// package cylogger
package main

import (
	"bytes"
	"flag"
	"fmt"
	"io"
	"log"
	"os"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"
	"sync"
	"time"
)

// TODO: Enable turning colors on and off maybe even per stream?

var loglevel = flag.String("loglevel", "info", "log level")

// LogLevel defines the severity of log messages
type LogLevel int

const (
	// LevelError is for critical errors that should always be displayed
	LevelError LogLevel = iota
	// LevelWarning is for important warnings
	LevelWarning
	// LevelInfo is for informational messages
	LevelInfo
	// LevelDebug is for detailed debugging information
	LevelDebug
	// LevelTrace is for very detailed tracing information
	LevelTrace
	// LevelLua is specifically for output from Lua scripts
	LevelLua
	LevelPrefix
)

// LevelStyle defines the visual style for a log level
type LevelStyle struct {
	Tag                    string // e.g., "ERROR", "INFO"
	TagColor               string // ANSI code for tag text
	TagBackgroundColor     string // ANSI code for tag background
	MessageColor           string // ANSI code for message text
	MessageBackgroundColor string // ANSI code for message background
}

// levelStyles maps LogLevel to its display style
var levelStyles = map[LogLevel]LevelStyle{
	LevelError: {
		Tag:                    "ERROR",
		TagColor:               BIRed,    // Bold Intense Red
		TagBackgroundColor:     On_White, // White background
		MessageColor:           White,    // Bold White text
		MessageBackgroundColor: On_IRed,  // Intense Red background
	},
	LevelWarning: {
		Tag:                    "WARNING",
		TagColor:               BIOrange,   // Bold Intense Orange
		TagBackgroundColor:     On_White,   // White background
		MessageColor:           White,      // Bold White text
		MessageBackgroundColor: On_IOrange, // Intense Orange background
	},
	LevelInfo: {
		Tag:      "INFO",
		TagColor: BGreen, // Bold Green
	},
	LevelDebug: {
		Tag:      "DEBUG",
		TagColor: BCyan, // Bold Cyan
	},
	LevelTrace: {
		Tag:      "TRACE",
		TagColor: BPurple, // Bold Purple
	},
	LevelLua: {
		Tag:      "LUA",
		TagColor: BBlue, // Bold Blue
	},
	LevelPrefix: {
		Tag:      "PREFIX", // Used for coloring the user prefix
		TagColor: BIBlack,  // Bold Intense Black (Dark Grey)
	},
}

// Logger is our custom logger with level support
type Logger struct {
	mu            sync.Mutex
	out           io.Writer
	currentLevel  LogLevel
	prefix        string
	userPrefix    string
	flag          int
	useColors     bool
	callerOffset  int
	defaultFields map[string]interface{}
	showGoroutine bool
}

var (
	// Default is the global logger instance
	Default *Logger
	// defaultLogLevel is the default log level if not specified
	defaultLogLevel = LevelInfo
	// Global mutex for DefaultLogger initialization
	initMutex sync.Mutex
)

// ParseLevel converts a string log level to LogLevel
func ParseLevel(levelStr string) LogLevel {
	switch strings.ToUpper(levelStr) {
	case "ERROR":
		return LevelError
	case "WARNING", "WARN":
		return LevelWarning
	case "INFO":
		return LevelInfo
	case "DEBUG":
		return LevelDebug
	case "TRACE":
		return LevelTrace
	case "LUA":
		return LevelLua
	default:
		return defaultLogLevel
	}
}

// String returns the string representation of the log level
func (l LogLevel) String() string {
	if name, ok := levelStyles[l]; ok {
		return name.Tag
	}
	return fmt.Sprintf("Level(%d)", l)
}

