package main

import (
	"fmt"
	"log"
	"math/rand"
	"os"
	"sort"
	"time"
)

var SPELLINGS = map[rune]string{
	'A': "AY",
	'B': "BEE",
	'C': "SEE",
	'D': "DEE",
	'E': "EE",
	'F': "EFF",
	'G': "GEE",
	'H': "AITCH",
	'I': "EYE",
	'J': "JAY",
	'K': "KAY",
	'L': "ELL",
	'M': "EMM",
	'N': "ENN",
	'O': "OH",
	'P': "PEE",
	'Q': "CUE",
	'R': "ARR",
	'S': "ESS",
	'T': "TEE",
	'U': "EWE",
	'V': "VEE",
	'W': "DOUBLE EWE",
	'X': "ECKS",
	'Y': "WHY",
	'Z': "ZEE",
}

var modeRandom = false
var modeInfinite = false
var modeStats = false

func main() {
	rand.Seed(time.Now().UnixNano())
	for i := 1; i < len(os.Args); i++ {
		if os.Args[i] == "--random" {
			modeRandom = true
		}
		if os.Args[i] == "--infinite" {
			modeInfinite = true
		}
		if os.Args[i] == "--stats" {
			modeStats = true
		}
	}

	totalAlphabets := 0
	// a count of how many alphabets stabilize in various quantities
	stats := make(map[int]int)
	for {
		var alphabet []rune
		if modeRandom {
			alphabet = randomAlphabet()
		} else {
			alphabet = []rune{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'}
		}
		prev := string(alphabet)
		fmt.Println(string(prev))
		i := 0
		for {
			if i > 100 {
				fmt.Println("Alphabet seems infinite.")
				break
			}
			alphabet = sortAlphabet(alphabet)
			if string(alphabet) == prev {
				if modeInfinite {
					fmt.Println(prev)
				}
				break
			}
			prev = string(alphabet)
			if !modeInfinite {
				fmt.Println(prev)
			}
			i++
		}
		fmt.Println("Iterations:", i)
		stats[i]++
		totalAlphabets++

		if modeStats {
			printStats(stats, totalAlphabets)
		}

		if !modeInfinite {
			return
		}
	}
}

// sort the provided alphabet (a slice of runes) by spelling, using the alphabet itself
// as the lexicographic ordering. Return the new alphabet.
func sortAlphabet(alphabet []rune) []rune {
	new_alphabet := make([]rune, len(alphabet))
	copy(new_alphabet, alphabet)
	sort.Slice(new_alphabet, func(i, j int) bool {
		i_spelling := SPELLINGS[new_alphabet[i]]
		j_spelling := SPELLINGS[new_alphabet[j]]

		i_index := -1
		j_index := -1

		k := 0
		for k = 0; k < len(i_spelling) && k < len(j_spelling); k++ {
			i_index = findIndex(alphabet, rune(i_spelling[k]))
			j_index = findIndex(alphabet, rune(j_spelling[k]))

			if i_index != j_index {
				break
			}
		}
		return i_index < j_index
	})
	return new_alphabet
}

func findIndex(alphabet []rune, target rune) int {
	for i, letter := range alphabet {
		if letter == target {
			return i
		}
	}
	log.Panicf("Tried to find a letter that doesn't exist")
	return -1
}

func randomAlphabet() []rune {
	a := []rune{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'}
	rand.Shuffle(len(a), func(i, j int) { a[i], a[j] = a[j], a[i] })
	return a
}

func printStats(counts map[int]int, total int) {
	keys := make([]int, 0, len(counts))
	for k, _ := range counts {
		keys = append(keys, k)
	}
	sort.Ints(keys)

	for _, k := range keys {
		if k == 101 {
			fmt.Printf("Infinite Loops: %.2f\n", float64(counts[k])/float64(total))
			continue
		}
		fmt.Printf("%d: %.2f\n", k, float64(counts[k])/float64(total))
	}
	fmt.Println(counts)
}