use std::collections::BTreeMap;
use std::convert::TryInto;
use futures::future::{Future, BoxFuture};

use crate::entity::account::*;
use crate::entity::character::*;
use crate::entity::gateway::{EntityGateway, EntityGatewayTransaction, GatewayError};
use crate::entity::item::*;
use crate::entity::room::*;

use async_std::sync::{Arc, Mutex};

#[derive(Clone)]
pub struct InMemoryGatewayTransaction {
    working_gateway: InMemoryGateway,
    original_gateway: InMemoryGateway,
}


fn copy_if_needed<K, V>(working_table: &mut BTreeMap<K, V>, original_table: &BTreeMap<K, V>, key: K) -> Option<()>
where
    K: Ord + Copy,
    V: Clone,
{
    if let std::collections::btree_map::Entry::Vacant(e) = working_table.entry(key) {
        e.insert(original_table.get(&key)?.clone());
    }

    Some(())
}

// functions here have been skipped as they are not used in transactions, add as needed
#[async_trait::async_trait]
impl EntityGateway for InMemoryGatewayTransaction {
    type Transaction<'t> = InMemoryGatewayTransaction where Self: 't;

    async fn create_user(&mut self, user: NewUserAccountEntity) -> Result<UserAccountEntity, GatewayError> {
        self.working_gateway.create_user(user).await
    }

    async fn get_user_by_id(&mut self, id: UserAccountId) -> Result<UserAccountEntity, GatewayError> {
        match self.working_gateway.get_user_by_id(id).await {
            Ok(user) => Ok(user),
            Err(_) => {
                self.original_gateway.get_user_by_id(id).await
            }
        }
    }

    async fn get_user_by_name(&mut self, username: String) -> Result<UserAccountEntity, GatewayError> {
        match self.working_gateway.get_user_by_name(username.clone()).await {
            Ok(user) => Ok(user),
            Err(_) => {
                self.original_gateway.get_user_by_name(username).await
            }
        }
    }

    async fn save_user(&mut self, user: &UserAccountEntity) -> Result<(), GatewayError>  {
        self.working_gateway.save_user(user).await
    }

    async fn create_user_settings(&mut self, settings: NewUserSettingsEntity) -> Result<UserSettingsEntity, GatewayError> {
        self.working_gateway.create_user_settings(settings).await
    }

    async fn get_user_settings_by_user(&mut self, user: &UserAccountEntity) -> Result<UserSettingsEntity, GatewayError> {
        match self.working_gateway.get_user_settings_by_user(user).await {
            Ok(user) => Ok(user),
            Err(_) => {
                self.original_gateway.get_user_settings_by_user(user).await
            }
        }
    }

    async fn save_user_settings(&mut self, settings: &UserSettingsEntity) -> Result<(), GatewayError>  {
        self.original_gateway.save_user_settings(settings).await
    }

    async fn save_character(&mut self, char: &CharacterEntity) -> Result<(), GatewayError>  {
        copy_if_needed(&mut *self.working_gateway.characters.lock().await,
                       &*self.original_gateway.characters.lock().await,
                       char.id
        );
        self.working_gateway.save_character(char).await
    }

    async fn create_item(&mut self, item: NewItemEntity) -> Result<ItemEntity, GatewayError> {
        self.working_gateway.create_item(item).await
    }

    async fn add_item_note(&mut self, item_id: &ItemEntityId, item_note: ItemNote) -> Result<(), GatewayError> {
        self.working_gateway.add_item_note(item_id, item_note).await
    }

    async fn feed_mag(&mut self, mag_item_id: &ItemEntityId, tool_item_id: &ItemEntityId) -> Result<(), GatewayError> {
        self.working_gateway.feed_mag(mag_item_id, tool_item_id).await
    }

    async fn change_mag_owner(&mut self, mag_item_id: &ItemEntityId, character: &CharacterEntity) -> Result<(), GatewayError> {
        self.working_gateway.change_mag_owner(mag_item_id, character).await
    }

