package dnfbridge

import (
	"context"
	"fmt"
	"math"

	dnfcharstat "longheng.io/server/internal/modules/dnf/charstat"
	dnfcompanion "longheng.io/server/internal/modules/dnf/companion"
	dnfrepo "longheng.io/server/internal/modules/dnf/repository"
)

const (
	// Balanced support soldiers are intentionally durable because they have no
	// player-style resurrection flow. 5000% means 50x the owner's effective HP.
	currentDungeonCompanionBalanceHPPercent int64 = 5000
	currentDungeonCompanionBalanceMPPercent int64 = 200
)

type currentDungeonCompanionProjectionOptions struct {
	EffectiveLevel int
	Mode1          []byte
	AIProfile      dnfcompanion.AIProfile
}

type currentDungeonCompanionBalanceSummary struct {
	OwnerLevel        int
	HPMax             int64
	MPMax             int64
	Strength          int64
	Intelligence      int64
	Vitality          int64
	Spirit            int64
	PhysicalDefense   int64
	MagicalDefense    int64
	PhysicalAttack    int64
	MagicalAttack     int64
	IndependentAttack int64
	MoveSpeed         int64
	AttackSpeed       int64
	CastSpeed         int64
}

func scaleCompanionBalanceValue(value, percent int64) int64 {
	if value <= 0 || percent <= 0 {
		return 0
	}
	if value > math.MaxInt64/percent {
		return math.MaxInt64
	}
	return value * percent / 100
}

func clampCompanionBalanceU32(value int64) int64 {
	if value < 0 {
		return 0
	}
	if value > math.MaxUint32 {
		return math.MaxUint32
	}
	return value
}

func buildCurrentDungeonCompanionBalancedVector(
	ownerStats dnfcharstat.Vector,
	level int,
) (dnfcharstat.Vector, currentDungeonCompanionBalanceSummary) {
	target := dnfcharstat.Vector{
		HPMax: clampCompanionBalanceU32(scaleCompanionBalanceValue(ownerStats.HPMax, currentDungeonCompanionBalanceHPPercent)),
		MPMax: clampCompanionBalanceU32(scaleCompanionBalanceValue(ownerStats.MPMax, currentDungeonCompanionBalanceMPPercent)),
		// The balance switch is a projection of the owner's effective combat
		// vector. Copy each dimension independently instead of using the larger
		// side of a pair and applying a compensating multiplier: a STR class
		// must not gain the owner's INT, and a support APC must not lose the
		// owner's lower physical/magical attack side.
		Strength:          ownerStats.Strength,
		Intelligence:      ownerStats.Intelligence,
		Vitality:          ownerStats.Vitality,
		Spirit:            ownerStats.Spirit,
		PhysicalAttack:    ownerStats.PhysicalAttack,
		MagicalAttack:     ownerStats.MagicalAttack,
		IndependentAttack: ownerStats.IndependentAttack,
		PhysicalDefense:   ownerStats.PhysicalDefense,
		MagicalDefense:    ownerStats.MagicalDefense,
		FireResistance:    ownerStats.FireResistance,
		WaterResistance:   ownerStats.WaterResistance,
		DarkResistance:    ownerStats.DarkResistance,
		LightResistance:   ownerStats.LightResistance,
		InventoryLimit:    ownerStats.InventoryLimit,
		HPRegenSpeed:      ownerStats.HPRegenSpeed,
		MPRegenSpeed:      ownerStats.MPRegenSpeed,
		MoveSpeed:         ownerStats.MoveSpeed,
		AttackSpeed:       ownerStats.AttackSpeed,
		CastSpeed:         ownerStats.CastSpeed,
		HitRecovery:       ownerStats.HitRecovery,
		JumpPower:         ownerStats.JumpPower,
		Weight:            ownerStats.Weight,
	}
	summary := currentDungeonCompanionBalanceSummary{
		OwnerLevel:        level,
		HPMax:             target.HPMax,
		MPMax:             target.MPMax,
		Strength:          target.Strength,
		Intelligence:      target.Intelligence,
		Vitality:          target.Vitality,
		Spirit:            target.Spirit,
		PhysicalDefense:   target.PhysicalDefense,
		MagicalDefense:    target.MagicalDefense,
		PhysicalAttack:    target.PhysicalAttack,
		MagicalAttack:     target.MagicalAttack,
		IndependentAttack: target.IndependentAttack,
		MoveSpeed:         target.MoveSpeed,
		AttackSpeed:       target.AttackSpeed,
		CastSpeed:         target.CastSpeed,
	}
	return target, summary
}

func (s *Service) buildCurrentDungeonCompanionBalanceMode1(
	ctx context.Context,
	session *gameSession,
	state dnfrepo.CompanionSourceState,
) (int, []byte, currentDungeonCompanionBalanceSummary, error) {
	if s == nil || state.Owner.CharacterID == "" || state.Source.CharacterID == "" {
		return 0, nil, currentDungeonCompanionBalanceSummary{}, fmt.Errorf("companion balance owner/source missing")
	}
	level := state.Owner.Level
	if level < 1 || level > 90 {
		return 0, nil, currentDungeonCompanionBalanceSummary{}, fmt.Errorf("companion balance owner level=%d", level)
	}

	ownerStats, ok := s.characterPVFStatsForUserInfo(ctx, session, state.Owner, true)
	if !ok {
		return 0, nil, currentDungeonCompanionBalanceSummary{}, fmt.Errorf("companion balance owner PVF stats unavailable")
	}
	// Use the owner's currently worn PVF stat budget instead of the source
	// character's equipment. This is the normalization boundary: appearance,
	// profession and skills remain source-owned while combat stats are owner-owned.
	ownerStats = s.addEquipmentPVFStatsForUserInfo(ctx, session, state.Owner, ownerStats)
	target, summary := buildCurrentDungeonCompanionBalancedVector(ownerStats, level)

	synthetic := dnfrepo.CloneCharacter(state.Source)
	synthetic.Level = level
	synthetic.Stats = characterPVFStatValues(target)
	synthetic.Stats["grow_type"] = state.Source.Stats["grow_type"]
	synthetic.Stats["stat_level"] = csharpSubtype1ProtocolStatLevel

	// Refresh exactly the frozen runtime equipment used for AIC creation and
	// mode0: source avatars plus the companion's temporary balanced gear.
	reader := csharpLegacyUserInfoReader{
		ctx:                         ctx,
		characterID:                 state.Source.CharacterID,
		service:                     s,
		session:                     session,
		suppressActorSkillResources: true,
		equipmentSnapshot:           &state.Equipment,
	}
	// This body is embedded in the APC projection alongside its 0/0 mode0;
	// it is not a player row addressed to the advertised game server.
	mode1 := reader.buildCurrentUserInfoMode1WithEquipmentForOwner(
		synthetic,
		true,
		currentDungeonCompanionProjectionObjectKey,
		true,
		0,
		currentSceneObjectRoute,
		currentSceneObjectContext,
	)
	if len(mode1) <= currentDungeonCompanionMode1ObjectKeyOffset+1 {
		return 0, nil, currentDungeonCompanionBalanceSummary{}, fmt.Errorf("companion balance mode1 too short: %d", len(mode1))
	}

	return level, mode1, summary, nil
}