-------------------------------------------------------------------------------
-- |
-- Module      :  Handler.Util
-- Stability   :  experimental
-- Portability :  portable
--
-- Several utilities for the handlers of this package.
{-# LANGUAGE CPP #-}
module Handler.Util
  ( withGame
  , fieldPos
  , setNormalTitle
  , legendStatic
  , timedLegendStatic
  , gridStatic
  , impGameH
  , expGameH
  , renderDiaSVG
  , renderSvgHtml
  , playerGridHtml
  , enemyGridHtml
  ) where

import Import
import Data.Maybe
import Data.Serialize (Serialize)
import Data.Text.Lazy (toStrict)
import Data.Text as T
import Diagrams.Prelude
import Diagrams.Backend.SVG
import Logic.DefaultAI
import Logic.GameExt
import Logic.Render
import Logic.Types
import Text.Blaze.Svg.Internal (Svg)
import Text.Blaze.Svg.Renderer.Text (renderSvg)
import Yesod.Routes.Class

-------------------------------------------------------------------------------
-- * Game Import/Export
-------------------------------------------------------------------------------

-- | Imports a game state in the Handler monad.
impGameH :: Serialize a => GameStateExt -> Handler (Either String (GameState a))
impGameH game = do
  key <- appKey <$> getYesod
  return $ impGame key game

-- | Exports a game state in the Handler monad.
expGameH :: Serialize a => GameState a -> Handler GameStateExt
expGameH game = do
  key <- appKey <$> getYesod
  expGame key game

-- | Bracket for actions in the Handler monad that require the game state.
withGame :: GameStateExt -> (GameState DefaultAI -> Handler a) -> Handler a
withGame gameE act = impGameH gameE >>= \g -> case g of
  Left _     -> redirect HomeR
  Right game -> act game

-------------------------------------------------------------------------------
-- * Static routes
-------------------------------------------------------------------------------

-- | Static route for the specified legend icon.
legendStatic :: LegendIcon -> Route App
legendStatic ico = StaticR $ case ico of
  LIShipWithArrow -> img_LIShipWithArrow_svg
  LIShipMovable   -> img_LIShipMovable_svg
  LIShipImmovable -> img_LIShipImmovable_svg
  LIShipHit       -> img_LIShipHit_svg
  LIShipSunk      -> img_LIShipSunk_svg
  LIFogOfWar      -> img_LIFogOfWar_svg
  LIWater         -> img_LIWater_svg
  LILastShot      -> img_LILastShot_svg

-- | Static route for the specified time-dependent icon.
timedLegendStatic :: TimedLegendIcon -> Route App
timedLegendStatic ico = StaticR $ case ico of
  TLIWater 0   -> img_TLIWater_0_svg
  TLIWater 5   -> img_TLIWater_5_svg
  TLIWater 10  -> img_TLIWater_10_svg
  TLIWater 15  -> img_TLIWater_15_svg
  TLIWater 20  -> img_TLIWater_20_svg
  TLIMarker 0  -> img_TLIMarker_0_svg
  TLIMarker 5  -> img_TLIMarker_5_svg
  TLIMarker 10 -> img_TLIMarker_10_svg
  TLIMarker 15 -> img_TLIMarker_15_svg
  TLIMarker 20 -> img_TLIMarker_20_svg
  _            -> img_LIFogOfWar_svg

-- | Static route for the grid.
gridStatic :: Route App
gridStatic = StaticR img_grid_svg

-------------------------------------------------------------------------------
-- * Misc
-------------------------------------------------------------------------------

-- | Converts coordinates in the grid SVG to a field position.
fieldPos :: (Double, Double) -> Maybe Pos
fieldPos p = listToMaybe $ sample renderReferenceGrid $ p2 p

-- | Set a default html title.
setNormalTitle :: Widget 
setNormalTitle = setTitleI MsgGameName

-- | Renders the player grid as inline SVG for HTML
playerGridHtml :: GameState a -> Action -> Html
playerGridHtml (GameState {..}) requiredAction
  = renderSvgHtml
  $ renderPlayerGrid
    (playerFleet currentPlayer)
    (playerShots otherPlayer)
    requiredAction
    gameRules
    turnNumber

-- | Renders the enemy grid as inline SVG for HTML
enemyGridHtml :: GameState a -> Bool -> Html
enemyGridHtml (GameState {..}) uncoverFleet
  = renderSvgHtml
  $ renderEnemyGrid
    (playerFleet otherPlayer)
    (playerShots currentPlayer)
    gameRules
    noviceModeOpt
    turnNumber
    (uncoverFleet || devModeOpt)

-- | Renders a diagram as an SVG text.
--
-- Uses breakOn to omit doctype and xml declaration, so the text can
-- be embedded in HTML. TODO: Is there a less hacky way to do that?

renderSvgHtml :: (Semigroup m, Monoid m) => QDiagram SVG R2 m -> Html
renderSvgHtml
  = preEscapedToMarkup
  . snd
  . T.breakOn "<svg xmlns="
  . toStrict
  . renderSvg
  . renderDiaSVG

-- | Renders a diagram to SVG
renderDiaSVG :: (Monoid m, Semigroup m) =>
                QDiagram SVG R2 m -> Text.Blaze.Svg.Internal.Svg
renderDiaSVG =
#if MIN_VERSION_diagrams_svg(0,8,0)
  renderDia SVG (SVGOptions Absolute Nothing)
#else
  renderDia SVG (SVGOptions Absolute)
#endif