    async fn use_mag_cell(&mut self, mag_item_id: &ItemEntityId, mag_cell_id: &ItemEntityId) -> Result<(), GatewayError> {
        self.working_gateway.use_mag_cell(mag_item_id, mag_cell_id).await
    }

    async fn add_weapon_modifier(&mut self, item_id: &ItemEntityId, modifier: &weapon::WeaponModifier) -> Result<(), GatewayError> {
        self.working_gateway.add_weapon_modifier(item_id, modifier).await
    }

    async fn get_character_inventory(&mut self, char_id: &CharacterEntityId) -> Result<InventoryEntity, GatewayError> {
        match self.working_gateway.get_character_inventory(char_id).await {
            Ok(inventory) => Ok(inventory),
            Err(_) => {
                self.original_gateway.get_character_inventory(char_id).await
            }
        }
    }

    async fn get_character_bank(&mut self, char_id: &CharacterEntityId, bank_identifier: &BankIdentifier) -> Result<BankEntity, GatewayError> {
        match self.working_gateway.get_character_bank(char_id, bank_identifier).await {
            Ok(bank) => Ok(bank),
            Err(_) => {
                self.original_gateway.get_character_bank(char_id, bank_identifier).await
            }
        }
    }

    async fn set_character_inventory(&mut self, char_id: &CharacterEntityId, inventory: &InventoryEntity) -> Result<(), GatewayError> {
        self.working_gateway.set_character_inventory(char_id, inventory).await
    }

    async fn set_character_bank(&mut self, char_id: &CharacterEntityId, bank: &BankEntity, bank_identifier: &BankIdentifier) -> Result<(), GatewayError> {
        self.working_gateway.set_character_bank(char_id, bank, bank_identifier).await
    }

    async fn get_character_equips(&mut self, char_id: &CharacterEntityId) -> Result<EquippedEntity, GatewayError> {
        match self.working_gateway.get_character_equips(char_id).await {
            Ok(equips) => Ok(equips),
            Err(_) => {
                self.original_gateway.get_character_equips(char_id).await
            }
        }
    }

    async fn set_character_equips(&mut self, char_id: &CharacterEntityId, equipped: &EquippedEntity) -> Result<(), GatewayError> {
        self.working_gateway.set_character_equips(char_id, equipped).await
    }

    async fn set_character_meseta(&mut self, char_id: &CharacterEntityId, meseta: Meseta) -> Result<(), GatewayError> {
        self.working_gateway.set_character_meseta(char_id, meseta).await
    }

    async fn get_character_meseta(&mut self, char_id: &CharacterEntityId) -> Result<Meseta, GatewayError> {
        match self.working_gateway.get_character_meseta(char_id).await {
            Ok(meseta) => Ok(meseta),
            Err(_) => {
                self.original_gateway.get_character_meseta(char_id).await
            }
        }
    }

    async fn set_bank_meseta(&mut self, char_id: &CharacterEntityId, bank_identifier: &BankIdentifier, meseta: Meseta) -> Result<(), GatewayError> {
        self.working_gateway.set_bank_meseta(char_id, bank_identifier, meseta).await
    }

    async fn get_bank_meseta(&mut self, char_id: &CharacterEntityId, bank_identifier: &BankIdentifier) -> Result<Meseta, GatewayError> {
        match self.working_gateway.get_bank_meseta(char_id, bank_identifier).await {
            Ok(meseta) => Ok(meseta),
            Err(_) => {
                self.original_gateway.get_bank_meseta(char_id, bank_identifier).await
            }
        }
    }

    async fn create_trade(&mut self, char_id1: &CharacterEntityId, char_id2: &CharacterEntityId) -> Result<TradeEntity, GatewayError> {
        self.working_gateway.create_trade(char_id1, char_id2).await
    }

    async fn set_character_playtime(&mut self, char_id: &CharacterEntityId, playtime: u32) -> Result<(), GatewayError> {
        copy_if_needed(&mut *self.working_gateway.characters.lock().await,
                       &*self.original_gateway.characters.lock().await,
                       *char_id
        );
        self.working_gateway.set_character_playtime(char_id, playtime).await
    }
}

