import os
from pathlib import Path
from PIL import Image, ImageFilter, ImageOps, ImageDraw, ImageChops
import tempfile

def validate_path(p: str) -> Path:
    path = Path(os.path.expanduser(p)).resolve()
    if not path.exists():
        raise FileNotFoundError(f"Path does not exist: {path}")
    return path


def temp_output(suffix=".png"):
    return tempfile.NamedTemporaryFile(delete=False, suffix=suffix).name

def ensure_path_from_img(img) -> Path:
    """
    Ensures that the input is converted to a valid image file path.

    If `img` is a PIL.Image object, it saves it to a temporary file and returns the path.
    If `img` is already a path (string or Path), it wraps and returns it as a Path.

    Args:
        img: A PIL.Image or a path string

    Returns:
        Path to the image file
    """

    if isinstance(img, Image.Image):
        temp_input = temp_output()
        img.save(temp_input)
        return Path(temp_input)
    return validate_path(img)

def resize_image(input_path: str, width: int, height: int, output_path: str = None) -> str:
    """
    Resize an image and save to a new file.

    Args:
        input_path (str): Path to source image.
        output_path (str): Path to save resized image.
        width (int): New width in pixels.
        height (int): New height in pixels.

    Returns:
        str: Path to resized image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path) as img:
        img = img.resize((width, height))
        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path)
    return str(output_path)

def convert_grayscale(input_path: str, output_path: str = None) -> str:
    """
    Convert an image to grayscale.

    Args:
        input_path (str): Source image path.
        output_path (str): Path to save grayscale version.

    Returns:
        str: Path to grayscale image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path) as img:
        gray = img.convert("L")
        output_path.parent.mkdir(parents=True, exist_ok=True)
        gray.save(output_path)
    return str(output_path)

def image_metadata(path: str) -> str:
    """
    Get image metadata.

    Args:
        path (str): Image path.

    Returns:
        str: Format, size, and mode info.
    """
    path = validate_path(path)
    with Image.open(path) as img:
        return "\n".join([
            f"Format: {img.format}",
            f"Size: {img.size}",
            f"Mode: {img.mode}"
        ])

def convert_format(input_path: str, format: str, output_path: str = None) -> str:
    """
    Convert an image to a new format.

    Args:
        input_path (str): Source image path.
        output_path (str): Destination path with extension.
        format (str): Format (e.g. 'png', 'jpeg').

    Returns:
        str: Path to converted image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path) as img:
        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path, format=format.upper())
    return str(output_path)

def blur_image(input_path: str, radius: float, output_path: str = None) -> str:
    """
    Apply Gaussian blur to an image.

    Args:
        input_path (str): Image path.
        output_path (str): Path to save blurred image.
        radius (float): Blur radius.

    Returns:
        str: Path to blurred image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path) as img:
        img = img.filter(ImageFilter.GaussianBlur(radius))
        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path)
    return str(output_path)

def rotate_image(input_path: str, angle: float, output_path: str = None) -> str:
    """
    Rotate an image.

    Args:
        input_path (str): Source path.
        output_path (str): Destination path.
        angle (float): Rotation angle in degrees.

    Returns:
        str: Path to rotated image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path) as img:
        img = img.rotate(angle, expand=True)
        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path)
    return str(output_path)

def crop_image(input_path: str, left: int, top: int, right: int, bottom: int, output_path: str = None) -> str:
    """
    Crop an image.

    Args:
        input_path (str): Source image.
        output_path (str): Destination.
        left, top, right, bottom (int): Crop box coordinates.

    Returns:
        str: Path to cropped image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path) as img:
        img = img.crop((left, top, right, bottom))
        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path)
    return str(output_path)

def thumbnail_image(input_path: str, max_width: int, max_height: int, output_path: str = None) -> str:
    """
    Resize image while maintaining aspect ratio.

    Args:
        input_path (str): Source.
        output_path (str): Target.
        max_width (int), max_height (int): Constraints.

    Returns:
        str: Path to thumbnail image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path) as img:
        img.thumbnail((max_width, max_height))
        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path)
    return str(output_path)

def add_watermark(input_path: str, text: str, x: int, y: int, output_path: str = None) -> str:
    """
    Add watermark text.

    Args:
        input_path (str): Image file.
        output_path (str): Save path.
        text (str): Watermark content.
        x (int), y (int): Position.

    Returns:
        str: Path to watermarked image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path).convert("RGBA") as img:
        watermark = Image.new("RGBA", img.size)
        draw = ImageDraw.Draw(watermark)
        draw.text((x, y), text, fill=(255, 255, 255, 128))
        img = Image.alpha_composite(img, watermark).convert("RGB")
        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path)
    return str(output_path)

def flip_image(input_path: str, mode: str, output_path: str = None) -> str:
    """
    Flip image horizontally or vertically.

    Args:
        input_path (str): Source.
        output_path (str): Destination.
        mode (str): 'horizontal' or 'vertical'.

