use crate::ship::items::ClientItemId;
use crate::entity::item::{Meseta, ItemNote};
use std::future::Future;
use std::pin::Pin;

use crate::ship::map::MapArea;
use crate::entity::character::{CharacterEntity, CharacterEntityId};
use crate::entity::gateway::{EntityGateway, EntityGatewayTransaction};
use crate::ship::items::state::{ItemState, ItemStateProxy, ItemStateAction, ItemAction, ItemStateError, FloorItem, InventoryItem, AddItemResult, FloorItemDetail, StackedItemDetail};

pub enum TriggerCreateItem {ItemAction, 
    Yes,
    No
}

fn take_item_from_floor(character_id: CharacterEntityId, item_id: ClientItemId)
                        -> impl for<'a> Fn((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), ())
                                               -> Pin<Box<dyn Future<Output=Result<((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), FloorItem), ItemStateError>> + Send + 'a>>
{
    move |(mut item_state, transaction), _| {
        Box::pin(async move {
            let mut floor = item_state.floor(&character_id)?;
            let item = floor.take_item(&item_id).ok_or(ItemStateError::NoFloorItem(item_id))?;
            item_state.set_floor(floor);

            Ok(((item_state, transaction), item))
        })
    }
}

fn add_floor_item_to_inventory(character: &CharacterEntity)
                               -> impl for<'a> Fn((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), FloorItem)
                                                  -> Pin<Box<dyn Future<Output=Result<((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), TriggerCreateItem), ItemStateError>> + Send + 'a>>
{
    let character = character.clone();
    move |(mut item_state, transaction), floor_item| {
        let character = character.clone();
        Box::pin(async move {
            let mut inventory = item_state.inventory(&character.id)?;

            let character_id = character.id;
            let transaction = floor_item.with_entity_id(Ok(transaction), |mut transaction: Result<_, ItemStateError>, entity_id| {
                async move {
                    if let Ok(transaction) = &mut transaction {
                        transaction.gateway().add_item_note(&entity_id, ItemNote::Pickup {
                            character_id
                        }).await?;
                    }
                    transaction
                }}).await?;

            let mut transaction = floor_item.with_mag(Ok(transaction), |mut transaction: Result<_, ItemStateError>, entity_id, _mag| {
                let character = character.clone();
                async move {
                    if let Ok(transaction) = &mut transaction {
                        transaction.gateway().change_mag_owner(&entity_id, &character).await?;
                    }
                    transaction
                }}).await?;

            let add_result = inventory.add_floor_item(floor_item)?;
            transaction.gateway().set_character_inventory(&character.id, &inventory.as_inventory_entity(&character.id)).await?;
            item_state.set_inventory(inventory);

            Ok(((item_state, transaction),
                match add_result {
                    AddItemResult::NewItem => TriggerCreateItem::Yes,
                    AddItemResult::AddToStack => TriggerCreateItem::No,
                    AddItemResult::Meseta => TriggerCreateItem::No,
                }))
        })
    }
}


pub async fn pick_up_item<EG>(
    item_state: &mut ItemState,
    entity_gateway: &mut EG,
    character: &CharacterEntity,
    item_id: &ClientItemId)
    -> Result<TriggerCreateItem, ItemStateError>
where
    EG: EntityGateway,
{
    entity_gateway.with_transaction(|transaction| async move {
        let item_state_proxy = ItemStateProxy::new(item_state);
        let ((item_state_proxy, transaction), result) = ItemStateAction::default()
            .act(take_item_from_floor(character.id, *item_id))
            .act(add_floor_item_to_inventory(character))
            .commit((item_state_proxy, transaction))
            .await?;
        item_state_proxy.commit();
        Ok((transaction, result))
    }).await
}

fn take_item_from_inventory(character_id: CharacterEntityId, item_id: ClientItemId)
                            -> impl for<'a> Fn((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), ())
                                               -> Pin<Box<dyn Future<Output=Result<((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), InventoryItem), ItemStateError>> + Send + 'a>>
{
    move |(mut item_state, mut transaction), _| {
        Box::pin(async move {
            let mut inventory = item_state.inventory(&character_id)?;
            let item = inventory.take_item(&item_id).ok_or_else (|| ItemStateError::NoFloorItem(item_id))?;

            transaction.gateway().set_character_inventory(&character_id, &inventory.as_inventory_entity(&character_id)).await?;
            item_state.set_inventory(inventory);