// New creates a new Logger instance
func New(out io.Writer, prefix string, flag int) *Logger {
	return &Logger{
		out:           out,
		currentLevel:  defaultLogLevel,
		prefix:        prefix,
		userPrefix:    "",
		flag:          flag,
		useColors:     true,
		callerOffset:  0,
		defaultFields: make(map[string]interface{}),
		showGoroutine: true,
	}
}

func InitFlag() {
	level := ParseLevel(*loglevel)
	Init(level)
}

// Init initializes the DefaultLogger
func Init(level LogLevel) {
	initMutex.Lock()
	defer initMutex.Unlock()

	if Default == nil {
		Default = New(os.Stdout, "", log.Lmicroseconds|log.Lshortfile)
	}
	Default.SetLevel(level)
}

// SetLevel sets the current log level
func (l *Logger) SetLevel(level LogLevel) {
	l.mu.Lock()
	defer l.mu.Unlock()
	l.currentLevel = level
}

// GetLevel returns the current log level
func (l *Logger) GetLevel() LogLevel {
	l.mu.Lock()
	defer l.mu.Unlock()
	return l.currentLevel
}

// SetCallerOffset sets the caller offset for correct file and line reporting
func (l *Logger) SetCallerOffset(offset int) {
	l.mu.Lock()
	defer l.mu.Unlock()
	l.callerOffset = offset
}

// SetShowGoroutine sets whether to include goroutine ID in log messages
func (l *Logger) SetShowGoroutine(show bool) {
	l.mu.Lock()
	defer l.mu.Unlock()
	l.showGoroutine = show
}

// ShowGoroutine returns whether goroutine ID is included in log messages
func (l *Logger) ShowGoroutine() bool {
	l.mu.Lock()
	defer l.mu.Unlock()
	return l.showGoroutine
}

// WithField adds a field to the logger's context
func (l *Logger) WithField(key string, value interface{}) *Logger {
	newLogger := &Logger{
		out:           l.out,
		currentLevel:  l.currentLevel,
		prefix:        l.prefix,
		userPrefix:    l.userPrefix,
		flag:          l.flag,
		useColors:     l.useColors,
		callerOffset:  l.callerOffset,
		defaultFields: make(map[string]interface{}),
		showGoroutine: l.showGoroutine,
	}

	// Copy existing fields
	for k, v := range l.defaultFields {
		newLogger.defaultFields[k] = v
	}

	// Add new field
	newLogger.defaultFields[key] = value
	return newLogger
}

// WithFields adds multiple fields to the logger's context
func (l *Logger) WithFields(fields map[string]interface{}) *Logger {
	newLogger := &Logger{
		out:           l.out,
		currentLevel:  l.currentLevel,
		prefix:        l.prefix,
		userPrefix:    l.userPrefix,
		flag:          l.flag,
		useColors:     l.useColors,
		callerOffset:  l.callerOffset,
		defaultFields: make(map[string]interface{}),
		showGoroutine: l.showGoroutine,
	}

	// Copy existing fields
	for k, v := range l.defaultFields {
		newLogger.defaultFields[k] = v
	}

	// Add new fields
	for k, v := range fields {
		newLogger.defaultFields[k] = v
	}
	return newLogger
}

func (l *Logger) WithPrefix(prefix string) *Logger {
	if Default == nil {
		Init(defaultLogLevel)
	}
	if l == nil {
		l = Default
	}
	newLogger := &Logger{
		out:           l.out,
		currentLevel:  l.currentLevel,
		prefix:        l.prefix,
		userPrefix:    strings.TrimSpace(l.userPrefix + " " + prefix),
		flag:          l.flag,
		useColors:     l.useColors,
		callerOffset:  l.callerOffset,
		defaultFields: make(map[string]interface{}),
		showGoroutine: l.showGoroutine,
	}

	// Copy existing fields
	for k, v := range l.defaultFields {
		newLogger.defaultFields[k] = v
	}
	return newLogger
}

func (l *Logger) ToFile(filename string) *Logger {
	file, err := os.OpenFile(filename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
	if err != nil {
		log.Fatal(err)
	}
	if Default == nil {
		Init(defaultLogLevel)
	}
	if l == nil {
		l = Default
	}
	newLogger := &Logger{
		out:           io.MultiWriter(l.out, file),
		currentLevel:  l.currentLevel,
		prefix:        l.prefix,
		userPrefix:    l.userPrefix,
		flag:          l.flag,
		useColors:     l.useColors,
		callerOffset:  l.callerOffset,
		defaultFields: make(map[string]interface{}),
		showGoroutine: l.showGoroutine,
	}
	return newLogger
}

