package common

import (
	"fmt"
	"math/rand"
	"net"
	"strconv"
	"strings"
	"time"

	"github.com/sirupsen/logrus"
)

// Sam returns the SAM bridge address as a string in the format "host:port"
func (f *I2PConfig) Sam() string {
	// Set default values
	host := "127.0.0.1"
	port := 7656

	// Override defaults if config values are set
	if f.SamHost != "" {
		host = f.SamHost
	}
	if f.SamPort != 0 {
		port = f.SamPort
	}

	// Log the SAM address being constructed
	log.WithFields(logrus.Fields{
		"host": host,
		"port": port,
	}).Debug("SAM address constructed")

	// Return formatted SAM address
	return net.JoinHostPort(host, strconv.Itoa(port))
}

// SetSAMAddress sets the SAM bridge host and port from a combined address string.
// If no address is provided, it sets default values for the host and port.
func (f *I2PConfig) SetSAMAddress(addr string) {
	if addr == "" {
		f.SamHost = "127.0.0.1"
		f.SamPort = 7656
		return
	}

	host, port, err := net.SplitHostPort(addr)
	if err != nil {
		// Only set host if it looks valid
		if net.ParseIP(addr) != nil || !strings.Contains(addr, ":") {
			f.SamHost = addr
		}
		return
	}

	f.SamHost = host
	if p, err := strconv.Atoi(port); err == nil && p > 0 && p < 65536 {
		f.SamPort = p
	}
}

// ID returns the tunnel name as a formatted string. If no tunnel name is set,
// generates a random 12-character name using lowercase letters.
func (f *I2PConfig) ID() string {
	generator := rand.New(rand.NewSource(time.Now().UnixNano()))
	// If no tunnel name set, generate random one
	if f.TunName == "" {
		// Generate 12 random lowercase letters
		b := make([]byte, 12)
		for i := range b {
			b[i] = "abcdefghijklmnopqrstuvwxyz"[generator.Intn(26)]
		}
		f.TunName = string(b)

		// Log the generated name
		log.WithField("TunName", f.TunName).Debug("Generated random tunnel name")
	}

	// Return formatted ID string
	return fmt.Sprintf("ID=%s", f.TunName)
}

// Leasesetsettings returns the lease set configuration strings for I2P
// Returns three strings: lease set key, private key, and private signing key settings
func (f *I2PConfig) LeaseSetSettings() (string, string, string) {
	// Initialize empty strings for each setting
	var leaseSetKey, privateKey, privateSigningKey string

	// Set lease set key if configured
	if f.LeaseSetKey != "" {
		leaseSetKey = fmt.Sprintf(" i2cp.leaseSetKey=%s ", f.LeaseSetKey)
	}

	// Set lease set private key if configured
	if f.LeaseSetPrivateKey != "" {
		privateKey = fmt.Sprintf(" i2cp.leaseSetPrivateKey=%s ", f.LeaseSetPrivateKey)
	}

	// Set lease set private signing key if configured
	if f.LeaseSetPrivateSigningKey != "" {
		privateSigningKey = fmt.Sprintf(" i2cp.leaseSetPrivateSigningKey=%s ", f.LeaseSetPrivateSigningKey)
	}

	// Log the constructed settings
	log.WithFields(logrus.Fields{
		"leaseSetKey":               leaseSetKey,
		"leaseSetPrivateKey":        privateKey,
		"leaseSetPrivateSigningKey": privateSigningKey,
	}).Debug("Lease set settings constructed")

	return leaseSetKey, privateKey, privateSigningKey
}

// FromPort returns the FROM_PORT configuration string for SAM bridges >= 3.1
// Returns an empty string if SAM version < 3.1 or if fromport is "0"
func (f *I2PConfig) FromPort() string {
	// Check SAM version compatibility
	if f.SamMax == "" || f.samMax() < 3.1 {
		log.Debug("SAM version < 3.1, FromPort not applicable")
		return ""
	}

