package logger

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

	"github.com/chenasraf/sofmani/platform"
	"github.com/davecgh/go-spew/spew"
	"github.com/mattn/go-runewidth"
	"golang.org/x/term"
)

// Highlight markers (using unlikely byte sequences)
const (
	highlightStart = "\x00HS\x00"
	highlightEnd   = "\x00HE\x00"
)

// ANSI color codes
const (
	ansiHighlight  = "\033[1;96m" // Bright cyan for highlights
	ansiBlueBold   = "\033[1;34m"
	ansiYellowBold = "\033[1;33m"
	ansiRedBold    = "\033[1;31m"
	ansiGreenBold  = "\033[1;32m"
	ansiReset      = "\033[0m"
)

// Highlight marks text to be displayed in white/bold in console output.
// Use this for installer names, types, and other important identifiers.
func Highlight(text string) string {
	return highlightStart + text + highlightEnd
}

// H is a shorthand alias for Highlight.
func H(text string) string {
	return Highlight(text)
}

// Logger provides logging functionality with support for file and console output.
type Logger struct {
	fileLogger  *log.Logger // fileLogger is the logger for writing to the log file.
	consoleOut  *log.Logger // consoleOut is the logger for writing to the console.
	logFile     *os.File    // logFile is the opened log file.
	logFilePath string      // logFilePath is the path to the log file.
	debug       bool        // debug indicates whether debug logging is enabled.
}

var logger *Logger        // logger is the global logger instance.
var customLogFile *string // customLogFile holds the custom log file path if set.

// GetLogDir returns the appropriate log directory based on the operating system.
func GetLogDir() string {
	var logDir string
	switch platform.GetPlatform() {
	case platform.PlatformLinux:
		stateDir := os.Getenv("XDG_STATE_HOME")
		if stateDir == "" {
			home, err := os.UserHomeDir()
			if err != nil {
				fmt.Printf("Could not get user home directory: %v\n", err)
				panic(err)
			}
			stateDir = filepath.Join(home, ".local", "state")
		}
		logDir = filepath.Join(stateDir, "sofmani")
	case platform.PlatformMacos:
		home, err := os.UserHomeDir()
		if err != nil {
			fmt.Printf("Could not get user home directory: %v\n", err)
			panic(err)
		}
		logDir = filepath.Join(home, "Library", "Logs", "sofmani")
	case platform.PlatformWindows:
		appData := os.Getenv("APPDATA")
		logDir = filepath.Join(appData, "sofmani", "Logs")
	}
	return logDir
}

// GetDefaultLogFile returns the default log file path.
func GetDefaultLogFile() string {
	return filepath.Join(GetLogDir(), "sofmani.log")
}

// GetLogFile returns the current log file path (custom or default).
func GetLogFile() string {
	if customLogFile != nil {
		return *customLogFile
	}
	return GetDefaultLogFile()
}

// SetLogFile sets a custom log file path.
func SetLogFile(path string) {
	customLogFile = &path
}

const maxLogSize = 10 * 1024 * 1024 // 10MB

// InitLogger initializes the global logger with the specified debug mode.
// It creates the log directory and file if they don't exist.
// If the log file exceeds maxLogSize, it will be truncated.
func InitLogger(debug bool) *Logger {
	filePath := GetLogFile()
	logDir := filepath.Dir(filePath)
	if _, err := os.Stat(logDir); os.IsNotExist(err) {
		err := os.MkdirAll(logDir, 0755)
		if err != nil {
			fmt.Printf("Could not create log directory: %v\n", err)
			os.Exit(1)
		}
	}

	// Truncate log file if it exceeds maxLogSize
	if info, err := os.Stat(filePath); err == nil && info.Size() > maxLogSize {
		if err := os.Truncate(filePath, 0); err != nil {
			fmt.Printf("Could not truncate log file: %v\n", err)
		}
	}

	logFile, err := os.OpenFile(filePath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		fmt.Printf("Could not create log file: %v\n", err)
		os.Exit(1)
	}

