use libpso::packet::ship::*;
use libpso::packet::messages::*;
use crate::entity::gateway::EntityGateway;
use crate::entity::item::Meseta;
use crate::common::serverstate::ClientId;
use crate::common::leveltable::CharacterLevelTable;
use crate::ship::ship::{SendShipPacket, ShipError, Rooms, Clients, ItemDropLocation};
use crate::ship::location::{ClientLocation, ClientLocationError};
use crate::ship::items::ClientItemId;
use crate::ship::packet::builder;
use crate::ship::items::state::ItemState;
use crate::ship::items::tasks::{drop_item, drop_partial_item, drop_meseta, equip_item, unequip_item, sort_inventory, use_item, feed_mag, sell_item, take_meseta};

pub async fn request_exp<EG: EntityGateway>(id: ClientId,
                                            request_exp: &RequestExp,
                                            entity_gateway: &mut EG,
                                            client_location: &ClientLocation,
                                            clients: &mut Clients,
                                            rooms: &mut Rooms,
                                            level_table: &CharacterLevelTable)
                                            -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error> {
    let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;
    let area_client = client_location.get_local_client(id).map_err(|err| -> ClientLocationError { err.into() })?;
    let room_id = client_location.get_room(id).map_err(|err| -> ClientLocationError { err.into() })?;
    let room = rooms.get_mut(room_id.0)
        .ok_or(ShipError::InvalidRoom(room_id.0 as u32))?
        .as_mut()
        .ok_or(ShipError::InvalidRoom(room_id.0 as u32))?;

    let monster = room.maps.enemy_by_id(request_exp.enemy_id as usize)?;
    let monster_stats = room.monster_stats.get(&monster.monster).ok_or(ShipError::UnknownMonster(monster.monster))?;

    let exp_gain = if request_exp.last_hitter == 1 {
        monster_stats.exp
    }
    else {
        ((monster_stats.exp as f32) * 0.8) as u32
    };

    let clients_in_area = client_location.get_clients_in_room(room_id).map_err(|err| -> ClientLocationError { err.into() })?;
    let gain_exp_pkt = builder::message::character_gained_exp(area_client, exp_gain);
    let mut exp_pkts: Box<dyn Iterator<Item = _> + Send> = Box::new(clients_in_area.clone().into_iter()
        .map(move |c| {
            (c.client, SendShipPacket::Message(Message::new(GameMessage::GiveCharacterExp(gain_exp_pkt.clone()))))
        }));

    let before_level = level_table.get_level_from_exp(client.character.char_class, client.character.exp);
    let after_level = level_table.get_level_from_exp(client.character.char_class, client.character.exp + exp_gain);
    let level_up = before_level != after_level;

    if level_up {
        let (_, before_stats) = level_table.get_stats_from_exp(client.character.char_class, client.character.exp);
        let (after_level, after_stats) = level_table.get_stats_from_exp(client.character.char_class, client.character.exp + exp_gain);

        let level_up_pkt = builder::message::character_leveled_up(area_client, after_level, before_stats, after_stats);
        exp_pkts = Box::new(exp_pkts.chain(clients_in_area.into_iter()
            .map(move |c| {
                (c.client, SendShipPacket::Message(Message::new(GameMessage::PlayerLevelUp(level_up_pkt.clone()))))
            })))
    }

    client.character.exp += exp_gain;
    entity_gateway.save_character(&client.character).await?;

    Ok(exp_pkts)
}

pub async fn player_drop_item<EG>(id: ClientId,
                                  player_drop_item: &PlayerDropItem,
                                  entity_gateway: &mut EG,
                                  client_location: &ClientLocation,
                                  clients: &mut Clients,
                                  rooms: &mut Rooms,
                                  item_state: &mut ItemState)
                            -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;
    let room_id = client_location.get_room(id).map_err(|err| -> ClientLocationError { err.into() })?;
    let room = rooms.get_mut(room_id.0)
        .ok_or(ShipError::InvalidRoom(room_id.0 as u32))?
        .as_mut()
        .ok_or(ShipError::InvalidRoom(room_id.0 as u32))?;
    let area = room.map_areas.get_area_map(player_drop_item.map_area)?;
    drop_item(item_state, entity_gateway, &client.character, &ClientItemId(player_drop_item.item_id), *area, (player_drop_item.x, player_drop_item.y, player_drop_item.z)).await?;
    let clients_in_area = client_location.get_clients_in_room(room_id).map_err(|err| -> ClientLocationError { err.into() })?;
    let pdi = player_drop_item.clone();
    Ok(Box::new(clients_in_area.into_iter()
                .map(move |c| {
                    (c.client, SendShipPacket::Message(Message::new(GameMessage::PlayerDropItem(pdi.clone()))))
                })))
}

