err := installer.ExtractArchive(archivePath, targetDir); err != nil {
			return fmt.Errorf("extraction failed: %w", err)
		}
	}

	return nil
}

// contextReader checks cancellation between local archive/hash reads. Network
// downloads additionally carry this context on their HTTP request.
type contextReader struct {
	ctx    context.Context
	reader io.Reader
}

func (r contextReader) Read(p []byte) (int, error) {
	if err := r.ctx.Err(); err != nil {
		return 0, err
	}
	return r.reader.Read(p)
}