@tool
extends McpTestSuite
## 回归测试：脸部那套「UV 矩形 + 预设 + 画笔」的契约。
##
## body_mesh 只有一个材质 mat_body，脸部不再单独换材质，而是由 shader 顶部的
## face_center / face_size 在本体 UV 上圈出表情矩形。**模型重导或改 UV 之后，脸就会画歪、
## 被裁掉、甚至糊到肚子上，而且不报任何错** —— 所以这里把「矩形必须落在头部孤岛里」钉死，
## 改模型时先让测试红一次。数值本身从 shader 源码里读，方便随手调。

const PLAYER_SCENE_PATH := "res://character/player/player.tscn"
const SHADER_PATH := "res://character/player/face/face_paint.gdshader"
const PRESET_DIR := "res://character/player/face/presets"
const BODY_MESH_PATH := "Body/mouse/MouseRig/Skeleton3D/body_mesh"
const BODY_MATERIAL_NAME := "mat_body"

## UV 是浮点，给点容差
const EPS := 0.004


func suite_name() -> String:
	return "face"


func _shader_code() -> String:
	var file := FileAccess.open(SHADER_PATH, FileAccess.READ)
	assert_true(file != null, "%s 加载失败" % SHADER_PATH)
	if file == null:
		return ""
	return file.get_as_text()


## 从 shader 源码里抓 `uniform vec2 名字 = vec2(a, b);` 的两个数。
func _shader_vec2(code: String, name: String) -> Vector2:
	var marker := "uniform vec2 %s = vec2(" % name
	var start := code.find(marker)
	assert_true(start >= 0, "shader 里找不到 uniform vec2 %s 的默认值" % name)
	if start < 0:
		return Vector2(INF, INF)
	start += marker.length()
	var stop := code.find(")", start)
	if stop < 0:
		return Vector2(INF, INF)
	var parts := code.substr(start, stop - start).split(",")
	if parts.size() != 2:
		return Vector2(INF, INF)
	return Vector2(float(parts[0].strip_edges()), float(parts[1].strip_edges()))


func _player() -> Node:
	var packed := load(PLAYER_SCENE_PATH) as PackedScene
	assert_true(packed != null, "%s 未能加载" % PLAYER_SCENE_PATH)
	if packed == null:
		return null
	var player := packed.instantiate()
	track(player)
	return player


func _body_mesh() -> MeshInstance3D:
	var player := _player()
	if player == null:
		return null
	return player.get_node_or_null(BODY_MESH_PATH) as MeshInstance3D


## 找「最高处那块 UV 孤岛」（= 头部）的 UV 范围。脸部矩形必须落在它里面。
func _head_island_uv_rect() -> Rect2:
	var mi := _body_mesh()
	if mi == null:
		return Rect2()
	var mesh := mi.mesh as ArrayMesh
	if mesh == null or mesh.get_surface_count() == 0:
		return Rect2()
	var arrays := mesh.surface_get_arrays(0)
	var uvs := arrays[Mesh.ARRAY_TEX_UV] as PackedVector2Array
	var verts := arrays[Mesh.ARRAY_VERTEX] as PackedVector3Array
	var indices := PackedInt32Array()
	if arrays[Mesh.ARRAY_INDEX] is PackedInt32Array:
		indices = arrays[Mesh.ARRAY_INDEX]
	if uvs.size() == 0 or indices.size() == 0:
		return Rect2()
	var parent := []
	parent.resize(uvs.size())
	for i in uvs.size():
		parent[i] = i
	for t in indices.size() / 3:
		_union(parent, indices[t * 3], indices[t * 3 + 1])
		_union(parent, indices[t * 3], indices[t * 3 + 2])
	var groups := {}
	for i in uvs.size():
		var root := _find(parent, i)
		if not groups.has(root):
			groups[root] = []
		groups[root].append(i)
	var best_root := -1
	var best_top := -INF
	for root in groups:
		var members: Array = groups[root]
		var top := -INF
		for i in members:
			top = maxf(top, verts[i].y)
		if top > best_top:
			best_top = top
			best_root = root
	var members: Array = groups.get(best_root, [])
	var uv_min := Vector2(INF, INF)
	var uv_max := Vector2(-INF, -INF)
	for i in members:
		var uv: Vector2 = uvs[i]
		uv_min = Vector2(minf(uv_min.x, uv.x), minf(uv_min.y, uv.y))
		uv_max = Vector2(maxf(uv_max.x, uv.x), maxf(uv_max.y, uv.y))
	return Rect2(uv_min, uv_max - uv_min)


func _find(parent: Array, index: int) -> int:
	while parent[index] != index:
		parent[index] = parent[parent[index]]
		index = parent[index]
	return index


func _union(parent: Array, a: int, b: int) -> void:
	var root_a := _find(parent, a)
	var root_b := _find(parent, b)
	if root_a != root_b:
		parent[root_b] = root_a