// GetGoroutineID extracts the goroutine ID from the runtime stack
func GetGoroutineID() string {
	buf := make([]byte, 64)
	n := runtime.Stack(buf, false)
	// Format of first line is "goroutine N [state]:"
	// We only need the N part
	buf = buf[:n]
	idField := bytes.Fields(bytes.Split(buf, []byte{':'})[0])[1]
	return string(idField)
}

// formatMessage formats a log message with level, time, file, and line information
func (l *Logger) formatMessage(level LogLevel, format string, args ...interface{}) string {
	var msg string
	if len(args) > 0 {
		msg = fmt.Sprintf(format, args...)
	} else {
		msg = format
	}

	// Format default fields if any
	var fields string
	if len(l.defaultFields) > 0 {
		var pairs []string
		for k, v := range l.defaultFields {
			pairs = append(pairs, fmt.Sprintf("%s=%v", k, v))
		}
		fields = " " + strings.Join(pairs, " ")
	}

	var tagFgColor, tagBgColor, messageBgColor string
	useSpecialFormatting := false // Flag for levels with custom message background/foreground
	if l.useColors {
		// Check if a message background color is defined for this level style
		if levelStyles[level].MessageBackgroundColor != "" {
			useSpecialFormatting = true
			// Retrieve all style components from the map
			tagFgColor = levelStyles[level].TagColor // Assign directly
			tagBgColor = levelStyles[level].TagBackgroundColor
			// messageFgColor = levelStyles[level].MessageColor
			messageBgColor = levelStyles[level].MessageBackgroundColor
		} else {
			// For other levels (INFO, DEBUG, etc.), only TagColor is guaranteed
			tagFgColor = levelStyles[level].TagColor // Use the defined tag color
			// tagBgColor, messageFgColor, messageBgColor remain empty (use terminal defaults)
		}
	}

	var caller string
	if l.flag&log.Lshortfile != 0 || l.flag&log.Llongfile != 0 {
		var file string
		var line int
		var ok bool
		// Start at a reasonable depth and scan up to 10 frames
		for depth := 4; depth < 15; depth++ {
			_, file, line, ok = runtime.Caller(depth)
			if !ok {
				break
			}
			// Check if the caller is within this logger package itself
			if !strings.Contains(file, "main.go") && !strings.Contains(file, "colors.go") {
				break
			}
		}
		if !ok {
			file = "???"
			line = 0
		}
		if l.flag&log.Lshortfile != 0 {
			file = filepath.Base(file)
		}
		// Caller string - no background color applied here
		caller = fmt.Sprintf("%-25s ", file+":"+strconv.Itoa(line))
	}

	// Format the timestamp with fixed width - no background color applied here
	var timeStr string
	if l.flag&(log.Ldate|log.Ltime|log.Lmicroseconds) != 0 {
		t := time.Now()
		if l.flag&log.Ldate != 0 {
			timeStr += fmt.Sprintf("%04d/%02d/%02d ", t.Year(), t.Month(), t.Day())
		}
		if l.flag&(log.Ltime|log.Lmicroseconds) != 0 {
			timeStr += fmt.Sprintf("%02d:%02d:%02d", t.Hour(), t.Minute(), t.Second())
			if l.flag&log.Lmicroseconds != 0 {
				timeStr += fmt.Sprintf(".%06d", t.Nanosecond()/1000)
			}
		}
		timeStr = fmt.Sprintf("%-15s ", timeStr)
	}

	// Add goroutine ID if enabled, with fixed width - no background color applied here
	var goroutineStr string
	if l.showGoroutine {
		goroutineID := GetGoroutineID()
		goroutineStr = fmt.Sprintf("[g:%-4s] ", goroutineID)
	}