pub fn drop_coordinates(id: ClientId,
                            drop_coordinates: &DropCoordinates,
                            client_location: &ClientLocation,
                            clients: &mut Clients,
                            rooms: &Rooms)
                            -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
{
    let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;
    let room_id = client_location.get_room(id).map_err(|err| -> ClientLocationError { err.into() })?;
    let room = rooms.get(room_id.0)
        .ok_or(ShipError::InvalidRoom(room_id.0 as u32))?
        .as_ref()
        .ok_or(ShipError::InvalidRoom(room_id.0 as u32))?;

    client.item_drop_location = Some(ItemDropLocation {
        map_area: *room.map_areas.get_area_map(drop_coordinates.map_area)?,
        x: drop_coordinates.x,
        z: drop_coordinates.z,
        item_id: ClientItemId(drop_coordinates.item_id),
    });

    Ok(Box::new(None.into_iter())) // TODO: do we need to send a packet here?
}

pub async fn no_longer_has_item<EG>(id: ClientId,
                                    no_longer_has_item: &PlayerNoLongerHasItem,
                                    entity_gateway: &mut EG,
                                    client_location: &ClientLocation,
                                    clients: &mut Clients,
                                    item_state: &mut ItemState)
                                    -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;
    let area_client = client_location.get_local_client(id).map_err(|err| -> ClientLocationError { err.into() })?;
    let room_id = client_location.get_room(id).map_err(|err| -> ClientLocationError { err.into() })?;
    if let Some(drop_location) = client.item_drop_location {
        if drop_location.item_id.0 != no_longer_has_item.item_id {
            return Err(ShipError::DropInvalidItemId(no_longer_has_item.item_id).into());
        }

        if no_longer_has_item.item_id == 0xFFFFFFFF {
            let dropped_meseta = drop_meseta(item_state, entity_gateway, &client.character, drop_location.map_area, (drop_location.x, drop_location.z), no_longer_has_item.amount).await?;

            let dropped_meseta_pkt = builder::message::drop_split_meseta_stack(area_client, &dropped_meseta)?;
            let no_longer_has_meseta_pkt = builder::message::player_no_longer_has_meseta(area_client, no_longer_has_item.amount as u32);
            client.item_drop_location = None;

            let clients_in_area = client_location.get_clients_in_room(room_id).map_err(|err| -> ClientLocationError { err.into() })?;
            Ok(Box::new(clients_in_area.into_iter()
                        .flat_map(move |c| {
                            std::iter::once((c.client, SendShipPacket::Message(Message::new(GameMessage::DropSplitStack(dropped_meseta_pkt.clone())))))
                                .chain(
                                    if c.client != id {
                                        Box::new(std::iter::once(
                                            (c.client, SendShipPacket::Message(Message::new(GameMessage::PlayerNoLongerHasItem(no_longer_has_meseta_pkt.clone()))))
                                        )) as Box<dyn Iterator<Item = _> + Send>
                                    }
                                    else {
                                        Box::new(std::iter::empty()) as Box<dyn Iterator<Item = _> + Send>
                                    }
                                )
                        })
            ))
        }
        else {
            let dropped_item = drop_partial_item(item_state, entity_gateway, &client.character, &drop_location.item_id, drop_location.map_area, (drop_location.x, drop_location.z), no_longer_has_item.amount).await?;

            let dropped_item_pkt = builder::message::drop_split_stack(area_client, &dropped_item)?;
            client.item_drop_location = None;

