package tiles

import (
	"fmt"
	"slices"
	"strconv"
	"strings"
	"unicode"
)

var jpnZiPaiTileTypes []string = []string{"DO", "NA", "XI", "BE", "BA", "FA", "ZH"}

// Translate numberized Zi Pai to 2-letter format
// rule can be "CHN" or "JPN"
// If rule is "CHN", it should translate as DO XI NA BE ZH FA BA
// If rule is  "JPN", it should translate as DO NA XI BE BA FA ZH
func ziPaiShortSplit(num int, rule string) (string, error) {
	if num < 1 || num > 7 {
		return "", fmt.Errorf("invalid zipai index %d", num)
	}
	switch rule {
	case "CHN":
		return TileTypes[num-1+27], nil
	case "JPN":
		return jpnZiPaiTileTypes[num-1], nil
	}
	return "", fmt.Errorf("error calling ziPaiShortSplit()")
}

func shortToArray(tiles string) ([]string, error) {
	var ret []string
	var stack []string
	var rule string

	// Check if it's jpn format
	tiles = strings.ToUpper(tiles)
	if strings.Contains(tiles, "M") || strings.Contains(tiles, "S") || strings.Contains(tiles, "P") {
		rule = "JPN"
	} else {
		rule = "CHN"
	}

	for _, char := range tiles {
		if unicode.IsDigit(char) {
			stack = append(stack, string(char))
		} else {
			switch string(char) {
			case "W", "M":
				for _, prefix := range stack {
					ret = append(ret, prefix+"W")
				}
			case "T", "S":
				for _, prefix := range stack {
					ret = append(ret, prefix+"T")
				}
			case "B", "P":
				for _, prefix := range stack {
					ret = append(ret, prefix+"B")
				}
			case "Z":
				for _, prefix := range stack {
					num, _ := strconv.Atoi(prefix)
					ziPaiStr, _ := ziPaiShortSplit(num, rule)
					ret = append(ret, ziPaiStr)
				}
			}
			stack = []string{}
		}
	}
	// Check return value valid, if not return error
	for _, t := range ret {
		if !slices.Contains(TileTypes, t) {
			return []string{}, fmt.Errorf("invalid tile string with %s", t)
		}
	}
	return ret, nil
}