#
#
#           The Nim Compiler
#        (c) Copyright 2017 Andreas Rumpf
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.
#

## Nimsuggest is a tool that helps to give editors IDE like capabilities.

when not defined(nimcore):
  {.error: "nimcore MUST be defined for Nim's core tooling".}

import strutils, os, parseopt, parseutils, sequtils, net, rdstdin, sexp
# Do NOT import suggest. It will lead to wierd bugs with
# suggestionResultHook, because suggest.nim is included by sigmatch.
# So we import that one instead.
import compiler / [options, commands, modules, sem,
  passes, passaux, msgs, nimconf,
  extccomp, condsyms,
  sigmatch, ast, scriptconfig,
  idents, modulegraphs, vm, prefixmatches, lineinfos, cmdlinehelper,
  pathutils]

when defined(windows):
  import winlean
else:
  import posix

const DummyEof = "!EOF!"
const Usage = """
Nimsuggest - Tool to give every editor IDE like capabilities for Nim
Usage:
  nimsuggest [options] projectfile.nim

Options:
  --port:PORT             port, by default 6000
  --address:HOST          binds to that address, by default ""
  --stdin                 read commands from stdin and write results to
                          stdout instead of using sockets
  --epc                   use emacs epc mode
  --debug                 enable debug output
  --log                   enable verbose logging to nimsuggest.log file
  --v1                    use version 1 of the protocol; for backwards compatibility
  --refresh               perform automatic refreshes to keep the analysis precise
  --maxresults:N          limit the number of suggestions to N
  --tester                implies --stdin and outputs a line
                          '""" & DummyEof & """' for the tester

The server then listens to the connection and takes line-based commands.

In addition, all command line options of Nim that do not affect code generation
are supported.
"""
type
  Mode = enum mstdin, mtcp, mepc, mcmdsug, mcmdcon
  CachedMsg = object
    info: TLineInfo
    msg: string
    sev: Severity
  CachedMsgs = seq[CachedMsg]

var
  gPort = 6000.Port
  gAddress = ""
  gMode: Mode
  gEmitEof: bool # whether we write '!EOF!' dummy lines
  gLogging = defined(logging)
  gRefresh: bool

  requests: Channel[string]
  results: Channel[Suggest]

proc writelnToChannel(line: string) =
  results.send(Suggest(section: ideMsg, doc: line))

proc sugResultHook(s: Suggest) =
  results.send(s)

proc errorHook(conf: ConfigRef; info: TLineInfo; msg: string; sev: Severity) =
  results.send(Suggest(section: ideChk, filePath: toFullPath(conf, info),
    line: toLinenumber(info), column: toColumn(info), doc: msg,
    forth: $sev))

proc myLog(s: string) =
  if gLogging: log(s)

const
  seps = {':', ';', ' ', '\t'}
  Help = "usage: sug|con|def|use|dus|chk|mod|highlight|outline|known file.nim[;dirtyfile.nim]:line:col\n" &
         "type 'quit' to quit\n" &
         "type 'debug' to toggle debug mode on/off\n" &
         "type 'terse' to toggle terse mode on/off"

type
  EUnexpectedCommand = object of Exception

proc parseQuoted(cmd: string; outp: var string; start: int): int =
  var i = start
  i += skipWhitespace(cmd, i)
  if cmd[i] == '"':
    i += parseUntil(cmd, outp, '"', i+1)+2
  else:
    i += parseUntil(cmd, outp, seps, i)
  result = i

proc sexp(s: IdeCmd|TSymKind|PrefixMatch): SexpNode = sexp($s)

proc sexp(s: Suggest): SexpNode =
  # If you change the order here, make sure to change it over in
  # nim-mode.el too.
  let qp = if s.qualifiedPath.len == 0: @[] else: s.qualifiedPath
  result = convertSexp([
    s.section,
    TSymKind s.symkind,
    qp.map(newSString),
    s.filePath,
    s.forth,
    s.line,
    s.column,
    s.doc,
    s.quality
  ])
  if s.section == ideSug:
    result.add convertSexp(s.prefix)

proc sexp(s: seq[Suggest]): SexpNode =
  result = newSList()
  for sug in s:
    result.add(sexp(sug))

