package clipboard

import (
	"bytes"
	"fmt"
	"os"
	"os/exec"
	"runtime"
)

// Copy places RTF and HTML onto the system clipboard.
// HTML is needed for web apps (Slack, Gmail); RTF for native apps (TextEdit, Word).
func Copy(rtf, html []byte) error {
	switch runtime.GOOS {
	case "darwin":
		return copyDarwin(rtf, html)
	case "linux":
		return copyLinux(rtf, html)
	default:
		return fmt.Errorf("unsupported platform: %s", runtime.GOOS)
	}
}

func copyDarwin(rtf, html []byte) error {
	rtfFile, err := writeTempFile("mach-*.rtf", rtf)
	if err != nil {
		return err
	}
	defer os.Remove(rtfFile)

	htmlFile, err := writeTempFile("mach-*.html", html)
	if err != nil {
		return err
	}
	defer os.Remove(htmlFile)

	// Use Swift to set public.rtf, public.html, and public.utf8-plain-text
	// on NSPasteboard. All three are needed:
	//   - public.html  → web apps (Slack, Gmail, Google Docs)
	//   - public.rtf   → native apps (TextEdit, Word, Pages)
	//   - public.string → plain text fallback (Slack/Electron requires this)
	swift := fmt.Sprintf(`
import AppKit
let rtfData = try! Data(contentsOf: URL(fileURLWithPath: "%s"))
let htmlData = try! Data(contentsOf: URL(fileURLWithPath: "%s"))
let htmlString = String(data: htmlData, encoding: .utf8) ?? ""
let pb = NSPasteboard.general
pb.clearContents()
pb.setData(rtfData, forType: .rtf)
pb.setData(htmlData, forType: .html)
pb.setString(htmlString, forType: .string)
`, rtfFile, htmlFile)

	cmd := exec.Command("swift", "-")
	cmd.Stdin = bytes.NewReader([]byte(swift))
	if out, err := cmd.CombinedOutput(); err != nil {
		return fmt.Errorf("clipboard write failed: %s: %w", string(out), err)
	}
	return nil
}

func copyLinux(rtf, html []byte) error {
	// xclip can only set one target at a time; prefer HTML for broader compat
	cmd := exec.Command("xclip", "-selection", "clipboard", "-t", "text/html", "-i")
	cmd.Stdin = bytes.NewReader(html)
	return cmd.Run()
}

func writeTempFile(pattern string, data []byte) (string, error) {
	f, err := os.CreateTemp("", pattern)
	if err != nil {
		return "", fmt.Errorf("failed to create temp file: %w", err)
	}
	if _, err := f.Write(data); err != nil {
		f.Close()
		os.Remove(f.Name())
		return "", fmt.Errorf("failed to write temp file: %w", err)
	}
	f.Close()
	return f.Name(), nil
}