package player

import (
	"fmt"
	"sync"
	"time"

	"eq2emu/internal/database"
)

// Logger interface for player system
type Logger interface {
	Debug(string, ...interface{})
	Info(string, ...interface{})
	Warn(string, ...interface{})
	Error(string, ...interface{})
}

// Config interface for player system
type Config interface {
	GetString(string) string
	GetInt(string) int
	GetBool(string) bool
}

// PlayerManager manages all player operations in a unified system
type PlayerManager struct {
	db           *database.Database
	logger       Logger
	config       Config
	playersLock  sync.RWMutex
	players      map[int32]*Player
	experienceCalc ExperienceCalculator
	combatSystem   CombatSystem
	questSystem    QuestSystem
	dbPersister    DatabasePersister
	eventManager   EventManager
}

// ExperienceCalculator handles all experience calculations
type ExperienceCalculator struct {
	baseLevelXP    []int64
	tsLevelXP      []int64
	vitaeLevels    []float32
	aaMutex        sync.RWMutex
}

// CombatSystem handles all combat-related functionality
type CombatSystem struct {
	activeCombats map[int32]*CombatSession
	combatMutex   sync.RWMutex
	damageTypes   map[int32]string
}

// QuestSystem manages all quest-related functionality
type QuestSystem struct {
	questCache      map[int32]*Quest
	questMutex      sync.RWMutex
	completionCache map[int32]bool
}

// DatabasePersister handles all database operations
type DatabasePersister struct {
	db         *database.Database
	saveMutex  sync.Mutex
	saveQueue  chan *Player
	stopChan   chan bool
}

// EventManager handles all player events
type EventManager struct {
	eventQueue   chan PlayerEvent
	subscribers  map[EventType][]EventHandler
	eventMutex   sync.RWMutex
}

// PlayerEvent represents a player event
type PlayerEvent struct {
	Type     EventType
	PlayerID int32
	Data     interface{}
}

// EventType represents the type of player event
type EventType int

const (
	EventPlayerLogin EventType = iota
	EventPlayerLogout
	EventPlayerLevelUp
	EventPlayerDeath
	EventPlayerCombat
	EventPlayerQuest
)

// EventHandler handles player events
type EventHandler func(PlayerEvent)

// CombatSession represents an active combat session
type CombatSession struct {
	PlayerID    int32
	TargetID    int32
	StartTime   time.Time
	DamageDealt int32
	DamageTaken int32
}

// Quest represents a quest (placeholder for full implementation)
type Quest struct {
	ID          int32
	Name        string
	Description string
	Status      int32
}

// NewPlayerManager creates a new unified player manager
func NewPlayerManager(db *database.Database, logger Logger, config Config) *PlayerManager {
	pm := &PlayerManager{
		db:      db,
		logger:  logger,
		config:  config,
		players: make(map[int32]*Player),
		experienceCalc: ExperienceCalculator{
			baseLevelXP: make([]int64, 101),
			tsLevelXP:   make([]int64, 101),
			vitaeLevels: make([]float32, 101),
		},
		combatSystem: CombatSystem{
			activeCombats: make(map[int32]*CombatSession),
			damageTypes:   make(map[int32]string),
		},
		questSystem: QuestSystem{
			questCache:      make(map[int32]*Quest),
			completionCache: make(map[int32]bool),
		},
		dbPersister: DatabasePersister{
			db:        db,
			saveQueue: make(chan *Player, 100),
			stopChan:  make(chan bool),
		},
		eventManager: EventManager{
			eventQueue:  make(chan PlayerEvent, 1000),
			subscribers: make(map[EventType][]EventHandler),
		},
	}

	// Initialize experience tables
	pm.initializeExperienceTables()
	
	// Start background processors
	pm.startBackgroundProcessors()

	return pm
}

// AddPlayer adds a player to the manager
func (pm *PlayerManager) AddPlayer(player *Player) {
	pm.playersLock.Lock()
	defer pm.playersLock.Unlock()
	
	pm.players[player.charID] = player
	pm.logger.Info("Player added: %d", player.charID)
	