	// Create file and console loggers
	fileLogger := log.New(logFile, "", log.LstdFlags)
	consoleOut := log.New(os.Stdout, "", log.LstdFlags)

	// Initialize the logger
	logger = &Logger{
		fileLogger:  fileLogger,
		consoleOut:  consoleOut,
		logFile:     logFile,
		logFilePath: filePath,
		debug:       debug,
	}

	return logger
}

// stripHighlightMarkers removes highlight markers from text (for file output).
func stripHighlightMarkers(text string) string {
	text = strings.ReplaceAll(text, highlightStart, "")
	text = strings.ReplaceAll(text, highlightEnd, "")
	return text
}

// processHighlights converts highlight markers to ANSI codes for console output.
func processHighlights(text string, baseColorSeq string) string {
	// Replace start marker with highlight color
	text = strings.ReplaceAll(text, highlightStart, ansiHighlight)
	// Replace end marker with reset + base color (to restore the log level color)
	text = strings.ReplaceAll(text, highlightEnd, ansiReset+baseColorSeq)
	return text
}

// log is an internal helper function for logging messages with a specific level and color.
func (l *Logger) log(level string, colorSeq string, format string, args ...any) {
	message := fmt.Sprintf("[%s] %s", level, fmt.Sprintf(format, args...))

	// Write to file (strip all highlight markers - file should have no colors)
	fileMessage := stripHighlightMarkers(message)
	l.fileLogger.Println(fileMessage)

	if level == "DEBUG" && !l.debug {
		return
	}

	// Write to console with color
	if colorSeq != "" {
		consoleMessage := processHighlights(message, colorSeq)
		// Wrap entire message in base color and reset at end
		l.consoleOut.Println(colorSeq + consoleMessage + ansiReset)
	} else {
		// No base color - just convert highlights to white
		consoleMessage := processHighlights(message, "")
		l.consoleOut.Println(consoleMessage)
	}
}

// Info logs an informational message.
func Info(format string, args ...any) {
	logger.log(" INFO", ansiBlueBold, format, args...)
}

// Warn logs a warning message.
func Warn(format string, args ...any) {
	logger.log(" WARN", ansiYellowBold, format, args...)
}

// Error logs an error message.
func Error(format string, args ...any) {
	logger.log("ERROR", ansiRedBold, format, args...)
}

// Debug logs a debug message. Only printed if debug mode is enabled.
func Debug(format string, args ...any) {
	logger.log("DEBUG", ansiGreenBold, format, args...)
}

// Spew logs a detailed representation of a value using spew.Dump.
// This is typically used for debugging complex data structures.
func Spew(v any) {
	// Print/debug the passed value (works like spew.Dump)
	spewDump := spew.Sdump(v)
	Debug("%s", spewDump)
}

// CloseLogger closes the log file.
func CloseLogger() {
	if logger != nil && logger.logFile != nil {
		err := logger.logFile.Close()
		if err != nil {
			fmt.Printf("Could not close log file: %v\n", err)
		}
	}
}

// Box-drawing characters for category headers
const (
	boxTopLeft      = "┌"
	boxTopRight     = "┐"
	boxBottomLeft   = "└"
	boxBottomRight  = "┘"
	boxHorizontal   = "─"
	boxVertical     = "│"
	boxLeftT        = "├"
	boxRightT       = "┤"
	boxDefaultWidth = 60
)

// getBoxWidth returns the width to use for category boxes.
// It uses the terminal width if it's narrower than the default, otherwise uses the default.
func getBoxWidth() int {
	width, _, err := term.GetSize(int(os.Stdout.Fd()))
	if err != nil || width <= 0 {
		return boxDefaultWidth
	}
	if width < boxDefaultWidth {
		return width
	}
	return boxDefaultWidth
}

