{-# OPTIONS #-}

-- ------------------------------------------------------------

module Hayoo.URIConfig
    ( hayooStart
    , hayooRefs
    , hayooGetPackage
    , hayooPackageNames

    , hackagePackages
    , hackageStart
    , isHaddockURI

    , editLatestPackage

    , packageVersion
    , packageVersion'
    , packageVersion''

    , fileName
    )
where

-- import           Control.Applicative

import           Data.List

import           Holumbus.Crawler

import           Text.XML.HXT.Core

-- ------------------------------------------------------------

hayooStart                      :: [URI]
hayooStart                      = hackageStart

hayooRefs                       :: Bool -> [String] -> URI -> Bool
hayooRefs                       = hackageRefs

hayooGetPackage                 :: String -> String
hayooGetPackage                 = hackageGetPackage

hackageHome                     :: String
hackageHome                     = "http://hackage.haskell.org/packages/"

hackagePackages                 :: String
hackagePackages                 = "http://hackage.haskell.org/package/"         -- no "s" at the end !!!

hackageStartPage                :: URI
hackageStartPage                =  hackageHome ++ "archive/pkg-list.html"

hackageStart                    :: [URI]
hackageStart                    =  [ hackageStartPage ]

hackageRefs                     :: Bool -> [String] -> URI -> Bool
hackageRefs withDoc pkgs        = simpleFollowRef'
                                  ( (hackagePackages ++ packageName')
                                    : ( if withDoc
                                        then [ packageDocPath  ++ modulePath ++ ext "html" ]
                                        else []
                                      )
                                  )
                                  [ packageDocPath ++ alternatives
                                                       [ "doc-index.*" ++ ext "html"            -- no index files
                                                       , "src/.*"                               -- no hscolored sources
                                                       ]
                                  , hackagePackages ++ packageName' ++ packageVersion''         -- no package pages with (old) version numbers
                                  ]
    where
    packageDocPath              = hackagePackageDocPath ++ packageName' ++ "/" ++ packageVersion' ++ "/doc/html/"

    packageName'
        | null pkgs             = fileName
        | otherwise             = alternatives pkgs

hackagePackageDocPath           :: String
hackagePackageDocPath           = hackageHome ++ "archive/"

hackageGetPackage               :: String -> String
hackageGetPackage u
    | hackagePackageDocPath `isPrefixOf` u
                                = takeWhile (/= '/') . drop (length hackagePackageDocPath) $ u
    | otherwise                 = ""

getHackagePackage               :: String -> String
getHackagePackage s
    | match (hackagePackages ++ packageName) s
                                = drop (length hackagePackages) s
    | otherwise                 = ""

isHaddockURI                    :: URI -> Bool
isHaddockURI                    = match (hackagePackageDocPath ++ fileName ++ "/.+/doc/html/.+[.]html")

-- ------------------------------------------------------------

-- common R.E.s

alternatives                    :: [String] -> String
alternatives                    = ("(" ++) . (++ ")") . intercalate "|"

moduleName                      :: String
moduleName                      = "[A-Z][A-Za-z0-9_]*"

modulePath                      :: String
modulePath                      = moduleName ++ "(-" ++ moduleName ++ ")*"

fileName                        :: String
fileName                        = "[^/?]+"

ext                             :: String -> String
ext                             = ("[.]" ++)

packageName                     :: String
packageName                     = "[A-Za-z]([A-Za-z0-9_]|-)*"

packageVersion
  , packageVersion'
  , packageVersion''            :: String

packageVersion                  = "[0-9]+([.][0-9]+)*"          -- there are package versions without sub version no
packageVersion''                = "-" ++ packageVersion
packageVersion'                 = alternatives [packageVersion, "latest"]

-- ------------------------------------------------------------

-- In the package doc URIs the package version number "/*.*.*/" is substituted by the alias "/latest/"

editLatestPackage               :: String -> String
editLatestPackage               = sed (const "/latest/") "/[0-9.]+/"

-- ------------------------------------------------------------

hayooPackageNames               :: SysConfigList -> IOSArrow b String
hayooPackageNames crawlPars     = ( ( readDocument crawlPars hackageStartPage
                                      >>>
                                      getHtmlReferences
                                      >>>
                                      arr getHackagePackage
                                      >>>
                                      isA (not . null)
                                    )
                                  )
                                  >>. (sort >>> nub)

-- ------------------------------------------------------------