    Returns:
        str: Path to flipped image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path) as img:
        if mode == "horizontal":
            img = img.transpose(Image.FLIP_LEFT_RIGHT)
        elif mode == "vertical":
            img = img.transpose(Image.FLIP_TOP_BOTTOM)
        else:
            raise ValueError("Invalid mode")
        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path)
    return str(output_path)

def invert_colors(input_path: str, output_path: str = None) -> str:
    """
    Invert RGB color values.

    Args:
        input_path (str): Image file.
        output_path (str): Save location.

    Returns:
        str: Path to inverted image.
    """
    if output_path is None:
        output_path = temp_output()

    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()
    with Image.open(input_path) as img:
        img = ImageOps.invert(img.convert("RGB"))
        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path)
    return str(output_path)

def list_images_in_directory(path: str) -> str:
    """
    List image files in a directory.

    Args:
        path (str): Directory path.

    Returns:
        str: Newline-separated list of image paths.
    """
    dir_path = Path(path).expanduser().resolve()
    if not dir_path.is_dir():
        raise NotADirectoryError(f"{dir_path} is not a directory.")
    exts = {".png", ".jpg", ".jpeg", ".webp", ".bmp", ".gif"}
    files = [str(p) for p in dir_path.iterdir() if p.suffix.lower() in exts]
    return "\n".join(files) if files else "No image files found."

def get_image_metadata(path: str) -> dict:
    """
    Get metadata from an image.

    Args:
        path (str): Image path.

    Returns:
        dict: Metadata fields including format, size, mode.
    """

    path = validate_path(path)
    with Image.open(path) as img:
        return {
            "path": str(path),
            "format": img.format,
            "mode": img.mode,
            "size": img.size,
            "width": img.width,
            "height": img.height,
            "info": img.info
        }

import random

def apply_random_color_variation(input_path: str, strength: float = 0.1,output_path: str = None) -> str:
    """
    Apply random color variation to an image and save the result.

    Args:
        input_path (str): Source image path.
        output_path (str): Target image path.
        strength (float): Amount of variation per channel (0.0 to 1.0, default = 0.1).

    Returns:
        str: Path to the color-augmented image.
    """
    if output_path is None:
        output_path = temp_output()
    input_path = validate_path(input_path)
    output_path = Path(output_path).expanduser().resolve()

    with Image.open(input_path).convert("RGB") as img:
        pixels = img.load()
        for y in range(img.height):
            for x in range(img.width):
                r, g, b = pixels[x, y]
                r = int(min(max(r + random.randint(-int(255 * strength), int(255 * strength)), 0), 255))
                g = int(min(max(g + random.randint(-int(255 * strength), int(255 * strength)), 0), 255))
                b = int(min(max(b + random.randint(-int(255 * strength), int(255 * strength)), 0), 255))
                pixels[x, y] = (r, g, b)

        output_path.parent.mkdir(parents=True, exist_ok=True)
        img.save(output_path)

    return str(output_path)


def add_images(image_path1: str, image_path2: str, output_path: str = None) -> str:
    """
    Add two images pixel-wise and save the result.

    Args:
        image_path1 (str): Path to the first image.
        image_path2 (str): Path to the second image.
        output_path (str): Path to save the resulting image.

    Returns:
        str: Path to the added image.
    """
    if output_path is None:
        output_path = temp_output()

    path1 = validate_path(image_path1)
    path2 = validate_path(image_path2)
    output_path = Path(output_path).expanduser().resolve()

    with Image.open(path1).convert("RGB") as img1, Image.open(path2).convert("RGB") as img2:
        if img1.size != img2.size:
            raise ValueError("Images must be the same size")
        result = ImageChops.add(img1, img2, scale=1.0, offset=0)
        output_path.parent.mkdir(parents=True, exist_ok=True)
        result.save(output_path)

    return str(output_path)
from PIL import Image
from pathlib import Path

def concat_images(image_path1: str, image_path2: str, mode: str = "horizontal", output_path: str = None) -> str:
    """
    Concatenate two images either horizontally or vertically.

    Args:
        image_path1 (str): Path to the first image.
        image_path2 (str): Path to the second image.
        output_path (str): Path to save the concatenated image.
        mode (str): 'horizontal' or 'vertical'.

    Returns:
        str: Path to the output image.
    """
    if output_path is None:
        output_path = temp_output()

    img1 = Image.open(image_path1).convert("RGB")
    img2 = Image.open(image_path2).convert("RGB")

    if mode == "horizontal":
        new_width = img1.width + img2.width
        new_height = max(img1.height, img2.height)
        new_img = Image.new("RGB", (new_width, new_height))
        new_img.paste(img1, (0, 0))
        new_img.paste(img2, (img1.width, 0))
    elif mode == "vertical":
        new_width = max(img1.width, img2.width)
        new_height = img1.height + img2.height
        new_img = Image.new("RGB", (new_width, new_height))
        new_img.paste(img1, (0, 0))
        new_img.paste(img2, (0, img1.height))
    else:
        raise ValueError("Invalid mode. Use 'horizontal' or 'vertical'.")

    output_path = Path(output_path).expanduser().resolve()
    output_path.parent.mkdir(parents=True, exist_ok=True)
    new_img.save(output_path)
    return str(output_path)