# tests/unit/battle_settlement/damage_math_test.gd — 战斗结算·伤害公式族纯函数单元测试
# 运行：godot --headless --path game --script res://tests/unit/battle_settlement/damage_math_test.gd
# 协议：DamageMath = 零状态纯算术宿主（headless 可跑）；掷点档位参数全读 settlement 表（零玩法数值字面量）。
# 注：0/100 等出现在断言中的数值 = 语义常量（中性池/百分比满额），非玩法行值。
extends SceneTree

const DamageMathScript := preload("res://core/damage_math.gd")
const ConfigDBScript := preload("res://core/config_db.gd")
const Kit := preload("res://tests/unit/test_kit.gd")   # T6 收口：_check/汇总退出样板单点

var db


func _init() -> void:
	db = ConfigDBScript.new()
	var load_ok: bool = db.load_tables("res://data/tables", true)
	Kit.check("前置：settlement 表加载零 error", load_ok and db.diagnostics_count("error") == 0)
	if load_ok:
		_test_pool_damage()
		_test_counter_component()
		_test_roll_discount_percent()
		_test_rolled_component()
	quit(Kit.finish("damage_math_test"))


func _floor_val() -> int:
	return int(db.settlement.damage_floor)


# ---- F2 乘区：池内加算 → 池间乘算 → floor（单一取整规则）----

func _test_pool_damage() -> void:
	var d := _floor_val() + 9   # 表值推导的任意正探针量（非玩法行值）
	Kit.check("中性双池 (0,0) 原样透传", DamageMathScript.pool_damage(d, 0, 0) == d)
	Kit.check("负敌方池压低不增高", DamageMathScript.pool_damage(d, 0, int(db.settlement.pool_clamp_lo)) <= d)
	Kit.check("正·主角池抬升不低于原值", DamageMathScript.pool_damage(d, int(db.settlement.pool_clamp_hi), 0) >= d)
	Kit.check("主角池单调不减（+50% vs +49% 探针档）", DamageMathScript.pool_damage(d, 50, 0) >= DamageMathScript.pool_damage(d, 49, 0))
	Kit.check("对称性：池值互换结果不变（乘算交换）", DamageMathScript.pool_damage(d, 30, -20) == DamageMathScript.pool_damage(d, -20, 30))
	Kit.check("输出非负（maxi(0,·) 封底）", DamageMathScript.pool_damage(d, int(db.settlement.pool_clamp_lo), int(db.settlement.pool_clamp_lo)) >= 0)


# ---- 克制分量：空桶不吃修正恒 0；落地下限保底（[1,+∞) 全来源）----

func _test_counter_component() -> void:
	var floor_v := _floor_val()
	Kit.check("空桶（点数≤0）恒 0 不吃修正", DamageMathScript.counter_component(0, floor_v, floor_v) == 0
		and DamageMathScript.counter_component(-1, 5, floor_v) == 0)
	Kit.check("正向修正直加", DamageMathScript.counter_component(floor_v, floor_v, floor_v) == floor_v * 2)
	Kit.check("负修正触底保落地伤害下限", DamageMathScript.counter_component(floor_v, -floor_v * 10, floor_v) == floor_v)
	Kit.check("下限参数缺省 = 0（无下限语义面）", DamageMathScript.counter_component(floor_v, -floor_v * 10) == 0)


# ---- 掷点折扣查档（纯函数）：满阈值恒全额；档位边界/末档语义与表数组一致 ----

func _test_roll_discount_percent() -> void:
	var threshold := 10   # 查档探针阈值（夹具值——档位参数本身全部来自表）
	var bounds: Array = db.settlement.roll_tier_bounds
	var discounts: Array = db.settlement.roll_tier_discounts
	Kit.check("前置：档位数 = 边界数 + 1（查档契约——档数 = 边界数 + 1）", discounts.size() == bounds.size() + 1 and discounts.size() > 0)
	Kit.check("掷点 ≥ 阈值恒全额 100", DamageMathScript.roll_discount_percent(threshold, threshold, bounds, discounts) == 100
		and DamageMathScript.roll_discount_percent(threshold + 5, threshold, bounds, discounts) == 100)
	# 缺口 = 1：落首档（缺口 ∈ [1, bounds[0]] → discounts[0]）
	var tier0_expected: int = int(discounts[0])
	if int(bounds[0]) >= 1:
		Kit.check("缺口 1 落首档", DamageMathScript.roll_discount_percent(threshold - 1, threshold, bounds, discounts) == tier0_expected)
	# 缺口超末边界：落末档
	var last_expected: int = int(discounts[-1])
	Kit.check("缺口超末边界落末档", DamageMathScript.roll_discount_percent(threshold - int(bounds[-1]) - 1, threshold, bounds, discounts) == last_expected)
	# 档位值降序（重档折扣更深）——表自检
	var descending := true
	for i in range(discounts.size() - 1):
		if int(discounts[i]) < int(discounts[i + 1]):
			descending = false
	Kit.check("档位值随档位加深不升（折扣单调）", descending)


# ---- 吃掷点分量算术：折扣→(暴击)→floor→+克制修正（单一取整链）----

func _test_rolled_component() -> void:
	var base := float(_floor_val() + 7)   # 表值推导探针基线
	var crit_mult: int = int(db.settlement.crit_multiplier)
	Kit.check("满额折扣无暴击 = floor(基线) + 修正 0", DamageMathScript.rolled_component(base, 100, false, crit_mult, 0) == int(floor(base)))
	Kit.check("满额折扣暴击按表倍率放大", DamageMathScript.rolled_component(base, 100, true, crit_mult, 0) == int(floor(base * float(crit_mult) / 100.0)))
	Kit.check("折扣降低不高于满额", DamageMathScript.rolled_component(base, 50, false, crit_mult, 0) <= DamageMathScript.rolled_component(base, 100, false, crit_mult, 0))
	Kit.check("克制修正加在 floor 之后（加法核）", DamageMathScript.rolled_component(base, 100, false, crit_mult, _floor_val()) == int(floor(base)) + _floor_val())
	Kit.check("复合序 = 基线×折扣%×暴击%（floor 只在链末）",
		DamageMathScript.rolled_component(base, 50, true, crit_mult, 0) == int(floor(base * 50.0 / 100.0 * float(crit_mult) / 100.0)))