"""Surfaces of the canister station, headless, in place:

    blender.exe -b ../CanisterStation.blend --python cs_surfaces.py [-- --nobake]

The feeder's recipe (models/nutrition-feeder/build/nf_surfaces.py, from the docking arm and the pressure hatch), for
the user's rule "realistic with good textures" from the first version:
  * tiling sets from the user's own Season 2 pack (already in the Unreal project), read in place by relative path from
    models/vessel-interior/textures/ModSci_Engineer/Textures: ScratchedMetal under the paints, BrushedMetal for the
    bare metal, Glass_DirtRough as a smudge mask, T_Scratch_Norm for fine scratches on the metal;
  * one mask map baked from each mesh in Cycles (R occlusion, G edges, B crevices): textures/T_CS_Body_Masks.png
    (4096) and T_CS_Canister_Masks.png (2048): shade in crevices, a little wear on edges (an industrial machine, but
    the ship is clean: low);
  * drawn textures (cs_textures.py): the radiation sign (a decal patch, alpha-masked), the status screen, the glow
    ring's colours along its circumference.
Tints are the picture's colours, sampled from reference/ref_user.png (linear): green panels 0.04 0.07 0.063, black
0.018, the grey head 0.14, cream 0.60 0.55 0.47, the light grey plate 0.48.
UV layers (order matters for Unreal):
    UVMap   (UV0) a unique unwrap into the mesh's mask map; the screen, the decal and the glow ring take their own
                  texture's 0..1 (from the build's UV_Special layer, or planar for the screen)
    UV_Tile (UV1) metres, box-projected, for the tiling sets
"""
import bpy, bmesh, math, os, sys, time, json
import numpy as np

HERE = os.path.dirname(os.path.abspath(__file__))
FOLDER = os.path.dirname(HERE)
TEX = os.path.join(FOLDER, "textures")
PACK = os.path.normpath(os.path.join(FOLDER, "..", "vessel-interior", "textures", "ModSci_Engineer", "Textures"))
SCR = ("Base/ScratchedMetal/T_ScratchedMetal_Diff.png", "Base/ScratchedMetal/T_ScratchedMetal_Rough.png", "Base/ScratchedMetal/T_ScratchedMetal_Normal.png")
BRU = ("Base/BrushedMetal/T_BrushedMetal_Diff.png", "Base/BrushedMetal/T_BrushedMetal_Rough.png", "Base/BrushedMetal/T_BrushedMetal_Normal.png")
DIRT = "Base/Glass/T_Glass_DirtRough.png"
SCRATCH_N = "Base/Glass/T_Scratch_Norm.png"
MASKS = {"SM_CanisterStation_Body": ("T_CS_Body_Masks", 4096), "SM_CanisterStation_Canister": ("T_CS_Canister_Masks", 2048)}
EDGE_R = 0.004

PAINT = dict(set=SCR, metal=0.0, tile=0.60, shade=(0.96, 1.03), rough=(0.42, 0.30), normal=0.14, dirt=0.04, dirt_tile=1.4,
             grime=0.18, wear=0.0, wear_col=(0.55, 0.56, 0.57), wear_rough=0.35)
SURF = {
    "M_CS_Green":  dict(PAINT, tint=(0.036, 0.063, 0.058)),
    "M_CS_Black":  dict(PAINT, tint=(0.016, 0.016, 0.017), rough=(0.55, 0.42)),
    "M_CS_Grey":   dict(PAINT, tint=(0.085, 0.090, 0.095), rough=(0.50, 0.38)),
    "M_CS_Cream":  dict(PAINT, tint=(0.56, 0.51, 0.44), rough=(0.40, 0.30), grime=0.14),
    "M_CS_Steel":  dict(PAINT, tint=(0.42, 0.425, 0.44), rough=(0.45, 0.34), grime=0.14),
    "M_CS_PanelDark": dict(PAINT, tint=(0.045, 0.052, 0.052), rough=(0.50, 0.38)),
    "M_CS_Chrome": dict(set=BRU, tint=(0.70, 0.66, 0.60), metal=1.0, tile=0.10, shade=(0.95, 1.04), rough=(0.24, 0.34),
                        normal=0.25, normal_map=SCRATCH_N, dirt=0.03, dirt_tile=0.6, grime=0.12, wear=0.0),
    "M_CS_Rubber": dict(PAINT, tint=(0.010, 0.010, 0.011), rough=(0.70, 0.60), normal=0.05, grime=0.0),
    "M_CS_Gap":    dict(set=(None, SCR[1], None), tint=(0.006, 0.006, 0.007), metal=0.0, tile=0.40, shade=(1.0, 1.0),
                        rough=(0.70, 0.55), normal=0.0, dirt=0.0, dirt_tile=1.0, grime=0.0, wear=0.0),
}
NOBAKE = {"M_CS_Screen", "M_CS_Glow", "M_CS_Decal"}
SPECIAL = {"M_CS_Screen", "M_CS_Glow", "M_CS_Decal"}


