--------------------------------------------------------------------------
--- This is the main module of the analysis server.
--- It provides operations to initialize the server system,
--- start the server on a socket, or use the analysis server
--- by other Curry applications.
---
--- @author Heiko Hoffmann, Michael Hanus
--- @version January 2017
--------------------------------------------------------------------------

module AnalysisServer(mainServer, initializeAnalysisSystem, analyzeModuleAsText,
                      analyzeModuleForBrowser, analyzeFunctionForBrowser,
                      analyzeGeneric, analyzePublic, analyzeInterface)
  where

import ReadNumeric   (readNat)
import Char          (isSpace)
import Directory
import FileGoodies   (splitDirectoryBaseName)
import FlatCurry.Types(QName)
import IO
import ReadShowTerm (readQTerm, showQTerm)
import Socket (Socket(..),listenOn,listenOnFresh,sClose,waitForSocketAccept)
import System       (system, sleep, setEnviron, getArgs)

import Analysis(Analysis,AOutFormat(..))
import Configuration
import GenericProgInfo
import Registry
import ServerFormats
import ServerFunctions(WorkerMessage(..))

-- Messages to communicate with the analysis server from external programs.
data AnalysisServerMessage = 
    GetAnalysis
  | AnalyzeModule    String String String Bool
  | AnalyzeEntity  String String String String
  | StopServer
  | SetCurryPath String
  | ParseError

--- Initializations to be done when the system is started.
initializeAnalysisSystem :: IO ()
initializeAnalysisSystem = updateRCFile

--- Start the analysis server on a socket.
mainServer :: Maybe Int -> IO ()
mainServer mbport = do
  putStrLn "Start Server"
  (port1,socket1) <- maybe listenOnFresh
                           (\p -> listenOn p >>= \s -> return (p,s))
                           mbport
  putStrLn ("Server Port: "++show port1)
  storeServerPortNumber port1
  getDefaultPath >>= setEnviron "CURRYPATH" 
  numworkers <- numberOfWorkers
  if numworkers>0
   then do
    serveraddress <- getServerAddress
    (workerport,workersocket) <- listenOnFresh
    debugMessage 2 ("SERVER: port to workers: "++show workerport)
    handles <- startWorkers numworkers workersocket serveraddress workerport []
    serverLoop socket1 handles
    sClose workersocket
   else
    serverLoop socket1 []


--- Run the analysis system and show the analysis results in standard textual
--- representation.
--- If the third argument is true, all operations are shown,
--- otherwise only the interface operations.
--- The fourth argument is a flag indicating whether the
--- (re-)analysis should be enforced.
--- Note that, before its first use, the analysis system must be initialized
--- by 'initializeAnalysisSystem'.
analyzeModuleAsText :: String -> String -> Bool -> Bool -> IO String
analyzeModuleAsText ananame mname optall enforce =
  analyzeModule ananame mname enforce AText >>=
             return . formatResult mname "Text" Nothing (not optall)

--- Run the analysis system to show the analysis results in the BrowserGUI.
--- Note that, before its first use, the analysis system must be initialized
--- by 'initializeAnalysisSystem'.
analyzeModuleForBrowser :: String -> String -> AOutFormat -> IO [(QName,String)]
analyzeModuleForBrowser ananame moduleName aoutformat =
  analyzeModule ananame moduleName False aoutformat >>=
    return . either pinfo2list (const [])
 where
   pinfo2list pinfo = let (pubinfo,privinfo) = progInfo2Lists pinfo
                       in pubinfo++privinfo

--- Run the analysis system to show the analysis result of a single function
--- in the BrowserGUI.
--- Note that before its first use, the analysis system must be initialized
--- by 'initializeAnalysisSystem'.
analyzeFunctionForBrowser :: String -> QName -> AOutFormat -> IO String
analyzeFunctionForBrowser ananame qn@(mname,_) aoutformat = do
  analyzeModule ananame mname False aoutformat >>=
    return . either (maybe "" id . lookupProgInfo qn) (const "")