#[async_trait::async_trait]
impl EntityGatewayTransaction for InMemoryGatewayTransaction {
    type ParentGateway = InMemoryGatewayTransaction;

    fn gateway(&mut self) -> &mut Self::ParentGateway {
        self
    }

    async fn commit(mut self) -> Result<(), GatewayError> {
        self.original_gateway.users.lock().await.extend(self.working_gateway.users.lock().await.clone());
        self.original_gateway.user_settings.lock().await.extend(self.working_gateway.user_settings.lock().await.clone());
        self.original_gateway.characters.lock().await.extend(self.working_gateway.characters.lock().await.clone());
        self.original_gateway.character_meseta.lock().await.extend(self.working_gateway.character_meseta.lock().await.clone());
        self.original_gateway.bank_meseta.lock().await.extend(self.working_gateway.bank_meseta.lock().await.clone());
        self.original_gateway.shared_bank_meseta.lock().await.extend(self.working_gateway.shared_bank_meseta.lock().await.clone());
        self.original_gateway.items.lock().await.extend(self.working_gateway.items.lock().await.clone());
        self.original_gateway.inventories.lock().await.extend(self.working_gateway.inventories.lock().await.clone());
        self.original_gateway.character_banks.lock().await.extend(self.working_gateway.character_banks.lock().await.clone());
        self.original_gateway.shared_banks.lock().await.extend(self.working_gateway.shared_banks.lock().await.clone());
        self.original_gateway.equips.lock().await.extend(self.working_gateway.equips.lock().await.clone());
        self.original_gateway.mag_modifiers.lock().await.extend(self.working_gateway.mag_modifiers.lock().await.clone());
        self.original_gateway.weapon_modifiers.lock().await.extend(self.working_gateway.weapon_modifiers.lock().await.clone());
        self.original_gateway.trades.lock().await.extend(self.working_gateway.trades.lock().await.clone());

        Ok(())
    }
}

#[derive(Clone)]
enum InventoryItemElement {
    Individual(ItemEntityId),
    Stacked(Vec<ItemEntityId>),
}

#[derive(Clone)]
pub struct InMemoryGateway {
    users: Arc<Mutex<BTreeMap<UserAccountId, UserAccountEntity>>>,
    user_settings: Arc<Mutex<BTreeMap<UserSettingsId, UserSettingsEntity>>>,
    characters: Arc<Mutex<BTreeMap<CharacterEntityId, CharacterEntity>>>,
    character_meseta: Arc<Mutex<BTreeMap<CharacterEntityId, Meseta>>>,
    bank_meseta: Arc<Mutex<BTreeMap<CharacterEntityId, Meseta>>>,
    shared_bank_meseta: Arc<Mutex<BTreeMap<(UserAccountId, BankName), Meseta>>>,
    items: Arc<Mutex<BTreeMap<ItemEntityId, ItemEntity>>>,
    inventories: Arc<Mutex<BTreeMap<CharacterEntityId, Vec<InventoryItemElement>>>>,
    character_banks: Arc<Mutex<BTreeMap<CharacterEntityId, BankEntity>>>,
    shared_banks: Arc<Mutex<BTreeMap<(UserAccountId, BankName), BankEntity>>>,
    equips: Arc<Mutex<BTreeMap<CharacterEntityId, EquippedEntity>>>,
    mag_modifiers: Arc<Mutex<BTreeMap<ItemEntityId, Vec<mag::MagModifier>>>>,
    weapon_modifiers: Arc<Mutex<BTreeMap<ItemEntityId, Vec<weapon::WeaponModifier>>>>,
    trades: Arc<Mutex<Vec<TradeEntity>>>,
}