# ------------------------------------------------------------------ UV layers
def uv_tile_layer(me):
    """metres, by the face's dominant axis"""
    uv = me.uv_layers.get("UV_Tile") or me.uv_layers.new(name="UV_Tile")
    co = np.zeros(len(me.vertices) * 3, np.float32)
    me.vertices.foreach_get("co", co)
    co = co.reshape(-1, 3)
    out = np.zeros((len(me.loops), 2), np.float32)
    for p in me.polygons:
        n = p.normal
        ax = 0 if abs(n.x) >= abs(n.y) and abs(n.x) >= abs(n.z) else (1 if abs(n.y) >= abs(n.z) else 2)
        for li in range(p.loop_start, p.loop_start + p.loop_total):
            c = co[me.loops[li].vertex_index]
            out[li] = (c[1], c[2]) if ax == 0 else ((c[0], c[2]) if ax == 1 else (c[0], c[1]))
    uv.data.foreach_set("uv", out.ravel())


def uv_atlas_layer(ob, rect):
    """UVMap: a unique unwrap of the mesh into its own mask map; special faces keep their own 0..1"""
    me = ob.data
    keep = {}
    for l in me.uv_layers:
        a = np.zeros(len(me.loops) * 2, np.float32)
        l.data.foreach_get("uv", a)
        keep[l.name] = a
    while len(me.uv_layers):
        me.uv_layers.remove(me.uv_layers[0])
    for nm in ("UVMap", "UV_Tile"):
        me.uv_layers.new(name=nm).data.foreach_set("uv", keep.get(nm, np.zeros(len(me.loops) * 2, np.float32)))
    me.uv_layers.active = me.uv_layers["UVMap"]
    me.uv_layers["UVMap"].active_render = True
    names = [m.name for m in me.materials]
    si = names.index("M_NF_Screen") if "M_NF_Screen" in names else -1
    vl = bpy.context.view_layer
    for o in vl.objects:
        o.select_set(False)
    ob.select_set(True)
    vl.objects.active = ob
    for p in me.polygons:
        p.select = p.material_index != si
    bpy.ops.object.mode_set(mode='EDIT')
    bpy.ops.mesh.select_mode(type='FACE')
    x0, y0, s = rect
    margin = 6.0 / (s * ATLAS_SIZE)
    bpy.ops.uv.smart_project(angle_limit=math.radians(55), island_margin=margin, area_weight=0.0, correct_aspect=True,
                             scale_to_bounds=False)
    bpy.ops.uv.select_all(action='SELECT')
    try:
        bpy.ops.uv.pack_islands(rotate=True, scale=True, margin_method='FRACTION', margin=margin, shape_method='CONCAVE')
    except Exception as ex:
        print("pack skipped", ob.name, ex)
    bpy.ops.object.mode_set(mode='OBJECT')
    a = np.zeros(len(me.loops) * 2, np.float32)
    me.uv_layers["UVMap"].data.foreach_get("uv", a)
    a = a.reshape(-1, 2)
    pad = 4.0 / (s * ATLAS_SIZE)
    a = np.array([x0, y0], np.float32) + (pad + np.clip(a, 0, 1) * (1 - 2 * pad)) * s
    if si >= 0:                                       # the glass: the whole UI texture, planar from picture pixels
        gx0, gy0, gx1, gy1 = GLASS
        for p in me.polygons:
            if p.material_index != si:
                continue
            for li in range(p.loop_start, p.loop_start + p.loop_total):
                c = me.vertices[me.loops[li].vertex_index].co
                u, v = c.x / S + U0, V0 - c.z / S
                a[li] = (min(max((u - gx0) / (gx1 - gx0), 0), 1), min(max(1.0 - (v - gy0) / (gy1 - gy0), 0), 1))
    me.uv_layers["UVMap"].data.foreach_set("uv", a.ravel())