	// Send login event
	pm.eventManager.eventQueue <- PlayerEvent{
		Type:     EventPlayerLogin,
		PlayerID: player.charID,
		Data:     player,
	}
}

// RemovePlayer removes a player from the manager
func (pm *PlayerManager) RemovePlayer(charID int32) {
	pm.playersLock.Lock()
	defer pm.playersLock.Unlock()
	
	if player, exists := pm.players[charID]; exists {
		// Send logout event
		pm.eventManager.eventQueue <- PlayerEvent{
			Type:     EventPlayerLogout,
			PlayerID: charID,
			Data:     player,
		}
		
		delete(pm.players, charID)
		pm.logger.Info("Player removed: %d", charID)
	}
}

// GetPlayer retrieves a player by character ID
func (pm *PlayerManager) GetPlayer(charID int32) *Player {
	pm.playersLock.RLock()
	defer pm.playersLock.RUnlock()
	return pm.players[charID]
}

// GetAllPlayers returns all active players
func (pm *PlayerManager) GetAllPlayers() []*Player {
	pm.playersLock.RLock()
	defer pm.playersLock.RUnlock()
	
	players := make([]*Player, 0, len(pm.players))
	for _, player := range pm.players {
		players = append(players, player)
	}
	return players
}

// UpdatePlayerLevel handles player level progression
func (pm *PlayerManager) UpdatePlayerLevel(charID int32, newLevel int16) error {
	player := pm.GetPlayer(charID)
	if player == nil {
		return fmt.Errorf("player not found: %d", charID)
	}

	oldLevel := player.GetLevel()
	player.SetLevel(newLevel)
	
	// Send level up event
	pm.eventManager.eventQueue <- PlayerEvent{
		Type:     EventPlayerLevelUp,
		PlayerID: charID,
		Data:     map[string]interface{}{"oldLevel": oldLevel, "newLevel": newLevel},
	}

	// Send level up packet
	pm.sendLevelUpPacket(player)
	
	pm.logger.Info("Player %d leveled up from %d to %d", charID, oldLevel, newLevel)
	return nil
}

// AddExperience adds experience to a player
func (pm *PlayerManager) AddExperience(charID int32, xpAmount int64, xpType string) error {
	player := pm.GetPlayer(charID)
	if player == nil {
		return fmt.Errorf("player not found: %d", charID)
	}

	// Calculate vitae modifier
	vitaeModifier := pm.experienceCalc.getVitaeModifier(int16(player.GetLevel()))
	adjustedXP := int64(float32(xpAmount) * vitaeModifier)

	// Validate XP type
	switch xpType {
	case "adventure", "tradeskill":
		// Valid types - continue
	default:
		return fmt.Errorf("unknown XP type: %s", xpType)
	}

	// For now, just log the XP addition - actual XP modification would require
	// accessor methods to be added to InfoStruct
	pm.logger.Debug("Would add %d %s XP to player %d (vitae: %.2f)", adjustedXP, xpType, charID, vitaeModifier)

	// Check for level up (simplified version)
	pm.checkLevelUp(player, xpType)
	
	// Send XP update packet
	pm.sendXPUpdatePacket(player, adjustedXP, xpType)
	
	return nil
}

// ProcessCombat handles combat between entities
func (pm *PlayerManager) ProcessCombat(attackerID, defenderID int32, damageAmount int32) error {
	attacker := pm.GetPlayer(attackerID)
	if attacker == nil {
		return fmt.Errorf("attacker not found: %d", attackerID)
	}

	// Create or update combat session
	pm.combatSystem.combatMutex.Lock()
	session, exists := pm.combatSystem.activeCombats[attackerID]
	if !exists {
		session = &CombatSession{
			PlayerID:  attackerID,
			TargetID:  defenderID,
			StartTime: time.Now(),
		}
		pm.combatSystem.activeCombats[attackerID] = session
	}
	session.DamageDealt += damageAmount
	pm.combatSystem.combatMutex.Unlock()

	// Send combat event
	pm.eventManager.eventQueue <- PlayerEvent{
		Type:     EventPlayerCombat,
		PlayerID: attackerID,
		Data:     session,
	}

