"""
blender_rebuild_forks.py
Usage: tooling/blender --background --python tooling/blender_rebuild_forks.py -- <source_dir> <output_base_dir> [body_type ...]

Rebuilds ONLY the fork body types (thin_m/f, heavy_m/f, child) through the same
segmentation pipeline that produced the healthy six (blender_segment_body.py),
using the T-1090 fix: the fork scale is applied to the mesh AND the embedded
armature rest pose so each segment stays internally consistent with its own
skeleton (required by the shared-skeleton compositor in character_visual.gd).

Sources (Source-tier Godot - UE exports):
  Regular_Male_FullBody.gltf   + scale (0.82, 1.0, 0.88) -> thin_m
  Regular_Female_FullBody.gltf + scale (0.82, 1.0, 0.88) -> thin_f
  Regular_Male_FullBody.gltf   + scale (1.20, 1.08, 1.0) -> heavy_m
  Regular_Female_FullBody.gltf + scale (1.20, 1.08, 1.0) -> heavy_f
  Teen_Male_FullBody.gltf      + scale (0.75, 0.72, 0.75) -> child  [gender-neutral]

The fork scale factors and source mapping are unchanged from
blender_process_bodies.py — this driver reuses the same table so the healthy six
are never touched. Output layout matches production: <out>/{body_type}/seg_*.glb.
"""

import sys
import os

script_dir = os.path.dirname(os.path.abspath(__file__))
sys.path.insert(0, script_dir)
from blender_segment_body import segment_body

# (gltf_filename, body_type_key, scale, source_label) — forks only.
FORK_MANIFEST = [
    ("Regular_Male_FullBody.gltf",    "thin_m",  (0.82, 1.0,  0.88), "Regular_Male_FullBody.gltf"),
    ("Regular_Female_FullBody.gltf",  "thin_f",  (0.82, 1.0,  0.88), "Regular_Female_FullBody.gltf"),
    ("Regular_Male_FullBody.gltf",    "heavy_m", (1.20, 1.08, 1.0),  "Regular_Male_FullBody.gltf"),
    ("Regular_Female_FullBody.gltf",  "heavy_f", (1.20, 1.08, 1.0),  "Regular_Female_FullBody.gltf"),
    ("Teen_Male_FullBody.gltf",       "child",   (0.75, 0.72, 0.75), "Teen_Male_FullBody.gltf"),
]

FORK_README = """\
# Fork body type — auto-generated from mesh + armature scaling (T-1090)

This directory contains **{body_type}** body segments, generated by applying a
proportional scale to the source body ({source}) mesh AND its armature rest pose
together, then segmenting:

  Scale: ({sx:.2f}, {sy:.2f}, {sz:.2f})

The scale is applied to the mesh vertices and the embedded armature rest pose
with the SAME affine (T-1090 fix). This keeps each segment internally consistent
with its own skeleton, which the shared-skeleton compositor
(character_visual.gd) requires — a mesh-only scale detaches the head and
explodes the limbs on relocation.

Cross-sectional differentiation (thin = narrow, heavy = wide) survives the
composite; global height normalises to the shared skeleton (see T-1090 report /
Q-060 for the shared-skeleton scale-normalisation note).

Status: auto-generated (rebuilt T-1090), 18 segments incl. seg_hips
"""


def write_fork_readme(output_dir, body_type, source, scale):
    sx, sy, sz = scale
    with open(os.path.join(output_dir, "README.md"), "w") as f:
        f.write(FORK_README.format(body_type=body_type, source=source, sx=sx, sy=sy, sz=sz))


if __name__ == "__main__":
    argv = sys.argv
    args = argv[argv.index("--") + 1:] if "--" in argv else []
    if len(args) < 2:
        print("Usage: -- <source_dir> <output_base_dir> [body_type ...]")
        sys.exit(1)

    source_dir = args[0]
    output_base_dir = args[1]
    only = set(args[2:])  # optional subset filter

    manifest = [m for m in FORK_MANIFEST if not only or m[1] in only]

    unique_sources = {gltf for (gltf, _, _, _) in manifest}
    missing = [
        os.path.join(source_dir, f)
        for f in sorted(unique_sources)
        if not os.path.exists(os.path.join(source_dir, f))
    ]
    if missing:
        print("\nERROR: Missing source GLTF files:")
        for p in missing:
            print(f"  {p}")
        sys.exit(1)

    results = []
    for (gltf_filename, body_type, scale, source_label) in manifest:
        gltf_path = os.path.join(source_dir, gltf_filename)
        output_dir = os.path.join(output_base_dir, body_type)
        print(f"\n{'='*60}\n  Fork: {body_type}  scale={scale}\n  Source: {gltf_filename}")
        exported, skipped = segment_body(gltf_path, output_dir, scale)
        write_fork_readme(output_dir, body_type, source_label, scale)
        results.append((body_type, exported, skipped))

    print(f"\n{'='*60}\n=== Fork rebuild complete ===")
    for body_type, exported, skipped in results:
        print(f"  {body_type}: {len(exported)} exported, {len(skipped)} skipped")