package game

import (
	"fmt"
	"path/filepath"
	"strings"

	"gopkg.in/yaml.v3"

	"thehouseoficarus/internal/behavior"
	"thehouseoficarus/internal/net"
	"thehouseoficarus/internal/player"
	"thehouseoficarus/internal/world"
)

type TechEffects struct {
	AccuracyPercent int     `yaml:"accuracy_percent"`
	StrengthPercent int     `yaml:"strength_percent"`
	DefensePercent  int     `yaml:"defense_percent"`
	RangedPercent   int     `yaml:"ranged_percent"`
	SciencePercent  int     `yaml:"science_percent"`
	ProtectMelee    bool    `yaml:"protect_melee"`
	ProtectRanged   bool    `yaml:"protect_ranged"`
	ProtectScience  bool    `yaml:"protect_science"`
	DamageReduction float64 `yaml:"damage_reduction"`
	HPRegenMulti    float64 `yaml:"hp_regen_multi"`
	PreserveDrain   float64 `yaml:"preserve_drain"`
	RetributionPct  float64 `yaml:"retribution_pct"`
}

type TechDef struct {
	ID        string      `yaml:"id"`
	Name      string      `yaml:"name"`
	Level     int         `yaml:"level"`
	DrainRate float64     `yaml:"drain_rate"`
	Category  string      `yaml:"category"`
	Group     string      `yaml:"group"`
	Effects   TechEffects `yaml:"effects"`
}

var AllTechs []*TechDef
var techByID map[string]*TechDef

func (g *Game) LoadTechs() error {
	dir := filepath.Join(g.DataDir, "techs")
	AllTechs = nil
	techByID = make(map[string]*TechDef)
	behavior.WalkYAMLDir(dir, func(path, id string, data []byte) error {
		var t TechDef
		if err := yaml.Unmarshal(data, &t); err != nil {
			return nil
		}
		t.ID = id
		AllTechs = append(AllTechs, &t)
		return nil
	})
	techByID = make(map[string]*TechDef, len(AllTechs))
	for _, t := range AllTechs {
		techByID[t.ID] = t
	}
	return nil
}

func GetTechDef(id string) *TechDef {
	return techByID[id]
}

func TechByPrefixMatch(input string) []*TechDef {
	input = strings.ToLower(input)
	var exact []*TechDef
	var prefix []*TechDef
	for _, t := range AllTechs {
		lower := strings.ToLower(t.Name)
		lowerID := strings.ToLower(t.ID)
		if lower == input || lowerID == input {
			exact = append(exact, t)
		} else if strings.HasPrefix(lower, input) || strings.HasPrefix(lowerID, input) {
			prefix = append(prefix, t)
		}
	}
	if len(exact) > 0 {
		return exact
	}
	return prefix
}

func techEffectString(tech *TechDef) string {
	var parts []string
	e := tech.Effects
	if e.AccuracyPercent > 0 {
		parts = append(parts, fmt.Sprintf("+%d%% Accuracy", e.AccuracyPercent))
	}
	if e.StrengthPercent > 0 {
		parts = append(parts, fmt.Sprintf("+%d%% Strength", e.StrengthPercent))
	}
	if e.DefensePercent > 0 {
		parts = append(parts, fmt.Sprintf("+%d%% Defense", e.DefensePercent))
	}
	if e.RangedPercent > 0 {
		parts = append(parts, fmt.Sprintf("+%d%% Ranged", e.RangedPercent))
	}
	if e.SciencePercent > 0 {
		parts = append(parts, fmt.Sprintf("+%d%% Science", e.SciencePercent))
	}
	if e.ProtectMelee {
		parts = append(parts, fmt.Sprintf("%.0f%% melee protection", e.DamageReduction*100))
	}
	if e.ProtectRanged {
		parts = append(parts, fmt.Sprintf("%.0f%% ranged protection", e.DamageReduction*100))
	}
	if e.ProtectScience {
		parts = append(parts, fmt.Sprintf("%.0f%% science protection", e.DamageReduction*100))
	}
	if e.HPRegenMulti > 0 {
		parts = append(parts, fmt.Sprintf("%.0fx HP regen", e.HPRegenMulti))
	}
	if e.PreserveDrain > 0 {
		parts = append(parts, fmt.Sprintf("%.0f%% drain reduction", e.PreserveDrain*100))
	}
	if e.RetributionPct > 0 {
		parts = append(parts, fmt.Sprintf("%.0f%% retribution", e.RetributionPct*100))
	}
	return strings.Join(parts, ", ")
}