# ------------------------------------------------------------------ bake
def use_gpu():
    sc = bpy.context.scene
    sc.render.engine = 'CYCLES'
    try:
        prefs = bpy.context.preferences.addons['cycles'].preferences
        prefs.compute_device_type = 'HIP'
        prefs.get_devices()
        for d in prefs.devices:
            d.use = d.type == 'HIP'
        sc.cycles.device = 'GPU'
        return 'HIP'
    except Exception as ex:
        print("GPU not set:", ex)
        sc.cycles.device = 'CPU'
        return 'CPU'


def bake_masks(parts):
    """parts: [(name, mesh)]. One emit bake of each mesh alone (occlusion counts only the mesh itself)."""
    t0 = time.time()
    kind = use_gpu()
    sc = bpy.context.scene
    N = ATLAS_SIZE
    for im in [i for i in bpy.data.images if i.name.startswith("T_NF_Masks")]:
        bpy.data.images.remove(im)
    masks = bpy.data.images.new("T_NF_Masks", N, N, alpha=False)
    masks.colorspace_settings.name = 'Non-Color'
    masks.pixels.foreach_set(np.tile(np.array((1.0, 0.0, 1.0, 1.0), np.float32), N * N))
    mm = bpy.data.materials.new("_bake_masks")
    mm.use_nodes = True
    nt = mm.node_tree
    nt.nodes.clear()
    ao = nt.nodes.new('ShaderNodeAmbientOcclusion'); ao.samples = 24; ao.only_local = True; ao.inputs["Distance"].default_value = 0.12
    cv = nt.nodes.new('ShaderNodeAmbientOcclusion'); cv.samples = 16; cv.only_local = True; cv.inputs["Distance"].default_value = 0.012
    bv = nt.nodes.new('ShaderNodeBevel'); bv.samples = 8; bv.inputs["Radius"].default_value = EDGE_R
    geo = nt.nodes.new('ShaderNodeNewGeometry')
    dot = nt.nodes.new('ShaderNodeVectorMath'); dot.operation = 'DOT_PRODUCT'
    nt.links.new(bv.outputs["Normal"], dot.inputs[0]); nt.links.new(geo.outputs["Normal"], dot.inputs[1])
    inv = nt.nodes.new('ShaderNodeMath'); inv.operation = 'SUBTRACT'; inv.inputs[0].default_value = 1.0
    nt.links.new(dot.outputs["Value"], inv.inputs[1])
    edg = nt.nodes.new('ShaderNodeMath'); edg.operation = 'MULTIPLY'; edg.inputs[1].default_value = 3.5; edg.use_clamp = True
    nt.links.new(inv.outputs[0], edg.inputs[0])
    cc = nt.nodes.new('ShaderNodeCombineColor')
    nt.links.new(ao.outputs["AO"], cc.inputs[0]); nt.links.new(edg.outputs[0], cc.inputs[1]); nt.links.new(cv.outputs["AO"], cc.inputs[2])
    em = nt.nodes.new('ShaderNodeEmission')
    nt.links.new(cc.outputs[0], em.inputs["Color"])
    om = nt.nodes.new('ShaderNodeOutputMaterial')
    nt.links.new(em.outputs[0], om.inputs["Surface"])
    ti = nt.nodes.new('ShaderNodeTexImage'); ti.image = masks
    nt.nodes.active = ti
    sc.cycles.samples = 24
    sc.cycles.use_denoising = False
    sc.render.bake.margin = 6
    sc.render.bake.use_clear = False
    for name, src in parts:
        me = src.copy()
        bm = bmesh.new()
        bm.from_mesh(me)
        names = [m.name for m in me.materials]
        bmesh.ops.delete(bm, geom=[f for f in bm.faces if names[f.material_index] in NOBAKE], context='FACES')
        for f in bm.faces:
            f.material_index = 0
        bm.to_mesh(me)
        bm.free()
        me.materials.clear()
        me.materials.append(mm)
        me.uv_layers.active = me.uv_layers["UVMap"]
        me.uv_layers["UVMap"].active_render = True
        tmp = bpy.data.objects.new("_bake_" + name, me)
        sc.collection.objects.link(tmp)
        for o2 in bpy.context.view_layer.objects:
            o2.select_set(False)
        tmp.select_set(True)
        bpy.context.view_layer.objects.active = tmp
        try:
            bpy.ops.object.bake(type='EMIT', margin=6, use_clear=False)
        finally:
            bpy.data.objects.remove(tmp)
            bpy.data.meshes.remove(me)
    os.makedirs(TEX, exist_ok=True)
    masks.filepath_raw = os.path.join(TEX, "T_NF_Masks.png")
    masks.file_format = 'PNG'
    masks.save()
    masks.filepath = bpy.path.relpath(masks.filepath_raw)
    bpy.data.materials.remove(mm)
    return masks, dict(device=kind, seconds=round(time.time() - t0, 1), size=N)