// CategoryDisplayMode controls how category headers are rendered.
type CategoryDisplayMode string

const (
	// CategoryDisplayBorder renders categories with a full border and spacing.
	CategoryDisplayBorder CategoryDisplayMode = "border"
	// CategoryDisplayBorderCompact renders categories with a border but no spacing.
	CategoryDisplayBorderCompact CategoryDisplayMode = "border-compact"
	// CategoryDisplayMinimal renders categories without a border or spacing.
	CategoryDisplayMinimal CategoryDisplayMode = "minimal"
)

// Category logs a category header with a decorative border.
// If desc is provided, it will be displayed below the category name with auto-wrapping.
// The displayMode controls the visual style: "border" (default), "border-compact", or "minimal".
func Category(name string, desc *string, displayMode CategoryDisplayMode) {
	switch displayMode {
	case CategoryDisplayMinimal:
		categoryMinimal(name, desc)
	case CategoryDisplayBorderCompact:
		categoryBorder(name, desc, false)
	default:
		categoryBorder(name, desc, true)
	}
}

// categoryBorder renders a category with box-drawing borders.
// If spaced is true, empty lines are added before and after.
func categoryBorder(name string, desc *string, spaced bool) {
	boxWidth := getBoxWidth()
	innerWidth := boxWidth - 4 // Account for "│ " and " │"

	// Build the border lines
	horizontalLine := strings.Repeat(boxHorizontal, boxWidth-2)
	topBorder := boxTopLeft + horizontalLine + boxTopRight
	bottomBorder := boxBottomLeft + horizontalLine + boxBottomRight
	separator := boxLeftT + horizontalLine + boxRightT

	// Log the header
	if spaced {
		Info("")
	}
	Info("%s", topBorder)
	Info("%s", formatBoxLine(name, innerWidth))

	// Log description if provided
	if desc != nil && len(*desc) > 0 {
		Info("%s", separator)
		for _, line := range wrapText(*desc, innerWidth) {
			Info("%s", formatBoxLine(line, innerWidth))
		}
	}

	Info("%s", bottomBorder)
	if spaced {
		Info("")
	}
}

// categoryMinimal renders a category as plain text without borders or spacing.
func categoryMinimal(name string, desc *string) {
	Info("%s", name)
	if desc != nil && len(*desc) > 0 {
		boxWidth := getBoxWidth()
		for _, line := range wrapText(*desc, boxWidth) {
			Info("%s", line)
		}
	}
}

// formatBoxLine formats a line of text to fit within the box.
func formatBoxLine(text string, innerWidth int) string {
	// Truncate if too long (using display width)
	text = runewidth.Truncate(text, innerWidth, "")
	// Pad to fill the width (using display width)
	displayWidth := runewidth.StringWidth(text)
	padding := strings.Repeat(" ", innerWidth-displayWidth)
	return boxVertical + " " + text + padding + " " + boxVertical
}

// wrapText wraps text to fit within maxWidth, respecting existing newlines.
// Uses display width to handle Unicode characters (including emojis) correctly.
func wrapText(text string, maxWidth int) []string {
	var result []string

	// Split by existing newlines first to respect user formatting
	for paragraph := range strings.SplitSeq(text, "\n") {
		if len(paragraph) == 0 {
			result = append(result, "")
			continue
		}

		// Wrap each paragraph
		words := strings.Fields(paragraph)
		if len(words) == 0 {
			result = append(result, "")
			continue
		}

		var currentLine string
		var currentWidth int
		for _, word := range words {
			wordWidth := runewidth.StringWidth(word)
			switch {
			case currentLine == "":
				currentLine = word
				currentWidth = wordWidth
			case currentWidth+1+wordWidth <= maxWidth:
				currentLine += " " + word
				currentWidth += 1 + wordWidth
			default:
				result = append(result, currentLine)
				currentLine = word
				currentWidth = wordWidth
			}
		}
		if currentLine != "" {
			result = append(result, currentLine)
		}
	}

	return result
}