	// Return formatted FROM_PORT if fromport is set
	if f.Fromport != "0" {
		log.WithField("fromPort", f.Fromport).Debug("FromPort set")
		return fmt.Sprintf(" FROM_PORT=%s ", f.Fromport)
	}

	log.Debug("FromPort not set")
	return ""
}

// ToPort returns the TO_PORT configuration string for SAM bridges >= 3.1
// Returns an empty string if SAM version < 3.1 or if toport is "0"
func (f *I2PConfig) ToPort() string {
	// Check SAM version compatibility
	if f.samMax() < 3.1 {
		log.Debug("SAM version < 3.1, ToPort not applicable")
		return ""
	}

	// Return formatted TO_PORT if toport is set
	if f.Toport != "0" {
		log.WithField("toPort", f.Toport).Debug("ToPort set")
		return fmt.Sprintf(" TO_PORT=%s ", f.Toport)
	}

	log.Debug("ToPort not set")
	return ""
}

// SessionStyle returns the SAM session style configuration string
// If no style is set, defaults to "STREAM"
func (f *I2PConfig) SessionStyle() string {
	if f.Style != "" {
		// Log custom style setting
		log.WithField("style", f.Style).Debug("Session style set")
		return fmt.Sprintf(" STYLE=%s ", f.Style)
	}

	// Log default style
	log.Debug("Using default STREAM style")
	return " STYLE=STREAM "
}

// samMax returns the maximum SAM version supported as a float64
// If parsing fails, returns default value 3.1
func (f *I2PConfig) samMax() float64 {
	// Parse SAM max version to integer
	i, err := strconv.ParseFloat(f.SamMax, 64)
	if err != nil {
		log.WithError(err).Warn("Failed to parse SamMax, using default 3.1")
		return 3.1
	}

	// Log the parsed version and return
	log.WithField("samMax", i).Debug("SAM max version parsed")
	return i
}

// MinSAM returns the minimum SAM version supported as a string
// If no minimum version is set, returns default value "3.0"
func (f *I2PConfig) MinSAM() string {
	if f.SamMin == "" {
		log.Debug("Using default MinSAM: 3.0")
		return "3.0"
	}
	log.WithField("minSAM", f.SamMin).Debug("MinSAM set")
	return f.SamMin
}

// MaxSAM returns the maximum SAM version supported as a string
// If no maximum version is set, returns default value "3.1"
func (f *I2PConfig) MaxSAM() string {
	if f.SamMax == "" {
		log.Debug("Using default MaxSAM: 3.1")
		return "3.1"
	}
	log.WithField("maxSAM", f.SamMax).Debug("MaxSAM set")
	return f.SamMax
}

// DestinationKey returns the DESTINATION configuration string for the SAM bridge
// If destination keys are set, returns them as a string, otherwise returns "TRANSIENT"
func (f *I2PConfig) DestinationKey() string {
	// Check if destination keys are set
	if f.DestinationKeys != nil {
		// Log the destination key being used
		log.WithField("destinationKey", f.DestinationKeys.String()).Debug("Destination key set")
		return fmt.Sprintf(" DESTINATION=%s ", f.DestinationKeys.String())
	}

	// Log and return transient destination
	log.Debug("Using TRANSIENT destination")
	return " DESTINATION=TRANSIENT "
}

// SignatureType returns the SIGNATURE_TYPE configuration string for SAM bridges >= 3.1
// Returns empty string if SAM version < 3.1 or if no signature type is set
func (f *I2PConfig) SignatureType() string {
	// Check SAM version compatibility
	if f.samMax() < 3.1 {
		log.Debug("SAM version < 3.1, SignatureType not applicable")
		return ""
	}

	// Return formatted signature type if set
	if f.SigType != "" {
		log.WithField("sigType", f.SigType).Debug("Signature type set")
		return fmt.Sprintf(" SIGNATURE_TYPE=%s ", f.SigType)
	}

	log.Debug("Signature type not set")
	return ""
}

// EncryptLease returns the lease set encryption configuration string
// Returns "i2cp.encryptLeaseSet=true" if encryption is enabled, empty string otherwise
func (f *I2PConfig) EncryptLease() string {
	if f.EncryptLeaseSet {
		log.Debug("Lease set encryption enabled")
		return " i2cp.encryptLeaseSet=true "
	}
	log.Debug("Lease set encryption not enabled")
	return ""
}