# ------------------------------------------------------------------ materials (node recipe from the docking arm)
def tex_image(path, colorspace="sRGB"):
    path = os.path.normpath(path)
    for im in bpy.data.images:
        if im.filepath and os.path.normpath(bpy.path.abspath(im.filepath)) == path:
            return im
    im = bpy.data.images.load(path)
    im.colorspace_settings.name = colorspace
    try:
        im.filepath = bpy.path.relpath(path)
    except Exception:
        pass
    return im


_RANGE = {}
def tex_range(im, lo=3, hi=97):
    if im.name not in _RANGE:
        n, ch = im.size[0] * im.size[1], im.channels
        px = np.empty(n * ch, np.float32)
        im.pixels.foreach_get(px)
        px = px.reshape(n, ch)
        if ch >= 3:
            c = px[:, :3]
            if im.colorspace_settings.name == 'sRGB':
                c = np.where(c <= 0.04045, c / 12.92, ((c + 0.055) / 1.055) ** 2.4)
            v = c @ np.array([0.2126, 0.7152, 0.0722], np.float32)
        else:
            v = px[:, 0]
        _RANGE[im.name] = (round(float(np.percentile(v, lo)), 4), round(float(np.percentile(v, hi)), 4))
    return _RANGE[im.name]


class Tree:
    def __init__(self, mat):
        mat.use_nodes = True
        self.nt = mat.node_tree
        self.nt.nodes.clear()
    def node(self, kind, label=None, **props):
        n = self.nt.nodes.new(kind)
        if label:
            n.label = label
        for k, v in props.items():
            setattr(n, k, v)
        i = len(self.nt.nodes) - 1
        n.location = (-2000 + 240 * (i // 4), 500 - 320 * (i % 4))
        return n
    def link(self, a, b):
        self.nt.links.new(a, b)
    def put(self, sock, v):
        if isinstance(v, bpy.types.NodeSocket):
            self.nt.links.new(v, sock)
        else:
            sock.default_value = v
    def math(self, op, a, b=None, clamp=False, label=None):
        n = self.node('ShaderNodeMath', label, operation=op, use_clamp=clamp)
        self.put(n.inputs[0], a)
        if b is not None:
            self.put(n.inputs[1], b)
        return n.outputs[0]
    def ranged(self, v, lo, hi, label=None, f0=0.0, f1=1.0, smooth=False):
        n = self.node('ShaderNodeMapRange', label)
        if smooth:
            n.interpolation_type = 'SMOOTHSTEP'
        self.put(n.inputs["Value"], v)
        n.inputs["From Min"].default_value = f0; n.inputs["From Max"].default_value = f1
        n.inputs["To Min"].default_value = lo; n.inputs["To Max"].default_value = hi
        return n.outputs["Result"]
    def mixc(self, fac, a, b, label=None):
        n = self.node('ShaderNodeMix', label, data_type='RGBA')
        self.put(n.inputs[0], fac)
        self.put(n.inputs[6], a if isinstance(a, bpy.types.NodeSocket) else tuple(a) + (1.0,))
        self.put(n.inputs[7], b if isinstance(b, bpy.types.NodeSocket) else tuple(b) + (1.0,))
        return n.outputs[2]
    def mixf(self, fac, a, b, label=None):
        n = self.node('ShaderNodeMix', label, data_type='FLOAT')
        self.put(n.inputs[0], fac); self.put(n.inputs[2], a); self.put(n.inputs[3], b)
        return n.outputs[0]
    def uv(self, name):
        return self.node('ShaderNodeUVMap', uv_map=name).outputs["UV"]
    def mapped(self, src, scale, label=None):
        n = self.node('ShaderNodeMapping', label)
        self.nt.links.new(src, n.inputs["Vector"])
        n.inputs["Scale"].default_value = (scale, scale, scale)
        return n.outputs["Vector"]
    def tex(self, im, vec, label=None):
        n = self.node('ShaderNodeTexImage', label, image=im)
        self.nt.links.new(vec, n.inputs["Vector"])
        return n


