#!/usr/bin/env stack
-- stack runghc --package reanimate
{-# LANGUAGE DataKinds         #-}
{-# LANGUAGE OverloadedStrings #-}
module Main(main) where

import           Algorithms.Geometry.PolygonTriangulation.Triangulate (triangulate')
import           Control.Lens
import           Control.Monad
import qualified Data.CircularSeq                                     as C
import qualified Data.Geometry                                        as Geo
import           Data.Geometry.PlanarSubdivision                      (PolygonFaceData (..))
import qualified Data.Geometry.Point                                  as Geo
import qualified Data.Geometry.Polygon                                as Geo
import qualified Data.PlaneGraph                                      as Geo
import           Data.Proxy
import           Graphics.SvgTree.Types
import           Linear.V2
import           Reanimate
import           Reanimate.Builtin.Documentation
import           Reanimate.PolyShape

import           Data.Ext
import           Data.List
import qualified Data.Vector                                          as V

scaleP n = lowerTransformations . scale n

env = addStatic (mkBackground "white") .
  mapA (withFillOpacity 0 . withStrokeColor "black" . withStrokeWidth (defaultStrokeWidth*0.1))

main :: IO ()
main = reanimate $ env $ scene $ do
  let --svg = scaleP 4 $ center $ latex "$F=ma$"
      svg = scaleP 4 $ center $ latex "$\\infty$"
      withHoles :: [PolyShapeWithHoles]
      withHoles = plGroupShapes . unionPolyShapes $ svgToPolyShapes svg
      hpoly = map toPoly withHoles
      rects :: [[RPoint]]
      rects = concatMap decomposeP hpoly
  -- newSpriteSVG_ $ scaleP 4 $ center $ latex "$F=ma$"
  forM_ rects $ \rect -> do
    newSpriteSVG_ $ mkLinePathClosed [ (x, y) | V2 x y <- rect ]
    wait (1/60)
  wait 1


-- map (decomposePolygon . plPolygonify 1 . mergePolyShapeHoles) $ plGroupShapes $ unionPolyShapes $ svgToPolyShapes $ latex "I"

toPoly :: PolyShapeWithHoles -> Geo.Polygon Geo.Multi () Double
toPoly (PolyShapeWithHoles outer holes) = Geo.MultiPolygon
  (toSeq outer)
  (map (Geo.SimplePolygon . toSeq) holes)
  where
    tol = 0.001
    toSeq p = C.fromList $
      [ Geo.Point2 x y :+ ()
      | V2 x y <- init $ plPolygonify tol p ]


decomposeP :: Geo.Polygon Geo.Multi () Double -> [[RPoint]]
decomposeP poly =
  [ [ V2 x y
    | v <- V.toList (Geo.boundaryVertices f pg)
    , let Geo.Point2 x y = pg^.Geo.vertexDataOf v . Geo.location ]
  | (f, Inside) <- V.toList (Geo.internalFaces pg) ]

  where
    pg = triangulate' Proxy poly