package cc.fascinated.bat.common;

import lombok.*;
import lombok.experimental.UtilityClass;
import org.jetbrains.annotations.Nullable;

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

/**
 * @author Fascinated (fascinated7)
 */
@UtilityClass
public final class TimeUtils {
    /**
     * Format a time in millis to a readable time format.
     *
     * @param millis the millis to format
     * @return the formatted time
     */
    public static String format(long millis) {
        return format(millis, BatTimeFormat.FIT);
    }

    /**
     * Format a time in millis to a readable time format.
     *
     * @param millis   the millis to format
     * @param timeUnit the time unit to format the millis to
     * @return the formatted time
     */
    public static String format(long millis, BatTimeFormat timeUnit) {
        return format(millis, timeUnit, false);
    }

    /**
     * Format a time in millis to a readable time format.
     *
     * @param millis   the millis to format
     * @param timeUnit the time unit to format the millis to
     * @param compact  whether to use a compact display
     * @return the formatted time
     */
    public static String format(long millis, BatTimeFormat timeUnit, boolean compact) {
        return format(millis, timeUnit, true, compact);
    }

    /**
     * Format a time in millis to a readable time format.
     *
     * @param millis   the millis to format
     * @param timeUnit the time unit to format the millis to
     * @param decimals whether to include decimals
     * @param compact  whether to use a compact display
     * @return the formatted time
     */
    public static String format(long millis, BatTimeFormat timeUnit, boolean decimals, boolean compact) {
        if (millis == -1L) { // Format permanent
            return "Perm" + (compact ? "" : "anent");
        }
        // Format the time to the best fitting time unit
        if (timeUnit == BatTimeFormat.FIT) {
            for (BatTimeFormat otherTimeUnit : BatTimeFormat.VALUES) {
                if (otherTimeUnit != BatTimeFormat.FIT && millis >= otherTimeUnit.getMillis()) {
                    timeUnit = otherTimeUnit;
                    break;
                }
            }
        }
        double time = MathUtils.format((double) millis / timeUnit.getMillis(), 1); // Format the time
        if (!decimals) { // Remove decimals
            time = (int) time;
        }
        String formatted = time + (compact ? timeUnit.getSuffix() : " " + timeUnit.getDisplay()); // Append the time unit
        if (time != 1.0 && !compact) { // Pluralize the time unit
            formatted += "s";
        }
        return formatted;
    }

    /**
     * Convert the given input into a time in millis.
     * <p>
     * E.g: 1d, 1h, 1d1h, etc
     * </p>
     *
     * @param input the input to parse
     * @return the time in millis
     */
    public static long fromString(String input) {
        Matcher matcher = BatTimeFormat.SUFFIX_PATTERN.matcher(input); // Match the given input
        long millis = 0; // The total millis

        // Match corresponding suffixes and add up the total millis
        while (matcher.find()) {
            int amount = Integer.parseInt(matcher.group(1)); // The amount of time to add
            String suffix = matcher.group(2); // The unit suffix
            BatTimeFormat timeUnit = BatTimeFormat.fromSuffix(suffix); // The time unit to add
            if (timeUnit != null) { // Increment the total millis
                millis += amount * timeUnit.getMillis();
            }
        }
        return millis;
    }

    /**
     * Represents a unit of time.
     */
    @NoArgsConstructor
    @AllArgsConstructor
    @Getter(AccessLevel.PRIVATE)
    @ToString
    public enum BatTimeFormat {
        FIT,
        YEARS("Year", "y", TimeUnit.DAYS.toMillis(365L)),
        MONTHS("Month", "mo", TimeUnit.DAYS.toMillis(30L)),
        WEEKS("Week", "w", TimeUnit.DAYS.toMillis(7L)),
        DAYS("Day", "d", TimeUnit.DAYS.toMillis(1L)),
        HOURS("Hour", "h", TimeUnit.HOURS.toMillis(1L)),
        MINUTES("Minute", "m", TimeUnit.MINUTES.toMillis(1L)),
        SECONDS("Second", "s", TimeUnit.SECONDS.toMillis(1L)),
        MILLISECONDS("Millisecond", "ms", 1L);

        /**
         * Our cached unit values.
         */
        public static final BatTimeFormat[] VALUES = values();

        /**
         * Our cached suffix pattern.
         */
        public static final Pattern SUFFIX_PATTERN = Pattern.compile("(\\d+)(mo|ms|[ywdhms])");

        /**
         * The display of this time unit.
         */
        private String display;

        /**
         * The suffix of this time unit.
         */
        private String suffix;

        /**
         * The amount of millis in this time unit.
         */
        private long millis;

        /**
         * Get the time unit with the given suffix.
         *
         * @param suffix the time unit suffix
         * @return the time unit, null if not found
         */
        @Nullable
        public static BatTimeFormat fromSuffix(String suffix) {
            for (BatTimeFormat unit : VALUES) {
                if (unit != FIT && unit.getSuffix().equals(suffix)) {
                    return unit;
                }
            }
            return null;
        }
    }
}