	// --- Level Tag Formatting and Padding ---
	levelStr := levelStyles[level].Tag
	visibleTagContent := fmt.Sprintf("[%s]", levelStr)
	visibleTagLen := len(visibleTagContent)
	paddingWidth := 10 // Target width for the level column (tag + padding)
	numSpaces := paddingWidth - visibleTagLen
	if numSpaces < 0 {
		numSpaces = 1 // Ensure at least one space
	}
	padding := strings.Repeat(" ", numSpaces)

	var levelTagFormatted string
	if useSpecialFormatting {
		// ERROR/WARNING: Tag has specific background and foreground
		levelTagFormatted = fmt.Sprintf("%s%s%s%s", tagBgColor, tagFgColor, visibleTagContent, Reset)
	} else {
		// Other levels: Tag has standard foreground color only
		levelTagFormatted = fmt.Sprintf("%s%s%s", tagFgColor, visibleTagContent, Reset)
	}
	levelColumn := levelTagFormatted + padding // Combine formatted tag and padding

	// --- User Prefix Formatting (part of message content for coloring purposes) ---
	userPrefixStr := ""
	if l.userPrefix != "" {
		// Format the string part here, colors applied later if needed
		userPrefixStr = fmt.Sprintf("[%s] ", l.userPrefix)
	}

	// --- Message Content ---
	messageContent := fmt.Sprintf("%s%s", msg, fields)

	// --- Assemble Final String ---
	var finalMsg strings.Builder

	// Part 1: Timestamp, Caller, Goroutine ID (always default colors)
	finalMsg.WriteString(l.prefix)
	finalMsg.WriteString(timeStr)
	finalMsg.WriteString(caller)
	finalMsg.WriteString(goroutineStr)

	// Part 2: Level Column (already formatted with tag colors and padding)
	finalMsg.WriteString(levelColumn)

	// Part 3: User Prefix + Message Content (apply special formatting if needed)
	if useSpecialFormatting {
		// ERROR/WARNING: Apply message background and foreground to User Prefix + Message
		finalMsg.WriteString(messageBgColor)
		// finalMsg.WriteString(messageFgColor) // This doesn't work...? For some reason?
		finalMsg.WriteString(userPrefixStr) // Write user prefix inside the colored block
		finalMsg.WriteString(messageContent)
		finalMsg.WriteString(Reset)
	} else {
		// Other levels: User Prefix and Message content use default colors
		// Apply specific color to user prefix if it exists
		if l.userPrefix != "" {
			prefixColor := levelStyles[LevelPrefix].TagColor
			finalMsg.WriteString(fmt.Sprintf("%s%s%s", prefixColor, userPrefixStr, Reset))
		} // No else needed, if userPrefix is empty, userPrefixStr is "" anyway
		finalMsg.WriteString(messageContent) // Append message with default colors
	}

	return finalMsg.String()
}

// log logs a message at the specified level
func (l *Logger) log(level LogLevel, format string, args ...interface{}) {
	// Always show LUA level logs regardless of the current log level
	if level != LevelLua && level > l.currentLevel {
		return
	}

	l.mu.Lock()
	defer l.mu.Unlock()

	// Get formatted message with potential background color
	msg := l.formatMessage(level, format, args...)
	fmt.Fprintln(l.out, msg)
}

// Error logs an error message
func (l *Logger) Error(format string, args ...interface{}) {
	l.log(LevelError, format, args...)
}

// Warning logs a warning message
func (l *Logger) Warning(format string, args ...interface{}) {
	l.log(LevelWarning, format, args...)
}

// Info logs an informational message
func (l *Logger) Info(format string, args ...interface{}) {
	l.log(LevelInfo, format, args...)
}

// Debug logs a debug message
func (l *Logger) Debug(format string, args ...interface{}) {
	l.log(LevelDebug, format, args...)
}

