CliThread.cpp

//==============================================================================
//
//  CliThread.cpp
//
//  Copyright (C) 2013-2022  Greg Utas
//
//  This file is part of the Robust Services Core (RSC).
//
//  RSC is free software: you can redistribute it and/or modify it under the
//  terms of the GNU General Public License as published by the Free Software
//  Foundation, either version 3 of the License, or (at your option) any later
//  version.
//
//  RSC is distributed in the hope that it will be useful, but WITHOUT ANY
//  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
//  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
//  details.
//
//  You should have received a copy of the GNU General Public License along
//  with RSC.  If not, see <http://www.gnu.org/licenses/>.
//
#include "CliThread.h"
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cstdio>
#include <ios>
#include <istream>
#include <sstream>
#include <utility>
#include "CinThread.h"
#include "CliBuffer.h"
#include "CliCommand.h"
#include "CliRegistry.h"
#include "CliStack.h"
#include "CoutThread.h"
#include "Debug.h"
#include "Duration.h"
#include "Element.h"
#include "FileSystem.h"
#include "FileThread.h"
#include "Formatters.h"
#include "NbCliParms.h"
#include "NbDaemons.h"
#include "NbIncrement.h"
#include "PosixSignal.h"
#include "PosixSignalRegistry.h"
#include "Restart.h"
#include "Singleton.h"
#include "Symbol.h"
#include "SymbolRegistry.h"
#include "TraceBuffer.h"

using std::ostream;
using std::string;

//------------------------------------------------------------------------------

namespace NodeBase
{
//  The maximum depth of nesting when >send directs output to another file.
//
constexpr size_t MaxOutputDepth = 8;

//  The default prompt for user input.
//
constexpr char CliPrompt = '>';

//------------------------------------------------------------------------------

CliThread::CliThread() :
   Thread(OperationsFaction, Singleton<CliDaemon>::Instance()),
   command_(nullptr),
   result_(0)
{
   Debug::ft("CliThread.ctor");

   AllocResources();
   SetInitialized();
}

//------------------------------------------------------------------------------

CliThread::~CliThread()
{
   Debug::ftnt("CliThread.dtor");

   auto thread = Singleton<CinThread>::Extant();
   if(thread != nullptr) thread->ClearClient(this);
}

//------------------------------------------------------------------------------

c_string CliThread::AbbrName() const
{
   return CliDaemonName;
}

//------------------------------------------------------------------------------

void CliThread::AllocResources()
{
   Debug::ft("CliThread.AllocResources");

   ibuf.reset(new CliBuffer);
   obuf.reset(new std::ostringstream);
   *obuf << std::boolalpha << std::nouppercase;
   stack_.reset(new CliStack);
   prompt_.clear();
   outFiles_.clear();
}

//------------------------------------------------------------------------------

fixed_string YesNoChars = "yn";
fixed_string YesNoHelp = "Enter y(yes) or n(no): ";

bool CliThread::BoolPrompt(const string& prompt)
{
   Debug::ft("CliThread.BoolPrompt");

   return (CharPrompt(prompt, YesNoChars, YesNoHelp) == 'y');
}

//------------------------------------------------------------------------------

char CliThread::CharPrompt
   (const string& prompt, const string& chars, const string& help, bool upper)
{
   Debug::ft("CliThread.CharPrompt");

   //  If input is being taken from a file rather than the console,
   //  return the first character.
   //
   if(chars.empty()) return NUL;
   if(ibuf->ReadingFromFile()) return chars.front();

   auto first = true;
   string text;

   //  Output the query until the user enters a character in CHARS.
   //  Echo the user's input to the console transcript file.
   //
   while(true)
   {
      ostringstreamPtr stream(new std::ostringstream);

      if(first)
         *stream << prompt << " [" << chars << "]: ";
      else
         *stream << help;

      Flush();
      CoutThread::Spool(stream);
      first = false;

      if(CinThread::GetLine(text) < 0) return NUL;

      text.pop_back();
      FileThread::Record(text, true);

      if(text.size() == 1)
      {
         char c = (upper ? text[0] : tolower(text[0]));
         if(chars.find(c) != string::npos) return c;
      }
   }
}

//------------------------------------------------------------------------------

void CliThread::Destroy()
{
   Debug::ft("CliThread.Destroy");

