"""Clipboard image extraction for macOS and Linux.

Provides a single function `save_clipboard_image(dest)` that checks the
system clipboard for image data, saves it to *dest* as PNG, and returns
True on success.  No external Python dependencies — uses only OS-level
CLI tools that ship with the platform (or are commonly installed).

Platform support:
  macOS  — osascript (always available), pngpaste (if installed)
  Linux  — xclip (apt install xclip)
"""

import logging
import subprocess
import sys
from pathlib import Path

logger = logging.getLogger(__name__)


def save_clipboard_image(dest: Path) -> bool:
    """Extract an image from the system clipboard and save it as PNG.

    Returns True if an image was found and saved, False otherwise.
    """
    dest.parent.mkdir(parents=True, exist_ok=True)
    if sys.platform == "darwin":
        return _macos_save(dest)
    return _linux_save(dest)


# ── macOS ────────────────────────────────────────────────────────────────

def _macos_save(dest: Path) -> bool:
    """Try pngpaste first (fast, handles more formats), fall back to osascript."""
    return _macos_pngpaste(dest) or _macos_osascript(dest)


def _macos_pngpaste(dest: Path) -> bool:
    """Use pngpaste (brew install pngpaste) — fastest, cleanest."""
    try:
        r = subprocess.run(
            ["pngpaste", str(dest)],
            capture_output=True, timeout=3,
        )
        if r.returncode == 0 and dest.exists() and dest.stat().st_size > 0:
            return True
    except FileNotFoundError:
        pass  # pngpaste not installed
    except Exception as e:
        logger.debug("pngpaste failed: %s", e)
    return False


def _macos_osascript(dest: Path) -> bool:
    """Use osascript to extract PNG data from clipboard (always available)."""
    # First check if clipboard contains image data
    try:
        info = subprocess.run(
            ["osascript", "-e", "clipboard info"],
            capture_output=True, text=True, timeout=3,
        )
        has_image = "«class PNGf»" in info.stdout or "«class TIFF»" in info.stdout
        if not has_image:
            return False
    except Exception:
        return False

    # Extract as PNG
    script = (
        'try\n'
        '  set imgData to the clipboard as «class PNGf»\n'
        f'  set f to open for access POSIX file "{dest}" with write permission\n'
        '  write imgData to f\n'
        '  close access f\n'
        'on error\n'
        '  return "fail"\n'
        'end try\n'
    )
    try:
        r = subprocess.run(
            ["osascript", "-e", script],
            capture_output=True, text=True, timeout=5,
        )
        if r.returncode == 0 and "fail" not in r.stdout and dest.exists() and dest.stat().st_size > 0:
            return True
    except Exception as e:
        logger.debug("osascript clipboard extract failed: %s", e)
    return False


# ── Linux ────────────────────────────────────────────────────────────────

def _linux_save(dest: Path) -> bool:
    """Use xclip to extract clipboard image."""
    # Check if clipboard has image content
    try:
        targets = subprocess.run(
            ["xclip", "-selection", "clipboard", "-t", "TARGETS", "-o"],
            capture_output=True, text=True, timeout=3,
        )
        if "image/png" not in targets.stdout:
            return False
    except FileNotFoundError:
        logger.debug("xclip not installed — clipboard image paste unavailable")
        return False
    except Exception:
        return False

    # Extract PNG data
    try:
        with open(dest, "wb") as f:
            subprocess.run(
                ["xclip", "-selection", "clipboard", "-t", "image/png", "-o"],
                stdout=f, stderr=subprocess.DEVNULL, timeout=5, check=True,
            )
        if dest.exists() and dest.stat().st_size > 0:
            return True
    except Exception as e:
        logger.debug("xclip image extraction failed: %s", e)
        dest.unlink(missing_ok=True)
    return False