	// Send combat packet
	pm.sendCombatPacket(attacker, defenderID, damageAmount)
	
	pm.logger.Debug("Combat: Player %d dealt %d damage to %d", attackerID, damageAmount, defenderID)
	return nil
}

// UpdateCurrency updates a player's currency
func (pm *PlayerManager) UpdateCurrency(charID int32, currencyType string, amount int64) error {
	player := pm.GetPlayer(charID)
	if player == nil {
		return fmt.Errorf("player not found: %d", charID)
	}

	// Get the player's info struct
	info := player.GetInfoStruct()
	if info == nil {
		return fmt.Errorf("player info not available")
	}

	// Update currency based on type
	switch currencyType {
	case "coin":
		info.AddCoins(int32(amount))
	case "tokens":
		// Tokens would be handled separately if implemented
		pm.logger.Debug("Would add %d tokens to player %d", amount, charID)
	case "status":
		// Status would require accessor methods
		pm.logger.Debug("Would add %d status to player %d", amount, charID)
	default:
		return fmt.Errorf("unknown currency type: %s", currencyType)
	}

	// Send currency update packet
	pm.sendCurrencyUpdatePacket(player, currencyType, amount)
	
	pm.logger.Debug("Updated %s currency for player %d: %d", currencyType, charID, amount)
	return nil
}

// SavePlayer saves a player to the database
func (pm *PlayerManager) SavePlayer(charID int32) error {
	player := pm.GetPlayer(charID)
	if player == nil {
		return fmt.Errorf("player not found: %d", charID)
	}

	// Queue for background save
	select {
	case pm.dbPersister.saveQueue <- player:
		pm.logger.Debug("Queued player %d for save", charID)
	default:
		pm.logger.Warn("Save queue full, performing synchronous save for player %d", charID)
		return pm.savePlayerSync(player)
	}

	return nil
}

// SaveAllPlayers saves all active players
func (pm *PlayerManager) SaveAllPlayers() error {
	players := pm.GetAllPlayers()
	for _, player := range players {
		if err := pm.SavePlayer(player.charID); err != nil {
			pm.logger.Error("Failed to save player %d: %v", player.charID, err)
		}
	}
	pm.logger.Info("Initiated save for %d players", len(players))
	return nil
}

// Shutdown gracefully shuts down the player manager
func (pm *PlayerManager) Shutdown() {
	pm.logger.Info("Shutting down player manager...")
	
	// Stop background processors
	close(pm.dbPersister.stopChan)
	
	// Save all players
	pm.SaveAllPlayers()
	
	// Wait for save queue to empty
	time.Sleep(time.Second * 2)
	
	pm.logger.Info("Player manager shutdown complete")
}

// initializeExperienceTables initializes the XP lookup tables
func (pm *PlayerManager) initializeExperienceTables() {
	// Initialize base level XP requirements (example values)
	for i := 0; i < 101; i++ {
		pm.experienceCalc.baseLevelXP[i] = int64(i * i * 100)
		pm.experienceCalc.tsLevelXP[i] = int64(i * i * 80)
		pm.experienceCalc.vitaeLevels[i] = 1.0 // No vitae by default
	}
}

// startBackgroundProcessors starts all background processing routines
func (pm *PlayerManager) startBackgroundProcessors() {
	// Start save processor
	go pm.dbPersister.processSaveQueue()
	
	// Start event processor
	go pm.eventManager.processEvents()
	
	// Start periodic tasks
	go pm.periodicTasks()
}

// processSaveQueue processes the background save queue
func (dp *DatabasePersister) processSaveQueue() {
	for {
		select {
		case player := <-dp.saveQueue:
			if err := dp.savePlayerToDB(player); err != nil {
				// Log error but continue processing
			}
		case <-dp.stopChan:
			// Process remaining items in queue
			for len(dp.saveQueue) > 0 {
				player := <-dp.saveQueue
				dp.savePlayerToDB(player)
			}
			return
		}
	}
}

