module Draw.GridSpec where

import Diagrams.Prelude (p2)
import Diagrams.Path (pathPoints)
import Test.Hspec (Spec, describe, it, shouldBe, shouldSatisfy)

import Data.Grid
import Data.GridShape
import Draw.Grid
import Draw.Lib (p2i)

spec :: Spec
spec = do
    describe "irregularGridPaths" $ do
        it "gives the border of a rectangular grid" $ do
            let g = sizeGrid (2, 3) :: Grid C ()
                (outer, _) = irregularGridPaths g
                pts = pathPoints outer
            length pts `shouldBe` 1
            let [opts] = pts
            opts `shouldSatisfy` elem (p2i (0, 0))
            opts `shouldSatisfy` elem (p2i (2, 0))
            opts `shouldSatisfy` elem (p2i (2, 3))
            opts `shouldSatisfy` elem (p2i (0, 3))

    describe "midPoint" $ do
        it "gives the center of a node edge" $ do
            let e = E (N 0 1) Horiz
            midPoint e `shouldBe` p2 (0.5, 1.0)
        it "gives the center of a cell edge" $ do
            let e = E (C 0 0) Vert
            midPoint e `shouldBe` p2 (0.5, 1.0)

    describe "offsetBorder" $ do
        it "gives the corners of a square cell" $ do
            let b = offsetBorder 0 [C 0 0]
                [vs] = pathPoints b
            length vs `shouldBe` 4
            vs `shouldSatisfy` elem (p2i (0, 0))
            vs `shouldSatisfy` elem (p2i (1, 0))
            vs `shouldSatisfy` elem (p2i (0, 1))
            vs `shouldSatisfy` elem (p2i (1, 1))
        it "omits in-between nodes of a rectangle" $ do
            let b = offsetBorder 0 [C 0 0, C 1 0]
                [vs] = pathPoints b
            length vs `shouldBe` 4
            vs `shouldSatisfy` elem (p2i (0, 0))
            vs `shouldSatisfy` elem (p2i (2, 0))
            vs `shouldSatisfy` elem (p2i (0, 1))
            vs `shouldSatisfy` elem (p2i (2, 1))
        it "offsets inside for negative offset" $ do
            let b = offsetBorder (-0.5) [C 0 0, C 1 0, C 1 1, C 0 1]
                [vs] = pathPoints b
            length vs `shouldBe` 4
            vs `shouldSatisfy` elem (p2 (0.5, 0.5))
            vs `shouldSatisfy` elem (p2 (0.5, 1.5))
            vs `shouldSatisfy` elem (p2 (1.5, 1.5))
            vs `shouldSatisfy` elem (p2 (1.5, 0.5))