//go:build darwin

package clipboard

import (
	"fmt"
	"os"
	"os/exec"
	"strings"
)

type darwinClipboard struct{}

// New creates a macOS clipboard (pbpaste/pbcopy).
func New() (Clipboard, error) {
	return newDarwinClipboard()
}

func newDarwinClipboard() (*darwinClipboard, error) {
	// Verify pbpaste and pbcopy are available
	if err := checkBinary("pbpaste"); err != nil {
		return nil, fmt.Errorf("clip-sync: pbpaste not found: %w", err)
	}
	if err := checkBinary("pbcopy"); err != nil {
		return nil, fmt.Errorf("clip-sync: pbcopy not found: %w", err)
	}
	return &darwinClipboard{}, nil
}

func (c *darwinClipboard) Read() (string, error) {
	cmd := exec.Command("pbpaste")
	out, err := cmd.Output()
	if err != nil {
		return "", fmt.Errorf("clipboard read (pbpaste): %w", err)
	}
	return strings.TrimRight(string(out), "\n\r"), nil
}

func (c *darwinClipboard) Write(text string) error {
	cmd := exec.Command("pbcopy")
	cmd.Stdin = strings.NewReader(text)
	if err := cmd.Run(); err != nil {
		return fmt.Errorf("clipboard write (pbcopy): %w", err)
	}
	return nil
}

// ReadImage reads a PNG image from the clipboard via AppleScript, writing it to
// a temporary file and reading it back.
func (c *darwinClipboard) ReadImage() (string, []byte, error) {
	tmp, err := os.CreateTemp("", "clip-sync-*.png")
	if err != nil {
		return "", nil, err
	}
	tmpPath := tmp.Name()
	tmp.Close()
	defer os.Remove(tmpPath)

	// AppleScript type code PNGf, wrapped in the chevron quotes AppleScript uses.
	script := `set f to (open for access POSIX file "` + tmpPath + `" with write permission)
set eof f to 0
write (the clipboard as «class PNGf») to f
close access f`
	if err := exec.Command("osascript", "-e", script).Run(); err != nil {
		return "", nil, ErrNoImage
	}

	data, err := os.ReadFile(tmpPath)
	if err != nil || len(data) == 0 {
		return "", nil, ErrNoImage
	}
	return "image/png", data, nil
}

// WriteImage writes a PNG image to the clipboard via AppleScript.
func (c *darwinClipboard) WriteImage(mime string, data []byte) error {
	if mime != "" && mime != "image/png" {
		return fmt.Errorf("clipboard: unsupported image mime %q (only PNG)", mime)
	}
	tmp, err := os.CreateTemp("", "clip-sync-*.png")
	if err != nil {
		return err
	}
	if _, err := tmp.Write(data); err != nil {
		tmp.Close()
		os.Remove(tmp.Name())
		return err
	}
	tmpPath := tmp.Name()
	tmp.Close()
	defer os.Remove(tmpPath)

	script := `set the clipboard to (read (POSIX file "` + tmpPath + `") as «class PNGf»)`
	if err := exec.Command("osascript", "-e", script).Run(); err != nil {
		return fmt.Errorf("clipboard write image (osascript): %w", err)
	}
	return nil
}