package com.ryanharter.android.util;

import android.content.Context;
import android.content.SharedPreferences;

/**
 * Keeps track of the number of app launches, and days since first launch, and
 * provides an easy way to determine whether you should show a rating prompt
 * or not.
 */
public class AppRater {

    private static final String PREF_NAME = "app_rater";

    private static final String LAUNCHES_REQUIRED = "launches_required";
    private static final String DAYS_REQUIRED = "days_required";

    private static final String KEY_FIRST_LAUNCH_TIME = "first_launch_time";
    private static final String KEY_LAUNCH_COUNT = "launch_count";
    private static final String KEY_DONT_SHOW_AGAIN = "dont_show_again";

    /**
     * Sets the number of launches and days required before we prompt.
     * @param launches The number of app launches required.
     * @param days The number of days since first launch required.
     */
    public static void setPromptRequirements(Context context, int launches, int days) {
        SharedPreferences prefs = getPreferences(context);
        SharedPreferences.Editor editor = prefs.edit();
        editor.putInt(LAUNCHES_REQUIRED, launches);
        editor.putInt(DAYS_REQUIRED, days);
        editor.apply();
    }

    /**
     * Increments the app launch counter.
     */
    public static void trackAppLaunch(Context context) {
        SharedPreferences prefs = getPreferences(context);
        SharedPreferences.Editor editor = prefs.edit();

        int currentCount = prefs.getInt(KEY_LAUNCH_COUNT, 0);
        editor.putInt(KEY_LAUNCH_COUNT, currentCount + 1);

        if (currentCount <= 0) {
            editor.putLong(KEY_FIRST_LAUNCH_TIME, System.currentTimeMillis());
        }

        editor.apply();
    }

    /**
     * Returns true if the rating prompt requirements have been met.
     *
     * @return True if you should show a prompt.
     */
    public static boolean shouldPrompt(Context context) {
        SharedPreferences prefs = getPreferences(context);
        if (prefs.getBoolean(KEY_DONT_SHOW_AGAIN, false)) {
            return false;
        }

        int launchCount = prefs.getInt(KEY_LAUNCH_COUNT, 0);
        if (launchCount < prefs.getInt(LAUNCHES_REQUIRED, 3)) {
            return false;
        }

        long firstLaunch = prefs.getLong(KEY_FIRST_LAUNCH_TIME, System.currentTimeMillis());
        int daysRequired = prefs.getInt(DAYS_REQUIRED, 0);
        if (System.currentTimeMillis() < firstLaunch + (daysRequired * 24 * 60 * 60 * 1000)) {
            return false;
        }

        return true;
    }

    /**
     * Sets the rater to always return false and never show a prompt again.
     */
    public static void dontShowAgain(Context context) {
        SharedPreferences prefs = getPreferences(context);
        prefs.edit().putBoolean(KEY_DONT_SHOW_AGAIN, true).apply();
    }

    private static SharedPreferences getPreferences(Context context) {
        return context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
    }
}