package login

import (
	"fmt"
	"net/url"
	"strings"
)

// ServerConfig represents the login server configuration
type ServerConfig struct {
	// Network settings
	ListenAddr string `json:"listen_addr"`
	ListenPort int    `json:"listen_port"`
	MaxClients int    `json:"max_clients"`

	// Web interface settings
	WebAddr        string `json:"web_addr"`
	WebPort        int    `json:"web_port"`
	WebCertFile    string `json:"web_cert_file"`
	WebKeyFile     string `json:"web_key_file"`
	WebKeyPassword string `json:"web_key_password"`
	WebUser        string `json:"web_user"`
	WebPassword    string `json:"web_password"`

	// Database settings
	DatabaseAddress  string `json:"database_address"`  // MySQL server address
	DatabasePort     int    `json:"database_port"`     // MySQL server port
	DatabaseUsername string `json:"database_username"` // MySQL username
	DatabasePassword string `json:"database_password"` // MySQL password
	DatabaseName     string `json:"database_name"`     // MySQL database name

	// Server settings
	ServerName string `json:"server_name"`
	LogLevel   string `json:"log_level"`

	// World servers configuration
	WorldServers []WorldServerInfo `json:"world_servers"`
}

// WorldServerInfo represents information about a world server
type WorldServerInfo struct {
	ID          int    `json:"id"`
	Name        string `json:"name"`
	Address     string `json:"address"`
	Port        int    `json:"port"`
	AdminPort   int    `json:"admin_port"`
	Key         string `json:"key"`
	Status      string `json:"status"`      // "up", "down", "locked"
	Population  int    `json:"population"`  // Current player count
	MaxPlayers  int    `json:"max_players"` // Maximum allowed players
	Description string `json:"description"`
	
	// Server flags
	Locked bool `json:"locked"`
	Hidden bool `json:"hidden"`
	
	// Connection tracking
	LastHeartbeat int64 `json:"last_heartbeat"`
}

// Validate validates the server configuration
func (c *ServerConfig) Validate() error {
	if c.ListenAddr == "" {
		return fmt.Errorf("listen_addr is required")
	}

	if c.ListenPort <= 0 || c.ListenPort > 65535 {
		return fmt.Errorf("listen_port must be between 1 and 65535")
	}

	if c.MaxClients <= 0 {
		c.MaxClients = 1000 // Default value
	}

	// Database configuration validation
	if c.DatabaseAddress == "" {
		c.DatabaseAddress = "localhost" // Default to localhost
	}
	
	if c.DatabasePort <= 0 {
		c.DatabasePort = 3306 // Default MySQL port
	}
	
	if c.DatabaseUsername == "" {
		return fmt.Errorf("database_username is required")
	}
	
	if c.DatabasePassword == "" {
		return fmt.Errorf("database_password is required")
	}
	
	if c.DatabaseName == "" {
		return fmt.Errorf("database_name is required")
	}

	if c.ServerName == "" {
		c.ServerName = "EQ2Go Login Server"
	}

	// Validate log level
	logLevel := strings.ToLower(c.LogLevel)
	switch logLevel {
	case "debug", "info", "warn", "error":
		c.LogLevel = logLevel
	case "":
		c.LogLevel = "info" // Default
	default:
		return fmt.Errorf("invalid log_level: %s (must be debug, info, warn, or error)", c.LogLevel)
	}

	// Validate web configuration
	if c.WebPort > 0 {
		if c.WebPort <= 0 || c.WebPort > 65535 {
			return fmt.Errorf("web_port must be between 1 and 65535")
		}

		if c.WebAddr == "" {
			c.WebAddr = "0.0.0.0"
		}

		// If TLS files are specified, both cert and key must be provided
		if c.WebCertFile != "" && c.WebKeyFile == "" {
			return fmt.Errorf("web_key_file is required when web_cert_file is specified")
		}
		if c.WebKeyFile != "" && c.WebCertFile == "" {
			return fmt.Errorf("web_cert_file is required when web_key_file is specified")
		}
	}

	// Validate world servers
	for i, ws := range c.WorldServers {
		if err := ws.Validate(); err != nil {
			return fmt.Errorf("world_server[%d]: %w", i, err)
		}
	}

	return nil
}

// BuildDatabaseDSN builds a MySQL DSN string from the database configuration
func (c *ServerConfig) BuildDatabaseDSN() string {
	// Format: username:password@tcp(address:port)/database?parseTime=true&charset=utf8mb4
	return fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?parseTime=true&charset=utf8mb4",
		url.QueryEscape(c.DatabaseUsername),
		url.QueryEscape(c.DatabasePassword),
		c.DatabaseAddress,
		c.DatabasePort,
		c.DatabaseName)
}

// Validate validates a world server configuration
func (w *WorldServerInfo) Validate() error {
	if w.ID <= 0 {
		return fmt.Errorf("id must be positive")
	}

	if w.Name == "" {
		return fmt.Errorf("name is required")
	}

	if w.Address == "" {
		return fmt.Errorf("address is required")
	}

	if w.Port <= 0 || w.Port > 65535 {
		return fmt.Errorf("port must be between 1 and 65535")
	}

	if w.AdminPort <= 0 || w.AdminPort > 65535 {
		return fmt.Errorf("admin_port must be between 1 and 65535")
	}

	if w.AdminPort == w.Port {
		return fmt.Errorf("admin_port cannot be the same as port")
	}

	if w.MaxPlayers <= 0 {
		w.MaxPlayers = 1000 // Default value
	}

	// Normalize status
	status := strings.ToLower(w.Status)
	switch status {
	case "up", "down", "locked":
		w.Status = status
	case "":
		w.Status = "down" // Default
	default:
		return fmt.Errorf("invalid status: %s (must be up, down, or locked)", w.Status)
	}

	return nil
}

// IsOnline returns whether the world server is currently online
func (w *WorldServerInfo) IsOnline() bool {
	return w.Status == "up"
}

// IsLocked returns whether the world server is locked
func (w *WorldServerInfo) IsLocked() bool {
	return w.Locked || w.Status == "locked"
}

// IsHidden returns whether the world server should be hidden from the server list
func (w *WorldServerInfo) IsHidden() bool {
	return w.Hidden
}

// GetPopulationPercentage returns the current population as a percentage of max capacity
func (w *WorldServerInfo) GetPopulationPercentage() float64 {
	if w.MaxPlayers <= 0 {
		return 0
	}
	return float64(w.Population) / float64(w.MaxPlayers) * 100
}

// GetPopulationLevel returns a string representation of the population level
func (w *WorldServerInfo) GetPopulationLevel() string {
	pct := w.GetPopulationPercentage()
	
	switch {
	case pct >= 95:
		return "FULL"
	case pct >= 80:
		return "HIGH"
	case pct >= 50:
		return "MEDIUM"
	case pct >= 25:
		return "LOW"
	default:
		return "LIGHT"
	}
}

// Clone creates a deep copy of the WorldServerInfo
func (w *WorldServerInfo) Clone() *WorldServerInfo {
	clone := *w
	return &clone
}