            let clients_in_area = client_location.get_clients_in_room(room_id).map_err(|err| -> ClientLocationError { err.into() })?;
            Ok(Box::new(clients_in_area.into_iter()
                        .map(move |c| {
                            (c.client, SendShipPacket::Message(Message::new(GameMessage::DropSplitStack(dropped_item_pkt.clone()))))
                        })))
        }
    }
    else if let Some(_tek) = client.tek {
        let neighbors = client_location.get_client_neighbors(id).map_err(|err| -> ClientLocationError { err.into() })?;
        let no_longer_has_item = no_longer_has_item.clone();
        Ok(Box::new(neighbors.into_iter()
                    .map(move |c| {
                        (c.client, SendShipPacket::Message(Message::new(GameMessage::PlayerNoLongerHasItem(no_longer_has_item.clone()))))
                    })))
    }
    else {
        Err(ShipError::InvalidItem(ClientItemId(no_longer_has_item.item_id)).into())
    }
}

pub fn update_player_position(id: ClientId,
                            message: &Message,
                            clients: &mut Clients,
                            client_location: &ClientLocation,
                            rooms: &Rooms)
                            -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error> {
    let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;
    if let Ok(room_id) = client_location.get_room(id).map_err(|err| -> ClientLocationError { err.into() }) {
        let room = rooms.get(room_id.0)
            .ok_or(ShipError::InvalidRoom(room_id.0 as u32))?
            .as_ref()
            .ok_or(ShipError::InvalidRoom(room_id.0 as u32))?;

        match &message.msg {
            GameMessage::PlayerChangedMap(p) => {
                client.x = p.x;
                client.y = p.y;
                client.z = p.z;
            },
            GameMessage::PlayerChangedMap2(p) => {
                client.area = room.map_areas.get_area_map(p.map_area).ok().cloned();
            },
            GameMessage::TellOtherPlayerMyLocation(p) => {
                client.x = p.x;
                client.y = p.y;
                client.z = p.z;
                client.area = room.map_areas.get_area_map(p.map_area).ok().cloned();
            },
            GameMessage::PlayerWarpingToFloor(p) => {
                client.area = room.map_areas.get_area_map(p.area as u16).ok().cloned();
            },
            GameMessage::PlayerTeleported(p) => {
                client.x = p.x;
                client.y = p.y;
                client.z = p.z;
            },
            GameMessage::PlayerStopped(p) => {
                client.x = p.x;
                client.y = p.y;
                client.z = p.z;
            },
            GameMessage::PlayerLoadedIn(p) => {
                client.x = p.x;
                client.y = p.y;
                client.z = p.z;
            },
            GameMessage::PlayerWalking(p) => {
                client.x = p.x;
                client.z = p.z;
            },
            GameMessage::PlayerRunning(p) => {
                client.x = p.x;
                client.z = p.z;
            },
            GameMessage::PlayerWarped(p) => {
                client.x = p.x;
                client.y = p.y;
            },
            // GameMessage::PlayerChangedFloor(p) => {client.area = MapArea::from_value(&room.mode.episode(), p.map).ok();},
            GameMessage::InitializeSpeechNpc(p) => {
                client.x = p.x;
                client.z = p.z;
            }
            _ => {},
        }
    } else {}
    let m = message.clone();
    Ok(Box::new(client_location.get_client_neighbors(id).unwrap().into_iter()
                    .map(move |client| {
                        (client.client, SendShipPacket::Message(m.clone()))
                    })))
}

pub async fn charge_attack<EG>(id: ClientId,
                               charge: &ChargeAttack,
                               entity_gateway: &mut EG,
                               client_location: &ClientLocation,
                               clients: &mut Clients,
                               item_state: &mut ItemState)
                               -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;

    // TODO: should probably validate this to be a legit number, I'd just hardcode 200 but vjaya
    take_meseta(item_state, entity_gateway, &client.character.id, Meseta(charge.meseta)).await?;

    let charge = charge.clone();
    Ok(Box::new(client_location.get_client_neighbors(id).unwrap().into_iter()
                    .map(move |client| {
                        (client.client, SendShipPacket::Message(Message::new(GameMessage::ChargeAttack(charge.clone()))))
                    })))
}

pub async fn player_uses_item<EG>(id: ClientId,
                          player_use_tool: &PlayerUseItem,
                          entity_gateway: &mut EG,
                          _client_location: &ClientLocation,
                          clients: &mut Clients,
                          item_state: &mut ItemState)
                          -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;
    use_item(item_state, entity_gateway, &mut client.character, &ClientItemId(player_use_tool.item_id), 1).await?;
    Ok(Box::new(None.into_iter())) // TODO: should probably tell other players we used an item
}