impl Default for InMemoryGateway {
    fn default() -> InMemoryGateway {
        InMemoryGateway {
            users: Arc::new(Mutex::new(BTreeMap::new())),
            user_settings: Arc::new(Mutex::new(BTreeMap::new())),
            characters: Arc::new(Mutex::new(BTreeMap::new())),
            character_meseta: Arc::new(Mutex::new(BTreeMap::new())),
            bank_meseta: Arc::new(Mutex::new(BTreeMap::new())),
            shared_bank_meseta: Arc::new(Mutex::new(BTreeMap::new())),
            items: Arc::new(Mutex::new(BTreeMap::new())),
            inventories: Arc::new(Mutex::new(BTreeMap::new())),
            character_banks: Arc::new(Mutex::new(BTreeMap::new())),
            shared_banks: Arc::new(Mutex::new(BTreeMap::new())),
            equips: Arc::new(Mutex::new(BTreeMap::new())),
            mag_modifiers: Arc::new(Mutex::new(BTreeMap::new())),
            weapon_modifiers: Arc::new(Mutex::new(BTreeMap::new())),
            trades: Arc::new(Mutex::new(Vec::new())),
        }
    }
}

fn apply_modifiers(items: &BTreeMap<ItemEntityId, ItemEntity>,
                   weapon_modifiers: &BTreeMap<ItemEntityId, Vec<weapon::WeaponModifier>>,
                   mag_modifiers: &BTreeMap<ItemEntityId, Vec<mag::MagModifier>>,
                   inventory: InventoryEntity ) -> InventoryEntity {
    let inventory_items = inventory.items.into_iter()
        .map(|item| {
            item.map_individual(|mut item| {
                item.item = match item.item {
                    ItemDetail::Weapon(mut weapon) => {
                        if let Some(weapon_modifiers) = weapon_modifiers.get(&item.id) {
                            for weapon_modifier in weapon_modifiers.iter() {
                                weapon.apply_modifier(weapon_modifier);
                            }
                        }
                        ItemDetail::Weapon(weapon)
                    },
                    ItemDetail::Mag(mag) => {
                        let mut mag = mag::Mag::baby_mag(mag.color as u16);
                        if let Some(mag_modifiers) = mag_modifiers.get(&item.id) {
                            for mag_modifier in mag_modifiers.iter() {
                                match mag_modifier {
                                    mag::MagModifier::FeedMag {food} => {
                                        if let Some(mag_feed) = items.get(food) {
                                            if let ItemDetail::Tool(mag_feed) = mag_feed.item {
                                                mag.feed(mag_feed.tool)
                                            }
                                        }
                                    },
                                    mag::MagModifier::OwnerChange(class, section_id) => {
                                        mag.change_owner(*class, *section_id)
                                    },
                                    mag::MagModifier::MagCell(mag_cell_id) => {
                                        if let Some(mag_cell) = items.get(mag_cell_id) {
                                            if let ItemDetail::Tool(mag_cell) = mag_cell.item {
                                                mag.apply_mag_cell(mag_cell.tool.try_into().unwrap()).unwrap()
                                            }
                                        }
                                    },
                                    _ => {}
                                }
                            }
                        }
                        ItemDetail::Mag(mag)
                    }
                    _ => {
                        item.item
                    }
                };

                item
            })
        })
        .collect();
    InventoryEntity::new(inventory_items)
}

#[async_trait::async_trait]
impl EntityGateway for InMemoryGateway {
    type Transaction<'t> = InMemoryGatewayTransaction where Self: 't;

    fn with_transaction<'a, F, Fut, R>(&'a mut self, func: F) -> BoxFuture<'a, Result<R, anyhow::Error>>
    where
        Fut: Future<Output = Result<(Self::Transaction<'a>, R), anyhow::Error>> + Send + 'a,
        F: FnOnce(Self::Transaction<'a>) -> Fut + Send + 'a,
        R: Send,
    {
        Box::pin(async move {
            let users = self.users.lock().await.clone();
            let user_settings = self.user_settings.lock().await.clone();
            let characters = self.characters.lock().await.clone();
            let character_meseta = self.character_meseta.lock().await.clone();
            let bank_meseta = self.bank_meseta.lock().await.clone();
            let shared_bank_meseta = self.shared_bank_meseta.lock().await.clone();
            let items = self.items.lock().await.clone();
            let inventories = self.inventories.lock().await.clone();
            let character_banks = self.character_banks.lock().await.clone();
            let shared_banks = self.shared_banks.lock().await.clone();
            let equips = self.equips.lock().await.clone();
            let mag_modifiers = self.mag_modifiers.lock().await.clone();
            let weapon_modifiers = self.weapon_modifiers.lock().await.clone();
            let trades = self.trades.lock().await.clone();