// Reliability returns the message reliability configuration string for the SAM bridge
// If a reliability setting is specified, returns formatted i2cp.messageReliability setting
func (f *I2PConfig) Reliability() string {
	if f.MessageReliability != "" {
		// Log the reliability setting being used
		log.WithField("reliability", f.MessageReliability).Debug("Message reliability set")
		return fmt.Sprintf(" i2cp.messageReliability=%s ", f.MessageReliability)
	}

	// Log when reliability is not set
	log.Debug("Message reliability not set")
	return ""
}

// Reduce returns I2CP reduce-on-idle configuration settings as a string if enabled
func (f *I2PConfig) Reduce() string {
	// Return early if reduce idle is not enabled
	if !f.ReduceIdle {
		log.Debug("Reduce idle settings not applied")
		return ""
	}

	// Log and return the reduce idle configuration
	result := fmt.Sprintf("i2cp.reduceOnIdle=%t i2cp.reduceIdleTime=%d i2cp.reduceQuantity=%d",
		f.ReduceIdle, f.ReduceIdleTime, f.ReduceIdleQuantity)
	log.WithField("config", result).Debug("Reduce idle settings applied")
	return result
}

// Close returns I2CP close-on-idle configuration settings as a string if enabled
func (f *I2PConfig) Close() string {
	// Return early if close idle is not enabled
	if !f.CloseIdle {
		log.Debug("Close idle settings not applied")
		return ""
	}

	// Log and return the close idle configuration
	result := fmt.Sprintf("i2cp.closeOnIdle=%t i2cp.closeIdleTime=%d",
		f.CloseIdle, f.CloseIdleTime)
	log.WithField("config", result).Debug("Close idle settings applied")
	return result
}

// DoZero returns the zero hop and fast receive configuration string settings
func (f *I2PConfig) DoZero() string {
	// Build settings using slices for cleaner concatenation
	var settings []string

	// Add inbound zero hop setting if enabled
	if f.InAllowZeroHop {
		settings = append(settings, fmt.Sprintf("inbound.allowZeroHop=%t", f.InAllowZeroHop))
	}

	// Add outbound zero hop setting if enabled
	if f.OutAllowZeroHop {
		settings = append(settings, fmt.Sprintf("outbound.allowZeroHop=%t", f.OutAllowZeroHop))
	}

	// Add fast receive setting if enabled
	if f.FastRecieve {
		settings = append(settings, fmt.Sprintf("i2cp.fastRecieve=%t", f.FastRecieve))
	}

	// Join all settings with spaces
	result := strings.Join(settings, " ")

	// Log the final settings
	log.WithField("zeroHopSettings", result).Debug("Zero hop settings applied")

	return result
}

// formatConfigPair creates a configuration string for inbound/outbound pairs
func (f *I2PConfig) formatConfigPair(direction, property string, value int) string {
	return fmt.Sprintf("%s.%s=%d", direction, property, value)
}

func (f *I2PConfig) InboundLength() string {
	return f.formatConfigPair("inbound", "length", f.InLength)
}

func (f *I2PConfig) OutboundLength() string {
	return f.formatConfigPair("outbound", "length", f.OutLength)
}

func (f *I2PConfig) InboundLengthVariance() string {
	return f.formatConfigPair("inbound", "lengthVariance", f.InVariance)
}

func (f *I2PConfig) OutboundLengthVariance() string {
	return f.formatConfigPair("outbound", "lengthVariance", f.OutVariance)
}

func (f *I2PConfig) InboundBackupQuantity() string {
	return f.formatConfigPair("inbound", "backupQuantity", f.InBackupQuantity)
}

func (f *I2PConfig) OutboundBackupQuantity() string {
	return f.formatConfigPair("outbound", "backupQuantity", f.OutBackupQuantity)
}

func (f *I2PConfig) InboundQuantity() string {
	return f.formatConfigPair("inbound", "quantity", f.InQuantity)
}

func (f *I2PConfig) OutboundQuantity() string {
	return f.formatConfigPair("outbound", "quantity", f.OutQuantity)
}

// Print returns a slice of strings containing all the I2P configuration settings
func (f *I2PConfig) Print() []string {
	// Get lease set settings
	lsk, lspk, lspsk := f.LeaseSetSettings()

