# vr_decals.py - stencil decals (textures/T_VR_Decals.png, made by vr_decal_atlas.py).
# Each decal is a quad cast onto its plate by a ray, 0.8 mm off the surface, skinned to the
# plate's bone. Right-side decals are cast separately (mirrored ray), so no text reads mirrored.
# Run after vr_build.build():  exec(...); place_all(ns)   (ns = vr_build's namespace)
import bpy, bmesh, json, math
from mathutils import Vector as V

ROOT = r"D:\HADAL - The Descent\models\veiled-robot"
ATLAS = ROOT + r"\textures\T_VR_Decals.png"


def decal_mat():
    m = bpy.data.materials.get("M_VR_Decal") or bpy.data.materials.new("M_VR_Decal")
    m.use_nodes = True; nt = m.node_tree; N = nt.nodes; L = nt.links.new
    for n in list(N):
        N.remove(n)
    out = N.new("ShaderNodeOutputMaterial"); bs = N.new("ShaderNodeBsdfPrincipled")
    tx = N.new("ShaderNodeTexImage"); tx.image = bpy.data.images.load(ATLAS, check_existing=True)
    tx.image.colorspace_settings.name = "sRGB"; tx.interpolation = 'Cubic'
    tc = N.new("ShaderNodeTexCoord")
    noi = N.new("ShaderNodeTexNoise"); noi.inputs["Scale"].default_value = 160; noi.inputs["Detail"].default_value = 10
    L(tc.outputs["Object"], noi.inputs["Vector"])
    wear = N.new("ShaderNodeMapRange")            # paint rubbed off in small flecks
    wear.inputs["From Min"].default_value = 0.30; wear.inputs["From Max"].default_value = 0.40
    L(noi.outputs["Fac"], wear.inputs["Value"])
    a = N.new("ShaderNodeMath"); a.operation = 'MULTIPLY'
    L(tx.outputs["Alpha"], a.inputs[0]); L(wear.outputs["Result"], a.inputs[1])
    a2 = N.new("ShaderNodeMath"); a2.operation = 'MULTIPLY'; a2.inputs[1].default_value = 0.92
    L(a.outputs["Value"], a2.inputs[0])
    bs.inputs["Base Color"].default_value = (0.72, 0.73, 0.70, 1); bs.inputs["Roughness"].default_value = 0.55
    L(a2.outputs["Value"], bs.inputs["Alpha"])
    L(bs.outputs["BSDF"], out.inputs["Surface"])
    m.diffuse_color = (0.8, 0.8, 0.8, 1)
    return m


def cast(part, origin, direction, up, region, width, name, coll):
    ob = bpy.data.objects[part]
    ok, loc, nrm, _ = ob.ray_cast(V(origin), V(direction).normalized())
    if not ok:
        return None
    n = nrm.normalized(); u = V(up); u = (u - n * u.dot(n)).normalized(); r = u.cross(n)
    meta = json.load(open(ROOT + r"\textures\T_VR_Decals.json"))
    S = meta["size"]; x0, y0, x1, y1 = meta["regions"][region]
    h = width * (y1 - y0) / (x1 - x0)
    c = loc + n * 0.0008
    pts = [c - r * width / 2 - u * h / 2, c + r * width / 2 - u * h / 2, c + r * width / 2 + u * h / 2, c - r * width / 2 + u * h / 2]
    uvs = [(x0 / S, 1 - y1 / S), (x1 / S, 1 - y1 / S), (x1 / S, 1 - y0 / S), (x0 / S, 1 - y0 / S)]
    old = bpy.data.objects.get(name)
    if old:
        me_o = old.data; bpy.data.objects.remove(old); bpy.data.meshes.remove(me_o)
    me = bpy.data.meshes.new(name); bm = bmesh.new()
    f = bm.faces.new([bm.verts.new(p) for p in pts])
    uvl = bm.loops.layers.uv.new("UVMap")
    for lp, uv in zip(f.loops, uvs):
        lp[uvl].uv = uv
    bm.to_mesh(me); bm.free()
    me.materials.append(bpy.data.materials["M_VR_Decal"])
    o = bpy.data.objects.new(name, me); coll.objects.link(o)
    bone = ob["vr_bone"]
    vg = o.vertex_groups.new(name=bone); vg.add(range(4), 1.0, 'REPLACE')
    rig = bpy.data.objects["VR_Rig"]; o.parent = rig
    md = o.modifiers.new("Armature", 'ARMATURE'); md.object = rig
    o.visible_shadow = False
    o["vr_bone"] = bone
    return o


