from __future__ import annotations

import json
import math
import sys
from pathlib import Path

import bpy
from mathutils import Vector


def arguments() -> tuple[Path, Path, Path, str, float]:
    if "--" not in sys.argv:
        raise RuntimeError("Expected Blender arguments after --")
    values = sys.argv[sys.argv.index("--") + 1 :]
    if len(values) != 5:
        raise RuntimeError(
            "Usage: convert-runewaker-actor.py <scene.obj> <output.glb> "
            "<report.json> <asset-id> <unit-scale>"
        )
    return Path(values[0]), Path(values[1]), Path(values[2]), values[3], float(values[4])


def triangle_count(obj: bpy.types.Object) -> int:
    if obj.type != "MESH":
        return 0
    return sum(max(0, len(polygon.vertices) - 2) for polygon in obj.data.polygons)


def material_image_key(material: bpy.types.Material) -> str:
    if material.use_nodes and material.node_tree is not None:
        for node in material.node_tree.nodes:
            if node.type == "TEX_IMAGE" and node.image is not None:
                return str(Path(bpy.path.abspath(node.image.filepath)).resolve(False)).casefold()
    return f"material:{material.name.casefold()}"


def deduplicate_materials(objects: list[bpy.types.Object]) -> dict[str, int]:
    canonical: dict[str, bpy.types.Material] = {}
    replacements = 0
    for obj in objects:
        for slot in obj.material_slots:
            material = slot.material
            if material is None:
                continue
            key = material_image_key(material)
            if key in canonical:
                if slot.material != canonical[key]:
                    slot.material = canonical[key]
                    replacements += 1
            else:
                canonical[key] = material
                material["semanticRole"] = "opaque"
                material["sourceFormat"] = "RuneWaker DDS"
    return {"unique": len(canonical), "replacements": replacements}


def three_bounds(objects: list[bpy.types.Object]) -> tuple[list[float], list[float]]:
    low = Vector((math.inf, math.inf, math.inf))
    high = Vector((-math.inf, -math.inf, -math.inf))
    for obj in objects:
        for corner in obj.bound_box:
            point = obj.matrix_world @ Vector(corner)
            for axis in range(3):
                low[axis] = min(low[axis], point[axis])
                high[axis] = max(high[axis], point[axis])
    if not all(math.isfinite(value) for value in (*low, *high)):
        raise RuntimeError("Actor conversion produced no finite mesh bounds")
    return (
        [round(low.x, 5), round(low.z, 5), round(-high.y, 5)],
        [round(high.x, 5), round(high.z, 5), round(-low.y, 5)],
    )


def main() -> None:
    source_obj, output_glb, report_file, asset_id, unit_scale = arguments()
    output_glb.parent.mkdir(parents=True, exist_ok=True)
    report_file.parent.mkdir(parents=True, exist_ok=True)

    bpy.ops.object.select_all(action="SELECT")
    bpy.ops.object.delete(use_global=False)
    result = bpy.ops.wm.obj_import(
        filepath=str(source_obj),
        forward_axis="NEGATIVE_Z",
        up_axis="Y",
        global_scale=unit_scale,
        use_split_objects=True,
        use_split_groups=True,
        validate_meshes=True,
    )
    if "FINISHED" not in result:
        raise RuntimeError(f"OBJ import failed: {result}")

    meshes = sorted(
        (obj for obj in bpy.context.scene.objects if obj.type == "MESH"),
        key=lambda obj: obj.name.casefold(),
    )
    if not meshes:
        raise RuntimeError("OBJ import produced no actor meshes")
    for obj in meshes:
        obj["sourceFormat"] = "RuneWaker ROS via preserved OBJ bridge"
        obj["sourceUnitScaleMeters"] = unit_scale
        obj.select_set(True)

    material_stats = deduplicate_materials(meshes)
    bounds_min, bounds_max = three_bounds(meshes)
    triangles = sum(triangle_count(obj) for obj in meshes)
    ground_offset = round(-bounds_min[1], 5)
    height = max(0.1, bounds_max[1] - bounds_min[1])
    width = max(bounds_max[0] - bounds_min[0], bounds_max[2] - bounds_min[2])

    bpy.context.view_layer.objects.active = meshes[0]
    result = bpy.ops.export_scene.gltf(
        filepath=str(output_glb),
        export_format="GLB",
        use_selection=True,
        export_yup=True,
        export_apply=False,
        export_animations=False,
        export_materials="EXPORT",
        export_cameras=False,
        export_lights=False,
        export_extras=True,
    )
    if "FINISHED" not in result:
        raise RuntimeError(f"GLB export failed: {result}")

    report = {
        "schemaVersion": 1,
        "assetId": asset_id,
        "status": "static-authentic-model",
        "source": source_obj.name,
        "coordinateTransform": {
            "nativeBridge": "three(x,y,z)=(runewaker.x,runewaker.y,-runewaker.z)",
            "metersPerSourceUnit": unit_scale,
        },
        "meshObjects": len(meshes),
        "triangles": triangles,
        "bounds": {"min": bounds_min, "max": bounds_max},
        "materials": material_stats,
        "runtime": {
            "groundOffset": ground_offset,
            "labelHeight": round(height + 0.35, 5),
            "markerRadius": round(max(0.4, min(3.0, width * 0.32)), 5),
        },
        "animations": [],
        "warnings": [
            "The preserved ROS bridge exposes static geometry only; HealerMan supplies procedural movement and combat motion."
        ],
    }
    report_file.write_text(json.dumps(report, indent=2) + "\n", encoding="utf-8")
    print(json.dumps(report, indent=2))


if __name__ == "__main__":
    main()