"""
setup_clothing_metadata.py

Usage: python3 tooling/setup_clothing_metadata.py <clothing_dir>

Creates coverage.json and reference_mask.png for all 5 initial clothing items.
This is a pure-Python script — no Blender required.

Arguments:
  clothing_dir  Root directory for clothing output (e.g. client/assets/characters/clothing/).
                Each item subdirectory must already exist.

Files created per item:
  coverage.json       -- segment hides + torso_variant (compositor input)
  reference_mask.png  -- greyscale recolor mask (all-white v0.2 placeholder: fully tintable)

coverage.json format:
  {
    "hides": ["torso", "arm_upper_l", ...],
    "torso_variant": "full"
  }

  hides entries use short segment names (without "seg_" prefix).
  torso_variant: "full"  = clothing hides seg_torso (full torso segment)
               : "upper" = clothing only hides seg_torso_upper (upper chest)

reference_mask.png:
  64x64 grayscale PNG. White (255) = fully tintable. v0.2 placeholder — all white.
  Final art will have partial masks (black areas = preserve material texture color).

Decisions: D-162 (clothing pre-baked per body type via Surface Deform)
"""

import sys
import os
import json
import zlib
import struct

# -------------------------------------------------------------------------
# Clothing catalogue metadata
# -------------------------------------------------------------------------

CLOTHING_ITEMS = {
    "coveralls_basic": {
        "description": "Full-body work suit",
        "hides": [
            "torso",
            "arm_upper_l", "arm_upper_r",
            "arm_lower_l", "arm_lower_r",
            "hand_l", "hand_r",
            "leg_upper_l", "leg_upper_r",
            "leg_lower_l", "leg_lower_r",
            "foot_l", "foot_r",
        ],
        "torso_variant": "full",
    },
    "jacket_utility": {
        "description": "Upper body outerwear",
        "hides": [
            "torso",
            "arm_upper_l", "arm_upper_r",
            "arm_lower_l", "arm_lower_r",
        ],
        "torso_variant": "full",
    },
    "pants_cargo": {
        # Note: pants hide leg segments but NOT foot segments. Boots (boots_work)
        # hide feet. This distinction matters for the compositor — a character
        # wearing pants + no boots shows bare feet via seg_foot_l/r.
        "description": "Lower body cargo trousers",
        "hides": [
            "leg_upper_l", "leg_upper_r",
            "leg_lower_l", "leg_lower_r",
        ],
        "torso_variant": "full",
    },
    "shirt_henley": {
        "description": "Upper body inner shirt",
        "hides": [
            "torso",
            "arm_upper_l", "arm_upper_r",
        ],
        "torso_variant": "full",
    },
    "boots_work": {
        "description": "Work boots (foot slot + lower leg shaft)",
        "hides": [
            "foot_l", "foot_r",
            "leg_lower_l", "leg_lower_r",
        ],
        "torso_variant": "full",
    },
}

MASK_WIDTH  = 64
MASK_HEIGHT = 64


# -------------------------------------------------------------------------
# Minimal PNG writer (no external dependencies)
# -------------------------------------------------------------------------

def _make_png_chunk(chunk_type, data):
    """Construct a PNG chunk with CRC."""
    payload = chunk_type + data
    crc = zlib.crc32(payload) & 0xFFFFFFFF
    return struct.pack(">I", len(data)) + payload + struct.pack(">I", crc)


def write_white_grayscale_png(path, width=64, height=64):
    """
    Write a minimal all-white grayscale PNG to `path`.
    Uses only Python built-ins (zlib, struct) — no Pillow required.
    """
    # PNG signature
    signature = b'\x89PNG\r\n\x1a\n'

    # IHDR: width, height, bit_depth=8, colortype=0 (grayscale),
    #       compression=0, filter=0, interlace=0
    ihdr_data = struct.pack(">IIBBBBB", width, height, 8, 0, 0, 0, 0)
    ihdr = _make_png_chunk(b'IHDR', ihdr_data)

    # IDAT: raw scanlines — filter byte 0x00 (None) + width bytes of 0xFF (white)
    raw_rows = b''.join(b'\x00' + b'\xff' * width for _ in range(height))
    compressed = zlib.compress(raw_rows, 9)
    idat = _make_png_chunk(b'IDAT', compressed)

    # IEND
    iend = _make_png_chunk(b'IEND', b'')

    with open(path, 'wb') as f:
        f.write(signature + ihdr + idat + iend)


# -------------------------------------------------------------------------
# Per-item setup
# -------------------------------------------------------------------------

def setup_item(item_id, config, clothing_dir):
    """
    Write coverage.json and reference_mask.png for one clothing item.
    Returns (coverage_ok, mask_ok).
    """
    item_dir = os.path.join(clothing_dir, item_id)
    os.makedirs(item_dir, exist_ok=True)

    # coverage.json
    coverage = {
        "hides": config["hides"],
        "torso_variant": config["torso_variant"],
    }
    coverage_path = os.path.join(item_dir, "coverage.json")
    with open(coverage_path, 'w') as f:
        json.dump(coverage, f, indent=2)
    coverage_ok = True

    # reference_mask.png (all-white placeholder)
    mask_path = os.path.join(item_dir, "reference_mask.png")
    write_white_grayscale_png(mask_path, MASK_WIDTH, MASK_HEIGHT)
    mask_ok = True

    return coverage_ok, mask_ok


# -------------------------------------------------------------------------
# Entry point
# -------------------------------------------------------------------------

if __name__ == "__main__":
    if len(sys.argv) < 2:
        print("Usage: python3 tooling/setup_clothing_metadata.py <clothing_dir>")
        sys.exit(1)

    clothing_dir = sys.argv[1]

    print(f"\nClothing Metadata Setup")
    print(f"  Output dir: {clothing_dir}")
    print(f"  Items:      {len(CLOTHING_ITEMS)}")

    all_ok = True
    for item_id, config in CLOTHING_ITEMS.items():
        coverage_ok, mask_ok = setup_item(item_id, config, clothing_dir)
        status = "OK" if (coverage_ok and mask_ok) else "FAILED"
        print(f"  {item_id:20s}  {status}  "
              f"coverage={'ok' if coverage_ok else 'FAIL'}  "
              f"mask={'ok' if mask_ok else 'FAIL'}")
        if not (coverage_ok and mask_ok):
            all_ok = False

    print(f"\n  Done. {'All OK.' if all_ok else 'Some items failed.'}")
    if not all_ok:
        sys.exit(1)