            let working_gateway = InMemoryGateway {
                users: Arc::new(Mutex::new(users)),
                user_settings: Arc::new(Mutex::new(user_settings)),
                characters: Arc::new(Mutex::new(characters)),
                character_meseta: Arc::new(Mutex::new(character_meseta)),
                bank_meseta: Arc::new(Mutex::new(bank_meseta)),
                shared_bank_meseta: Arc::new(Mutex::new(shared_bank_meseta)),
                items: Arc::new(Mutex::new(items)),
                inventories: Arc::new(Mutex::new(inventories)),
                character_banks: Arc::new(Mutex::new(character_banks)),
                shared_banks: Arc::new(Mutex::new(shared_banks)),
                equips: Arc::new(Mutex::new(equips)),
                mag_modifiers: Arc::new(Mutex::new(mag_modifiers)),
                weapon_modifiers: Arc::new(Mutex::new(weapon_modifiers)),
                trades: Arc::new(Mutex::new(trades)),
            };

            let transaction = InMemoryGatewayTransaction {
                working_gateway,
                original_gateway: self.clone(),
            };

            let (transaction, result) = func(transaction).await?;

            transaction.commit().await?;
            Ok(result)
        })
    }

    async fn create_user(&mut self, user: NewUserAccountEntity) -> Result<UserAccountEntity, GatewayError> {
        let mut users = self.users.lock().await;
        let id = users
            .iter()
            .fold(0, |sum, (i, _)| std::cmp::max(sum, i.0))
            + 1;
        let user = UserAccountEntity {
            id: UserAccountId(id),
            username: user.username,
            password: user.password,
            guildcard: user.guildcard,
            team_id: user.team_id,
            banned_until: user.banned_until,
            muted_until: user.muted_until,
            created_at: chrono::Utc::now(),
            flags: user.flags,
            activated: user.activated,
            at_login: false,
            at_character: false,
            at_ship: false,
        };
        users.insert(user.id, user.clone());
        Ok(user)
    }

    async fn get_user_by_id(&mut self, id: UserAccountId) -> Result<UserAccountEntity, GatewayError> {
        let users = self.users.lock().await;
        users.get(&id).cloned().ok_or(GatewayError::Error)
    }

    async fn get_user_by_name(&mut self, username: String) -> Result<UserAccountEntity, GatewayError> {
        let users = self.users.lock().await;
        users
            .iter()
            .find(|(_, k)| k.username == username)
            .map(|(_, k)| k.clone())
            .ok_or(GatewayError::Error)
    }

    async fn save_user(&mut self, user: &UserAccountEntity) -> Result<(), GatewayError>  {
        let mut users = self.users.lock().await;
        users.insert(user.id, user.clone());
        Ok(())
    }

    async fn create_user_settings(&mut self, settings: NewUserSettingsEntity) -> Result<UserSettingsEntity, GatewayError> {
        let mut user_settings = self.user_settings.lock().await;
        let id = user_settings
            .iter()
            .fold(0, |sum, (i, _)| std::cmp::max(sum, i.0))
            + 1;
        let new_settings = UserSettingsEntity {
            id: UserSettingsId(id),
            user_id: settings.user_id,
            settings: settings.settings,
        };
        user_settings.insert(new_settings.id, new_settings.clone());
        Ok(new_settings)
    }

    async fn get_user_settings_by_user(&mut self, user: &UserAccountEntity) -> Result<UserSettingsEntity, GatewayError> {
        let user_settings = self.user_settings.lock().await;
        user_settings
            .iter()
            .find(|(_, k)| k.user_id == user.id)
            .map(|(_, k)| k.clone())
            .ok_or(GatewayError::Error)
    }

