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

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

useRootItem :: Int -> World -> World
useRootItem crid w = (worldEventFlags . at InventoryChange ?~ ()) . fromMaybe w $ do
    cr <- w ^? cWorld . lWorld . creatures . ix crid
    itRef <- cr ^? crManipulation . manObject . imRootSelectedItem
    itmtree <- invRootTrees (_crInv cr) ^? ix itRef
    let itm = itmtree ^. ldtValue . _1
    case itmtree ^. ldtValue . _2 of
        HeldPlatformSF ->
            return $
                heldEffect (bimap _iatType fst3 itmtree) cr w
                    & pointerToItem itm . itUse . heldHammer .~ HammerDown
        GadgetPlatformSF ->
            return $
                heldEffect (bimap _iatType fst3 itmtree) cr w
                    & pointerToItem itm . itUse . heldHammer .~ HammerDown
        EquipmentPlatformSF -> do
            guard (_crHammerPosition cr == HammerUp)
            invid <- itm ^? itLocation . ilInvID
            return $ toggleEquipmentAt invid cr w
        _ -> Nothing
  where
    fst3 (x,_,_) = x

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
            & crpoint . crInv . ix invid . itLocation . ilEquipPosition ?~ newp
            & onequip itm cr
--            & crpoint %~ assignNewHotkey invid
            & cWorld . lWorld %~ assignNewHotkey invid
    MoveEquipment{_allocNewPos = newp, _allocOldPos = oldp} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
            & crpoint . crEquipment . at oldp .~ Nothing
--            & crpoint . crInvEquipped . at invid ?~ newp
            & crpoint . crInv . ix invid . itLocation . ilEquipPosition ?~ 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 . crInv . ix invid . itLocation . ilEquipPosition ?~ newp
--            & crpoint . crInvEquipped . at sid ?~ oldp
            & crpoint . crInv . ix sid . itLocation . ilEquipPosition ?~ oldp
    ReplaceEquipment{_allocNewPos = newp, _allocRemoveID = rid} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
--            & crpoint . crInvEquipped . at invid ?~ newp
            & crpoint . crInv . ix invid . itLocation . ilEquipPosition ?~ newp
--            & crpoint . crInvEquipped . at rid .~ Nothing
            & crpoint . crInv . ix rid . itLocation . ilEquipPosition .~ Nothing
            & onremove (itmat rid) cr
            & onequip itm cr
--            & crpoint %~ removeHotkey rid
--            & crpoint %~ assignNewHotkey invid
            & cWorld . lWorld %~ removeHotkey rid
            & cWorld . lWorld %~ assignNewHotkey invid
    RemoveEquipment{_allocOldPos = oldp} ->
        w
            & crpoint . crEquipment . at oldp .~ Nothing
--            & crpoint . crInvEquipped . at invid .~ Nothing
            & crpoint . crInv . ix invid . itLocation . ilEquipPosition .~ Nothing
            & onremove itm cr
--            & crpoint %~ removeHotkey invid
            & cWorld . lWorld %~ 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' = doItmCrWdWd ((_eeOnEquip . _uequipEffect . _itUse) itm') itm'
    onremove itm' = doItmCrWdWd ((_eeOnRemove . _uequipEffect . _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
    itm <- cr ^? crInv . ix invid
    ituse <- cr ^? crInv . ix invid . itUse
    case ituse of
        UseHeld{} -> return w
        UseConsume eff -> return $ useC eff itm cr w
        UseEquip{} -> return $ doequipmentchange invid
        UseHotkey{} -> return $ doequipmentchange invid
        UseNothing{} -> return w
        UseAttach{} -> do
            return $ selectUse itm cr w
        _ -> Nothing
  where
    doequipmentchange invid = fromMaybe w $ do
        guard (_crHammerPosition cr == HammerUp)
        return $ toggleEquipmentAt invid cr w

--            & 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