# Critique (read-only): dump objects, triangle counts, n-gons, material base colours / roughness / metallic / emission
import bpy, json, bmesh
out = {"objects": {}, "materials": {}}
for o in bpy.data.objects:
    if o.type != "MESH":
        continue
    me = o.data
    nt = sum(len(p.vertices) - 2 for p in me.polygons)
    ng = sum(1 for p in me.polygons if len(p.vertices) > 4)
    out["objects"][o.name] = dict(tris=nt, faces=len(me.polygons), ngons=ng, verts=len(me.vertices),
                                  mats=[s.material.name if s.material else None for s in o.material_slots],
                                  uv=[u.name for u in me.uv_layers], hidden=o.hide_render,
                                  dims=[round(d, 3) for d in o.dimensions], mods=[m.type for m in o.modifiers])
for m in bpy.data.materials:
    if not m.use_nodes:
        continue
    info = {}
    for n in m.node_tree.nodes:
        if n.type == "BSDF_PRINCIPLED":
            def val(name):
                i = n.inputs.get(name)
                if i is None: return None
                if i.is_linked:
                    return "linked:" + i.links[0].from_node.type + ":" + i.links[0].from_node.name
                v = i.default_value
                try: return [round(x, 3) for x in v]
                except TypeError: return round(v, 3)
            for k in ("Base Color", "Metallic", "Roughness", "Emission Color", "Emission Strength", "Transmission Weight", "Coat Weight", "Alpha"):
                info[k] = val(k)
        if n.type == "TEX_IMAGE" and n.image:
            info.setdefault("images", []).append(n.image.name + " (" + n.image.filepath + ")")
        if n.type == "RGB":
            info.setdefault("rgb", []).append([round(x, 3) for x in n.outputs[0].default_value])
        if n.type == "VALTORGB":
            info.setdefault("ramp", []).append([[round(e.position, 2)] + [round(x, 3) for x in e.color] for e in n.color_ramp.elements])
        if n.type == "MIX" and n.data_type == "RGBA":
            info.setdefault("mixcols", []).append([[round(x, 3) for x in n.inputs[6].default_value], [round(x, 3) for x in n.inputs[7].default_value]])
    out["materials"][m.name] = info
print("JSONSTART" + json.dumps(out) + "JSONEND")