    async fn save_user_settings(&mut self, settings: &UserSettingsEntity) -> Result<(), GatewayError>  {
        let mut user_settings = self.user_settings.lock().await;
        user_settings.insert(settings.id, settings.clone());
        Ok(())
    }

    async fn get_characters_by_user(&mut self, user: &UserAccountEntity) -> Result<[Option<CharacterEntity>; 4], GatewayError> {
        let characters = self.characters.lock().await;
        const NONE: Option<CharacterEntity> = None;
        let mut chars = [NONE; 4];
        characters
            .iter()
            .filter(|(_, c)| c.user_id == user.id)
            .for_each(|(_, c)| chars[c.slot as usize] = Some(c.clone()));
        Ok(chars)
    }

    async fn create_character(&mut self, character: NewCharacterEntity) -> Result<CharacterEntity, GatewayError> {
        let mut characters = self.characters.lock().await;
        let id = characters
            .iter()
            .fold(0, |sum, (i, _)| std::cmp::max(sum, i.0))
            + 1;

        let new_character = CharacterEntity {
            id: CharacterEntityId(id),
            user_id: character.user_id,
            slot: character.slot,
            name: character.name,
            exp: character.exp,
            char_class: character.char_class,
            section_id: character.section_id,
            appearance: character.appearance,
            techs: character.techs,
            config: character.config,
            info_board: character.info_board,
            guildcard: character.guildcard,
            materials: character.materials,
            tech_menu: character.tech_menu,
            option_flags: character.option_flags,
            playtime: 0,
        };
        characters.insert(new_character.id, new_character.clone());
        Ok(new_character)
    }

    async fn save_character(&mut self, char: &CharacterEntity) -> Result<(), GatewayError>  {
        let mut characters = self.characters.lock().await;
        characters.insert(char.id, char.clone());
        Ok(())
    }

    async fn get_guild_card_data_by_user(&mut self, user: &UserAccountEntity) -> Result<GuildCardDataEntity, GatewayError> {
        Ok(GuildCardDataEntity::new(user.id))
    }

    async fn create_item(&mut self, item: NewItemEntity) -> Result<ItemEntity, GatewayError> {
        let mut items = self.items.lock().await;
        let id = items
            .iter()
            .fold(0, |sum, (i, _)| std::cmp::max(sum, i.0))
            + 1;
        let new_item = ItemEntity {
            id: ItemEntityId(id),
            item: item.item,
        };
        items.insert(ItemEntityId(id), new_item.clone());
        Ok(new_item)
    }

    async fn add_item_note(&mut self, _item_id: &ItemEntityId, _item_note: ItemNote) -> Result<(), GatewayError> {
        Ok(())
    }

    async fn feed_mag(&mut self, mag_item_id: &ItemEntityId, tool_item_id: &ItemEntityId) -> Result<(), GatewayError> {
        self.mag_modifiers.lock().await
            .entry(*mag_item_id)
            .or_insert_with(Vec::new)
            .push(mag::MagModifier::FeedMag {
                food: *tool_item_id
            });
        Ok(())
    }

    async fn change_mag_owner(&mut self, mag_item_id: &ItemEntityId, character: &CharacterEntity) -> Result<(), GatewayError> {
        self.mag_modifiers.lock().await
            .entry(*mag_item_id)
            .or_insert_with(Vec::new)
            .push(mag::MagModifier::OwnerChange(character.char_class, character.section_id));
        Ok(())
    }

    async fn use_mag_cell(&mut self, mag_item_id: &ItemEntityId, mag_cell_id: &ItemEntityId) -> Result<(), GatewayError> {
        self.mag_modifiers.lock().await
            .entry(*mag_item_id)
            .or_insert_with(Vec::new)
            .push(mag::MagModifier::MagCell(*mag_cell_id));
        Ok(())
    }

    async fn add_weapon_modifier(&mut self, item_id: &ItemEntityId, modifier: &weapon::WeaponModifier) -> Result<(), GatewayError> {
        self.weapon_modifiers.lock().await
            .entry(*item_id)
            .or_insert_with(Vec::new)
            .push(modifier.clone());
        Ok(())
    }

