content: {- | Module      :  XMonad.Actions.Search
     Copyright   :  (C) 2007 Gwern Branwen
     License     :  None; public domain
  
     Maintainer  :  <gwern0@gmail.com>
     Stability   :  unstable
     Portability :  unportable; depends on XSelection, XPrompt
  
     A module for easily running Internet searches on web sites through xmonad.
     Modeled after the handy Surfraw CLI search tools at <https://secure.wikimedia.org/wikipedia/en/wiki/Surfraw>.
  
     Additional sites welcomed. -}
  module XMonad.Actions.Search (   -- * Usage
                                   -- $usage
                                   search,
                                   SearchEngine(..),
                                   searchEngine,
                                   searchEngineF,
                                   promptSearch,
                                   promptSearchBrowser,
                                   selectSearch,
                                   selectSearchBrowser,
                                   isPrefixOf,
                                   escape,
                                   use,
                                   intelligent,
                                   (!>),
                                   prefixAware,
                                   namedEngine,
  
                                   amazon,
                                   alpha,
                                   codesearch,
                                   deb,
                                   debbts,
                                   debpts,
                                   dictionary,
                                   google,
                                   hackage,
                                   hoogle,
                                   images,
                                   imdb,
                                   isohunt,
                                   lucky,
                                   maps,
                                   mathworld,
                                   openstreetmap,
                                   scholar,
                                   thesaurus,
                                   wayback,
                                   wikipedia,
                                   wiktionary,
                                   youtube,
                                   duckduckgo,
                                   multi,
                                    -- * Use case: searching with a submap
                                    -- $tip
  
                                    -- * Types
                                   Browser, Site, Query, Name, Search
                            ) where
  
  import Codec.Binary.UTF8.String (encode)
  import Data.Char (isAlphaNum, isAscii)
  import Data.List (isPrefixOf)
  import Text.Printf
  import XMonad (X(), liftIO)
  import XMonad.Prompt (XPrompt(showXPrompt, nextCompletion, commandToComplete), mkXPrompt, XPConfig(), historyCompletionP, getNextCompletion)
  import XMonad.Prompt.Shell (getBrowser)
  import XMonad.Util.Run (safeSpawn)
  import XMonad.Util.XSelection (getSelection)
  
  
  {- $usage
  
     This module is intended to allow easy access to databases on the
     Internet through xmonad's interface. The idea is that one wants to
     run a search but the query string and the browser to use must come
     from somewhere. There are two places the query string can come from
     - the user can type it into a prompt which pops up, or the query
     could be available already in the X Windows copy\/paste buffer
     (perhaps you just highlighted the string of interest).
  
     Thus, there are two main functions: 'promptSearch', and
     'selectSearch' (implemented using the more primitive 'search'). To
     each of these is passed an engine function; this is a function that
     knows how to search a particular site.
  
     For example, the 'google' function knows how to search Google, and
     so on. You pass 'promptSearch' and 'selectSearch' the engine you
     want, the browser you want, and anything special they might need;
     this whole line is then bound to a key of you choosing in your
     xmonad.hs. For specific examples, see each function.  This module
     is easily extended to new sites by using 'searchEngine'.
  
     The currently available search engines are:
  
  * 'amazon' -- Amazon keyword search.
  
  * 'alpha' -- Wolfram|Alpha query.
  
  * 'codesearch' -- Google Labs Code Search search.
  
  * 'deb'    -- Debian package search.
  
  * 'debbts' -- Debian Bug Tracking System.
  
  * 'debpts'  -- Debian Package Tracking System.
  
  * 'dictionary' -- dictionary.reference.com search.
  
  * 'google' -- basic Google search.
  
  * 'hackage' -- Hackage, the Haskell package database.
  
  * 'hoogle' -- Hoogle, the Haskell libraries API search engine.
  
  * 'images' -- Google images.
  
  * 'imdb'   -- the Internet Movie Database.
  
  * 'isohunt' -- isoHunt search.
  
  * 'lucky' -- Google "I'm feeling lucky" search.
  
  * 'maps'   -- Google maps.
  
  * 'mathworld' -- Wolfram MathWorld search.
  
  * 'openstreetmap' -- OpenStreetMap free wiki world map.
  
  * 'scholar' -- Google scholar academic search.
  
