package converter

import java.util.*

enum class Measure(val category: String, val shortNameOfMetric: String, val fullNameOfMetric: String, val pluralNameOfMetric: String, val coefficientNum: Double){
    METER("length", "m", "meter", "meters", 1.0),
    KILOMETER("length", "km","kilometer","kilometers", 1000.0),
    CENTIMETER("length", "cm","centimeter","centimeters", 0.01),
    MILLIMETER("length", "mm","millimeter","millimeters", 0.001),
    MILE("length", "mi","mile","miles", 1609.35),
    YARD("length", "yd","yard","yards", 0.9144),
    FOOT("length", "ft","foot","feet", 0.3048),
    INCH("length", "in","inch","inches", 0.0254),
    GRAM("weights", "g", "gram", "grams", 1.0),
    KILOGRAM("weights", "kg", "kilogram", "kilograms", 1000.0),
    MILLIGRAM("weights", "mg", "milligram", "milligrams", 0.001),
    POUND("weights", "lb", "pound", "pounds", 453.592),
    OUNCE("weights", "oz", "ounce", "ounces", 28.3495),
    CELSIUS("degrees", "celsius", "degree Celsius", "degrees Celsius", 1.0),
    FAHRENHEIT("degrees", "fahrenheit", "degree Fahrenheit", "degrees Fahrenheit", 1.0),
    KELVIN("degrees", "k", "Kelvin", "Kelvins", 1.0),
    NULL("???","???", "???", "???", 1.0)
}


fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    loop@ do{

        print("Enter what you want to convert (or exit): ")
        var inputAny = sc.next()
        var input: Double
        if(checkExit(inputAny)) {
            break
        } else if (isDigitsOnly(inputAny)) { // вот тут надо выяснить в строке число или слово
            input = inputAny.toDouble()
        } else {
            print("Enter correct number")
            break@loop;
        }

        var inputMetric = sc.next()
        if (inputMetric == "degree" || inputMetric == "degrees") {
            inputMetric = sc.next()
        }
        var to = sc.next()
        var toInputMetric = sc.next()

        /*присвоение метрик*/
        var nameOfMetric = isMetric(inputMetric)
        var toNameOfMetric = isMetric(toInputMetric)

        var nameOutOfMetric: String
        var nameOutOfConvertMetric: String
        var res: Double

        if(checkCategory(nameOfMetric, toNameOfMetric)) {
            nameOutOfMetric = isPlural(input, nameOfMetric)
            if(nameOfMetric.category == "degrees") {
                res = convertDegrees(input, nameOfMetric, toNameOfMetric)
            } else {

                if(checkNegative(input)){
                    print(when(nameOfMetric.category) {
                        "length" -> "Length shouldn't be negative"
                        "weights" -> "Weight shouldn't be negative"
                        else -> "????"
                    })
                    break;
                } else {
                res = convertWeightLength(input, nameOfMetric, toNameOfMetric)
                }
            }
            nameOutOfConvertMetric = isPlural(res, toNameOfMetric)
            print("$input $nameOutOfMetric is $res $nameOutOfConvertMetric\n")
        } else {
            nameOutOfMetric = metricName(nameOfMetric, inputMetric, input)
            nameOutOfConvertMetric = metricName(toNameOfMetric, toInputMetric, input)
            print("Conversion from $nameOutOfMetric to $nameOutOfConvertMetric is impossible\n")
        }

    } while (true)
}



/*определение наименование входящей метрики*/
fun metricName(metric: Measure, input: String, num: Double): String {
    if(num == 1.0) {
        return when(input.toLowerCase()) {
        metric.fullNameOfMetric.toLowerCase() -> metric.fullNameOfMetric
        metric.pluralNameOfMetric.toLowerCase() -> metric.pluralNameOfMetric
        else -> metric.shortNameOfMetric
        }
    } else {
        return when(input.toLowerCase()) {
        metric.fullNameOfMetric.toLowerCase() -> metric.pluralNameOfMetric
        metric.pluralNameOfMetric.toLowerCase() -> metric.pluralNameOfMetric
        else -> metric.shortNameOfMetric
        }
    }
}

/*конвертация метрик длины и веса*/
fun convertWeightLength(input: Double, metric: Measure, toMetric: Measure): Double {
    return (input * metric.coefficientNum) / toMetric.coefficientNum
}

/*конвертация градусы*/
fun convertDegrees(input: Double, nameOfMetric: Measure, toNameOfMetric: Measure): Double {
    return when{
        nameOfMetric == Measure.CELSIUS && toNameOfMetric == Measure.FAHRENHEIT -> input * 9 / 5 + 32
        nameOfMetric == Measure.FAHRENHEIT && toNameOfMetric == Measure.CELSIUS -> (input - 32.0) * 5 / 9
        nameOfMetric == Measure.CELSIUS && toNameOfMetric == Measure.KELVIN -> input + 273.15
        nameOfMetric == Measure.KELVIN && toNameOfMetric == Measure.CELSIUS -> input - 273.15
        nameOfMetric == Measure.FAHRENHEIT && toNameOfMetric == Measure.KELVIN -> (input + 459.67) * 5 / 9
        nameOfMetric == Measure.KELVIN && toNameOfMetric == Measure.FAHRENHEIT -> input * 9 / 5 - 459.67
        else -> input
    }
}

/*сопоставление категорий метрик*/
fun checkCategory(metric: Measure, toMetric: Measure): Boolean{
    return metric.category == toMetric.category && metric.category != "???" && toMetric.category != "???"
}

/*проверка exit*/
fun checkExit(input: String): Boolean{
    return input == "exit"
}

/**/
fun checkNegative(inputNum: Double): Boolean {
    return inputNum < 0.0 || inputNum < 0.0
}

/*определение наименование метрики*/
fun isMetric(inputMetric: String): Measure {
    return when(inputMetric.toLowerCase()){
        "m", "meter", "meters" -> Measure.METER
        "km","kilometer","kilometers" -> Measure.KILOMETER
        "cm","centimeter","centimeters" -> Measure.CENTIMETER
        "mm","millimeter","millimeters" -> Measure.MILLIMETER
        "mi","mile","miles" -> Measure.MILE
        "yd","yard","yards" -> Measure.YARD
        "ft","foot","feet" -> Measure.FOOT
        "in","inch","inches" -> Measure.INCH
        "g", "gram", "grams" -> Measure.GRAM
        "kg", "kilogram", "kilograms" -> Measure.KILOGRAM
        "mg", "milligram", "milligrams" -> Measure.MILLIGRAM
        "lb", "pound", "pounds" -> Measure.POUND
        "oz", "ounce", "ounces" -> Measure.OUNCE
        "dc", "c", "celsius" -> Measure.CELSIUS
        "df", "f", "fahrenheit" -> Measure.FAHRENHEIT
        "k", "kelvin", "kelvins" -> Measure.KELVIN
        else -> Measure.NULL
    }
}

/*определение множественности метрики*/
fun isPlural(num: Double, metric: Measure): String {
    return if (num == 1.0) metric.fullNameOfMetric else metric.pluralNameOfMetric
}
/*
fun hasNumber(input: String): Boolean {
    val regex: Regex = Regex("(?:-{1})?(\\d+)(?:\\.{1}\\d+)?")
    val isNumber: (String) -> Boolean = regex::matches
    return isNumber(input)
}*/