proc listEpc(): SexpNode =
  # This function is called from Emacs to show available options.
  let
    argspecs = sexp("file line column dirtyfile".split(" ").map(newSSymbol))
    docstring = sexp("line starts at 1, column at 0, dirtyfile is optional")
  result = newSList()
  for command in ["sug", "con", "def", "use", "dus", "chk", "mod"]:
    let
      cmd = sexp(command)
      methodDesc = newSList()
    methodDesc.add(cmd)
    methodDesc.add(argspecs)
    methodDesc.add(docstring)
    result.add(methodDesc)

proc findNode(n: PNode; trackPos: TLineInfo): PSym =
  #echo "checking node ", n.info
  if n.kind == nkSym:
    if isTracked(n.info, trackPos, n.sym.name.s.len): return n.sym
  else:
    for i in 0 ..< safeLen(n):
      let res = findNode(n[i], trackPos)
      if res != nil: return res

proc symFromInfo(graph: ModuleGraph; trackPos: TLineInfo): PSym =
  let m = graph.getModule(trackPos.fileIndex)
  if m != nil and m.ast != nil:
    result = findNode(m.ast, trackPos)

proc execute(cmd: IdeCmd, file, dirtyfile: AbsoluteFile, line, col: int;
             graph: ModuleGraph) =
  let conf = graph.config
  myLog("cmd: " & $cmd & ", file: " & file.string &
        ", dirtyFile: " & dirtyfile.string &
        "[" & $line & ":" & $col & "]")
  conf.ideCmd = cmd
  if cmd == ideChk:
    conf.structuredErrorHook = errorHook
    conf.writelnHook = myLog
  else:
    conf.structuredErrorHook = nil
    conf.writelnHook = myLog
  if cmd == ideUse and conf.suggestVersion != 0:
    graph.resetAllModules()
  var isKnownFile = true
  let dirtyIdx = fileInfoIdx(conf, file, isKnownFile)

  if not dirtyfile.isEmpty: msgs.setDirtyFile(conf, dirtyIdx, dirtyfile)
  else: msgs.setDirtyFile(conf, dirtyIdx, AbsoluteFile"")

  conf.m.trackPos = newLineInfo(dirtyIdx, line, col)
  conf.m.trackPosAttached = false
  conf.errorCounter = 0
  if conf.suggestVersion == 1:
    graph.usageSym = nil
  if not isKnownFile:
    graph.compileProject()
  if conf.suggestVersion == 0 and conf.ideCmd in {ideUse, ideDus} and
      dirtyfile.isEmpty:
    discard "no need to recompile anything"
  else:
    let modIdx = graph.parentModule(dirtyIdx)
    graph.markDirty dirtyIdx
    graph.markClientsDirty dirtyIdx
    if conf.ideCmd != ideMod:
      graph.compileProject(modIdx)
  if conf.ideCmd in {ideUse, ideDus}:
    let u = if conf.suggestVersion != 1: graph.symFromInfo(conf.m.trackPos) else: graph.usageSym
    if u != nil:
      listUsages(conf, u)
    else:
      localError(conf, conf.m.trackPos, "found no symbol at this position " & (conf $ conf.m.trackPos))

proc executeEpc(cmd: IdeCmd, args: SexpNode;
                graph: ModuleGraph) =
  let
    file = AbsoluteFile args[0].getStr
    line = args[1].getNum
    column = args[2].getNum
  var dirtyfile = AbsoluteFile""
  if len(args) > 3:
    dirtyfile = AbsoluteFile args[3].getStr("")
  execute(cmd, file, dirtyfile, int(line), int(column), graph)

proc returnEpc(socket: Socket, uid: BiggestInt, s: SexpNode|string,
               return_symbol = "return") =
  let response = $convertSexp([newSSymbol(return_symbol), uid, s])
  socket.send(toHex(len(response), 6))
  socket.send(response)

template checkSanity(client, sizeHex, size, messageBuffer: typed) =
  if client.recv(sizeHex, 6) != 6:
    raise newException(ValueError, "didn't get all the hexbytes")
  if parseHex(sizeHex, size) == 0:
    raise newException(ValueError, "invalid size hex: " & $sizeHex)
  if client.recv(messageBuffer, size) != size:
    raise newException(ValueError, "didn't get all the bytes")

