package main

import (
	"flag"
	"fmt"
	"math/rand"
	"os"
	"time"
)

var (
	surfaces, modifier, diceThrows, attacks int
	advantage, disadvantage                 bool
)

type Color string

const (
	ColorBlack  Color = "\u001b[30m"
	ColorRed          = "\u001b[31m"
	ColorGreen        = "\u001b[32m"
	ColorYellow       = "\u001b[33m"
	ColorBlue         = "\u001b[34m"
	ColorReset        = "\u001b[0m"
)

func main() {

	rand.Seed(time.Now().Unix())
	ParseFlags()

	switch {
	case advantage:
		fmt.Println(string(ColorGreen), "Rolling with advantage...", string(ColorReset))
		fmt.Println(string(ColorGreen), Advantage(SimpleCast(), SimpleCast()), string(ColorReset))
	case disadvantage:
		fmt.Println(string(ColorRed), "Rolling with disadvantage...", string(ColorReset))
		fmt.Println(string(ColorRed), Disadvantage(SimpleCast(), SimpleCast()), string(ColorReset))
	case attacks < 1:
		fmt.Println("Attack amount cannot be below 1.")
		os.Exit(1)
	case attacks > 1:
		for i := 0; i < attacks; i++ {
			fmt.Println()
			fmt.Println(string(ColorYellow), "Attack:", i+1, string(ColorReset))
			Cast(surfaces, diceThrows)
		}
	default:

		fmt.Println(string(ColorYellow), "Single die cast:", string(ColorReset))
		Cast(surfaces, diceThrows)
	}
}

func ParseFlags() {
	flag.IntVar(&surfaces, "surfaces", 20, "Use to specify die surfaces, does not apply to advantage and disadvantage")
	flag.IntVar(&surfaces, "s", 20, "Use to specify die surfaces, defaults to 20")

	flag.IntVar(&diceThrows, "throws", 1, "Specify amount of dice to cast")
	flag.IntVar(&diceThrows, "c", 1, "Specify amount of dice to cast")

	flag.IntVar(&modifier, "modifier", 0, "Add modifier to result of rolls")
	flag.IntVar(&modifier, "m", 0, "Add modifier to result of rolls")

	flag.IntVar(&attacks, "attacks", 1, "Roll a set rules multiple times, does not apply to advantage and disadvantage")
	flag.IntVar(&attacks, "a", 1, "Roll a set rules multiple times, does not apply to advantage and disadvantage")

	flag.BoolVar(&advantage, "advantage", false, "Roll with advantage")
	flag.BoolVar(&disadvantage, "disadvantage", false, "Roll with disadvantage")

	flag.Parse()
}

func Cast(dieSurfaces, castAmount int) {
	var (
		casts       []int
		cast, total int
	)

	for i := 0; i < castAmount; i++ {
		cast = rand.Intn(dieSurfaces) + 1
		casts = append(casts, cast)
		total += cast
	}

	if castAmount > 1 {
		fmt.Println(string(ColorBlue), "\tIndividual rolls:", casts, string(ColorReset))
	}

	if modifier != 0 {
		fmt.Println("\tWithout modifier:", total)
		fmt.Println(string(ColorGreen), "\tWith modifier:", total+modifier, string(ColorReset))
	} else {
		fmt.Println(string(ColorGreen), "\t", total, string(ColorReset))
	}
}

func SimpleCast() int {

	var cast = rand.Intn(20) + 1

	fmt.Println("Without modifier:", cast)
	return cast + modifier
}

func Advantage(x, y int) int {
	fmt.Println("x:", x)
	fmt.Println("Y:", y)
	if x > y {
		return x
	} else {
		return y
	}
}

func Disadvantage(x, y int) int {
	fmt.Println("x:", x)
	fmt.Println("Y:", y)
	if x < y {
		return x
	} else {
		return y
	}
}