    async fn get_character_inventory(&mut self, char_id: &CharacterEntityId) -> Result<InventoryEntity, GatewayError> {
        let inventories = self.inventories.lock().await;
        let items = self.items.lock().await;
        let weapon_modifiers = self.weapon_modifiers.lock().await;
        let mag_modifiers = self.mag_modifiers.lock().await;
        Ok(inventories
           .iter()
           .find(|(id, _)| **id == *char_id)
           .map(|(_, inv)| {
               InventoryEntity {
                   items: inv
                       .iter()
                       .map(|inv_item_id| {
                           match inv_item_id {
                               InventoryItemElement::Individual(individual_id) => {
                                   InventoryItemEntity::Individual(items.get(individual_id).unwrap().clone())
                               },
                               InventoryItemElement::Stacked(stacked_ids) => {
                                   InventoryItemEntity::Stacked(
                                       stacked_ids.iter()
                                           .map(|stacked_id| {
                                               items.get(stacked_id).unwrap().clone()
                                           })
                                           .collect()
                                   )
                               }
                           }
                       })
                       .collect()
               }
           })
           .map(|inv| apply_modifiers(&items, &weapon_modifiers, &mag_modifiers, inv))
           .unwrap_or_default())
    }

    async fn get_character_bank(&mut self, char_id: &CharacterEntityId, bank_identifier: &BankIdentifier) -> Result<BankEntity, GatewayError> {
        match bank_identifier {
            BankIdentifier::Character => {
                let character_banks = self.character_banks.lock().await;
                Ok(character_banks
                   .iter()
                   .find(|(id, _)| **id == *char_id)
                   .map(|(_, b)| b.clone())
                   .unwrap_or_default())
            },
            BankIdentifier::Shared(bank_name) => {
                let user_id = self.characters
                    .lock()
                    .await
                    .iter()
                    .find(|(id, _)| **id == *char_id)
                    .unwrap()
                    .1
                    .user_id;
                let shared_banks = self.shared_banks.lock().await;
                Ok(shared_banks
                   .iter()
                   .find(|((id, name), _)| *id == user_id && *name == *bank_name)
                   .map(|(_, b)| b.clone())
                   .unwrap_or_default())
            }
        }
    }

    async fn set_character_inventory(&mut self, char_id: &CharacterEntityId, inventory: &InventoryEntity) -> Result<(), GatewayError> {
        let mut inventories = self.inventories.lock().await;
        inventories.insert(*char_id, inventory.items
                           .iter()
                           .map(|inventory_item| {
                               match inventory_item {
                                   InventoryItemEntity::Individual(individual) => {
                                       InventoryItemElement::Individual(individual.id)
                                   },
                                   InventoryItemEntity::Stacked(stacked) => {
                                       InventoryItemElement::Stacked(
                                           stacked.iter()
                                               .map(|stacked| {
                                                   stacked.id
                                               })
                                               .collect()
                                       )
                                   }
                               }
                           })
                           .collect());
        Ok(())
    }

    async fn set_character_bank(&mut self, char_id: &CharacterEntityId, bank: &BankEntity, bank_identifier: &BankIdentifier) -> Result<(), GatewayError> {
        match bank_identifier {
            BankIdentifier::Character => {
                let mut character_banks = self.character_banks.lock().await;
                character_banks.insert(*char_id, bank.clone());
            },
            BankIdentifier::Shared(bank_name) => {
                let user_id = self.characters
                    .lock()
                    .await
                    .iter()
                    .find(|(id, _)| **id == *char_id)
                    .unwrap()
                    .1
                    .user_id;
                let mut shared_banks = self.shared_banks.lock().await;
                shared_banks.insert((user_id, bank_name.clone()), bank.clone());
            }
        }