proc toStdout() {.gcsafe.} =
  while true:
    let res = results.recv()
    case res.section
    of ideNone: break
    of ideMsg: echo res.doc
    of ideKnown: echo res.quality == 1
    else: echo res

proc toSocket(stdoutSocket: Socket) {.gcsafe.} =
  while true:
    let res = results.recv()
    case res.section
    of ideNone: break
    of ideMsg: stdoutSocket.send(res.doc & "\c\L")
    of ideKnown: stdoutSocket.send($(res.quality == 1) & "\c\L")
    else: stdoutSocket.send($res & "\c\L")

proc toEpc(client: Socket; uid: BiggestInt) {.gcsafe.} =
  var list = newSList()
  while true:
    let res = results.recv()
    case res.section
    of ideNone: break
    of ideMsg:
      list.add sexp(res.doc)
    of ideKnown:
      list.add sexp(res.quality == 1)
    else:
      list.add sexp(res)
  returnEpc(client, uid, list)

template setVerbosity(level: typed) =
  gVerbosity = level
  conf.notes = NotesVerbosity[gVerbosity]

proc connectToNextFreePort(server: Socket, host: string): Port =
  server.bindaddr(Port(0), host)
  let (_, port) = server.getLocalAddr
  result = port

type
  ThreadParams = tuple[port: Port; address: string]

proc replStdinSingleCmd(line: string) =
  requests.send line
  toStdout()
  echo ""
  flushFile(stdout)

proc replStdin(x: ThreadParams) {.thread.} =
  if gEmitEof:
    echo DummyEof
    while true:
      let line = readLine(stdin)
      requests.send line
      if line == "quit": break
      toStdout()
      echo DummyEof
      flushFile(stdout)
  else:
    echo Help
    var line = ""
    while readLineFromStdin("> ", line):
      replStdinSingleCmd(line)
    requests.send "quit"

proc replCmdline(x: ThreadParams) {.thread.} =
  replStdinSingleCmd(x.address)
  requests.send "quit"

proc replTcp(x: ThreadParams) {.thread.} =
  var server = newSocket()
  server.bindAddr(x.port, x.address)
  var inp = "".TaintedString
  server.listen()
  while true:
    var stdoutSocket = newSocket()
    accept(server, stdoutSocket)

    stdoutSocket.readLine(inp)
    requests.send inp
    toSocket(stdoutSocket)
    stdoutSocket.send("\c\L")
    stdoutSocket.close()

proc argsToStr(x: SexpNode): string =
  if x.kind != SList: return x.getStr
  doAssert x.kind == SList
  doAssert x.len >= 4
  let file = x[0].getStr
  let line = x[1].getNum
  let col = x[2].getNum
  let dirty = x[3].getStr
  result = x[0].getStr.escape
  if dirty.len > 0:
    result.add ';'
    result.add dirty.escape
  result.add ':'
  result.add line
  result.add ':'
  result.add col

proc replEpc(x: ThreadParams) {.thread.} =
  var server = newSocket()
  let port = connectToNextFreePort(server, "localhost")
  server.listen()
  echo port
  stdout.flushFile()

  var client = newSocket()
  # Wait for connection
  accept(server, client)
  while true:
    var
      sizeHex = ""
      size = 0
      messageBuffer = ""
    checkSanity(client, sizeHex, size, messageBuffer)
    let
      message = parseSexp($messageBuffer)
      epcApi = message[0].getSymbol
    case epcApi
    of "call":
      let
        uid = message[1].getNum
        cmd = message[2].getSymbol
        args = message[3]

      when false:
        x.ideCmd[] = parseIdeCmd(message[2].getSymbol)
        case x.ideCmd[]
        of ideSug, ideCon, ideDef, ideUse, ideDus, ideOutline, ideHighlight:
          setVerbosity(0)
        else: discard
      let fullCmd = cmd & " " & args.argsToStr
      myLog "MSG CMD: " & fullCmd
      requests.send(fullCmd)
      toEpc(client, uid)
    of "methods":
      returnEpc(client, message[1].getNum, listEpc())
    of "epc-error":
      # an unhandled exception forces down the whole process anyway, so we
      # use 'quit' here instead of 'raise'
      quit("received epc error: " & $messageBuffer)
    else:
      let errMessage = case epcApi
                       of "return", "return-error":
                         "no return expected"
                       else:
                         "unexpected call: " & epcAPI
      quit errMessage

