{-# LANGUAGE LambdaCase #-}

module Dodge.Creature.Impulse.UseItem (
    useItem,
) where

import Dodge.Equipment
import Control.Lens
import Data.Maybe
import Dodge.Data.ComposedItem
import Dodge.Data.DoubleTree
import Dodge.Data.World
import Dodge.DoubleTree
import Dodge.Euse
import Dodge.HeldUse
import Dodge.Inventory
import Dodge.Item.Grammar
import Dodge.Item.Location
import qualified IntMapHelp as IM

useItem :: Int -> PressType -> World -> Maybe World
useItem invid pt w = fmap (worldEventFlags . at InventoryChange ?~ ()) $ do
    cr <- w ^? cWorld . lWorld . creatures . ix 0
    itmloc <- allInvLocs (_crInv cr) ^? ix invid . _2
    let usedloc = useLocation itmloc
    useItemLoc cr usedloc pt w

useItemLoc ::
    Creature ->
    LocationLDT ItemLink ComposedItem ->
    PressType ->
    World ->
    Maybe World
useItemLoc cr loc pt w
    | HeldPlatformSF <- sf
      , fromMaybe False $ loc ^? locLDT . ldtValue . _1 . itLocation . ilIsRoot
      , Aiming {} <- cr ^. crStance . posture =
        return $ heldEffect pt (bimap _iatType (^. _1) ldt) cr w
    | GadgetPlatformSF <- sf =
        return $ gadgetEffect pt loc cr w
    | UnderBarrelPlatformSF <- sf
      , fromMaybe False $ loc ^? locLDT . ldtValue . _1 . itLocation . ilIsAttached
      , Aiming {} <- cr ^. crStance . posture =
        return $ heldEffect pt (bimap _iatType (^. _1) ldt) cr w
    | RemoteDetonatorSF <- sf
      , pt == InitialPress =
        return $ activateDetonator ldt w
    | ITEMSCAN <- itm ^. itType
      , pt == InitialPress =
        return $ toggleExamineInv w
    | MAPPER <- itm ^. itType
      , pt == InitialPress =
        return $ toggleMapperInv itm w
    | Just b <- itm ^? itUse . useToggle
      , pt == InitialPress =
        return $ w & pointerToItem itm . itUse . useToggle .~ not b
    | isJust $ itm ^? itUse . uequipEffect
      , pt == InitialPress
      , Just invid' <- itm ^? itLocation . ilInvID =
        return $ toggleEquipmentAt invid' cr w
    | otherwise = Nothing
  where
    sf = loc ^. locLDT . ldtValue . _2
    ldt = loc ^. locLDT
    itm = ldt ^. ldtValue . _1

useLocation ::
    LocationLDT ItemLink ComposedItem ->
    LocationLDT ItemLink ComposedItem
useLocation loc
    | isJust $ loc ^? locLDT . ldtValue . _1 . itUse . uequipEffect = loc
    | isJust $ loc ^? locLDT . ldtValue . _1 . itUse . uaParams . apProjectiles . ix 0 =
        loc
    | sf <- loc ^. locLDT . ldtValue . _2
      , structureUseAtLoc sf =
        loc
    | otherwise = locToTop loc

structureUseAtLoc :: ItemStructuralFunction -> Bool
structureUseAtLoc = \case
    HeldPlatformSF -> True
    UnderBarrelPlatformSF -> True
    GadgetPlatformSF -> True
    MapperSF -> True
    _ -> False

activateDetonator ::
    LabelDoubleTree ItemLink ComposedItem ->
    World ->
    World
activateDetonator det = fromMaybe id $ do
    pjid <- det ^? ldtValue . _1 . itUse . uaParams . apProjectiles . ix 0
    return $ cWorld . lWorld . projectiles . ix pjid . pjTimer .~ 0

toggleEquipmentAt :: Int -> Creature -> World -> World
toggleEquipmentAt invid cr w = case getEquipmentAllocation invid w of
    DoNotMoveEquipment -> w
    PutOnEquipment{_allocNewPos = newp} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
            & crpoint . crInv . ix invid . itLocation . ilEquipSite ?~ newp
            & onequip itm cr
    MoveEquipment{_allocNewPos = newp, _allocOldPos = oldp} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
            & crpoint . crEquipment . at oldp .~ Nothing
            & crpoint . crInv . ix invid . itLocation . ilEquipSite ?~ newp
    SwapEquipment{_allocNewPos = newp, _allocOldPos = oldp, _allocSwapID = sid} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
            & crpoint . crEquipment . at oldp ?~ sid
            & crpoint . crInv . ix invid . itLocation . ilEquipSite ?~ newp
            & crpoint . crInv . ix sid . itLocation . ilEquipSite ?~ oldp
    ReplaceEquipment{_allocNewPos = newp, _allocRemoveID = rid} ->
        w
            & crpoint . crEquipment . at newp ?~ invid
            & crpoint . crInv . ix invid . itLocation . ilEquipSite ?~ newp
            & crpoint . crInv . ix rid . itLocation . ilEquipSite .~ Nothing
            & onremove (itmat rid) cr
            & onequip itm cr
    RemoveEquipment{_allocOldPos = oldp} ->
        w
            & crpoint . crEquipment . at oldp .~ Nothing
            & crpoint . crInv . ix invid . itLocation . ilEquipSite .~ Nothing
            & onremove itm cr
  where
    crpoint = cWorld . lWorld . creatures . ix (_crID cr)
    itmat i = _crInv cr IM.! i
    itm = itmat invid
    onequip itm' = doItmCrWdWd ((_eeOnEquip . _uequipEffect . _itUse) itm') itm'
    --onremove itm' = doItmCrWdWd ((_eeOnRemove . _uequipEffect . _itUse) itm') itm'
    onremove itm' = effectOnRemove itm'

toggleExamineInv :: World -> World
toggleExamineInv w = case w ^? hud . hudElement . subInventory of
    Just ExamineInventory{} -> w & hud . hudElement . subInventory .~ NoSubInventory
    _ -> w & hud . hudElement . subInventory .~ ExamineInventory

toggleMapperInv :: Item -> World -> World
toggleMapperInv itm w = case w ^? hud . hudElement . subInventory of
    Just MapperInventory{} -> w & hud . hudElement . subInventory .~ NoSubInventory
    _ -> w & hud . hudElement . subInventory .~ MapperInventory 0 1 (_itID itm)