	// Build the configuration settings slice
	settings := []string{
		f.InboundLength(),
		f.OutboundLength(),
		f.InboundLengthVariance(),
		f.OutboundLengthVariance(),
		f.InboundBackupQuantity(),
		f.OutboundBackupQuantity(),
		f.InboundQuantity(),
		f.OutboundQuantity(),
		f.UsingCompression(),
		f.DoZero(),       // Zero hop settings
		f.Reduce(),       // Reduce idle settings
		f.Close(),        // Close idle settings
		f.Reliability(),  // Message reliability
		f.EncryptLease(), // Lease encryption
		lsk, lspk, lspsk, // Lease set keys
		f.Accesslisttype(),         // Access list type
		f.Accesslist(),             // Access list
		f.LeaseSetEncryptionType(), // Lease set encryption type
	}

	return settings
}

// Accesslisttype returns the I2CP access list configuration string based on the AccessListType setting
func (f *I2PConfig) Accesslisttype() string {
	switch f.AccessListType {
	case ACCESS_TYPE_WHITELIST:
		log.Debug("Access list type set to whitelist")
		return "i2cp.enableAccessList=true"
	case ACCESS_TYPE_BLACKLIST:
		log.Debug("Access list type set to blacklist")
		return "i2cp.enableBlackList=true"
	case ACCESS_TYPE_NONE:
		log.Debug("Access list type set to none")
		return ""
	default:
		log.Debug("Access list type not set")
		return ""
	}
}

// Accesslist generates the I2CP access list configuration string based on the configured access list
func (f *I2PConfig) Accesslist() string {
	// Only proceed if access list type and values are set
	if f.AccessListType != "" && len(f.AccessList) > 0 {
		// Join access list entries with commas
		accessList := strings.Join(f.AccessList, ",")

		// Log the generated access list
		log.WithField("accessList", accessList).Debug("Access list generated")

		// Return formatted access list configuration
		return fmt.Sprintf("i2cp.accessList=%s", accessList)
	}

	// Log when access list is not set
	log.Debug("Access list not set")
	return ""
}

// LeaseSetEncryptionType returns the I2CP lease set encryption type configuration string.
// If no encryption type is set, returns default value "4,0".
// Validates that all encryption types are valid integers.
func (f *I2PConfig) LeaseSetEncryptionType() string {
	// Use default encryption type if none specified
	if f.LeaseSetEncryption == "" {
		log.Debug("Using default lease set encryption type: 4,0")
		return "i2cp.leaseSetEncType=4,0"
	}

	// Validate each encryption type is a valid integer
	for _, s := range strings.Split(f.LeaseSetEncryption, ",") {
		if _, err := strconv.Atoi(s); err != nil {
			log.WithField("invalidType", s).Panic("Invalid encrypted leaseSet type")
			// panic("Invalid encrypted leaseSet type: " + s)
		}
	}

	// Log and return the configured encryption type
	log.WithField("leaseSetEncType", f.LeaseSetEncryption).Debug("Lease set encryption type set")
	return fmt.Sprintf("i2cp.leaseSetEncType=%s", f.LeaseSetEncryption)
}

func NewConfig(opts ...func(*I2PConfig) error) (*I2PConfig, error) {
	var config I2PConfig
	config.SamHost = "127.0.0.1"
	config.SamPort = 7656
	config.SamMin = DEFAULT_SAM_MIN
	config.SamMax = DEFAULT_SAM_MAX
	config.TunName = ""
	config.TunType = "server"
	config.Style = SESSION_STYLE_STREAM
	config.InLength = 3
	config.OutLength = 3
	config.InQuantity = 2
	config.OutQuantity = 2
	config.InVariance = 1
	config.OutVariance = 1
	config.InBackupQuantity = 3
	config.OutBackupQuantity = 3
	config.InAllowZeroHop = false
	config.OutAllowZeroHop = false
	config.EncryptLeaseSet = false
	config.LeaseSetKey = ""
	config.LeaseSetPrivateKey = ""
	config.LeaseSetPrivateSigningKey = ""
	config.FastRecieve = false
	config.UseCompression = true
	config.ReduceIdle = false
	config.ReduceIdleTime = 15
	config.ReduceIdleQuantity = 4
	config.CloseIdle = false
	config.CloseIdleTime = 300000
	config.MessageReliability = "none"
	for _, opt := range opts {
		if err := opt(&config); err != nil {
			return nil, err
		}
	}
	return &config, nil
}