--- Analyze a complete module for a given analysis result format.
--- The third argument is a flag indicating whether the
--- (re-)analysis should be enforced.
--- Note that before its first use, the analysis system must be initialized
--- by 'initializeAnalysisSystem'.
analyzeModule :: String -> String -> Bool -> AOutFormat
              -> IO (Either (ProgInfo String) String)
analyzeModule ananame moduleName enforce aoutformat = do
  let (mdir,mname) = splitDirectoryBaseName moduleName
  getDefaultPath >>= setEnviron "CURRYPATH"
  curdir <- getCurrentDirectory
  unless (mdir==".") $ setCurrentDirectory mdir
  numworkers <- numberOfWorkers
  aresult <-
   if numworkers>0
     then do
      serveraddress <- getServerAddress
      (port,socket) <- listenOnFresh
      handles <- startWorkers numworkers socket serveraddress port []
      result <- runAnalysisWithWorkers ananame aoutformat enforce handles mname
      stopWorkers handles
      sClose socket
      return result
     else runAnalysisWithWorkers ananame aoutformat enforce [] mname
  setCurrentDirectory curdir
  return aresult

--- Start the analysis system with a particular analysis.
--- The analysis must be a registered one if workers are used.
--- If it is a combined analysis, the base analysis must be also
--- a registered one.
analyzeGeneric :: Analysis a -> String -> IO (Either (ProgInfo a) String)
analyzeGeneric analysis moduleName = do
  initializeAnalysisSystem
  let (mdir,mname) = splitDirectoryBaseName moduleName
  getDefaultPath >>= setEnviron "CURRYPATH" 
  curdir <- getCurrentDirectory
  unless (mdir==".") $ setCurrentDirectory mdir
  numworkers <- numberOfWorkers
  aresult <-
    if numworkers>0
     then do
      serveraddress <- getServerAddress
      (port,socket) <- listenOnFresh
      handles <- startWorkers numworkers socket serveraddress port []
      result <- analyzeMain analysis mname handles False True
      stopWorkers handles
      sClose socket
      return result
     else
      analyzeMain analysis mname [] False True
  setCurrentDirectory curdir
  return aresult
 
--- Start the analysis system with a given analysis to compute properties
--- of a module interface.
--- The analysis must be a registered one if workers are used.
--- If it is a combined analysis, the base analysis must be also
--- a registered one.
analyzePublic :: Analysis a -> String -> IO (Either (ProgInfo a) String)
analyzePublic analysis moduleName =
  analyzeGeneric analysis moduleName
  >>= return . either (Left . publicProgInfo) Right

--- Start the analysis system with a given analysis to compute properties
--- of a module interface.
--- The analysis must be a registered one if workers are used.
--- If it is a combined analysis, the base analysis must be also
--- a registered one.
analyzeInterface :: Analysis a -> String -> IO (Either [(QName,a)] String)
analyzeInterface analysis moduleName =
  analyzeGeneric analysis moduleName
  >>= return . either (Left . publicListFromProgInfo) Right

--------------------------------------------------------------------------
-- start a number of workers at server start
startWorkers:: Int -> Socket -> String -> Int -> [Handle] -> IO [Handle]
startWorkers number workersocket serveraddress workerport handles = do
  if number>0
    then do
      debugMessage 4 ("Number:"++(show number))
      let command = baseDir++"/cass_worker "++serveraddress++" "
                                            ++(show workerport)++" &"
      debugMessage 4 ("system command: "++command)
      system command
      debugMessage 4 ("Wait for socket accept for client "++show number)
      connection <- waitForSocketAccept workersocket waitTime
      debugMessage 4 ("Socket accept for client "++show number)
      case connection of
        Just (_,handle) -> do
          startWorkers (number-1) workersocket serveraddress workerport
                       (handle:handles)
        Nothing -> do
          putStrLn ("startWorkers: connection error worker "++(show number))
          startWorkers (number-1) workersocket serveraddress workerport handles
    else return handles

-- stop all workers at server stop
stopWorkers :: [Handle] -> IO ()
stopWorkers [] = done
stopWorkers (handle:whandles) = do
  hPutStrLn handle (showQTerm StopWorker)
  hClose handle
  stopWorkers whandles

--------------------------------------------------------------------------
-- server loop to answer analysis requests over network
serverLoop :: Socket -> [Handle] -> IO ()
serverLoop socket1 whandles = do
  --debugMessage 3 "SERVER: serverLoop"
  connection <- waitForSocketAccept socket1 waitTime
  case connection of 
    Just (_,handle) -> serverLoopOnHandle socket1 whandles handle
    Nothing -> do
      putStrLn "serverLoop: connection error: time out in waitForSocketAccept"
      sleep 1
      serverLoop socket1 whandles

