module Data.Text.ParagraphLayout.PlainSpec (spec) where

import Data.List (intersperse)
import Data.Text.Glyphize (Font)

import Test.Hspec
import Test.Hspec.Golden
import System.FilePath ((</>))
import Data.Text.ParagraphLayout.FontLoader
import Data.Text.ParagraphLayout.Fragment
import Data.Text.ParagraphLayout.LineHeight
import Data.Text.ParagraphLayout.ParagraphData
import Data.Text.ParagraphLayout.Plain

prettyShow :: ParagraphLayout -> String
prettyShow (ParagraphLayout pr sls) = showParagraphLayout where
    showParagraphLayout = concat
        [ "ParagraphLayout {paragraphRect = "
        , show pr
        , ", spanLayouts = ["
        , newline
        , showSpanLayouts
        , newline
        , "]}"
        , newline
        ]
    showSpanLayouts = concat $ intersperse commaNewline $ map showSpanLayout sls
    showSpanLayout (SpanLayout frags) = concat
        [ indent1
        , "SpanLayout ["
        , concat $ intersperse ", " $ map showFrag frags
        , "]"
        ]
    showFrag (Fragment r pen glyphs) = concat
        [ "Fragment {fragmentRect = "
        , show r
        , ", "
        , "fragmentPen = "
        , show pen
        , ", "
        , "fragmentGlyphs ="
        , newline
        , indent2
        , "["
        , showGlyphs glyphs
        , "]"
        , newline
        , indent1
        , "}"
        ]
    showGlyphs = concat . intersperse (commaNewline ++ indent2) . map show
    indent1 = "    "
    indent2 = indent1 ++ indent1
    newline = "\n"
    commaNewline = "," ++ newline

shouldBeGolden :: ParagraphLayout -> FilePath -> Golden ParagraphLayout
shouldBeGolden output_ name = Golden
    { output = output_
    , encodePretty = show
    , writeToFile = \path -> writeFile path . prettyShow
    , readFromFile = \path -> readFile path >>= return . read
    , goldenFile = ".golden" </> name </> "golden"
    , actualFile = Just (".golden" </> name </> "actual")
    , failFirstTime = False
    }

emptyLayout :: ParagraphLayout
emptyLayout = ParagraphLayout (Rect 0 0 0 0) []

emptySpanLayout :: ParagraphLayout
emptySpanLayout = ParagraphLayout (Rect 0 0 0 0) [SpanLayout []]

opts :: Font -> ParagraphOptions
opts font = ParagraphOptions font Normal 8000

spec :: Spec
spec = do
    -- Note: This font does not contain Japanese glyphs.
    describe "layoutPlain" $ before loadUbuntuRegular $ do
        it "handles input with no spans" $ \font -> do
            let result = layoutPlain $ emptyParagraph $ opts font
            result `shouldBe` emptyLayout
        it "handles one span with no text" $ \font -> do
            let result = layoutPlain $ emptySpanParagraph $ opts font
            result `shouldBe` emptySpanLayout
        it "handles Czech hello" $ \font -> do
            let result = layoutPlain $ czechHelloParagraph $ opts font
            result `shouldBeGolden` "czechHelloParagraph"
        it "handles mixed languages in LTR layout" $ \font -> do
            let result = layoutPlain $ mixedLanguageLTRParagraph $ opts font
            result `shouldBeGolden` "mixedLanguageLTRParagraph"
        it "handles normal line height" $ \font -> do
            let result = layoutPlain $ trivialParagraph $ (opts font) {
                paragraphLineHeight = Normal
            }
            result `shouldBeGolden` "lineHeightNormal"
        it "handles larger line height" $ \font -> do
            let result = layoutPlain $ trivialParagraph $ (opts font) {
                paragraphLineHeight = Absolute 1600
            }
            result `shouldBeGolden` "lineHeightLarger"
        it "handles smaller line height" $ \font -> do
            let result = layoutPlain $ trivialParagraph $ (opts font) {
                paragraphLineHeight = Absolute 599
            }
            result `shouldBeGolden` "lineHeightSmaller"
        it "wraps by characters when line is ultra narrow" $ \font -> do
            let result = layoutPlain $ czechHelloParagraph $ (opts font) {
                paragraphMaxWidth = 100
            }
            result `shouldBeGolden` "czechHelloParagraphUltraNarrow"
        -- TODO: Update the golden samples when word breaking is implemented.
        it "wraps lorem ipsum at 20em" $ \font -> do
            let result = layoutPlain $ loremIpsumParagraph $ (opts font) {
                paragraphMaxWidth = 20000
            }
            result `shouldBeGolden` "loremIpsum20em"
        it "wraps lorem ipsum at 100em" $ \font -> do
            let result = layoutPlain $ loremIpsumParagraph $ (opts font) {
                paragraphMaxWidth = 100000
            }
            result `shouldBeGolden` "loremIpsum100em"
        it "wraps mixed-script words correctly" $ \font -> do
            let result = layoutPlain $ mixedScriptWordsParagraph $ (opts font) {
                paragraphMaxWidth = 6000
            }
            result `shouldBeGolden` "mixedScriptWordsParagraph"