package color

import (
	"os"
	"strings"
	"sync"
)

// ANSI color codes
const (
	resetCode  = "\033[0m"
	redCode    = "\033[31m"
	greenCode  = "\033[32m"
	yellowCode = "\033[33m"
	blueCode   = "\033[34m"
	purpleCode = "\033[35m"
	cyanCode   = "\033[36m"
	whiteCode  = "\033[37m"
	grayCode   = "\033[90m"
)

var (
	useColors bool
	colorMu   sync.RWMutex
)

// Color function; makes a call to makeColorFunc with the associated color code
var (
	Reset  = makeColorFunc(resetCode)
	Red    = makeColorFunc(redCode)
	Green  = makeColorFunc(greenCode)
	Yellow = makeColorFunc(yellowCode)
	Blue   = makeColorFunc(blueCode)
	Purple = makeColorFunc(purpleCode)
	Cyan   = makeColorFunc(cyanCode)
	White  = makeColorFunc(whiteCode)
	Gray   = makeColorFunc(grayCode)
)

func init() {
	useColors = DetectShellColors()
}

func makeColorFunc(code string) func(string) string {
	return func(text string) string {
		colorMu.RLock()
		enabled := useColors
		colorMu.RUnlock()

		if enabled {
			return code + text + resetCode
		}
		return text
	}
}

// DetectShellColors checks if the current shell supports colors
func DetectShellColors() bool {
	// Check NO_COLOR environment variable (standard)
	if os.Getenv("NO_COLOR") != "" {
		return false
	}

	// Check FORCE_COLOR environment variable
	if os.Getenv("FORCE_COLOR") != "" {
		return true
	}

	// Check if stdout is a terminal
	if !isTerminal(os.Stdout) {
		return false
	}

	// Check TERM environment variable
	term := os.Getenv("TERM")
	if term == "" || term == "dumb" {
		return false
	}

	// Common color-supporting terminals
	return strings.Contains(term, "color") ||
		strings.Contains(term, "xterm") ||
		strings.Contains(term, "screen") ||
		strings.Contains(term, "tmux") ||
		term == "linux" ||
		isWindowsTerminal()
}

// SetColors enables or disables colors globally
func SetColors(enabled bool) {
	colorMu.Lock()
	useColors = enabled
	colorMu.Unlock()
}

// ColorsEnabled returns current global color setting
func ColorsEnabled() bool {
	colorMu.RLock()
	defer colorMu.RUnlock()
	return useColors
}