const Memory = {
  /**
   * @type {State}
   */
  state: new State(),


  /**
   * @returns {string}
   */
  save () {
    const saveMonster = (monsterData, monsterState) => {
      monsterData.level = monsterState.level;
      monsterData.hp = monsterState.hp;

      if (monsterData.statusEffect && monsterData.statusEffect.slug === 'lifeleech') {
        monsterData.statusEffect = null;
      }

      return monsterData;
    };

    /**
     * @type {State}
     */
    const saveData = JSON.parse(JSON.stringify(Memory.state));

    // monsters
    for (const idx in saveData.monsters) {
      saveData.monsters[idx] = saveMonster(saveData.monsters[idx], Memory.state.monsters[idx]);
    }

    // player - monsters
    for (const idx in saveData.player.monsters) {
      saveData.player.monsters[idx] = saveMonster(saveData.player.monsters[idx], Memory.state.player.monsters[idx]);
    }

    saveData.player.activeMonsterIdx = Memory.state.player.monsters.indexOf(Memory.state.player.activeMonster);

    // opponent - monsters
    for (const idx in saveData.opponent.monsters) {
      saveData.opponent.monsters[idx] = saveMonster(saveData.opponent.monsters[idx], Memory.state.opponent.monsters[idx]);
    }

    saveData.opponent.activeMonsterIdx = Memory.state.opponent.monsters.indexOf(Memory.state.opponent.activeMonster);

    // hash
    return btoa(JSON.stringify(saveData));
  },

  /**
   * @param {string} saveData
   */
  async load (saveData) {
    /**
     * @param {Monster} monsterData
     */
    const loadMonster = async (monsterData) => {
      const monster = await fetchMonster(monsterData.slug);

      monster.level = monsterData.level;
      monster.hp = monsterData.hp;
      monster.exp = monsterData.exp;
      monster.tasteWarm = monsterData.tasteWarm;
      monster.tasteCold = monsterData.tasteCold;
      monster.gender = monsterData.gender;
      monster.heldItem = await loadItem(monsterData.heldItem);
      monster.statusEffect = await loadStatusEffect(monsterData.statusEffect);
      monster.statModifiers = monsterData.statModifiers;
      monster.experienceModifier = monsterData.experienceModifier;
      monster.moneyModifier = monsterData.moneyModifier;
      monster.activeTechniques = await Promise.all(monsterData.activeTechniques.map(async (technique) => {
        return loadTechnique(technique);
      }));

      return monster;
    };

    /**
     * @param {InventoryItem} inventoryItemData
     */
    const loadInventoryItem = async (inventoryItemData) => {
      const inventoryItem = new InventoryItem(await fetchItem(inventoryItemData.item.slug));

      inventoryItem.quantity = inventoryItemData.quantity;

      return inventoryItem;
    };

    /**
     * @param {Item} itemData
     */
    const loadItem = async (itemData) => {
      if (!itemData) {
        return null;
      }

      const item = await fetchItem(itemData.slug);

      return item;
    };

    /**
     * @param {StatusEffect} statusEffectData
     */
    const loadStatusEffect = async (statusEffectData) => {
      if (!statusEffectData) {
        return null;
      }

      const statusEffect = await fetchStatusEffect(statusEffectData.slug);

      statusEffect.turnsLeft = statusEffectData.turnsLeft;

      return statusEffect;
    };

    /**
     * @param {Technique} techniqueData
     */
    const loadTechnique = async (techniqueData) => {
      const technique = await fetchTechnique(techniqueData.slug);

      technique.turnLastUse = techniqueData.turnLastUse;

      return technique;
    };

    /**
     * @type {State}
     */
    const loadedState = JSON.parse(atob(saveData));

    Memory.state.turn = loadedState.turn;
    Memory.state.money = loadedState.money;
    Memory.state.monsters = await Promise.all(loadedState.monsters.map(async (monsterData) => await loadMonster(monsterData)));
    Memory.state.player.monsters = await Promise.all(loadedState.player.monsters.map(async (monsterData) => await loadMonster(monsterData)));
    Memory.state.player.inventory = await Promise.all(loadedState.player.inventory.map(async (itemData) => await loadInventoryItem(itemData)));
    Memory.state.player.activeMonster = Memory.state.player.monsters[loadedState.player.activeMonsterIdx];
    Memory.state.opponent.monsters = await Promise.all(loadedState.opponent.monsters.map(async (monsterData) => await loadMonster(monsterData)));
    Memory.state.opponent.inventory = await Promise.all(loadedState.opponent.inventory.map(async (itemData) => await loadInventoryItem(itemData)));
    Memory.state.opponent.activeMonster = Memory.state.opponent.monsters[loadedState.opponent.activeMonsterIdx];
    Memory.state.activeTechnique = await loadTechnique(loadedState.activeTechnique);

    UI.drawOpponentMonster();
    UI.drawActiveMonster();
    UI.drawActiveTechniques();
  },
};