package main

import (
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"io/ioutil"
	"os"

	"github.com/fatih/color"
	"gitlab.com/EternalWanderer/dice-roller/Dice"
)

const exampleFile string = "/etc/sheet-parser/example.json"

var (
	path, pathFlag, skillString, saveString, statString             string
	modifier, diceThrows, surfaces                                  int
	X, Y                                                            int
	char                                                            Character
	skillMap                                                        = make(map[string]int)
	statMap                                                         = make(map[string]int)
	advantage, disadvantage, stat_list, skill_list, verbose, trivia bool
)

func parseFlags() {
	flag.StringVar(&pathFlag, "file", pathFlag, "Used to point to character sheet")
	flag.StringVar(&pathFlag, "f", pathFlag, "Used to point to character sheet")
	flag.StringVar(&skillString, "skill", "", "Skill to parse")
	flag.StringVar(&statString, "stat", "", "Stat check")
	flag.StringVar(&saveString, "save", "", "Saving throw to... throw")

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

	flag.BoolVar(&stat_list, "stat-list", false, "Print list of stats, can also be used with -save flag")
	flag.BoolVar(&skill_list, "skill-list", false, "Print list of skills to be used in combination with the -skill flag")
	flag.BoolVar(&verbose, "verbose", false, "Print stat numbers, to be used in combination with -stat-list or -skill-list")
	flag.BoolVar(&verbose, "v", false, "Print stat numbers, to be used in combination with -stat-list or -skill-list")

	flag.BoolVar(&trivia, "t", false, "Print character name, level and proficiency")
	flag.BoolVar(&trivia, "trivia", false, "Print character name, level and proficiency")

	flag.Parse()
}

func handleError(err error) {
	if err != nil {
		fmt.Println(err.Error())
		os.Exit(1)
	}
}

func readJson() {
	envPath, isSet := os.LookupEnv("CHARSHEET")
	switch {
	case len(pathFlag) > 0:
		path = pathFlag
	case isSet:
		path = envPath
	default:
		path = exampleFile
	}

	fmt.Println("Opening file:", path)
	var file, err = os.Open(path)
	handleError(err)
	defer file.Close()

	byteValue, _ := ioutil.ReadAll(file)

	err = json.Unmarshal(byteValue, &char)
	handleError(err)

}

func initMaps() {
	for i := 0; i < len(char.Skills); i++ {
		skillMap[char.Skills[i].SkillName] = i
	}

	for i := 0; i < len(char.Stats); i++ {
		statMap[char.Stats[i].StatName] = i
	}
}

func main() {
	parseFlags()
	readJson()
	initMaps()

	switch {

	case trivia:
		fmt.Printf("Name: %s\tLevel: %d\tProficiency: %d\n", char.Misc.Name, char.Misc.Level, getProficiency())
		fmt.Printf("Race: %s\tClass: %s\tBackground: %s\n", char.Misc.Race, char.Misc.Class, char.Misc.Background)

	case stat_list && skill_list:
		printStatList(verbose)
		printSkillList(verbose)
	case stat_list:
		printStatList(verbose)
	case skill_list:
		printSkillList(verbose)

	case advantage && disadvantage:
		fmt.Println("You can't roll with both advantage and disadvantage")
		os.Exit(1)
	case len(saveString) > 0:
		result, planeResult, err := savingThrow(getStat(saveString))
		badCheck(saveString, err)
		if advantage {
			color.Yellow("Rolling %s saving throw with advantage...", saveString)
			fmt.Printf("x: %d\ty: %d\n", X, Y)
			fmt.Printf("Modifier: %d\n", result-planeResult)
			color.Green("%d\n", result)
		} else if disadvantage {
			color.Yellow("Rolling %s saving throw with disadvantage...", saveString)
			fmt.Printf("x: %d\ty: %d\n", X, Y)
			fmt.Printf("Modifier: %d\n", result-planeResult)
			color.Red("%d\n", result)
		} else {
			color.Yellow("Rolling %s saving throw...", saveString)
			fmt.Printf("Without modifier: %d\tModifier: %d\n", planeResult, result-planeResult)
			color.Green("%d\n", result)
		}

	case len(skillString) > 0:
		result, planeResult, err := skillCheck(getSkill(skillString))
		badCheck(skillString, err)
		if advantage {
			color.Yellow("Rolling %s check with advantage...", skillString)
			fmt.Printf("x: %d\ty: %d\n", X, Y)
			fmt.Printf("Modifier: %d\n", result-planeResult)
			color.Green("%d\n", result)
		} else if disadvantage {
			color.Yellow("Rolling %s check with disadvantage...", skillString)
			fmt.Printf("x: %d\ty: %d\n", X, Y)
			fmt.Printf("Modifier: %d\n", result-planeResult)
			color.Red("%d\n", result)
		} else {
			color.Yellow("Rolling %s check...", skillString)
			fmt.Printf("Without modifier: %d\tModifier: %d\n", planeResult, result-planeResult)
			color.Green("%d\n", result)
		}

