module Dodge.Creature.Impulse.UseItem (
    useRootItem,
    useItemLeftClick,
    itemUseEffect,
    useItemHotkey,
) where

import Dodge.SelectUse
import Dodge.Item.Grammar
import Dodge.Data.ComposedItem
import Dodge.Data.DoubleTree
import Control.Lens
import Control.Monad
--import Data.Foldable
import Data.Maybe
import Dodge.Cuse
import Dodge.Data.World
import Dodge.Euse
import Dodge.HeldUse
import Dodge.Hotkey
import Dodge.Inventory
import Dodge.Item.Location
import Dodge.Luse
import qualified IntMapHelp as IM

useRootItem :: Int -> World -> World
useRootItem crid w = fromMaybe w $ do
        cr <- w ^? cWorld . lWorld . creatures . ix crid
        itRef <- cr ^? crManipulation . manObject . imRootItem
        it <- invTrees (_crInv cr) ^? ix itRef
        return $
            itemUseEffect cr it w
                & worldEventFlags . at InventoryChange ?~ ()

itemUseEffect :: Creature -> LabelDoubleTree ComposeLinkType Item -> World -> World
itemUseEffect cr it w = case it ^. ldtValue . itUse of
    UseHeld{} -> heldEffect it cr w
            & pointerToItem itm . itUse . heldHammer .~ HammerDown
    UseHotkey{} -> doequipmentchange
    EquipUse{} -> doequipmentchange
    (ConsumeUse eff) -> useC eff (_ldtValue it) cr w
    CraftUse{} -> w
    AttachUse{} -> selectUse it cr  w
    TargetingUse {} -> w
    AmmoMagUse{} -> w
    ScopeUse{} -> w
    BulletModUse{} -> w
  where
    itm = it ^. ldtValue
    doequipmentchange = fromMaybe w $ do
        guard (_crHammerPosition cr == HammerUp)
        invid <- itm ^? itLocation . ilInvID
        return $ toggleEquipmentAt invid cr w

toggleEquipmentAt :: Int -> Creature -> World -> World
toggleEquipmentAt invid cr w = case getEquipmentAllocation w of
    DoNotMoveEquipment -> w
    PutOnEquipment{_allocNewPos = newp} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
            & crpoint . crInvEquipped . at invid ?~ newp
            & onequip itm cr
            & crpoint %~ assignNewHotkey invid
    MoveEquipment{_allocNewPos = newp, _allocOldPos = oldp} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
            & crpoint . crEquipment . at oldp .~ Nothing
            & crpoint . crInvEquipped . at invid ?~ newp
    SwapEquipment{_allocNewPos = newp, _allocOldPos = oldp, _allocSwapID = sid} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
            & crpoint . crEquipment . at oldp ?~ sid
            & crpoint . crInvEquipped . at invid ?~ newp
            & crpoint . crInvEquipped . at sid ?~ oldp
    ReplaceEquipment{_allocNewPos = newp, _allocRemoveID = rid} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
            & crpoint . crInvEquipped . at invid ?~ newp
            & crpoint . crInvEquipped . at rid .~ Nothing
            & onremove (itmat rid) cr
            & onequip itm cr
            & crpoint %~ removeHotkey rid
            & crpoint %~ assignNewHotkey invid
    RemoveEquipment{_allocOldPos = oldp} ->
        w
            & crpoint . crEquipment . at oldp .~ Nothing
            & crpoint . crInvEquipped . at invid .~ Nothing
            & onremove itm cr
            & crpoint %~ removeHotkey invid
  where
    crpoint = cWorld . lWorld . creatures . ix (_crID cr)
    itmat i = _crInv cr IM.! i
    itm = itmat itRef
    itRef = cr ^?! crManipulation . manObject . imSelectedItem -- unsafe!! TODO change?
    onequip itm' = useE ((_eeOnEquip . _equipEffect . _itUse) itm') itm'
    onremove itm' = useE ((_eeOnRemove . _equipEffect . _itUse) itm') itm'

-- need to make sure that the root item is not erroneously selected in the
-- following
useItemLeftClick :: Creature -> World -> World
useItemLeftClick cr w = fromMaybe w $ do
    guard . not $ _crInvLock cr
    invid <- cr ^? crManipulation . manObject . imSelectedItem
    ituse <- cr ^? crInv . ix invid . itUse
    case ituse of
        UseHeld{} -> return w
        ConsumeUse{} -> return $ useItemLeftClick' cr w
        EquipUse{} -> return $ useItemLeftClick' cr w
        UseHotkey{} -> return $ useItemLeftClick' cr w
        AmmoMagUse{} -> return w
        _ -> Nothing

useItemLeftClick' :: Creature -> World -> World
--useItemLeftClick' cr' w = fromMaybe (f w) $ do
useItemLeftClick' cr' w = fromMaybe w $ do
    cr <- w ^? cWorld . lWorld . creatures . ix (_crID cr')
    itRef <- cr ^? crManipulation . manObject . imSelectedItem
    it <- invTrees (_crInv cr) ^? ix itRef
    return $
        itemUseEffect cr it w
            & worldEventFlags . at InventoryChange ?~ ()
--            & f
--  where
--    f = cWorld . lWorld . creatures . ix (_crID cr') . crHammerPosition .~ HammerDown

useItemHotkey :: Int -> Int -> World -> World
useItemHotkey crid invid w = fromMaybe w $ do
    cr <- w ^? cWorld . lWorld . creatures . ix crid
    itm <- cr ^? crInv . ix invid
    luse <- itm ^? itUse . leftUse
    return $
        w
            & cWorld . lWorld . creatures . ix crid . crInv . ix invid . itUse . leftHammer .~ HammerDown
            & useL luse itm cr

-- TODO determine itmShouldBeUsed with reference to config options