package battle

import (
	"encoding/json"
	"math"
)

// DamageType 伤害类型：物理 / 法术 / 真实
type DamageType string

const (
	DamageTypePhysical DamageType = "physical"
	DamageTypeMagical  DamageType = "magical"
	DamageTypeTrue     DamageType = "true"
)

// TargetType 技能目标类型
type TargetType string

const (
	TargetSingle TargetType = "single"
	TargetSelf   TargetType = "self"
	TargetAlly   TargetType = "ally"
)

// BaseStats 角色六维基础素质（与 DB base_stats JSONB 对齐）
type BaseStats struct {
	Str float64 `json:"str"`
	Vit float64 `json:"vit"`
	Wis float64 `json:"wis"`
	Agi float64 `json:"agi"`
	Spi float64 `json:"spi"`
	Luk float64 `json:"luk"`
	// Blood 为巫族特殊属性，可替换灵
	Blood float64 `json:"blood,omitempty"`
}

// SkillInstance 战斗中的一次技能实例（包含运行时 CD）
type SkillInstance struct {
	InstanceID string     `json:"instance_id"`
	SkillID    string     `json:"skill_id"`
	Name       string     `json:"name"`
	DamageType DamageType `json:"damage_type"`
	Element    string     `json:"element"`    // fire/water/lightning/earth/nature/yin/yang/chaos/none
	Alignment  string     `json:"alignment"`  // light/dark/neutral
	ScalingAttr string    `json:"scaling_attr"` // str/vit/wis/agi/spi/luk/blood
	BaseCoef   float64    `json:"base_coef"`
	CD         int        `json:"cd"`         // 总 CD（ticks）
	Cost       float64    `json:"cost"`       // 内力消耗
	TriggerRate float64   `json:"trigger_rate"` // 基础触发率，1.0=100%
	TargetType TargetType `json:"target_type"`

	// 运行时字段
	CDRemaining int `json:"-"`
}

// IsNormal 判断是否为普通攻击兜底技能
func (s *SkillInstance) IsNormal() bool {
	return s == nil || s.SkillID == "normal_attack"
}

// Status 简易战斗状态
type Status struct {
	Type     string
	Stacks   int
	Duration int
}

// Fighter 战斗实体（玩家或怪物）
type Fighter struct {
	ID       string
	Name     string
	RaceID   string
	Job      string
	Side     string // attacker / defender
	IsPlayer bool

	// 基础素质
	Base BaseStats

	// 派生战斗属性
	HPMax     float64
	HP        float64
	PhysAtk   float64
	MagAtk    float64
	Speed     float64
	CritRate  float64
	EvadeRate float64
	PhysDR    float64
	MagDR     float64

	// 战斗资源（内力）
	Mana    float64
	ManaMax float64

	// 阵营 / 元素
	WorldTier int
	RealmTier int
	Alignment string
	Element   string

	// 技能
	Skills []*SkillInstance

	// 状态
	Stunned       bool
	StunRemaining int
	SlowRemaining int

	// ATB
	Gauge       float64
	ActionCount int
}

// IsAlive 是否存活
func (f *Fighter) IsAlive() bool {
	return f != nil && f.HP > 0
}

// EffectiveSpeed 计算当前有效速度（含减速）
func (f *Fighter) EffectiveSpeed() float64 {
	speed := f.Speed
	if f.SlowRemaining > 0 {
		slow := cfgFloat("combat.cc.slow_value", 0.2)
		speed *= (1 - slow)
	}
	if speed < 1 {
		speed = 1
	}
	return speed
}

// ResetGauge 行动后清空行动条
func (f *Fighter) ResetGauge() {
	f.Gauge = 0
}

// ReduceCooldowns 每 tick 减少技能 CD
func (f *Fighter) ReduceCooldowns() {
	for _, s := range f.Skills {
		if s.CDRemaining > 0 {
			s.CDRemaining--
		}
	}
}

// AddCooldown 为指定技能进入 CD
func (f *Fighter) AddCooldown(s *SkillInstance) {
	if s == nil || s.CD <= 0 {
		return
	}
	for _, sk := range f.Skills {
		if sk.InstanceID == s.InstanceID && sk.SkillID == s.SkillID {
			sk.CDRemaining = s.CD
			return
		}
	}
}

// RegenMana 每 tick 回复内力
func (f *Fighter) RegenMana() {
	regen := cfgFloat("combat.mana.regen_per_tick", 0.15)
	f.Mana += regen
	if f.Mana > f.ManaMax {
		f.Mana = f.ManaMax
	}
}

// ManaRegenAfterAction 行动后额外回复内力
func (f *Fighter) ManaRegenAfterAction() {
	regen := cfgFloat("combat.mana.regen_per_action", 3)
	f.Mana += regen
	if f.Mana > f.ManaMax {
		f.Mana = f.ManaMax
	}
}

// CanSpendMana 是否有足够内力释放技能
func (f *Fighter) CanSpendMana(cost float64) bool {
	return f.Mana >= cost
}