   Singleton<CliThread>::Destroy();
}

//------------------------------------------------------------------------------

void CliThread::Display(ostream& stream,
   const string& prefix, const Flags& options) const
{
   Thread::Display(stream, prefix, options);

   auto lead1 = prefix + spaces(2);
   auto lead2 = prefix + spaces(4);

   stream << prefix << "ibuf : " << CRLF;
   ibuf->Display(stream, lead1, options);
   stream << prefix << "obuf : " << obuf.get() << CRLF;
   stream << prefix << "stack : " << CRLF;
   stack_->Display(stream, lead1, options);
   stream << prefix << "prompt   : " << prompt_ << CRLF;
   stream << prefix << "command  : " << strObj(command_) << CRLF;
   stream << prefix << "cookie   : " << CRLF;
   cookie_.Display(stream, lead1, options);
   stream << prefix << "result   : " << result_ << CRLF;
   stream << prefix << "stream   : " << stream_.get() << CRLF;

   stream << prefix << "outFiles : " << CRLF;
   for(size_t i = 0; i < outFiles_.size(); ++i)
   {
      stream << lead1 << strIndex(i) << outFiles_.at(i) << CRLF;
   }

   stream << prefix << "appsData : " << CRLF;
   for(auto a = appsData_.cbegin(); a != appsData_.cend(); ++a)
   {
      stream << lead1 << strIndex(a->first) << CRLF;
      a->second->Display(stream, lead2, options);
   }
}

//------------------------------------------------------------------------------

word CliThread::DisplayHelp(const string& path, const string& key) const
{
   Debug::ft("CliThread.DisplayHelp");

   //  Open the help file addressed by PATH.
   //
   auto stream = FileSystem::CreateIstream(path.c_str());
   if(stream == nullptr) return -2;

   //  Find line that contains "? KEY" and display the lines that follow, up
   //  to the next line that begins with '?'.  If a line begins with '?' and
   //  ends with '*', it is a wildcard that matches KEY if KEY's begins with
   //  the same characters as those that precede the asterisk.
   //
   auto found = false;
   string line;

   while(stream->peek() != EOF)
   {
      FileSystem::GetLine(*stream, line);

      if(line.empty())
      {
         if(found) *obuf << CRLF;
         continue;
      }

      switch(line.front())
      {
      case '/':
         continue;

      case '?':
         if(found) return 0;
         while(line.back() == SPACE) line.pop_back();
         line.erase(0, 2);

         if(!line.empty() && line.back() == '*')
         {
            auto keyStart = key.substr(0, line.size() - 1);
            auto lineStart = line.substr(0, line.size() - 1);
            if(strCompare(lineStart, keyStart, false) == 0) found = true;
         }
         else
         {
            if(strCompare(line, key, false) == 0) found = true;
         }
         break;

      default:
         if(found) *obuf << line << CRLF;
      }
   }

   return (found ? 0 : -1);
}

//------------------------------------------------------------------------------

bool CliThread::EndOfInput() const
{
   Debug::ft("CliThread.EndOfInput");

   if(!ibuf->FindNextNonBlank()) return true;

   ibuf->ErrorAtPos(*this, "Error: extra input");
   return false;
}

//------------------------------------------------------------------------------

void CliThread::Enter()
{
   Debug::ft("CliThread.Enter");

   //  Put the root increment on the stack and start reading commands.
   //
   stack_->SetRoot(*Singleton<NbIncrement>::Instance());
   while(true) ReadCommands();
}

//------------------------------------------------------------------------------

word CliThread::Execute(const string& input)
{
   Debug::ft("CliThread.Execute");

   word result = -1;

   Flush();
   auto rc = ibuf->PutLine(*this, input);

   if(rc == StreamOk)
   {
      auto comm = ParseCommand();
      if(comm != nullptr) result = InvokeCommand(*comm);
   }

   Flush();
   return result;
}

//------------------------------------------------------------------------------

ostream* CliThread::FileStream()
{
   Debug::ft("CliThread.FileStream");

   stream_ = FileThread::CreateStream();
   return stream_.get();
}

//------------------------------------------------------------------------------

void CliThread::Flush()
{
   Debug::ft("CliThread.Flush");

   //  Send output to either the console or a separate file.
   //
   if((obuf != nullptr) && (obuf->tellp() > 0))
   {
      if(outFiles_.empty())
         CoutThread::Spool(obuf);
      else
         FileThread::Spool(outFiles_.back(), obuf);

      Pause();
   }

   //  Create a new output buffer for the next command's results.
   //
   obuf.reset(new std::ostringstream);
   *obuf << std::boolalpha << std::nouppercase;
}