proc execCmd(cmd: string; graph: ModuleGraph; cachedMsgs: CachedMsgs) =
  let conf = graph.config

  template sentinel() =
    # send sentinel for the input reading thread:
    results.send(Suggest(section: ideNone))

  template toggle(sw) =
    if sw in conf.globalOptions:
      excl(conf.globalOptions, sw)
    else:
      incl(conf.globalOptions, sw)
    sentinel()
    return

  template err() =
    echo Help
    sentinel()
    return

  var opc = ""
  var i = parseIdent(cmd, opc, 0)
  case opc.normalize
  of "sug": conf.ideCmd = ideSug
  of "con": conf.ideCmd = ideCon
  of "def": conf.ideCmd = ideDef
  of "use": conf.ideCmd = ideUse
  of "dus": conf.ideCmd = ideDus
  of "mod": conf.ideCmd = ideMod
  of "chk": conf.ideCmd = ideChk
  of "highlight": conf.ideCmd = ideHighlight
  of "outline": conf.ideCmd = ideOutline
  of "quit":
    sentinel()
    quit()
  of "debug": toggle optIdeDebug
  of "terse": toggle optIdeTerse
  of "known": conf.ideCmd = ideKnown
  else: err()
  var dirtyfile = ""
  var orig = ""
  i = parseQuoted(cmd, orig, i)
  if cmd[i] == ';':
    i = parseQuoted(cmd, dirtyfile, i+1)
  i += skipWhile(cmd, seps, i)
  var line = -1
  var col = 0
  i += parseInt(cmd, line, i)
  i += skipWhile(cmd, seps, i)
  i += parseInt(cmd, col, i)

  if conf.ideCmd == ideKnown:
    results.send(Suggest(section: ideKnown, quality: ord(fileInfoKnown(conf, AbsoluteFile orig))))
  else:
    if conf.ideCmd == ideChk:
      for cm in cachedMsgs: errorHook(conf, cm.info, cm.msg, cm.sev)
    execute(conf.ideCmd, AbsoluteFile orig, AbsoluteFile dirtyfile, line, col, graph)
  sentinel()

proc recompileFullProject(graph: ModuleGraph) =
  #echo "recompiling full project"
  resetSystemArtifacts(graph)
  graph.vm = nil
  graph.resetAllModules()
  GC_fullcollect()
  compileProject(graph)
  #echo GC_getStatistics()

proc mainThread(graph: ModuleGraph) =
  let conf = graph.config
  if gLogging:
    for it in conf.searchPaths:
      log(it.string)

  proc wrHook(line: string) {.closure.} =
    if gMode == mepc:
      if gLogging: log(line)
    else:
      writelnToChannel(line)

  conf.writelnHook = wrHook
  conf.suggestionResultHook = sugResultHook
  graph.doStopCompile = proc (): bool = requests.peek() > 0
  var idle = 0
  var cachedMsgs: CachedMsgs = @[]
  while true:
    let (hasData, req) = requests.tryRecv()
    if hasData:
      conf.writelnHook = wrHook
      conf.suggestionResultHook = sugResultHook
      execCmd(req, graph, cachedMsgs)
      idle = 0
    else:
      os.sleep 250
      idle += 1
    if idle == 20 and gRefresh:
      # we use some nimsuggest activity to enable a lazy recompile:
      conf.ideCmd = ideChk
      conf.writelnHook = proc (s: string) = discard
      cachedMsgs.setLen 0
      conf.structuredErrorHook = proc (conf: ConfigRef; info: TLineInfo; msg: string; sev: Severity) =
        cachedMsgs.add(CachedMsg(info: info, msg: msg, sev: sev))
      conf.suggestionResultHook = proc (s: Suggest) = discard
      recompileFullProject(graph)

var
  inputThread: Thread[ThreadParams]

proc mainCommand(graph: ModuleGraph) =
  let conf = graph.config
  clearPasses(graph)
  registerPass graph, verbosePass
  registerPass graph, semPass
  conf.cmd = cmdIdeTools
  wantMainModule(conf)

  if not fileExists(conf.projectFull):
    quit "cannot find file: " & conf.projectFull.string

  add(conf.searchPaths, conf.libpath)