pub async fn player_used_medical_center<EG>(id: ClientId,
                                            pumc: &PlayerUsedMedicalCenter,
                                            entity_gateway: &mut EG,
                                            client_location: &ClientLocation,
                                            clients: &mut Clients,
                                            item_state: &mut ItemState)
                                            -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;

    take_meseta(item_state, entity_gateway, &client.character.id, Meseta(10)).await?;

    let pumc = pumc.clone();
    Ok(Box::new(client_location.get_client_neighbors(id).unwrap().into_iter()
                    .map(move |client| {
                        (client.client, SendShipPacket::Message(Message::new(GameMessage::PlayerUsedMedicalCenter(pumc.clone()))))
                    })))
}


pub async fn player_feed_mag<EG>(id: ClientId,
                                 mag_feed: &PlayerFeedMag,
                                 entity_gateway: &mut EG,
                                 client_location: &ClientLocation,
                                 clients: &Clients,
                                 item_state: &mut ItemState)
                                 -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get(&id).ok_or(ShipError::ClientNotFound(id))?;
    feed_mag(item_state, entity_gateway, &client.character, &ClientItemId(mag_feed.mag_id), &ClientItemId(mag_feed.item_id)).await?;

    let mag_feed = mag_feed.clone();
    Ok(Box::new(client_location.get_client_neighbors(id).unwrap().into_iter()
                    .map(move |client| {
                        (client.client, SendShipPacket::Message(Message::new(GameMessage::PlayerFeedMag(mag_feed.clone()))))
                    })))
}

pub async fn player_equips_item<EG>(id: ClientId,
                                    pkt: &PlayerEquipItem,
                                    entity_gateway: &mut EG,
                                    clients: &Clients,
                                    item_state: &mut ItemState)
                                    -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get(&id).ok_or(ShipError::ClientNotFound(id))?;
    let equip_slot = if pkt.sub_menu > 0 {
        ((pkt.sub_menu & 0x7) - 1) % 4
    }
    else {
        0
    };
    equip_item(item_state, entity_gateway, &client.character, &ClientItemId(pkt.item_id), equip_slot).await?;
    Ok(Box::new(None.into_iter())) // TODO: tell other players you equipped an item
}

pub async fn player_unequips_item<EG>(id: ClientId,
                                    pkt: &PlayerUnequipItem,
                                    entity_gateway: &mut EG,
                                    clients: &Clients,
                                    item_state: &mut ItemState)
                                    -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get(&id).ok_or(ShipError::ClientNotFound(id))?;
    unequip_item(item_state, entity_gateway, &client.character, &ClientItemId(pkt.item_id)).await?;
    Ok(Box::new(None.into_iter())) // TODO: tell other players if you unequip an item
}

pub async fn player_sorts_items<EG>(id: ClientId,
                                    pkt: &SortItems,
                                    entity_gateway: &mut EG,
                                    clients: &Clients,
                                    item_state: &mut ItemState)
                                    -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get(&id).ok_or(ShipError::ClientNotFound(id))?;
    let item_ids = pkt.item_ids
        .iter()
        .filter_map(|item_id| {
            if *item_id != 0 {
                Some(ClientItemId(*item_id))
            }
            else {
                None
            }
        })
        .collect();
    sort_inventory(item_state, entity_gateway, &client.character, item_ids).await?;
    Ok(Box::new(None.into_iter())) // TODO: clients probably care about each others item orders
}

pub async fn player_sells_item<EG> (id: ClientId,
                                    sold_item: &PlayerSoldItem,
                                    entity_gateway: &mut EG,
                                    clients: &mut Clients,
                                    item_state: &mut ItemState)
                                    -> Result<Box<dyn Iterator<Item = (ClientId, SendShipPacket)> + Send>, anyhow::Error>
where
    EG: EntityGateway
{
    let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;
    sell_item(item_state, entity_gateway, &client.character, ClientItemId(sold_item.item_id), sold_item.amount as u32).await?;
    // TODO: send the packet to other clients
    Ok(Box::new(None.into_iter()))
}