package com.camilstaps.common;

import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;

import org.json.JSONException;

import java.text.ParseException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

/**
 * A set of DatedStrings to store in SharedPreferences
 * @author Camil Staps
 */
public class DatedStringPreferenceSet {

    /**
     * Get a Set from the SharedPreferences
     * @param context
     * @param key the SharedPreferences key
     * @param type the type of DatedString to cast to
     * @return the set
     */
    public static Set<Object> get(Context context, String key, Class type) {
        Set<Object> set = new HashSet<>();
        for (String s : PreferenceManager.getDefaultSharedPreferences(context).getStringSet(key, new HashSet<String>())) {
            try {
                set.add(type.cast(DatedString.fromString(s, type)));
            } catch (JSONException e) {
                e.printStackTrace();
            } catch (ParseException e) {
                e.printStackTrace();
            }
        }
        return set;
    }

    /**
     * Put a Set to the SharedPreferences
     * @param context
     * @param key the SharedPreferences key
     * @param set
     */
    public static void put(Context context, String key, Set<DatedString> set) {
        SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(context).edit();
        Set<String> putSet = new HashSet<>();
        for (DatedString item : set) {
            putSet.add(item.toString());
        }
        editor.putStringSet(key, putSet);
        editor.apply();
    }

    /**
     * Add one DatedString to a set
     * @param context
     * @param key the SharedPreferences key
     * @param object the DatedString to add
     */
    public static void add(Context context, String key, DatedString object) {
        Set<DatedString> set = (Set) DatedStringPreferenceSet.get(context, key, DatedString.class);
        set.add(object);
        DatedStringPreferenceSet.put(context, key, (Set) set);
    }

    /**
     * Remove all DatedStrings with the same Date as the given DatedString, and put this new DatedString if any object was removed
     * @param context
     * @param key the SharedPreferences key
     * @param object the object to 'update'
     */
    public static void update(Context context, String key, DatedString object) {
        Set<DatedString> set = (Set) get(context, key, object.getClass());
        Iterator<DatedString> iterator = set.iterator();
        boolean add = false;
        while (iterator.hasNext()) {
            DatedString this_object = iterator.next();
            if (this_object.getDate().equals(object.getDate())) {
                iterator.remove();
                add = true;
            }
        }
        if (add) {
            set.add(object);
        }
        put(context, key, set);
    }

    /**
     * Check if a certain Date exists as the Date of a DatedString in some set
     * @param context
     * @param key the SharedPreferences key
     * @param date the Date
     * @return
     */
    public static boolean has(Context context, String key, Date date) {
        Set<DatedString> set = (Set) get(context, key, DatedString.class);
        for (DatedString item : set) {
            if (item.getDate().equals(date)) {
                return true;
            }
        }
        return false;
    }

    /**
     * Update the object if it already exists, or add it if it doesn't
     * @see #update(android.content.Context, String, DatedString)
     * @see #add(android.content.Context, String, DatedString)
     * @param context
     * @param key the SharedPreferences key
     * @param object the object to 'update' or add
     */
    public static void updateOrAdd(Context context, String key, DatedString object) {
        if (has(context, key, object.getDate())) {
            update(context, key, object);
        } else {
            add(context, key, object);
        }
    }

    /**
     * Remove all elements of a set
     * @param context
     * @param key the SharedPreferences key
     */
    public static void clear(Context context, String key) {
        put(context, key, new HashSet<DatedString>());
    }

    /**
     * Remove all elements with a certain Date from a set
     * @param context
     * @param key the SharedPreferences key
     * @param date the Date
     */
    public static void remove(Context context, String key, Date date) {
        Set<DatedString> set = (Set) get(context, key, DatedString.class);
        Iterator<DatedString> iterator = set.iterator();
        boolean add = false;
        while (iterator.hasNext()) {
            DatedString this_object = iterator.next();
            if (this_object.getDate().equals(date)) {
                iterator.remove();
            }
        }
        put(context, key, set);
    }

}