  # do not stop after the first error:
  conf.errorMax = high(int)
  # do not print errors, but log them
  conf.writelnHook = proc (s: string) = log(s)
  conf.structuredErrorHook = nil

  # compile the project before showing any input so that we already
  # can answer questions right away:
  compileProject(graph)

  open(requests)
  open(results)

  case gMode
  of mstdin: createThread(inputThread, replStdin, (gPort, gAddress))
  of mtcp: createThread(inputThread, replTcp, (gPort, gAddress))
  of mepc: createThread(inputThread, replEpc, (gPort, gAddress))
  of mcmdsug: createThread(inputThread, replCmdline,
                            (gPort, "sug \"" & conf.projectFull.string & "\":" & gAddress))
  of mcmdcon: createThread(inputThread, replCmdline,
                            (gPort, "con \"" & conf.projectFull.string & "\":" & gAddress))
  mainThread(graph)
  joinThread(inputThread)
  close(requests)
  close(results)

proc processCmdLine*(pass: TCmdLinePass, cmd: string; conf: ConfigRef) =
  var p = parseopt.initOptParser(cmd)
  while true:
    parseopt.next(p)
    case p.kind
    of cmdEnd: break
    of cmdLongoption, cmdShortOption:
      case p.key.normalize
      of "help", "h":
        stdout.writeline(Usage)
        quit()
      of "port":
        gPort = parseInt(p.val).Port
        gMode = mtcp
      of "address":
        gAddress = p.val
        gMode = mtcp
      of "stdin": gMode = mstdin
      of "cmdsug":
        gMode = mcmdsug
        gAddress = p.val
        incl(conf.globalOptions, optIdeDebug)
      of "cmdcon":
        gMode = mcmdcon
        gAddress = p.val
        incl(conf.globalOptions, optIdeDebug)
      of "epc":
        gMode = mepc
        conf.verbosity = 0          # Port number gotta be first.
      of "debug": incl(conf.globalOptions, optIdeDebug)
      of "v2": conf.suggestVersion = 0
      of "v1": conf.suggestVersion = 1
      of "tester":
        gMode = mstdin
        gEmitEof = true
        gRefresh = false
      of "log": gLogging = true
      of "refresh":
        if p.val.len > 0:
          gRefresh = parseBool(p.val)
        else:
          gRefresh = true
      of "maxresults":
        conf.suggestMaxResults = parseInt(p.val)
      else: processSwitch(pass, p, conf)
    of cmdArgument:
      let a = unixToNativePath(p.key)
      if dirExists(a) and not fileExists(a.addFileExt("nim")):
        conf.projectName = findProjectNimFile(conf, a)
        # don't make it worse, report the error the old way:
        if conf.projectName.len == 0: conf.projectName = a
      else:
        conf.projectName = a
      # if processArgument(pass, p, argsCount): break

proc handleCmdLine(cache: IdentCache; conf: ConfigRef) =
  let self = NimProg(
    suggestMode: true,
    processCmdLine: processCmdLine,
    mainCommand: mainCommand
  )
  self.initDefinesProg(conf, "nimsuggest")

  if paramCount() == 0:
    stdout.writeline(Usage)
    return

  self.processCmdLineAndProjectPath(conf)

  if gMode != mstdin:
    conf.writelnHook = proc (msg: string) = discard
  # Find Nim's prefix dir.
  let binaryPath = findExe("nim")
  if binaryPath == "":
    raise newException(IOError,
        "Cannot find Nim standard library: Nim compiler not in PATH")
  conf.prefixDir = AbsoluteDir binaryPath.splitPath().head.parentDir()
  if not dirExists(conf.prefixDir / RelativeDir"lib"):
    conf.prefixDir = AbsoluteDir""

  #msgs.writelnHook = proc (line: string) = log(line)
  myLog("START " & conf.projectFull.string)

  discard self.loadConfigsAndRunMainCommand(cache, conf)

handleCmdline(newIdentCache(), newConfigRef())