func (g *Game) totalTechBonus(p *player.Player) int {
	total := 0
	for _, itemID := range p.Equipment {
		def, err := g.ItemStore.Load(itemID)
		if err == nil {
			total += def.Stats().TechnologyBonus
		}
	}
	return total
}

func (g *Game) techLevelBonus(p *player.Player, stat string) int {
	if len(p.ActiveTechs) == 0 {
		return 0
	}

	totalPercent := 0
	for id := range p.ActiveTechs {
		def := GetTechDef(id)
		if def == nil {
			continue
		}
		switch stat {
		case "accuracy":
			totalPercent += def.Effects.AccuracyPercent
		case "strength":
			totalPercent += def.Effects.StrengthPercent
		case "defense":
			totalPercent += def.Effects.DefensePercent
		case "ranged":
			totalPercent += def.Effects.RangedPercent
		case "science":
			totalPercent += def.Effects.SciencePercent
		}
	}

	if totalPercent == 0 {
		return 0
	}

	var baseLevel int
	switch stat {
	case "accuracy":
		baseLevel = p.Level(player.Accuracy)
	case "strength":
		baseLevel = p.Level(player.Strength)
	case "defense":
		baseLevel = p.Level(player.Defense)
	case "ranged":
		baseLevel = p.Level(player.Ranged)
	case "science":
		baseLevel = p.Level(player.Science)
	}

	return baseLevel * totalPercent / 100
}

func (g *Game) tryRecharge(sess *net.Session, p *player.Player, input string) bool {
	lower := strings.ToLower(strings.TrimSpace(input))
	instances := g.World.FindObjInstances(p.RoomID, lower)
	for _, st := range instances {
		if st.DefID == "charging_station" || st.DefID == "power_conduit" {
			if p.Battery >= p.MaxBattery() {
				sess.WriteLine("Your battery is already full.")
			} else {
				p.Battery = p.MaxBattery()
				g.AccountStore.SaveCharacter(p)
				sess.WriteLine(g.colorize(sess, "battery",
					"You connect to the charging station. Your battery is fully recharged."))
			}
			return true
		}
	}
	return false
}

func (g *Game) applyTechProtection(p *player.Player, mob *world.MobInstance, dmg int) int {
	return g.damageAfterTechProtection(p, mob.AttackType, dmg)
}

// damageAfterTechProtection reduces incoming damage if the player has the
// protection tech matching the given attack type active. Shared by mob combat
// and room hazards.
//
// Reserved tech IDs (must exist in data/techs/):
//
//	protect_melee  — mapped to stab/slash/crush attacks
//	protect_ranged — mapped to ranged attacks
//	protect_science — mapped to science attacks
//
// Also retribution — checked by name in killPlayer (cmd_attack.go).
func (g *Game) damageAfterTechProtection(p *player.Player, attackType string, dmg int) int {
	if len(p.ActiveTechs) == 0 {
		return dmg
	}

	if attackType == "" {
		attackType = "crush"
	}

	var protectTechID string
	switch attackType {
	case "stab", "slash", "crush":
		protectTechID = "protect_melee"
	case "ranged":
		protectTechID = "protect_ranged"
	case "science":
		protectTechID = "protect_science"
	}

	if protectTechID != "" && p.HasActiveTech(protectTechID) {
		def := GetTechDef(protectTechID)
		if def != nil {
			reduced := int(float64(dmg) * (1.0 - def.Effects.DamageReduction))
			if reduced < 0 {
				reduced = 0
			}
			return reduced
		}
	}
	return dmg
}