  * 'thesaurus' -- thesaurus.reference.com search.
  
  * 'wayback' -- the Wayback Machine.
  
  * 'wikipedia' -- basic Wikipedia search.
  
  * 'youtube' -- Youtube video search.
  
  * 'duckduckgo' -- DuckDuckGo search engine.
  
  * 'multi' -- Search based on the prefix. \"amazon:Potter\" will use amazon, etc. With no prefix searches google.
  
  Feel free to add more! -}
  
  {- $tip
  
  In combination with "XMonad.Actions.Submap" you can create a powerful
  and easy way to search without adding a whole bunch of bindings.
  
  First import the necessary modules:
  
  > import qualified XMonad.Prompt         as P
  > import qualified XMonad.Actions.Submap as SM
  > import qualified XMonad.Actions.Search as S
  
  Then add the following to your key bindings:
  
  > ...
  > -- Search commands
  > , ((modm, xK_s), SM.submap $ searchEngineMap $ S.promptSearch P.def)
  > , ((modm .|. shiftMask, xK_s), SM.submap $ searchEngineMap $ S.selectSearch)
  >
  > ...
  >
  > searchEngineMap method = M.fromList $
  >       [ ((0, xK_g), method S.google)
  >       , ((0, xK_h), method S.hoogle)
  >       , ((0, xK_w), method S.wikipedia)
  >       ]
  
  Or in combination with XMonad.Util.EZConfig:
  
  > ...
  > ] -- end of regular keybindings
  > -- Search commands
  > ++ [("M-s " ++ k, S.promptSearch P.def f) | (k,f) <- searchList ]
  > ++ [("M-S-s " ++ k, S.selectSearch f) | (k,f) <- searchList ]
  >
  > ...
  >
  > searchList :: [(String, S.SearchEngine)]
  > searchList = [ ("g", S.google)
  >              , ("h", S.hoohle)
  >              , ("w", S.wikipedia)
  >              ]
  
  Make sure to set firefox to open new pages in a new window instead of
  in a new tab: @Firefox -> Edit -> Preferences -> Tabs -> New pages
  should be opened in...@
  
  Now /mod-s/ + /g/\//h/\//w/ prompts you for a search string, then
  opens a new firefox window that performs the search on Google, Hoogle
  or Wikipedia respectively.
  
  If you select something in whatever application and hit /mod-shift-s/ +
  /g/\//h/\//w/ it will search the selected string with the specified
  engine.
  
  Happy searching! -}
  
  -- | A customized prompt indicating we are searching, and the name of the site.
  data Search = Search Name
  instance XPrompt Search where
      showXPrompt (Search name)= "Search [" ++ name ++ "]: "
      nextCompletion _ = getNextCompletion
      commandToComplete _ c = c
  
  -- | Escape the search string so search engines understand it. Only
  -- digits and ASCII letters are not encoded. All non ASCII characters
  -- which are encoded as UTF8
  escape :: String -> String
  escape = concatMap escapeURIChar
  
  escapeURIChar :: Char -> String
  escapeURIChar c | isAscii c && isAlphaNum c = [c]
                  | otherwise                 = concatMap (printf "%%%02X") $ encode [c]
  
  type Browser      = FilePath
  type Query        = String
  type Site         = String -> String
  type Name         = String
  data SearchEngine = SearchEngine Name Site
  
  -- | Given an already defined search engine, extracts its transformation
  --   function, making it easy to create compound search engines.
  --   For an instance you can use @use google@ to get a function which
  --   makes the same transformation as the google search engine would.
  use :: SearchEngine -> Site
  use (SearchEngine _ engine) = engine
  
  -- | Given a browser, a search engine's transformation function, and a search term, perform the
  --   requested search in the browser.
  search :: Browser -> Site -> Query -> X ()
  search browser site query = safeSpawn browser [site query]
  
  {- | Given a base URL, create the 'SearchEngine' that escapes the query and
     appends it to the base. You can easily define a new engine locally using
     exported functions without needing to modify "XMonad.Actions.Search":
  
  > myNewEngine = searchEngine "site" "http://site.com/search="
  
     The important thing is that the site has a interface which accepts the escaped query
     string as part of the URL. Alas, the exact URL to feed searchEngine varies
     from site to site, often considerably, so there\'s no general way to cover this.
  
