{-# LANGUAGE OverloadedStrings #-}
import           Data.List   (sortOn)
import           Data.Time   (defaultTimeLocale, formatTime)
import           Hakyll


--------------------------------------------------------------------------------
main :: IO ()
main = hakyllWith defaultConfiguration{ deployCommand = "ipfs add -Q -r _site" } $do
    match "images/*" $ do
        route   idRoute
        compile copyFileCompiler

    match "resources/*" $ do
        route   idRoute
        compile copyFileCompiler

    match "css/*" $ do
        route   idRoute
        compile compressCssCompiler

    match "js/*" $ do
        route   idRoute
        compile compressCssCompiler

    match (fromList ["index.markdown", "contact.markdown"]) $ do
        route   $ setExtension "html"
        compile $ pandocCompiler
            >>= loadAndApplyTemplate "templates/default.html" defaultContext
            >>= relativizeUrls

    match "posts/*" $ do
      route $ setExtension "html"
      compile $ pandocCompiler
        >>= loadAndApplyTemplate "templates/post.html"    postCtx
        >>= loadAndApplyTemplate "templates/default.html" postCtx
        >>= relativizeUrls

    create ["posts.html"] $ do
        route idRoute
        compile $ do
            posts <- modFirst =<< loadAll "posts/*"
            let archiveCtx =
                    listField "posts" postCtx (return posts) <>
                    constField "title" "Posts"               <>
                    defaultContext

            makeItem ""
                >>= loadAndApplyTemplate "templates/guides.html" archiveCtx
                >>= loadAndApplyTemplate "templates/default.html" archiveCtx
                >>= relativizeUrls


    match "templates/*" $ compile templateBodyCompiler

modFirst :: [Item a] -> Compiler [Item a]
modFirst = fmap reverse . modified
  where
    modified = sortByM (getItemModificationTime . itemIdentifier)
    sortByM f xs = map fst . sortOn snd <$> mapM (\x -> (,) x <$> f x) xs

--------------------------------------------------------------------------------
postCtx :: Context String
postCtx =
    dateField "date" "%B %e, %Y" <>
    modifiedField "modified" "%B %e, %Y" <>
    defaultContext
  where
    modifiedField key format = field key $ \i -> do
      time <- getItemModificationTime $ itemIdentifier i
      return $ formatTime defaultTimeLocale format time