// Trace logs a trace message
func (l *Logger) Trace(format string, args ...interface{}) {
	l.log(LevelTrace, format, args...)
}

// Lua logs a Lua message
func (l *Logger) Lua(format string, args ...interface{}) {
	l.log(LevelLua, format, args...)
}

// Global log functions that use DefaultLogger

// Error logs an error message using the default logger
func Error(format string, args ...interface{}) {
	if Default == nil {
		Init(defaultLogLevel)
	}
	Default.Error(format, args...)
}

// Warning logs a warning message using the default logger
func Warning(format string, args ...interface{}) {
	if Default == nil {
		Init(defaultLogLevel)
	}
	Default.Warning(format, args...)
}

// Info logs an informational message using the default logger
func Info(format string, args ...interface{}) {
	if Default == nil {
		Init(defaultLogLevel)
	}
	Default.Info(format, args...)
}

// Debug logs a debug message using the default logger
func Debug(format string, args ...interface{}) {
	if Default == nil {
		Init(defaultLogLevel)
	}
	Default.Debug(format, args...)
}

// Trace logs a trace message using the default logger
func Trace(format string, args ...interface{}) {
	if Default == nil {
		Init(defaultLogLevel)
	}
	Default.Trace(format, args...)
}

// Lua logs a Lua message using the default logger
func Lua(format string, args ...interface{}) {
	if Default == nil {
		Init(defaultLogLevel)
	}
	Default.Lua(format, args...)
}

// LogPanic logs a panic error and its stack trace
func LogPanic(r interface{}) {
	if Default == nil {
		Init(defaultLogLevel)
	}
	stack := make([]byte, 4096)
	n := runtime.Stack(stack, false)
	Default.Error("PANIC: %v\n%s", r, stack[:n])
}

// SetLevel sets the log level for the default logger
func SetLevel(level LogLevel) {
	if Default == nil {
		Init(level)
		return
	}
	Default.SetLevel(level)
}

// GetLevel gets the log level for the default logger
func GetLevel() LogLevel {
	if Default == nil {
		Init(defaultLogLevel)
	}
	return Default.GetLevel()
}

// WithField returns a new logger with the field added to the default logger's context
func WithField(key string, value interface{}) *Logger {
	if Default == nil {
		Init(defaultLogLevel)
	}
	return Default.WithField(key, value)
}

// WithFields returns a new logger with the fields added to the default logger's context
func WithFields(fields map[string]interface{}) *Logger {
	if Default == nil {
		Init(defaultLogLevel)
	}
	return Default.WithFields(fields)
}

// SetShowGoroutine enables or disables goroutine ID display in the default logger
func SetShowGoroutine(show bool) {
	if Default == nil {
		Init(defaultLogLevel)
	}
	Default.SetShowGoroutine(show)
}

// ShowGoroutine returns whether goroutine ID is included in default logger's messages
func ShowGoroutine() bool {
	if Default == nil {
		Init(defaultLogLevel)
	}
	return Default.ShowGoroutine()
}

func main() {
	Init(LevelDebug)

	// Test basic logging
	Debug("This is a debug message")
	Info("This is an info message")
	Warning("This is a warning message")
	Error("This is an error message")

	// Test logging with fields
	logger := WithField("user", "testuser")
	logger.Info("User logged in")

	// Test logging with multiple fields
	fields := map[string]interface{}{
		"user": "testuser",
		"role": "admin",
		"id":   12345,
	}
	WithFields(fields).Info("User details")

	// Test error logging with fields
	WithField("error", "connection failed").Error("Database error")

	logger.WithPrefix("CUSTOM").Info("This is a message with a custom prefix")

	// Test goroutine ID display
	SetShowGoroutine(true)
	Info("This message should show goroutine ID")

	// Test different log levels
	SetLevel(LevelInfo)
	Debug("This debug message should not appear")
	Info("This info message should appear")

	// Test with custom prefix
	WithField("prefix", "custom").Info("Message with custom prefix")
	Lua("This is a Lua message")
}