     Generally, examining the resultant URL of a search will allow you to reverse-engineer
     it if you can't find the necessary URL already described in other projects such as Surfraw. -}
  searchEngine :: Name -> String -> SearchEngine
  searchEngine name site = searchEngineF name (\s -> site ++ (escape s))
  
  {- | If your search engine is more complex than this (you may want to identify
     the kind of input and make the search URL dependent on the input or put the query
     inside of a URL instead of in the end) you can use the alternative 'searchEngineF' function.
  
  > searchFunc :: String -> String
  > searchFunc s | "wiki:"   `isPrefixOf` s = "http://en.wikipedia.org/wiki/" ++ (escape $ tail $ snd $ break (==':') s)
  >              | "http://" `isPrefixOf` s = s
  >              | otherwise               = (use google) s
  > myNewEngine = searchEngineF "mymulti" searchFunc
  
     @searchFunc@ here searches for a word in wikipedia if it has a prefix
     of \"wiki:\" (you can use the 'escape' function to escape any forbidden characters), opens an address
     directly if it starts with \"http:\/\/\" and otherwise uses the provided google search engine.
     You can use other engines inside of your own through the 'use' function as shown above to make
     complex searches.
  
     The user input will be automatically escaped in search engines created with 'searchEngine',
     'searchEngineF', however, completely depends on the transformation function passed to it. -}
  searchEngineF :: Name -> Site -> SearchEngine
  searchEngineF = SearchEngine
  
  -- The engines.
  amazon, alpha, codesearch, deb, debbts, debpts, dictionary, google, hackage, hoogle,
    images, imdb, isohunt, lucky, maps, mathworld, openstreetmap, scholar, thesaurus, wayback, wikipedia, wiktionary,
    youtube, duckduckgo :: SearchEngine
  amazon        = searchEngine "amazon"        "http://www.amazon.com/exec/obidos/external-search?index=all&keyword="
  alpha         = searchEngine "alpha"         "http://www.wolframalpha.com/input/?i="
  codesearch    = searchEngine "codesearch"    "http://www.google.com/codesearch?q="
  deb           = searchEngine "deb"           "http://packages.debian.org/"
  debbts        = searchEngine "debbts"        "http://bugs.debian.org/"
  debpts        = searchEngine "debpts"        "http://packages.qa.debian.org/"
  dictionary    = searchEngine "dict"          "http://dictionary.reference.com/browse/"
  google        = searchEngine "google"        "http://www.google.com/search?num=100&q="
  hackage       = searchEngine "hackage"       "http://hackage.haskell.org/package/"
  hoogle        = searchEngine "hoogle"        "http://www.haskell.org/hoogle/?q="
  images        = searchEngine "images"        "http://images.google.fr/images?q="
  imdb          = searchEngine "imdb"          "http://www.imdb.com/find?s=all&q="
  isohunt       = searchEngine "isohunt"       "http://isohunt.com/torrents/?ihq="
  lucky         = searchEngine "lucky"         "http://www.google.com/search?btnI&q="
  maps          = searchEngine "maps"          "http://maps.google.com/maps?q="
  mathworld     = searchEngine "mathworld"     "http://mathworld.wolfram.com/search/?query="
  openstreetmap = searchEngine "openstreetmap" "http://gazetteer.openstreetmap.org/namefinder/?find="
  scholar       = searchEngine "scholar"       "http://scholar.google.com/scholar?q="
  thesaurus     = searchEngine "thesaurus"     "http://thesaurus.reference.com/search?q="
  wikipedia     = searchEngine "wiki"          "http://en.wikipedia.org/wiki/Special:Search?go=Go&search="
  wiktionary    = searchEngine "wikt"          "http://en.wiktionary.org/wiki/Special:Search?go=Go&search="
  youtube       = searchEngine "youtube"       "http://www.youtube.com/results?search_type=search_videos&search_query="
  wayback       = searchEngineF "wayback"      ("http://web.archive.org/web/*/"++)
  duckduckgo    = searchEngine "duckduckgo"    "https://duckduckgo.com/?t=lm&q="
  
  multi :: SearchEngine
  multi = namedEngine "multi" $ foldr1 (!>) [amazon, alpha, codesearch, deb, debbts, debpts, dictionary, google, hackage, hoogle, images, imdb, isohunt, lucky, maps, mathworld, openstreetmap, scholar, thesaurus, wayback, wikipedia, wiktionary, duckduckgo, (prefixAware google)]
  
  {- | This function wraps up a search engine and creates a new one, which works
     like the argument, but goes directly to a URL if one is given rather than
     searching.
  