def dress(mat, r, masks=None):
    """a coated or bare metal surface: a tiling set + smudges; with the baked masks also shade in crevices"""
    t = Tree(mat)
    b = t.node('ShaderNodeBsdfPrincipled')
    out = t.node('ShaderNodeOutputMaterial')
    t.link(b.outputs[0], out.inputs["Surface"])
    u0 = t.uv("UV_Tile")
    mp = t.mapped(u0, 1.0 / r["tile"], "one repeat = %.2f m" % r["tile"])
    diff, rough, normal = r["set"]
    dirt = t.tex(tex_image(os.path.join(PACK, DIRT), "Non-Color"), t.mapped(u0, 1.0 / r["dirt_tile"]), "smudges and dust").outputs["Color"]
    ao = edge = crev = None
    if masks is not None:
        sep = t.node('ShaderNodeSeparateColor')
        t.link(t.tex(masks, t.uv("UVMap"), "baked: R occlusion, G edges, B crevices").outputs["Color"], sep.inputs[0])
        ao, edge, crev = sep.outputs[0], sep.outputs[1], sep.outputs[2]
    tint = tuple(r["tint"])
    col = tint
    if diff:
        im = tex_image(os.path.join(PACK, diff))
        lo, hi = tex_range(im)
        bw = t.node('ShaderNodeRGBToBW')
        t.link(t.tex(im, mp, "surface, diffuse").outputs["Color"], bw.inputs[0])
        sh = t.ranged(bw.outputs[0], r["shade"][0], r["shade"][1], "shade the tint", lo, hi)
        vm = t.node('ShaderNodeVectorMath', "tint x shade", operation='SCALE')
        vm.inputs[0].default_value = tint
        t.link(sh, vm.inputs["Scale"])
        col = vm.outputs["Vector"]
    grime = None
    if crev is not None and r["grime"] > 0:
        grime = t.math('MULTIPLY', t.math('POWER', t.math('SUBTRACT', 1.0, crev), 1.4), r["grime"], clamp=True, label="shade in crevices")
        col = t.mixc(grime, col, (0.02, 0.019, 0.018), "darken crevices")
    if ao is not None:
        col = t.mixc(t.ranged(ao, 0.25, 0.0, "occlusion", 0.0, 1.0), col, (0.004, 0.005, 0.006), "occlusion")
    rim = tex_image(os.path.join(PACK, rough), "Non-Color")
    rlo, rhi = tex_range(rim)
    ro = t.tex(rim, mp, "surface, roughness").outputs["Color"]
    rr = t.ranged(ro, r["rough"][0], r["rough"][1], "roughness range", rlo, rhi)
    rr = t.math('ADD', rr, t.math('MULTIPLY', dirt, r["dirt"]), clamp=True, label="smudges dull the sheen")
    if grime is not None:
        rr = t.math('ADD', rr, t.math('MULTIPLY', grime, 0.30), clamp=True, label="crevices are matte")
    t.put(b.inputs["Base Color"], col)
    t.put(b.inputs["Roughness"], rr)
    t.put(b.inputs["Metallic"], r["metal"])
    nm_file = r.get("normal_map") or normal
    if nm_file and r["normal"] > 0:
        nd = t.node('ShaderNodeNormalMap', "fine relief", uv_map="UV_Tile")
        nd.inputs["Strength"].default_value = r["normal"]
        t.link(t.tex(tex_image(os.path.join(PACK, nm_file), "Non-Color"), mp, "surface, normal").outputs["Color"], nd.inputs["Color"])
        t.link(nd.outputs["Normal"], b.inputs["Normal"])
    mat.diffuse_color = tuple(r["tint"]) + (1.0,)
    mat.metallic = r["metal"]


def dress_glow(mat, color, strength):
    t = Tree(mat)
    b = t.node('ShaderNodeBsdfPrincipled')
    out = t.node('ShaderNodeOutputMaterial')
    t.link(b.outputs[0], out.inputs["Surface"])
    b.inputs["Base Color"].default_value = (0.5, 0.8, 0.9, 1)
    b.inputs["Roughness"].default_value = 0.15
    b.inputs["Emission Color"].default_value = tuple(color) + (1,)
    b.inputs["Emission Strength"].default_value = strength
    mat.diffuse_color = tuple(color) + (1.0,)


def dress_screen(mat, img):
    """the UI under a glossy glass: the texture is the emission, a clear coat gives the glass its reflections"""
    t = Tree(mat)
    b = t.node('ShaderNodeBsdfPrincipled')
    out = t.node('ShaderNodeOutputMaterial')
    t.link(b.outputs[0], out.inputs["Surface"])
    tx = t.tex(img, t.uv("UVMap"), "status screen (nf_screen_ui.py)")
    b.inputs["Base Color"].default_value = (0.004, 0.006, 0.008, 1)
    b.inputs["Roughness"].default_value = 0.60
    b.inputs["Specular IOR Level"].default_value = 0.03     # a matte anti-glare glass: no mirror of the room's lights
    t.link(tx.outputs["Color"], b.inputs["Emission Color"])
    b.inputs["Emission Strength"].default_value = 2.0
    mat.diffuse_color = (0.05, 0.25, 0.35, 1)