--- Reads a line from an input handle and returns it.
hGetLineUntilEOF  :: Handle -> IO String
hGetLineUntilEOF h = do
  eof <- hIsEOF h
  if eof
   then return ""
   else do c <- hGetChar h
           if c=='\n' then return ""
                      else do cs <- hGetLineUntilEOF h
                              return (c:cs)

serverLoopOnHandle :: Socket -> [Handle] -> Handle -> IO ()
serverLoopOnHandle socket1 whandles handle = do
  eof <- hIsEOF handle
  if eof
   then do hClose handle
           debugMessage 2 "SERVER connection: eof"
           serverLoop socket1 whandles
   else do
     string <- hGetLineUntilEOF handle
     debugMessage 2 ("SERVER got message: "++string)
     let force = False
     case parseServerMessage string of
       ParseError -> do
         sendServerError handle ("Illegal message received: "++string)
         serverLoopOnHandle socket1 whandles handle
       GetAnalysis -> do
         sendServerResult handle showAnalysisNamesAndFormats
         serverLoopOnHandle socket1 whandles handle
       AnalyzeModule ananame outForm modname public ->
         catch (runAnalysisWithWorkers ananame AText force whandles modname >>=
                return . formatResult modname outForm Nothing public >>=
                sendResult)
               sendAnalysisError
       AnalyzeEntity ananame outForm modname functionName ->
         catch (runAnalysisWithWorkers ananame AText force whandles modname >>=
                return . formatResult modname outForm
                                      (Just functionName) False >>= sendResult)
               sendAnalysisError
       SetCurryPath path -> do
         setEnviron "CURRYPATH" path
         changeWorkerPath path whandles
         sendServerResult handle ""
         serverLoopOnHandle socket1 whandles handle
       StopServer -> do
         stopWorkers whandles
         sendServerResult handle ""
         hClose handle
         sClose socket1
         putStrLn "Stop Server"
         removeServerPortNumber
 where
  sendResult resultstring = do
    debugMessage 4 ("formatted result:\n"++resultstring)
    sendServerResult handle resultstring
    serverLoopOnHandle socket1 whandles handle

  sendAnalysisError err = do
    sendServerError handle ("ERROR in analysis server: "++showError err)
    serverLoopOnHandle socket1 whandles handle

-- Send a server result in the format "ok <n>\n<result text>" where <n>
-- is the number of lines of the <result text>.
sendServerResult :: Handle -> String -> IO ()
sendServerResult handle resultstring = do
  let resultlines = lines resultstring
  hPutStrLn handle ("ok " ++ show (length resultlines))
  hPutStr handle (unlines resultlines)
  hFlush handle

-- Send a server error in the format "error <error message>\n".
sendServerError :: Handle -> String -> IO ()
sendServerError handle errstring = do
  debugMessage 1 errstring
  hPutStrLn handle ("error "++errstring)
  hFlush handle

-- Inform the worker threads about a given changed library search path
changeWorkerPath :: String -> [Handle] -> IO ()
changeWorkerPath _ [] = done
changeWorkerPath path (handle:whandles) = do
  hPutStrLn handle (showQTerm (ChangePath path))
  changeWorkerPath path whandles

-- parse incoming message for type of request
parseServerMessage :: String -> AnalysisServerMessage
parseServerMessage message = case words message of
  [] -> ParseError
  w:ws -> case w of 
    "GetAnalysis" -> GetAnalysis
    "AnalyzeModule" -> case ws of 
      s1:s2:s3:[] -> checkFormat s2 $ AnalyzeModule s1 s2 s3 False
    "AnalyzeInterface" -> case ws of 
      s1:s2:s3:[] -> checkFormat s2 $ AnalyzeModule s1 s2 s3 True
      _ -> ParseError
    "AnalyzeFunction" -> case ws of
      s1:s2:s3:s4:[] -> checkFormat s2 $ AnalyzeEntity s1 s2 s3 s4
      _ -> ParseError
    "AnalyzeTypeConstructor" -> case ws of
      s1:s2:s3:s4:[] -> checkFormat s2 $ AnalyzeEntity s1 s2 s3 s4
      _ -> ParseError
    "AnalyzeDataConstructor" -> case ws of
      s1:s2:s3:s4:[] -> checkFormat s2 $ AnalyzeEntity s1 s2 s3 s4
      _ -> ParseError  
    "SetCurryPath" -> case ws of
      s:[] -> SetCurryPath s
      _ -> ParseError
    "StopServer" -> StopServer
    _ -> ParseError 
 where
  checkFormat fmt msg = if fmt `elem` serverFormats then msg else ParseError

--- Show all analysis names and formats.
showAnalysisNamesAndFormats :: String
showAnalysisNamesAndFormats =
  unlines (concatMap (\an -> map ((an++" ")++) serverFormats)
                     registeredAnalysisNames)