  > myIntelligentGoogleEngine = intelligent google
  
     Now if you search for http:\/\/xmonad.org it will directly open in your browser-}
  intelligent :: SearchEngine -> SearchEngine
  intelligent (SearchEngine name site) = searchEngineF name (\s -> if (fst $ break (==':') s) `elem` ["http", "https", "ftp"] then s else (site s))
  
  -- | > removeColonPrefix "foo://bar" ~> "//bar"
  -- > removeColonPrefix "foo//bar" ~> "foo//bar"
  removeColonPrefix :: String -> String
  removeColonPrefix s = if ':' `elem` s then drop 1 $ dropWhile (':' /=) s else s
  
  {- | Connects a few search engines into one. If the search engines\' names are
     \"s1\", \"s2\" and \"s3\", then the resulting engine will use s1 if the query
     is @s1:word@, s2 if you type @s2:word@ and s3 in all other cases.
  
     Example:
  
  > multiEngine = intelligent (wikipedia !> mathworld !> (prefixAware google))
  
    Now if you type \"wiki:Haskell\" it will search for \"Haskell\" in Wikipedia,
    \"mathworld:integral\" will search mathworld, and everything else will fall back to
    google. The use of intelligent will make sure that URLs are opened directly. -}
  (!>) :: SearchEngine -> SearchEngine -> SearchEngine
  (SearchEngine name1 site1) !> (SearchEngine name2 site2) = searchEngineF (name1 ++ "/" ++ name2) (\s -> if (name1++":") `isPrefixOf` s then site1 (removeColonPrefix s) else site2 s)
  
  {- | Makes a search engine prefix-aware. Especially useful together with '!>'.
     It will automatically remove the prefix from a query so that you don\'t end
       up searching for google:xmonad if google is your fallback engine and you
       explicitly add the prefix. -}
  prefixAware :: SearchEngine -> SearchEngine
  prefixAware (SearchEngine name site) = SearchEngine name (\s -> if (name++":") `isPrefixOf` s then site $ removeColonPrefix s else site s)
  
  {- | Changes search engine's name -}
  namedEngine :: Name -> SearchEngine -> SearchEngine
  namedEngine name (SearchEngine _ site) = searchEngineF name site
  
  {- | Like 'search', but for use with the output from a Prompt; it grabs the
     Prompt's result, passes it to a given searchEngine and opens it in a given
     browser. -}
  promptSearchBrowser :: XPConfig -> Browser -> SearchEngine -> X ()
  promptSearchBrowser config browser (SearchEngine name site) =
      mkXPrompt (Search name) config (historyCompletionP ("Search [" `isPrefixOf`)) $ search browser site
  
  {- | Like 'search', but in this case, the string is not specified but grabbed
   from the user's response to a prompt. Example:
  
  > , ((modm, xK_g), promptSearch greenXPConfig google)
  
     This specializes "promptSearchBrowser" by supplying the browser argument as
     supplied by 'getBrowser' from "XMonad.Prompt.Shell". -}
  promptSearch :: XPConfig -> SearchEngine -> X ()
  promptSearch config engine = liftIO getBrowser >>= \ browser -> promptSearchBrowser config browser engine
  
  -- | Like 'search', but for use with the X selection; it grabs the selection,
  --   passes it to a given searchEngine and opens it in a given browser.
  selectSearchBrowser :: Browser -> SearchEngine -> X ()
  selectSearchBrowser browser (SearchEngine _ site) = search browser site =<< getSelection
  
  {- | Like 'search', but for use with the X selection; it grabs the selection,
     passes it to a given searchEngine and opens it in the default browser . Example:
  
  > , ((modm .|. shiftMask, xK_g), selectSearch google)
  
     This specializes "selectSearchBrowser" by supplying the browser argument as
     supplied by 'getBrowser' from "XMonad.Prompt.Shell". -}
  selectSearch :: SearchEngine -> X ()
  selectSearch engine = liftIO getBrowser >>= \browser -> selectSearchBrowser browser engine
  