package q3606

import (
	"slices"
	"strings"
)

func isValidCode(code string) bool {
	for i := range len(code) {
		c := code[i]
		if (c < 'a' || c > 'z') &&
			(c < 'A' || c > 'Z') &&
			(c < '0' || c > '9') &&
			c != '_' {
			return false
		}
	}
	return len(code) > 0
}

func businessToI(b string) int8 {
	switch b {
	case "electronics":
		return 1
	case "grocery":
		return 2
	case "pharmacy":
		return 3
	case "restaurant":
		return 4
	}
	return 0
}

func validateCoupons(code []string, businessLine []string, isActive []bool) []string {
	validCodes := []int{}
	for i := range code {
		if isValidCode(code[i]) && businessToI(businessLine[i]) > 0 && isActive[i] {
			validCodes = append(validCodes, i)
		}
	}

	slices.SortFunc(validCodes, func(a, b int) int {
		ba, bb := businessToI(businessLine[a]), businessToI(businessLine[b])
		if ba != bb {
			return int(ba - bb)
		}
		return strings.Compare(code[a], code[b])
	})

	ret := make([]string, 0, len(validCodes))
	for _, i := range validCodes {
		ret = append(ret, code[i])
	}
	return ret
}

var _ = validateCoupons