def place_all(ns):
    decal_mat()
    top = bpy.data.collections["VeiledRobot"]
    coll = bpy.data.collections.get("VR | Decals") or bpy.data.collections.new("VR | Decals")
    if coll.name not in [c.name for c in top.children]:
        top.children.link(coll)
    for o in list(coll.objects):
        bpy.data.objects.remove(o)
    F_UA, F_LA, F_TH, F_CA = ns["F_UA"], ns["F_LA"], ns["F_TH"], ns["F_CA"]
    R3 = lambda M, v: M.to_3x3() @ V(v)
    jobs = [  # part, origin, direction, up, region, width
        ("VR_ChestPlate", (0, -0.5, 1.455), (0, 1, 0), (0, 0, 1), "unit", 0.15),
        ("VR_ChestPlate", (0.105, -0.5, 1.352), (0, 1, 0), (0, 0, 1), "badge", 0.034),
        ("VR_ChestPlate", (-0.105, -0.5, 1.352), (0, 1, 0), (0, 0, 1), "badge", 0.034),
        ("VR_Abdomen", (0, -0.5, 1.19), (0, 1, 0), (0, 0, 1), "emblem", 0.055),
        ("VR_BackUnit", (0, 0.5, 1.43), (0, -1, 0), (0, 0, 1), "frame07", 0.075),
        ("VR_BackUnit", (0, 0.5, 1.345), (0, -1, 0), (0, 0, 1), "ruler", 0.09),
        ("VR_Head", (-0.5, 0.06, 1.74), (1, 0, 0), (0, 0, 1), "code", 0.06),
        ("VR_Pelvis", (0, -0.5, 1.015), (0, 1, 0), (0, 0, 1), "code", 0.07),
    ]
    side = [
        ("VR_UpperArm_l", F_UA @ V((0.5, 0, 0.10)), R3(F_UA, (-1, 0, 0)), R3(F_UA, (0, 1, 0)), "unit", 0.13),
        ("VR_UpperArm_l", F_UA @ V((0, -0.5, 0.06)), R3(F_UA, (0, 1, 0)), R3(F_UA, (0, 0, -1)), "badge", 0.03),
        ("VR_Forearm_l", F_LA @ V((0.5, 0, 0.15)), R3(F_LA, (-1, 0, 0)), R3(F_LA, (0, 1, 0)), "code", 0.075),
        ("VR_Thigh_l", F_TH @ V((0, 0.5, 0.17)), R3(F_TH, (0, -1, 0)), R3(F_TH, (0, 0, -1)), "ruler", 0.09),
        ("VR_Thigh_l", F_TH @ V((0.5, 0.03, 0.15)), R3(F_TH, (-1, 0, 0)), R3(F_TH, (0, 0, -1)), "frame07", 0.05),
        ("VR_Shin_l", F_CA @ V((0, 0.5, 0.15)), R3(F_CA, (0, -1, 0)), R3(F_CA, (0, 0, -1)), "chevron", 0.06),
        ("VR_HipPlate_l", (0.5, 0.0, 1.105), (-1, 0, 0), (0, 0, 1), "badge", 0.035),
        ("VR_Shin_l", F_CA @ V((0.5, 0.02, 0.24)), R3(F_CA, (-1, 0, 0)), R3(F_CA, (0, 0, -1)), "code", 0.06),
    ]
    mir = lambda v: V((-v[0], v[1], v[2]))
    for p, o, d, u, reg, w in side:
        jobs.append((p, o, d, u, reg, w))
        jobs.append((p[:-2] + "_r", mir(o), mir(d), mir(u), reg, w))
    made, missed = 0, []
    for i, (p, o, d, u, reg, w) in enumerate(jobs):
        ob = cast(p, o, d, u, reg, w, f"VR_Decal_{i:02d}_{p[3:]}", coll)
        if ob:
            made += 1
        else:
            missed.append(p)
    return {"decals": made, "missed": missed}