"""
lineartization usage examples
=============================
Demonstrates the call styles: one-liner / custom config / raw ndarray.

Usage:
    python demo.py <input_image> <output_dir>

There are no built-in default paths: both arguments are required.

Tip: extraction quality depends on the source resolution -- the higher the
resolution, the cleaner the result. For low-resolution inputs use the
``minimum`` method.
"""
import os
import sys

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from lineartization import (
    LineArtConfig,
    extract_lineart,
    extract_lineart_file,
    load_image,
    save_image,
)


def demo_simple(src, out_dir):
    """Example 1: one-liner (skeleton mode)."""
    print("=== Example 1: one-liner ===")
    extract_lineart_file(src, os.path.join(out_dir, "simple.png"))
    print("  wrote simple.png")


def demo_config(src, out_dir):
    """Example 2: custom config (minimum mode + protected region)."""
    print("=== Example 2: custom config ===")
    cfg = LineArtConfig(
        method="minimum",
        denoise="strong",
        line_width=2,                              # uniform 2 px stroke
        protect_areas=[(120, 220, 940, 1050)],     # keep this region intact
    )
    extract_lineart_file(src, os.path.join(out_dir, "configured.png"),
                         cfg, verbose=True)
    print("  wrote configured.png")


def demo_two_variants(src, out_dir):
    """Example 3: the two minimum variants (true-black on / off)."""
    print("=== Example 3: minimum variants ===")
    for flag, name in ((True, "true-black"), (False, "no-true-black")):
        cfg = LineArtConfig(method="minimum", min_true_black=flag)
        extract_lineart_file(src, os.path.join(out_dir, f"minimum_{name}.png"), cfg)
        print(f"  wrote minimum_{name}.png")


def demo_ndarray(src, out_dir):
    """Example 4: work directly on an ndarray (embeddable in your pipeline)."""
    print("=== Example 4: ndarray processing ===")
    img = load_image(src)
    print(f"  input size: {img.shape[1]}x{img.shape[0]}")
    lineart = extract_lineart(img, LineArtConfig(line_width=2))
    black_ratio = (lineart < 128).mean() * 100
    print(f"  black ratio: {black_ratio:.2f}%")
    save_image(os.path.join(out_dir, "ndarray.png"), lineart)
    print("  wrote ndarray.png")


def main(argv):
    if len(argv) != 3:
        print(__doc__.strip())
        print("\nError: expected exactly 2 arguments "
              "(<input_image> <output_dir>).")
        return 2

    src, out_dir = argv[1], argv[2]
    if not os.path.exists(src):
        print(f"Error: input image not found: {src}")
        return 2
    os.makedirs(out_dir, exist_ok=True)

    demo_simple(src, out_dir)
    demo_config(src, out_dir)
    demo_two_variants(src, out_dir)
    demo_ndarray(src, out_dir)
    print("\nAll examples finished.")
    return 0


if __name__ == "__main__":
    raise SystemExit(main(sys.argv))