func test_player_has_face_rig_wired() -> void:
	var player := _player()
	if player == null:
		return
	var rig := player.get_node_or_null("FaceRig") as FaceRig
	assert_true(rig != null, "Player 下缺少 FaceRig 节点")
	if rig == null:
		return
	assert_eq(rig.surface_index, 0, "body_mesh 只剩一个材质，FaceRig 必须覆盖 surface 0")
	assert_true(rig.get_node_or_null(rig.mesh_path) is MeshInstance3D,
		"FaceRig.mesh_path（%s）解析不到 MeshInstance3D —— 换模型后路径要跟着改" % rig.mesh_path)
	# 表情位置/大小只写在 shader 里；脚本一旦也传这三个 uniform，就会把调好的值盖掉
	var script_text := FileAccess.open("res://character/player/face/face_rig.gd", FileAccess.READ).get_as_text()
	for name in ["face_center", "face_size", "face_flip_y"]:
		assert_true(not script_text.contains("set_shader_parameter(\"%s\"" % name),
			"face_rig.gd 又在传 %s 了 —— shader 顶部调好的值会被脚本覆盖" % name)


func test_body_mesh_has_single_material() -> void:
	var mi := _body_mesh()
	assert_true(mi != null, "找不到 %s" % BODY_MESH_PATH)
	if mi == null:
		return
	var mesh := mi.mesh as ArrayMesh
	assert_true(mesh != null, "body_mesh 的 mesh 不是 ArrayMesh")
	if mesh == null:
		return
	assert_eq(mesh.get_surface_count(), 1, "body_mesh 应该只有一个材质槽了")
	var material := mesh.surface_get_material(0)
	assert_true(material != null, "surface 0 没有材质")
	if material == null:
		return
	assert_eq(material.resource_name, BODY_MATERIAL_NAME,
		"body_mesh 的材质不再是 %s，FaceRig 抄身体参数会失效" % BODY_MATERIAL_NAME)
	var standard := material as StandardMaterial3D
	assert_true(standard != null, "%s 不是 StandardMaterial3D" % BODY_MATERIAL_NAME)
	if standard != null:
		assert_true(standard.albedo_texture != null, "%s 没有 BaseColor 贴图，身体底色会变成白" % BODY_MATERIAL_NAME)


## 脸部矩形必须整块落在头部孤岛里，否则表情会画到身体别的部位上。
## 表情矩形（中心 ± 半个大小）必须整块落在头部孤岛里，否则表情会糊到别的部位上。
func test_face_rect_inside_head_island() -> void:
	var code := _shader_code()
	if code.is_empty():
		return
	var center := _shader_vec2(code, "face_center")
	var size := _shader_vec2(code, "face_size")
	if not center.is_finite() or not size.is_finite():
		return
	var head := _head_island_uv_rect()
	assert_true(head.size.x > 0.0 and head.size.y > 0.0, "没算出头部 UV 孤岛 —— 模型结构变了？")
	if head.size.x <= 0.0:
		return
	var rect_min := center - size * 0.5
	var rect_max := center + size * 0.5
	assert_true(rect_min.x >= head.position.x - EPS and rect_min.y >= head.position.y - EPS,
		"表情矩形左下角 %s 跑出了头部 UV 孤岛 %s（中心 %s 大小 %s）" % [rect_min, head, center, size])
	assert_true(rect_max.x <= head.end.x + EPS and rect_max.y <= head.end.y + EPS,
		"表情矩形右上角 %s 超出了头部 UV 孤岛 %s（中心 %s 大小 %s）—— 模型改过 UV 还是值调过头了？"
		% [rect_max, head, center, size])


func test_face_shader_has_expected_uniforms() -> void:
	var file := FileAccess.open(SHADER_PATH, FileAccess.READ)
	assert_true(file != null, "%s 加载失败" % SHADER_PATH)
	if file == null:
		return
	var code := file.get_as_text()
	for required in [
		"body_tex", "body_tint", "surface_roughness", "surface_metallic",
		"face_center", "face_size", "face_flip_y",
		"base_tex", "base_uv_min", "base_uv_size", "paint_tex",
	]:
		assert_true(code.contains("uniform ") and code.contains(required), "shader 少了 uniform %s" % required)
	assert_true(code.contains("texture(body_tex, UV)"),
		"shader 必须用 body_tex 采样全身底色，否则脸和身体不是同一块皮肤")
	assert_true(code.contains("ROUGHNESS = surface_roughness"), "shader 必须复用 mat_body 的 roughness")
	assert_true(code.contains("METALLIC = surface_metallic"), "shader 必须复用 mat_body 的 metallic")
	# alpha 只代表墨线覆盖率，不能写进空间 ALPHA，否则身体面片会被抠出洞
	assert_true(not code.contains("ALPHA ="), "面部 shader 写了 ALPHA，会把面片渲染成镂空")


func test_face_shader_copies_body_pbr_values() -> void:
	var mesh_node := _body_mesh()
	if mesh_node == null:
		return
	var body_material := mesh_node.mesh.surface_get_material(0) as StandardMaterial3D
	assert_true(body_material != null, "surface 0 应有 StandardMaterial3D")
	if body_material == null:
		return
	assert_true(absf(body_material.roughness - 0.65) < 0.001,
		"mat_body roughness 改变：当前 %f；FaceRig 会动态读取它，测试值跟着改" % body_material.roughness)
	assert_eq(body_material.metallic, 0.0, "mat_body metallic 改变；FaceRig 会动态读取它")


