import os, sys, argparse

# Dependency Check
try:
    from PIL import Image, ImageOps
except ImportError:
    print("❌ Error: Pillow library not found.")
    print("👉 Please run: pip install Pillow")
    sys.exit(1)

# Configuration
# Paths are relative to where the script is run, assuming run from root or automation folder
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
SOURCE_DIR = os.path.join(BASE_DIR, "Raw_Assets")
OUTPUT_DIR = os.path.join(BASE_DIR, "Ready_Assets")

# Target Dimensions (Width, Height)
ASSETS = {
    "AppIcon":          (1024, 1024),
    "logo_header":      (300,  80),
    "scanner_frame":    (600,  800),
    "empty_library":    (800,  800),
    "share_watermark":  (400,  100),
    "card_placeholder": (600,  840),
}

# Assets whose target aspect ratio differs significantly from a typical AI square output.
# These use thumbnail+pad (letterbox) instead of center-crop to preserve full image content.
PAD_ASSETS = {"logo_header", "share_watermark"}

def resize_fit(img, size):
    """Center-crop and scale to exact size. Best when source matches target aspect ratio."""
    return ImageOps.fit(img, size, method=Image.Resampling.LANCZOS)

def resize_pad(img, size, bg_color=(0, 0, 0, 0)):
    """Scale to fit within size, then pad with bg_color to reach exact dimensions.
    Preserves the full image — nothing is cropped. Ideal for logos and banners."""
    img.thumbnail(size, Image.Resampling.LANCZOS)
    canvas = Image.new("RGBA", size, bg_color)
    offset = ((size[0] - img.width) // 2, (size[1] - img.height) // 2)
    canvas.paste(img, offset)
    return canvas

def process_assets(force_pad=False, force_crop=False):
    print(f"📂 Working Directory: {BASE_DIR}")

    # Create directories if they don't exist
    if not os.path.exists(SOURCE_DIR):
        os.makedirs(SOURCE_DIR)
        print(f"✅ Created source folder: {SOURCE_DIR}")
        print("👉 ACTION REQUIRED: Place your raw AI images here (e.g., 'AppIcon.png') and run this script again.")
        return

    if not os.path.exists(OUTPUT_DIR):
        os.makedirs(OUTPUT_DIR)
        print(f"✅ Created output folder: {OUTPUT_DIR}")

    print(f"🚀 Processing images from 'Raw_Assets'...")

    for name, size in ASSETS.items():
        found = False
        # Check for common image extensions
        for ext in [".png", ".jpg", ".jpeg", ".webp"]:
            source_path = os.path.join(SOURCE_DIR, name + ext)
            if os.path.exists(source_path):
                try:
                    img = Image.open(source_path)
                    if img.mode != 'RGBA': img = img.convert('RGBA')

                    # Choose resize strategy:
                    # - PAD_ASSETS (and --pad flag) use thumbnail+letterbox to avoid cropping banner images.
                    # - Everything else uses center-crop (ImageOps.fit) for a clean full-bleed fill.
                    use_pad = (name in PAD_ASSETS or force_pad) and not force_crop
                    if use_pad:
                        processed_img = resize_pad(img, size)
                        mode_label = "pad"
                    else:
                        processed_img = resize_fit(img, size)
                        mode_label = "crop"

                    output_path = os.path.join(OUTPUT_DIR, name + ".png")
                    processed_img.save(output_path, "PNG")
                    print(f"✅ Generated: {name}.png ({size[0]}x{size[1]}, {mode_label})")
                    found = True
                    break
                except Exception as e:
                    print(f"❌ Error processing {name}: {e}")

        if not found:
            print(f"⚠️  Skipped: {name} (File not found in Raw_Assets)")

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Resize raw AI assets to Xcode-ready dimensions.")
    group = parser.add_mutually_exclusive_group()
    group.add_argument("--pad",  action="store_true", help="Force thumbnail+pad for ALL assets (no cropping).")
    group.add_argument("--crop", action="store_true", help="Force center-crop for ALL assets (overrides default pad assets).")
    args = parser.parse_args()
    process_assets(force_pad=args.pad, force_crop=args.crop)