"""Render the 12 tutorial material/model combinations with desktop Blender.

Usage:
  build_blender_native/bin/blender --background --factory-startup \
    --python tools/web/generate-pbr-tutorial-renders.py -- \
    web/app/public/tutorial/pbr/studio.blend \
    web/app/public/assets/pbr-library/pbr-library.blend \
    web/app/public/tutorial/pbr/renders
"""

import hashlib
import json
import pathlib
import sys

import bpy


MODELS = [
    ("PBR Suzanne", "suzanne"),
    ("PBR Cube", "cube"),
    ("PBR Torus", "torus"),
]
MATERIALS = [
    ("PBR Metal Brushed", "metal-brushed"),
    ("PBR Glass", "glass"),
    ("PBR Wood", "wood"),
    ("PBR Emission Cyan", "emission-cyan"),
]


def sha256_file(path):
    digest = hashlib.sha256()
    with path.open("rb") as handle:
        for chunk in iter(lambda: handle.read(1024 * 1024), b""):
            digest.update(chunk)
    return digest.hexdigest()


def append_library(blend_path):
    with bpy.data.libraries.load(str(blend_path), link=False) as (data_from, data_to):
        data_to.objects = list(data_from.objects)
        data_to.materials = list(data_from.materials)
        data_to.images = list(data_from.images)
    return data_to.objects, data_to.materials


def main(studio_path, library_path, renders_dir):
    studio = pathlib.Path(studio_path).resolve()
    library = pathlib.Path(library_path).resolve()
    out = pathlib.Path(renders_dir).resolve()
    out.mkdir(parents=True, exist_ok=True)

    bpy.ops.wm.open_mainfile(filepath=str(studio))
    scene = bpy.context.scene
    objects, materials = append_library(library)
    material_by_name = {material.name: material for material in materials if material}
    model_by_name = {}
    for obj in objects:
        if obj is None:
            continue
        scene.collection.objects.link(obj)
        model_by_name[obj.name] = obj
        obj.hide_render = True

    scene.render.engine = "BLENDER_EEVEE"
    scene.render.resolution_x = 1024
    scene.render.resolution_y = 1024
    scene.render.resolution_percentage = 100
    scene.render.image_settings.file_format = "PNG"
    scene.render.image_settings.color_mode = "RGBA"
    scene.render.image_settings.color_depth = "8"
    scene.render.film_transparent = False
    scene.render.dither_intensity = 0
    scene.eevee.taa_render_samples = 64
    scene.view_settings.look = "None"

    manifest = []
    for model_name, model_slug in MODELS:
        model = model_by_name[model_name]
        for material_name, material_slug in MATERIALS:
            for other in model_by_name.values():
                other.hide_render = other is not model
            material = material_by_name.get(material_name)
            if material is None:
                raise RuntimeError(f"missing material {material_name}")
            model.data.materials.clear()
            model.data.materials.append(material)
            png = out / f"{model_slug}-{material_slug}.png"
            jpg = out / f"{model_slug}-{material_slug}.jpg"
            scene.render.filepath = str(png)
            bpy.ops.render.render(write_still=True)
            scene.render.image_settings.file_format = "JPEG"
            scene.render.image_settings.color_mode = "RGB"
            scene.render.image_settings.quality = 90
            scene.render.filepath = str(jpg)
            bpy.ops.render.render(write_still=True)
            scene.render.image_settings.file_format = "PNG"
            scene.render.image_settings.color_mode = "RGBA"
            manifest.append({
                "model": model_name,
                "modelSlug": model_slug,
                "material": material_name,
                "materialSlug": material_slug,
                "png": str(png.relative_to(pathlib.Path(__file__).resolve().parents[2])).replace("\\", "/"),
                "jpg": str(jpg.relative_to(pathlib.Path(__file__).resolve().parents[2])).replace("\\", "/"),
                "width": 1024,
                "height": 1024,
                "bytes": png.stat().st_size,
                "sha256": sha256_file(png),
            })

    (out / "manifest.json").write_text(
        json.dumps({
            "schemaVersion": 1,
            "renderer": "DESKTOP_BLENDER_EEVEE",
            "blenderVersion": ".".join(str(value) for value in bpy.app.version),
            "renders": manifest,
        }, indent=2, ensure_ascii=True) + "\n",
        encoding="utf-8",
        newline="\n",
    )
    print(json.dumps({"renders": len(manifest), "output": str(out)}))


if __name__ == "__main__":
    arguments = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
    if len(arguments) != 3:
        raise SystemExit("usage: blender --background --factory-startup --python generate-pbr-tutorial-renders.py -- STUDIO LIBRARY RENDERS")
    main(*arguments)