package color

import (
	"fmt"
	"strings"
)

const Reset = "\033[0m"

var ansiFg = map[string]int{
	"black":   30,
	"red":     31,
	"green":   32,
	"yellow":  33,
	"blue":    34,
	"magenta": 35,
	"cyan":    36,
	"white":   37,
}

var ansiBg = map[string]int{
	"black":   40,
	"red":     41,
	"green":   42,
	"yellow":  43,
	"blue":    44,
	"magenta": 45,
	"cyan":    46,
	"white":   47,
}

var ansiBrightFg = map[string]int{
	"bright_black":   90,
	"bright_red":     91,
	"bright_green":   92,
	"bright_yellow":  93,
	"bright_blue":    94,
	"bright_magenta": 95,
	"bright_cyan":    96,
	"bright_white":   97,
}

var ansiBrightBg = map[string]int{
	"bright_black":   100,
	"bright_red":     101,
	"bright_green":   102,
	"bright_yellow":  103,
	"bright_blue":    104,
	"bright_magenta": 105,
	"bright_cyan":    106,
	"bright_white":   107,
}

var xtermFg = map[string]int{
	"black":           0,
	"red":             1,
	"green":           2,
	"yellow":          3,
	"blue":            4,
	"magenta":         5,
	"cyan":            6,
	"white":           7,
	"bright_black":    8,
	"bright_red":      9,
	"bright_green":    10,
	"bright_yellow":   11,
	"bright_blue":     12,
	"bright_magenta":  13,
	"bright_cyan":     14,
	"bright_white":    15,
}

var ansiStyles = map[string]string{
	"bold":      "\033[1m",
	"dim":       "\033[2m",
	"italic":    "\033[3m",
	"underline": "\033[4m",
}

func Fg(mode, name string) string {
	if mode == "none" || mode == "" {
		return ""
	}
	if mode == "xterm256" {
		if c, ok := xtermFg[name]; ok {
			return fmt.Sprintf("\033[38;5;%dm", c)
		}
		return ""
	}
	if c, ok := ansiFg[name]; ok {
		return fmt.Sprintf("\033[%dm", c)
	}
	if c, ok := ansiBrightFg[name]; ok {
		return fmt.Sprintf("\033[%dm", c)
	}
	return ""
}

func Bg(mode, name string) string {
	if mode == "none" || mode == "" {
		return ""
	}
	if mode == "xterm256" {
		if c, ok := xtermFg[name]; ok {
			return fmt.Sprintf("\033[48;5;%dm", c)
		}
		return ""
	}
	if c, ok := ansiBg[name]; ok {
		return fmt.Sprintf("\033[%dm", c)
	}
	if c, ok := ansiBrightBg[name]; ok {
		return fmt.Sprintf("\033[%dm", c)
	}
	return ""
}

func Style(name string) string {
	if s, ok := ansiStyles[name]; ok {
		return s
	}
	return ""
}

func Wrap(mode, name, text string) string {
	if mode == "none" || mode == "" {
		return text
	}
	return Fg(mode, name) + text + Reset
}

var knownColors []string

func init() {
	seen := make(map[string]bool)
	for name := range ansiFg {
		if !seen[name] {
			knownColors = append(knownColors, name)
			seen[name] = true
		}
	}
	for name := range ansiBrightFg {
		if !seen[name] {
			knownColors = append(knownColors, name)
			seen[name] = true
		}
	}
	for name := range ansiStyles {
		if !seen[name] {
			knownColors = append(knownColors, name)
			seen[name] = true
		}
	}
}

func KnownColors() []string { return knownColors }

func Tag(mode, text string) string {
	if mode == "none" || mode == "" {
		return cleanTags(text)
	}
	result := text
	for _, name := range knownColors {
		if _, isStyle := ansiStyles[name]; isStyle {
			result = replaceTag(result, name, Style(name), Reset)
		} else {
			result = replaceTag(result, name, Fg(mode, name), Reset)
		}
	}
	return result
}

func replaceTag(s, name, open, close string) string {
	tag := "<" + name + ">"
	end := "</" + name + ">"
	for {
		start := strings.Index(s, tag)
		if start < 0 {
			break
		}
		closeIdx := strings.Index(s[start+len(tag):], end)
		if closeIdx < 0 {
			break
		}
		closeIdx += start + len(tag)
		inner := s[start+len(tag) : closeIdx]
		replacement := open + inner + close
		s = s[:start] + replacement + s[closeIdx+len(end):]
	}
	return s
}

func cleanTags(text string) string {
	result := text
	for _, name := range knownColors {
		result = strings.ReplaceAll(result, "<"+name+">", "")
		result = strings.ReplaceAll(result, "</"+name+">", "")
	}
	return result
}