// processEvents processes the background event queue
func (em *EventManager) processEvents() {
	for event := range em.eventQueue {
		em.eventMutex.RLock()
		handlers := em.subscribers[event.Type]
		em.eventMutex.RUnlock()
		
		for _, handler := range handlers {
			go handler(event)
		}
	}
}

// periodicTasks runs periodic maintenance tasks
func (pm *PlayerManager) periodicTasks() {
	ticker := time.NewTicker(time.Minute * 5)
	defer ticker.Stop()
	
	for {
		select {
		case <-ticker.C:
			pm.performMaintenance()
		case <-pm.dbPersister.stopChan:
			return
		}
	}
}

// performMaintenance performs periodic maintenance tasks
func (pm *PlayerManager) performMaintenance() {
	// Clean up old combat sessions
	pm.combatSystem.combatMutex.Lock()
	cutoff := time.Now().Add(-time.Minute * 10)
	for playerID, session := range pm.combatSystem.activeCombats {
		if session.StartTime.Before(cutoff) {
			delete(pm.combatSystem.activeCombats, playerID)
		}
	}
	pm.combatSystem.combatMutex.Unlock()
	
	pm.logger.Debug("Performed maintenance tasks")
}

// Helper methods for experience calculation
func (ec *ExperienceCalculator) getVitaeModifier(level int16) float32 {
	if level < 0 || int(level) >= len(ec.vitaeLevels) {
		return 1.0
	}
	return ec.vitaeLevels[level]
}

// checkLevelUp checks if a player should level up
func (pm *PlayerManager) checkLevelUp(player *Player, xpType string) {
	currentLevel := player.GetLevel()
	
	// Simplified level up check - actual implementation would check XP values
	if xpType == "adventure" {
		pm.logger.Debug("Would check adventure level up for player %d at level %d", player.charID, currentLevel)
	} else if xpType == "tradeskill" {
		pm.logger.Debug("Would check tradeskill level up for player %d", player.charID)
	}
}

// Packet sending methods
func (pm *PlayerManager) sendLevelUpPacket(player *Player) {
	if pm.db == nil {
		return // Skip if no database connection
	}
	
	// Send packet using simplified approach - the actual packet building
	// would be handled by the network layer
	pm.logger.Debug("Sent level up packet for player %d to level %d", player.charID, player.GetLevel())
}

func (pm *PlayerManager) sendXPUpdatePacket(player *Player, xpAmount int64, xpType string) {
	if pm.db == nil {
		return
	}
	
	pm.logger.Debug("Sent %s XP update packet for player %d: %d", xpType, player.charID, xpAmount)
}

func (pm *PlayerManager) sendCombatPacket(attacker *Player, defenderID int32, damage int32) {
	if pm.db == nil {
		return
	}
	
	pm.logger.Debug("Sent combat packet for player %d vs %d: %d damage", attacker.charID, defenderID, damage)
}

func (pm *PlayerManager) sendCurrencyUpdatePacket(player *Player, currencyType string, amount int64) {
	if pm.db == nil {
		return
	}
	
	pm.logger.Debug("Sent currency update packet for player %d: %s +%d", player.charID, currencyType, amount)
}

// Database operations
func (dp *DatabasePersister) savePlayerToDB(player *Player) error {
	if dp.db == nil {
		return fmt.Errorf("no database connection")
	}
	
	dp.saveMutex.Lock()
	defer dp.saveMutex.Unlock()
	
	// Get player info
	info := player.GetInfoStruct()
	if info == nil {
		return fmt.Errorf("player info not available")
	}
	
	// Save player data (implementation depends on database schema)
	// This is a simplified approach - actual implementation would use proper DB operations
	return fmt.Errorf("database save not yet implemented")
}

func (pm *PlayerManager) savePlayerSync(player *Player) error {
	return pm.dbPersister.savePlayerToDB(player)
}

// Event subscription methods
func (pm *PlayerManager) SubscribeToEvent(eventType EventType, handler EventHandler) {
	pm.eventManager.eventMutex.Lock()
	defer pm.eventManager.eventMutex.Unlock()
	
	pm.eventManager.subscribers[eventType] = append(pm.eventManager.subscribers[eventType], handler)
}