            Ok(((item_state, transaction), item))
        })
    }
}


fn add_inventory_item_to_shared_floor(character_id: CharacterEntityId, map_area: MapArea, drop_position: (f32, f32, f32))
                                  -> impl for<'a> Fn((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), InventoryItem)
                                                     -> Pin<Box<dyn Future<Output=Result<((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), ()), ItemStateError>> + Send + 'a>>
{
    move |(mut item_state, transaction), inventory_item| {
        Box::pin(async move {
            let transaction = inventory_item.with_entity_id(Ok(transaction), |mut transaction: Result<_, ItemStateError>, entity_id| {
                async move {
                    if let Ok(transaction) = &mut transaction {
                        transaction.gateway().add_item_note(&entity_id, ItemNote::PlayerDrop {
                            character_id,
                            map_area,
                            x: drop_position.0,
                            y: drop_position.1,
                            z: drop_position.2,
                        }).await?;
                    }
                    transaction
                }}).await?;

            let mut floor = item_state.floor(&character_id)?;
            floor.add_inventory_item(inventory_item, map_area, drop_position);
            item_state.set_floor(floor);

            Ok(((item_state, transaction), ()))
        })
    }
}

pub async fn drop_item<EG>(
    item_state: &mut ItemState,
    entity_gateway: &mut EG,
    character: &CharacterEntity,
    item_id: &ClientItemId,
    map_area: MapArea,
    drop_position: (f32, f32, f32))
    -> Result<(), ItemStateError>
where
    EG: EntityGateway,
{
    entity_gateway.with_transaction(|transaction| async move {
        let item_state_proxy = ItemStateProxy::new(item_state);
        let ((item_state_proxy, transaction), result) = ItemStateAction::default()
            .act(take_item_from_inventory(character.id, *item_id))
            .act(add_inventory_item_to_shared_floor(character.id, map_area, drop_position))
            .commit((item_state_proxy, transaction))
            .await?;
        item_state_proxy.commit();
        Ok((transaction, result))
    }).await
}


fn take_partial_item_from_inventory(character_id: CharacterEntityId, item_id: ClientItemId, amount: u32)
                                    -> impl for<'a> Fn((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), ())
                                                       -> Pin<Box<dyn Future<Output=Result<((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), StackedItemDetail), ItemStateError>> + Send + 'a>>
{
    move |(mut item_state, mut transaction), _| {
        Box::pin(async move {
            let mut inventory = item_state.inventory(&character_id)?;
            let item = inventory.take_partial_item(&item_id, amount).ok_or_else (|| ItemStateError::NoFloorItem(item_id))?;

            transaction.gateway().set_character_inventory(&character_id, &inventory.as_inventory_entity(&character_id)).await?;
            item_state.set_inventory(inventory);

            Ok(((item_state, transaction), item))
        })
    }
}

fn add_partial_inventory_item_to_shared_floor(character_id: CharacterEntityId, map_area: MapArea, drop_position: (f32, f32))
                                              -> impl for<'a> Fn((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), StackedItemDetail)
                                                                 -> Pin<Box<dyn Future<Output=Result<((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), FloorItem), ItemStateError>> + Send + 'a>>
{
    move |(mut item_state, transaction), stacked_item| {
        Box::pin(async move {
            let floor_item = FloorItem {
                item_id: item_state.new_item_id()?,
                item: FloorItemDetail::Stacked(stacked_item),
                map_area,
                x: drop_position.0,
                y: 0.0,
                z: drop_position.1,
            };

