package com.company;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Author 6543
 * Datum 2019-10-14
 * License GPL3
 */

public enum Version {
    UNKNOWN,
    SUPPORTED_LATEST,
    SUPPORTED_OLD,
    DEVELOPMENT,
    UNSUPPORTED_OLD,
    UNSUPPORTED_NEW;



    public static Version check(String min, String last, String value) {

        final Pattern pattern_stable_release = Pattern.compile("^(\\d)\\.(\\d+)\\.(\\d+)$");
        final Pattern pattern_dev_release = Pattern.compile("^(\\d).(\\d+).(\\d+)(\\D)(.+)");
        Matcher m ;

        if (!pattern_stable_release.matcher(min).find() || !pattern_stable_release.matcher(last).find()) {
            throw new IllegalArgumentException("VersionCheck: wrong format for min or last version given");
        }

        m = pattern_stable_release.matcher(value);
        if (m.find()) {

            switch (correlate(min, last, m.group())){
                case 0:
                    return UNSUPPORTED_OLD;
                case 1:
                    return SUPPORTED_OLD;
                case 2:
                    return SUPPORTED_LATEST;
                default:
                    return UNSUPPORTED_NEW;
            }

        }
        m = pattern_dev_release.matcher(value);
        if (m.find()) {

            m = Pattern.compile("^(\\d)\\.(\\d+)\\.(\\d+)").matcher(value);
            m.find();

            if (correlate(min, last, m.group())>0) {
                return DEVELOPMENT;
            } else {
                return UNSUPPORTED_OLD;
            }

        }

        return UNKNOWN;

    }

    //helper
    // 0 to less
    // 1 in range
    // 2 at the top
    // 3 above
    private static int correlate(String min, String last, String value){
        int min_check = compare(value,min);
        int max_check = compare(value,last);
        int range_check = compare(min,last);

        switch (range_check) {
            case 2:
                throw new IllegalArgumentException("Minimum Version higher than Last Version");
            case 1: //min == last
                switch (min_check) {
                    case 0:
                        return 0;
                    case 1:
                        return 2;
                    default:
                        return 3;
                }
            default:
                if (max_check >1) return 3;
                if (max_check == 1) return 2;
                if (min_check < 1) return 0;
                return 1;
        }

    }

    /**
     * @description compare doted formatted Versions
     * @return 0|1|2
     * 0 = less
     * 1 = same
     * 2 = more
     */
    public static int compare(String A, String B) {
        //throw new IllegalArgumentException
        if((!A.matches("[0-9]+(\\.[0-9]+)*")) || (!B.matches("[0-9]+(\\.[0-9]+)*"))) throw new IllegalArgumentException("Invalid version format");

        if (A.contains(".") || B.contains(".")) {
            // example 2 vs 1.3
            if (!(A.contains(".") && B.contains("."))) {
                if (A.contains(".")) {
                    return compare(A,B + ".0");
                }
                if (B.contains(".")) {
                    return compare(A + ".0",B);
                }
            }

            //normal compare
            int a = Integer.parseInt(A.substring(0,A.indexOf(".")));
            int b = Integer.parseInt(B.substring(0,B.indexOf(".")));
            if (a < b) return 0;
            if (a == b) return compare(A.substring(A.indexOf(".")+1),B.substring(B.indexOf(".")+1));
            return 2; //if (a > b)
        } else {
            int a = Integer.parseInt(A);
            int b = Integer.parseInt(B);
            if (a < b) return 0;
            if (a == b) return 1;
            return 2; //if (a > b)
        }
    }
}