## 内置表情用的是项目里的透明图集副本（原始表情图已随模型一起删掉）。
func test_builtin_atlas_is_transparent_ink() -> void:
	var texture: Texture2D = load(FaceRig.ATLAS_PATH)
	assert_true(texture != null, "%s 加载失败" % FaceRig.ATLAS_PATH)
	if texture == null:
		return
	var image := texture.get_image()
	var transparent := false
	var visible_ink := false
	for y in range(0, image.get_height(), 8):
		for x in range(0, image.get_width(), 8):
			var a := image.get_pixel(x, y).a
			transparent = transparent or a < 0.05
			visible_ink = visible_ink or a > 0.5
	assert_true(transparent, "内置表情图集没有透明背景，可能忘了去蓝底")
	assert_true(visible_ink, "内置表情图集里没有可见笔画")


func test_builtin_face_uv_tiles_exist() -> void:
	assert_eq(FaceRig.BUILTIN_EXPRESSIONS.size(), 2, "内置表情清单应包含两张 atlas 表情")
	if FaceRig.BUILTIN_EXPRESSIONS.size() < 2:
		return
	assert_eq(FaceRig.BUILTIN_EXPRESSIONS[0]["id"], "builtin:face_01", "第一个内置表情 ID 改变")
	assert_eq(FaceRig.BUILTIN_EXPRESSIONS[1]["id"], "builtin:face_02", "第二个内置表情 ID 改变")
	for entry in FaceRig.BUILTIN_EXPRESSIONS:
		var rect: Rect2 = entry["rect"]
		assert_true(rect.position.x >= 0.0 and rect.position.y >= 0.0, "表情图集 rect 起点越界")
		assert_true(rect.end.x <= 1.0 and rect.end.y <= 1.0, "表情图集 rect 终点越界")


## 联机同步靠这几个方法名，改名了要一起改 —— 改了就不同步，而且不报错
func test_face_sync_methods_exist() -> void:
	var script := load("res://character/player/face/face_rig.gd") as GDScript
	assert_true(script != null, "face_rig.gd 加载失败")
	if script == null:
		return
	var names: Array[String] = []
	for m in script.get_script_method_list():
		names.append(str(m.get("name")))
	for required in [
		"_pull_remote_face", "_rpc_request_face", "_rpc_send_face",
		"get_expression_catalog", "select_expression", "save_drawing_as_expression",
	]:
		assert_true(names.has(required), "face_rig.gd 少了 %s，表情列表/保存/联机可能失效" % required)


## 「没有底图」用运行时创建的 RGBA ImageTexture，而不是磁盘上的全透明 PNG。
## Godot 导入器会把整张同 alpha 的 PNG 优化成 RGB，丢掉 alpha；运行时的 Image 则保留。
func test_runtime_blank_texture_preserves_alpha() -> void:
	var image := Image.create(2, 2, false, Image.FORMAT_RGBA8)
	var texture := ImageTexture.create_from_image(image)
	assert_true(texture != null, "运行时空白 ImageTexture 创建失败")
	if texture == null:
		return
	var loaded := texture.get_image()
	assert_eq(loaded.get_format(), Image.FORMAT_RGBA8, "空白贴图被降成了 RGB 格式")
	assert_eq(loaded.get_pixel(0, 0).a, 0.0, "空白贴图 alpha 应为 0")
	assert_eq(loaded.get_pixel(1, 1).a, 0.0, "空白贴图中心 alpha 应为 0")


func test_presets_are_square() -> void:
	var dir := DirAccess.open(PRESET_DIR)
	assert_true(dir != null, "打不开预设目录 %s" % PRESET_DIR)
	if dir == null:
		return
	var found := 0
	for f in dir.get_files():
		if not f.ends_with(".png"):
			continue
		found += 1
		var tex: Texture2D = load(PRESET_DIR + "/" + f)
		assert_true(tex != null, "预设 %s 加载失败" % f)
		if tex == null:
			continue
		var s := tex.get_size()
		assert_eq(int(s.x), int(s.y), "预设 %s 不是正方形（%s），贴到脸上会拉伸" % [f, s])
		var image := tex.get_image()
		var transparent := false
		var visible_ink := false
		for y in range(0, image.get_height(), 4):
			for x in range(0, image.get_width(), 4):
				var a := image.get_pixel(x, y).a
				transparent = transparent or a < 0.05
				visible_ink = visible_ink or a > 0.5
		assert_true(transparent, "预设 %s 没有透明背景，可能忘了去蓝底" % f)
		assert_true(visible_ink, "预设 %s 没有可见笔画" % f)
	assert_gt(found, 0, "%s 里一张预设都没有" % PRESET_DIR)