module TextViewport.Buffer.Buffer where

import Data.Sequence qualified as Seq
import TextViewport.Buffer.Item (Item)

newtype Buffer = Buffer { unBuffer :: Seq.Seq Item }
  deriving (Eq, Show)

-- | Build a buffer from a list
fromList :: [Item] -> Buffer
fromList xs = Buffer (Seq.fromList xs)

-- | Modify an item at index
modifyItem :: Int -> (Item -> Item) -> Buffer -> Buffer
modifyItem ix f (Buffer xs) =
    Buffer (Seq.adjust' f ix xs)

-- | Insert an item
insertItem :: Int -> Item -> Buffer -> Buffer
insertItem ix x (Buffer xs) =
    Buffer (Seq.insertAt ix x xs)

-- | Delete an item
deleteItem :: Int -> Buffer -> Buffer
deleteItem ix (Buffer xs) =
    Buffer (Seq.deleteAt ix xs)

-- | Append an item
appendItem :: Item -> Buffer -> Buffer
appendItem x (Buffer xs) =
    Buffer (xs Seq.|> x)

-- | Extract underlying Seq (if needed)
toSeq :: Buffer -> Seq.Seq Item
toSeq (Buffer xs) = xs