// SpendMana 消耗内力
func (f *Fighter) SpendMana(cost float64) {
	f.Mana -= cost
	if f.Mana < 0 {
		f.Mana = 0
	}
}

// TakeDamage 受到伤害
func (f *Fighter) TakeDamage(dmg float64) {
	f.HP -= dmg
	if f.HP < 0 {
		f.HP = 0
	}
}

// AddSkill 添加技能
func (f *Fighter) AddSkill(s *SkillInstance) {
	if s == nil {
		return
	}
	f.Skills = append(f.Skills, s)
}

// ActiveSkillIDs 返回用于战报展示的技能 ID 列表
func (f *Fighter) ActiveSkillIDs() []string {
	ids := make([]string, 0, len(f.Skills))
	for _, s := range f.Skills {
		if s.SkillID != "normal_attack" {
			ids = append(ids, s.SkillID)
		}
	}
	return ids
}

// NewFighter 通过基础属性创建一个战斗实体
func NewFighter(id, name, raceID, side string, worldTier, realmTier int, base BaseStats, alignment, element string, isPlayer bool) *Fighter {
	f := &Fighter{
		ID:        id,
		Name:      name,
		RaceID:    raceID,
		Side:      side,
		IsPlayer:  isPlayer,
		Base:      base,
		WorldTier: worldTier,
		RealmTier: realmTier,
		Alignment: alignment,
		Element:   element,
	}
	f.recalcDerived()
	f.ManaMax = cfgFloat("combat.mana.max", 100)
	f.Mana = f.ManaMax
	return f
}

// NewFighterFromJSON 从 DB JSONB 解析基础属性后创建实体
func NewFighterFromJSON(id, name, raceID, side string, worldTier, realmTier int, data []byte, alignment, element string, isPlayer bool) *Fighter {
	var base BaseStats
	_ = json.Unmarshal(data, &base)
	return NewFighter(id, name, raceID, side, worldTier, realmTier, base, alignment, element, isPlayer)
}

// recalcDerived 根据基础素质重算战斗属性
func (f *Fighter) recalcDerived() {
	hpCoef := hpCoefForTier(f.WorldTier)
	f.HPMax = f.Base.Vit*hpCoef + realmBaseHP(f.RealmTier)
	f.HP = f.HPMax

	atkCoef := cfgFloat("combat.atk.coefficient", 1.0)
	magAtkCoef := cfgFloat("combat.magic_atk.coefficient", 1.0)
	f.PhysAtk = f.Base.Str*atkCoef
	f.MagAtk = f.Base.Spi*magAtkCoef
	if f.Base.Blood > 0 {
		// 巫族可用血属性部分替代灵
		f.MagAtk += f.Base.Blood * magAtkCoef * 0.5
		f.PhysAtk += f.Base.Blood * atkCoef * 0.5
	}

	f.Speed = f.Base.Agi

	critCap := cfgFloat("combat.crit.rate_cap", 0.6)
	f.CritRate = math.Min(critCap, f.Base.Luk*0.0015)

	evaCap := cfgFloat("combat.evade.rate_cap", 0.5)
	f.EvadeRate = math.Min(evaCap, f.Base.Agi*0.001)

	defCoef := cfgFloat("combat.defense.coefficient", 0.5)
	defConst := defenseConstantForTier(f.WorldTier)
	f.PhysDR = math.Min(0.75, f.Base.Vit*defCoef/(f.Base.Vit*defCoef+defConst))
	f.MagDR = math.Min(0.75, f.Base.Spi*defCoef/(f.Base.Spi*defCoef+defConst))
}

func realmBaseHP(realmTier int) float64 {
	switch realmTier {
	case 1:
		return 100
	case 2:
		return 300
	case 3:
		return 700
	case 4:
		return 1500
	case 5:
		return 3000
	case 6:
		return 6000
	default:
		return 100
	}
}

func hpCoefForTier(worldTier int) float64 {
	defaults := map[int]float64{
		1: 10,
		2: 12,
		3: 15,
		4: 20,
		5: 28,
		6: 38,
	}
	key := "combat.hp.coefficient_tier_" + tierKey(worldTier)
	if v, ok := cfgGet(key); ok {
		return toFloat(v, defaults[worldTier])
	}
	return defaults[worldTier]
}

func defenseConstantForTier(worldTier int) float64 {
	defaults := map[int]float64{
		1: 100,
		2: 150,
		3: 220,
		4: 320,
		5: 460,
		6: 640,
	}
	key := "combat.defense.constant_tier_" + tierKey(worldTier)
	if v, ok := cfgGet(key); ok {
		return toFloat(v, defaults[worldTier])
	}
	return defaults[worldTier]
}

func tierKey(tier int) string {
	switch tier {
	case 1:
		return "1"
	case 2:
		return "2"
	case 3:
		return "3"
	case 4:
		return "4"
	case 5:
		return "5"
	case 6:
		return "6"
	default:
		return "1"
	}
}