        Ok(())
    }

    async fn get_character_equips(&mut self, char_id: &CharacterEntityId) -> Result<EquippedEntity, GatewayError> {
        let equips = self.equips.lock().await;
        Ok(equips
            .iter()
            .find(|(id, _)| **id == *char_id)
            .map(|(_, inv)| inv.clone())
            .unwrap_or_default())
    }

    async fn set_character_equips(&mut self, char_id: &CharacterEntityId, equipped: &EquippedEntity) -> Result<(), GatewayError> {
        let mut equips = self.equips.lock().await;
        equips.insert(*char_id, equipped.clone());
        Ok(())
    }

    async fn set_character_meseta(&mut self, char_id: &CharacterEntityId, meseta: Meseta) -> Result<(), GatewayError> {
        let mut character_meseta = self.character_meseta.lock().await;
        character_meseta.insert(*char_id, meseta);
        Ok(())
    }

    async fn get_character_meseta(&mut self, char_id: &CharacterEntityId) -> Result<Meseta, GatewayError> {
        let mut character_meseta = self.character_meseta.lock().await;
        if let Some(meseta) = character_meseta.get_mut(char_id) {
            Ok(*meseta)
        }
        else {
            Err(GatewayError::Error)
        }
    }

    async fn set_bank_meseta(&mut self, char_id: &CharacterEntityId, bank_identifier: &BankIdentifier, meseta: Meseta) -> Result<(), GatewayError> {
        match bank_identifier {
            BankIdentifier::Character => {
                let mut bank_meseta = self.bank_meseta.lock().await;
                bank_meseta.insert(*char_id, meseta);
            }
            BankIdentifier::Shared(bank_name) => {
                let user_id = self.characters
                    .lock()
                    .await
                    .iter()
                    .find(|(id, _)| **id == *char_id)
                    .unwrap()
                    .1
                    .user_id;
                self.shared_bank_meseta
                    .lock()
                    .await
                    .insert((user_id, bank_name.clone()), meseta);
            }
        }
        Ok(())
    }

    async fn get_bank_meseta(&mut self, char_id: &CharacterEntityId, bank_identifier: &BankIdentifier) -> Result<Meseta, GatewayError> {
        match bank_identifier {
            BankIdentifier::Character => {
                let mut bank_meseta = self.bank_meseta.lock().await;
                if let Some(meseta) = bank_meseta.get_mut(char_id) {
                    Ok(*meseta)
                }
                else {
                    Err(GatewayError::Error)
                }
            },
            BankIdentifier::Shared(bank_name) => {
                let mut shared_bank_meseta = self.shared_bank_meseta.lock().await;
                let user_id = self.characters
                    .lock()
                    .await
                    .iter()
                    .find(|(id, _)| **id == *char_id)
                    .unwrap()
                    .1
                    .user_id;
                if let Some(meseta) = shared_bank_meseta.get_mut(&(user_id, bank_name.clone())) {
                    Ok(*meseta)
                }
                else {
                    Ok(Meseta(0))
                }
            }
        }
    }

    async fn create_trade(&mut self, char_id1: &CharacterEntityId, char_id2: &CharacterEntityId) -> Result<TradeEntity, GatewayError> {
        let mut trades = self.trades.lock().await;
        let id = trades.len() as u32;
        let new_trade = TradeEntity {
            id: TradeId(id),
            character1: *char_id1,
            character2: *char_id2,
        };
        trades.push(new_trade.clone());
        Ok(new_trade)
    }

    async fn set_character_playtime(&mut self, char_id: &CharacterEntityId, playtime: u32) -> Result<(), GatewayError> {
        let mut characters = self.characters.lock().await;
        if let Some(character) = characters.get_mut(char_id) {
            character.playtime = playtime;
            Ok(())
        }
        else {
            Err(GatewayError::Error)
        }
    }

    // I do not care to replicate this in testing
    async fn create_room(&mut self, room: NewRoomEntity) -> Result<RoomEntity, GatewayError> {
        Ok(RoomEntity {
            id: RoomEntityId(0),
            name: room.name,
            section_id: room.section_id,
            episode: room.episode,
            difficulty: room.difficulty,
            mode: room.mode,
        })
    }

    // I do not care to replicate this in testing
    async fn add_room_note(&mut self, _room_id: RoomEntityId, _note: RoomNote) -> Result<(), GatewayError> {
        Ok(())
    }
}