// Copyright (c) 2016 Florian Fischer. All rights reserved.
// Use of this source code is governed by a MIT license found in the LICENSE file.

package logic

import (
	"errors"
	"fmt"
	"strconv"
	"strings"
)

type Cmd struct {
	Cmd  string
	Argv []int
	Argc int
}

var cmdTable = map[string]int{
	"d": 1, "dice": 1,
	"p": 2, "print": 2,
	"q": 3, "quit": 3,
	"h": 4, "help": 4,
	"i": 5, "insert": 5,
	"c": 6, "cancel": 6,
	"r": 7, "reroll": 7,
	"pos": 8, "positions": 8,
}

// we ignore arguments which are to much
func ParseCmd(s string) (Cmd, error) {
	s = strings.Trim(s, " \t\r\n")
	split := strings.Split(s, " ")
	if len(split) == 0 {
		return Cmd{}, errors.New("Empty command")
	}

	argv := make([]int, 0, 5)
	argc := 0

	switch split[0] {
	case "d", "dice":
		fallthrough
	case "p", "print":
		fallthrough
	case "q", "quit":
		return Cmd{Cmd: split[0]}, nil
	case "h", "help":
		if len(split) > 1 {
			if i, exists := cmdTable[split[1]]; exists {
				argv = append(argv, i)
				argc++
			} else {
				return Cmd{}, fmt.Errorf("Invalid help topic \"%s\"", split[1])
			}
		}
		if argc < 1 {
			argv = append(argv, 0)
			argc++
		}
	case "i", "insert":
		fallthrough
	case "c", "cancel":
		if len(split) < 2 {
			return Cmd{}, errors.New(split[0] + ": missing argument")
		}
		if e, exists := ScorePositions[split[1]]; exists {
			argv = append(argv, e)
		} else if i, err := strconv.Atoi(split[1]); err != nil {
			return Cmd{}, err
		} else if i < 1 || i > 13 {
			return Cmd{}, fmt.Errorf("%s: %d out of range", split[0], i)
		} else {
			argv = append(argv, i-1)
		}
		argc++
	case "r", "reroll":
		for _, v := range split[1:] {
			i, err := strconv.Atoi(v)
			if err != nil {
				return Cmd{}, err
			}
			if i < 1 || i > 5 {
				return Cmd{}, fmt.Errorf("r: %d out of range", i)
			}
			argv = append(argv, i)
			argc++
			// ignore additional arguments
			if argc == 5 {
				break
			}
		}
	case "pos", "position":
		split[0] = "h"
		argv = append(argv, cmdTable["pos"])
		argc++
	default:
		return Cmd{}, fmt.Errorf("Invalid command \"%v\"", split[0])
	}

	return Cmd{split[0], argv[0:argc], argc}, nil
}

func CmdHelp(cmd int) []string {
	s := make([]string, 0, 6)
	switch cmd {
	case 1:
		s = append(s, fmt.Sprint("d - print dice"))
		s = append(s, fmt.Sprint("Print out the dice"))
	case 2:
		s = append(s, fmt.Sprint("p - print score"))
		s = append(s, fmt.Sprint("Print out your score"))
	case 3:
		s = append(s, fmt.Sprint("q - quit the game"))
		s = append(s, fmt.Sprint("Terminates the game"))
	case 4:
		s = append(s, fmt.Sprint("h [cmd] - print help"))
		s = append(s, fmt.Sprint("Print the help for a specific command or gernal help."))
	case 5:
		s = append(s, fmt.Sprint("i [pos] - insert into score"))
		s = append(s, fmt.Sprint("Insert your current dice into your score."))
		s = append(s, fmt.Sprint("See \"h pos\" for a explenation of the score entries"))
	case 6:
		s = append(s, fmt.Sprint("c [pos] - cancel a entry"))
		s = append(s, fmt.Sprint("Write 0 into your score."))
		s = append(s, fmt.Sprint("See \"h pos\" for a explenation of the score entries"))
	case 7:
		s = append(s, fmt.Sprint("r [dice] - reroll some dice"))
		s = append(s, fmt.Sprint("Reroll the specified dice."))
		s = append(s, fmt.Sprint("The dice to reroll are represented by a list of their indices in the dice set."))
		s = append(s, fmt.Sprint("Example:"))
		s = append(s, fmt.Sprint("\t\"r 1 4 5\" rerolls dice number 1, 4 and 5"))
		s = append(s, fmt.Sprint("\t\"r\" rerolls all dice"))
	case 8:
		s = append(s, fmt.Sprint("Positions:"))
		s = append(s, fmt.Sprint("1:  Aces"))
		s = append(s, fmt.Sprint("2:  Twos"))
		s = append(s, fmt.Sprint("3:  Threes"))
		s = append(s, fmt.Sprint("4:  Fours"))
		s = append(s, fmt.Sprint("5:  Fives"))
		s = append(s, fmt.Sprint("6:  Sixes"))
		s = append(s, fmt.Sprint("7:  ThreeOfAKind"))
		s = append(s, fmt.Sprint("8:  FourOfAKind"))
		s = append(s, fmt.Sprint("9:  FullHouse"))
		s = append(s, fmt.Sprint("10: SmallStraight"))
		s = append(s, fmt.Sprint("11: LargeStraight"))
		s = append(s, fmt.Sprint("12: Yahtzee"))
		s = append(s, fmt.Sprint("13: Chance"))
	default:
		s = append(s, fmt.Sprint("h [cmd] - print help"))
		s = append(s, fmt.Sprint("p - print score"))
		s = append(s, fmt.Sprint("d - print dice"))
		s = append(s, fmt.Sprint("q - quit the game"))
		s = append(s, fmt.Sprint("i [pos] - insert into score"))
		s = append(s, fmt.Sprint("r [dice] - reroll some dice"))
		s = append(s, fmt.Sprint("c [pos] - cancel a entry"))
	}
	return s
}