            let transaction = floor_item.with_entity_id(Ok(transaction), |mut transaction: Result<_, ItemStateError>, entity_id| {
                async move {
                    if let Ok(transaction) = &mut transaction {
                        transaction.gateway().add_item_note(&entity_id, ItemNote::PlayerDrop {
                            character_id,
                            map_area,
                            x: drop_position.0,
                            y: 0.0,
                            z: drop_position.1,
                        }).await?;
                    }
                    transaction
                }}).await?;

            let mut floor = item_state.floor(&character_id)?;
            let floor_item = floor.add_item(floor_item).clone();
            item_state.set_floor(floor);

            Ok(((item_state, transaction), floor_item))
        })
    }
}

pub async fn drop_partial_item<'a, EG>(
    item_state: &'a mut ItemState,
    entity_gateway: &mut EG,
    character: &CharacterEntity,
    item_id: &ClientItemId,
    map_area: MapArea,
    drop_position: (f32, f32),
    amount: u32)
    -> Result<FloorItem, ItemStateError>
where
    EG: EntityGateway,
{
    entity_gateway.with_transaction(|transaction| async move {
        let item_state_proxy = ItemStateProxy::new(item_state);
        let ((item_state_proxy, transaction), result) = ItemStateAction::default()
            .act(take_partial_item_from_inventory(character.id, *item_id, amount))
            .act(add_partial_inventory_item_to_shared_floor(character.id, map_area, drop_position))
            .commit((item_state_proxy, transaction))
            .await?;
        item_state_proxy.commit();
        Ok((transaction, result))
    }).await
}


fn take_meseta_from_inventory(character_id: CharacterEntityId, amount: u32)
                              -> impl for<'a> Fn((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), ())
                                                 -> Pin<Box<dyn Future<Output=Result<((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), u32), ItemStateError>> + Send + 'a>>
{
    move |(mut item_state, mut transaction), _| {
        Box::pin(async move {
            let mut inventory = item_state.inventory(&character_id)?;
            inventory.remove_meseta(amount)?;
            transaction.gateway().set_character_meseta(&character_id, inventory.meseta).await?;

            Ok(((item_state, transaction), amount))
        })
    }
}

fn add_meseta_to_shared_floor(character_id: CharacterEntityId, map_area: MapArea, drop_position: (f32, f32))
                              -> impl for<'a> Fn((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), u32)
                                                 -> Pin<Box<dyn Future<Output=Result<((ItemStateProxy<'a>, Box<dyn EntityGatewayTransaction + 'a>), FloorItem), ItemStateError>> + Send + 'a>>
{

    move |(mut item_state, transaction), amount| {
        Box::pin(async move {
            let floor_item = FloorItem {
                item_id: item_state.new_item_id()?,
                item: FloorItemDetail::Meseta(Meseta(amount)),
                map_area: map_area,
                x: drop_position.0,
                y: 0.0,
                z: drop_position.1,
            };

            let mut floor = item_state.floor(&character_id)?;
            let floor_item = floor.add_item(floor_item).clone();
            item_state.set_floor(floor);

            Ok(((item_state, transaction), floor_item))
        })
    }
}

pub async fn drop_meseta<'a, EG>(
    item_state: &'a mut ItemState,
    entity_gateway: &mut EG,
    character: &CharacterEntity,
    map_area: MapArea,
    drop_position: (f32, f32),
    amount: u32)
    -> Result<FloorItem, ItemStateError>
where
    EG: EntityGateway,
{
    entity_gateway.with_transaction(|transaction| async move {
        let item_state_proxy = ItemStateProxy::new(item_state);
        let ((item_state_proxy, transaction), result) = ItemStateAction::default()
            .act(take_meseta_from_inventory(character.id, amount))
            .act(add_meseta_to_shared_floor(character.id, map_area, drop_position))
            .commit((item_state_proxy, transaction))
            .await?;
        item_state_proxy.commit();
        Ok((transaction, result))
    }).await
}