module Rakka.Wiki.Interpreter.Image
    ( interpreters
    )
    where

import           Control.Monad
import           Data.Maybe
import           Network.URI
import           Rakka.Page
import           Rakka.SystemConfig
import           Rakka.Wiki.Interpreter
import           Rakka.Wiki


interpreters :: [Interpreter]
interpreters = [ imageInterp
               , imgFrameInterp
               ]


-- <a href="..." class="inlineImage ...">
--   <img src="..." alt="..." />
-- </a>
imageInterp :: Interpreter
imageInterp
    = InlineCommandInterpreter {
        iciName      = "img"
      , iciInterpret
          = \ ctx (InlineCommand _ attrs inside) ->
            do BaseURI baseURI <- getSysConf (ctxSysConf ctx) (BaseURI undefined)

               let pageName = lookup "src" attrs
               when (pageName == Nothing)
                        $ fail "\"src\" attribute is missing"

               let hrefAttr    = ("href", uriToString id (mkPageURI   baseURI (fromJust pageName)) "")
                   srcAttr     = ("src" , uriToString id (mkObjectURI baseURI (fromJust pageName)) "")
                   altAttr     = do alt <- lookup "alt" attrs
                                    return ("alt", alt)
                   classAttr   = case lookup "float" attrs of
                                   Nothing      -> ("class", "inlineImage")
                                   Just "left"  -> ("class", "inlineImage leftFloat")
                                   Just "right" -> ("class", "inlineImage rightFloat")
                                   Just others  -> error ("unknown \"float\" attribute: " ++ others)
                   anchorAttrs = [hrefAttr, classAttr]
                   imgAttrs    = catMaybes [Just srcAttr, altAttr]

               return (Anchor anchorAttrs [Image imgAttrs])
      }


-- <div class="imageFrame ...">
--   <div class="imageData">
--     <p>
--       <a href="...">
--         <img src="..." />
--       </a>
--     </p>
--   </div>
--   <div class="imageCaption">
--     ...
--   </div>
-- </div>
imgFrameInterp :: Interpreter
imgFrameInterp
    = BlockCommandInterpreter {
        bciName      = "imgframe"
      , bciInterpret
          = \ ctx (BlockCommand _ attrs inside) ->
            do BaseURI baseURI <- getSysConf (ctxSysConf ctx) (BaseURI undefined)

               let pageName = lookup "src" attrs
               when (pageName == Nothing)
                        $ fail "\"src\" attribute is missing"

               let hrefAttr    = ("href", uriToString id (mkPageURI   baseURI (fromJust pageName)) "")
                   srcAttr     = ("src" , uriToString id (mkObjectURI baseURI (fromJust pageName)) "")
                   classAttr   = case lookup "float" attrs of
                                   Nothing      -> ("class", "imageFrame")
                                   Just "left"  -> ("class", "imageFrame leftFloat")
                                   Just "right" -> ("class", "imageFrame rightFloat")
                                   Just others  -> error ("unknown \"float\" attribute: " ++ others)
               
               return (Div [classAttr]
                       [ Div [("class", "imageData")]
                         [ Paragraph [ Anchor [hrefAttr]
                                                  [ Image [srcAttr] ] ]
                         ]
                       , Div [("class", "imageCaption")] inside
                       ]
                      )
      }