module Dodge.SelectionSections (
    scrollSelectionSections,
    ssLookupDown,
    ssLookupGT,
    ssSetCursor,
    firstPosSelectionSections,
) where

import Control.Lens
import qualified Data.IntMap.Strict as IM
import Data.Maybe
import Dodge.Data.SelectionList

scrollSelectionSections :: Int -> SelectionSections a -> SelectionSections a
scrollSelectionSections yi sss
    | yi == 0 = sss
    | yi > 0 = foldr ($) sss $ replicate yi scrollUpSelectionSections
    | otherwise = foldr ($) sss $ replicate (negate yi) scrollDownSelectionSections

-- when is this used? it needs to correctly set the cursor
firstPosSelectionSections :: SelectionSections a -> SelectionSections a
firstPosSelectionSections sss = fromMaybe sss $ do
    (i, j, si) <- ssLookupMin sss
    return $
        sss
            & sssSelPos ?~ (i, j)

--        & sssSetCursor
--        & sssSections . ix i . ssCursor ?~ SectionCursor j j (_siHeight si) (_siColor si)

--sssSetCursor :: SelectionSections a -> SelectionSections a
--sssSetCursor sss = sss

scrollUpSelectionSections :: SelectionSections a -> SelectionSections a
scrollUpSelectionSections sss = fromMaybe (firstPosSelectionSections sss) $ do
    (i, j) <- sss ^? sssSelPos . _Just
    (i', j', si) <- ssLookupUp i j sss
    return $ sss & sssSelPos ?~ (i', j')

--        & sssSections . ix i' . ssCursor ?~ SectionCursor j' j' (_siHeight si) (_siColor si)

scrollDownSelectionSections :: SelectionSections a -> SelectionSections a
scrollDownSelectionSections sss = fromMaybe (firstPosSelectionSections sss) $ do
    (i, j) <- sss ^? sssSelPos . _Just
    --    j <- sss ^? sssSections . ix i . ssCursor . _Just . scurSel
    (i', j', si) <- ssLookupDown i j sss
    return $ sss & sssSelPos ?~ (i', j')

--        & sssSections . ix i' . ssCursor ?~ SectionCursor j' j' (_siHeight si) (_siColor si)

ssSetCursor ::
    (SelectionSections a -> Maybe (Int, Int, SelectionItem a)) ->
    SelectionSections a ->
    SelectionSections a
ssSetCursor f sss = fromMaybe sss $ do
    (i, j, si) <- f sss
    return $
        sss
            & sssSelPos ?~ (i, j)

--        & sssSections . ix i . ssCursor ?~ SectionCursor j j (_siHeight si) (_siColor si)

ssLookupMax :: SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupMax sss = do
    (i, _) <- IM.lookupMax (sss ^. sssSections)
    ssLookupLE' i sss

ssLookupUp :: Int -> Int -> SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupUp i j sss = case ssLookupLT i j sss of
    Nothing -> ssLookupMax sss
    x -> x

ssLookupDown :: Int -> Int -> SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupDown i j sss = case ssLookupGT i j sss of
    Nothing -> ssLookupMin sss
    x -> x

ssLookupLT :: Int -> Int -> SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupLT i j sss = fromMaybe (ssLookupLT' i sss) $ do
    ss <- sss ^? sssSections . ix i
    (j', si) <- IM.lookupLT j (ss ^. ssItems)
    return $ Just (i, j', si)

ssLookupLT' :: Int -> SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupLT' i sss = do
    (i', ss) <- IM.lookupLT i (sss ^. sssSections)
    case IM.lookupMax (ss ^. ssItems) of
        Just (j', si) -> return (i', j', si)
        Nothing -> ssLookupLT' i' sss

ssLookupLE' :: Int -> SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupLE' i sss = do
    (i', ss) <- IM.lookupLE i (sss ^. sssSections)
    case IM.lookupMax (ss ^. ssItems) of
        Just (j', si) -> return (i', j', si)
        Nothing -> ssLookupLT' i' sss

ssLookupMin :: SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupMin sss = do
    (i, _) <- IM.lookupMin (sss ^. sssSections)
    ssLookupGE' i sss

ssLookupGT :: Int -> Int -> SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupGT i j sss = fromMaybe (ssLookupGT' i sss) $ do
    ss <- sss ^? sssSections . ix i
    (j', si) <- IM.lookupGT j (ss ^. ssItems)
    return $ Just (i, j', si)

ssLookupGT' :: Int -> SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupGT' i sss = do
    (i', ss) <- IM.lookupGT i (sss ^. sssSections)
    case IM.lookupMin (ss ^. ssItems) of
        Just (j', si) -> return (i', j', si)
        Nothing -> ssLookupGT' i' sss

ssLookupGE' :: Int -> SelectionSections a -> Maybe (Int, Int, SelectionItem a)
ssLookupGE' i sss = do
    (i', ss) <- IM.lookupGE i (sss ^. sssSections)
    case IM.lookupMin (ss ^. ssItems) of
        Just (j', si) -> return (i', j', si)
        Nothing -> ssLookupGT' i' sss