	case len(statString) > 0:
		result, planeResult, err := statCheck(getStat(statString))
		badCheck(statString, err)
		if advantage {
			color.Yellow("Rolling %s check with advantage...", statString)
			fmt.Printf("x: %d\ty: %d\n", X, Y)
			fmt.Printf("Modifier: %d\n", result-planeResult)
			color.Green("%d\n", result)
		} else if disadvantage {
			color.Yellow("Rolling %s check with disadvantage...", statString)
			fmt.Printf("x: %d\ty: %d\n", X, Y)
			fmt.Printf("Modifier: %d\n", result-planeResult)
			color.Red("%d\n", result)
		} else {
			color.Yellow("Rolling %s check...", statString)
			fmt.Printf("Without modifier: %d\tModifier: %d\n", planeResult, result-planeResult)
			color.Green("%d\n", result)
		}

	default:
		flag.Usage()
	}
}

func getProficiency() int {
	// https://worldbuildersjunction.com/what-is-proficiency-bonus-in-dd-5e-how-it-works-calculated/
	return (char.Misc.Level-1)/4 + 2
}

func getSkill(skillName string) Skill {
	return char.Skills[skillMap[skillName]]
}

func getStat(statName string) Stat {
	return char.Stats[statMap[statName]]
}

func getModifier(stat Stat) int {
	// https://worldbuildersjunction.com/dungeon-and-dragons-ability-scores-explained-for-beginners/
	return (stat.Score - 10) / 2
}

func rollDice() int {
	var die int
	switch {
	case advantage:
		die, X, Y = Dice.Advantage()
	case disadvantage:
		die, X, Y = Dice.Disadvantage()
	default:
		die = Dice.SimpleCast()
	}
	switch die {
	case 20:
		color.Magenta("Natural 20!\n")
	case 1:
		color.Magenta("Natural 1!\n")
	}
	return die
}
func badCheck(errorMessage string, err error) {
	if err == nil {
		return
	}
	fmt.Println(err)
	fmt.Println(errorMessage)
	os.Exit(1)
}

func statErrorCheck() error {
	for i := 0; i < len(char.Stats); i++ {
		if statString == char.Stats[i].StatName || saveString == char.Stats[i].StatName {
			return nil
		}
	}
	return errors.New("Unknown stat:")
}

func skillErrorCheck() error {
	for i := 0; i < len(char.Skills); i++ {
		if skillString == char.Skills[i].SkillName {
			return nil
		}
	}
	return errors.New("Unknown skill:")
}

func statCheck(stat Stat) (int, int, error) {
	die := rollDice()
	return die + getModifier(stat), die, statErrorCheck()

}

func savingThrow(stat Stat) (int, int, error) {
	die := rollDice()
	planeDie := die

	if stat.Proficient {
		die += getProficiency()
	}
	return die + getModifier(stat), planeDie, statErrorCheck()
}

func skillCheck(skill Skill) (int, int, error) {
	die := rollDice()
	if char.Misc.ReliableTalent && skill.Proficient && die < 10 {
		die = 10
	}
	planeDie := die

	die += getModifier(getStat(skill.BaseStat))

	switch {
	case skill.Expertise:
		die += getProficiency() * 2
	case skill.Proficient:
		die += getProficiency()
	case !skill.Proficient && char.Misc.JackOfAllTrades:
		die += (getProficiency() / 2)
	}
	return die, planeDie, skillErrorCheck()
}

func printStatList(verbose bool) {
	color.Magenta("Listing stats...")
	if verbose {
		var proficiency string
		for i := 0; i < len(char.Stats); i++ {
			name := char.Stats[i].StatName
			isProficient := char.Stats[i].Proficient
			if isProficient {
				proficiency = "Proficient"
			} else {
				proficiency = "Not proficient"
			}
			score := char.Stats[i].Score
			fmt.Printf("Stat: %s\t%s\tStat score: %d\tStat modifier: %d\n", name, proficiency, score, getModifier(char.Stats[i]))
		}
	} else {
		for i := 0; i < len(char.Stats); i++ {
			fmt.Println(char.Stats[i].StatName)
		}
	}
}

func printSkillList(verbose bool) {
	color.Magenta("Listing skills...")
	var proficiency string
	var expertise string
	if verbose {
		for i := 0; i < len(char.Skills); i++ {
			name := char.Skills[i].SkillName
			localModifier := getModifier(getStat(char.Skills[i].BaseStat))
			if char.Skills[i].Proficient {
				proficiency = "Proficient"
				localModifier += getProficiency()
			} else {
				proficiency = "Not proficient"
			}
			if char.Skills[i].Expertise {
				expertise = "Has expertise"
				localModifier += getProficiency()
			} else {
				expertise = "Doesn't have expertise"
			}
			fmt.Printf("Skill: %s\tSkill modifier: %d\t%s\t%s\n", name, localModifier, proficiency, expertise)
		}
	} else {
		for i := 0; i < len(char.Skills); i++ {
			fmt.Println(char.Skills[i].SkillName)
		}
	}
}