//------------------------------------------------------------------------------

bool CliThread::GenerateReportPreemptably()
{
   Debug::ft("CliThread.GenerateReportPreemptably");

   //  Generate the report preemptably unless tracing is on in the lab
   //  and the user specifically wants to trace report generation.
   //
   if(Debug::TraceOn())
   {
      if(!Element::RunningInLab()) return true;

      if(BoolPrompt(StopTracingPrompt))
      {
         Singleton<TraceBuffer>::Instance()->StopTracing();
         return true;
      }

      if(BoolPrompt(TraceReportPrompt)) return false;
   }

   return true;
}

//------------------------------------------------------------------------------

CliAppData* CliThread::GetAppData(CliAppData::Id aid) const
{
   Debug::ft("CliThread.GetAppData");

   auto a = appsData_.find(aid);
   if(a != appsData_.cend()) return a->second.get();
   return nullptr;
}

//------------------------------------------------------------------------------

void CliThread::Inform(const std::ostringstream& stream)
{
   Debug::ft("CliThread.Inform(stream)");

   Inform(stream.str());
}

//------------------------------------------------------------------------------

void CliThread::Inform(const string& str)
{
   Debug::ft("CliThread.Inform(string)");

   *obuf << str;
   Flush();
}

//------------------------------------------------------------------------------

word CliThread::IntPrompt(const string& prompt, word min, word max)
{
   Debug::ft("CliThread.IntPrompt");

   word result = -1;

   //  If input is being taken from a file rather than the console,
   //  return 0.
   //
   if(ibuf->ReadingFromFile()) return 0;

   auto first = true;
   string text;

   //  Output the query until the user enters an integer.  Echo the
   //  user's input to the console transcript file.
   //
   while(true)
   {
      ostringstreamPtr stream(new std::ostringstream);

      if(first)
         *stream << prompt;
      else
         *stream << "Enter " << min << " to " << max << ": ";

      Flush();
      CoutThread::Spool(stream);
      first = false;

      if(CinThread::GetLine(text) < 0) return -1;
      text.pop_back();

      string input(text);
      FileThread::Record(input, true);
      auto rc = CliBuffer::GetInt(input, result, false);
      if(rc != CliParm::Ok) continue;
      if((result >= min) && (result <= max)) return result;
   }
}

//------------------------------------------------------------------------------

word CliThread::InvokeCommand(const CliCommand& comm)
{
   Debug::ft("CliThread.InvokeCommand");

   //  Initialize the cookie so that it will look for the command's
   //  first parameter.
   //
   cookie_.Initialize();

   //  Execute the command and output the results.
   //
   Pause();
   command_ = &comm;
   SetResult(comm.ProcessCommand(*this));
   command_ = nullptr;
   return result_;
}

//------------------------------------------------------------------------------

word CliThread::InvokeSubcommand(const CliCommand& comm)
{
   Debug::ft("CliThread.InvokeSubcommand");

   auto prev = command_;
   command_ = &comm;
   SetResult(comm.ProcessCommand(*this));
   command_ = prev;
   return result_;
}

//------------------------------------------------------------------------------

void CliThread::Notify(CliAppData::Event event) const
{
   Debug::ft("CliThread.Notify");

   for(auto a = appsData_.cbegin(); a != appsData_.cend(); ++a)
   {
      a->second->EventOccurred(event);
   }
}

//------------------------------------------------------------------------------

const CliCommand* CliThread::ParseCommand() const
{
   Debug::ft("CliThread.ParseCommand");

   string token1;
   string token2;
   string tag;
   auto inIncr = true;

   //  Record the command in any output file.  (CliBuffer::GetLine copies
   //  each input to the console and/or the console transcript file.)
   //
   if(!outFiles_.empty())
   {
      auto input = ibuf->GetInput();
      FileThread::Spool(outFiles_.back(), input, true);
   }

   //  Get the first token, which must be the name of a command or
   //  increment.
   //
   if(ibuf->GetStr(tag, token1) != CliParm::Ok) return nullptr;
   if(!tag.empty()) return nullptr;

   auto comm = stack_->FindCommand(token1);

   if(comm != nullptr)
   {
      //  <command>
      //
      return comm;
   }

   auto incr = stack_->FindIncrement(token1);

   if(incr == nullptr)
   {
      incr = Singleton<CliRegistry>::Instance()->FindIncrement(token1);

      if(incr == nullptr)
      {
         //  <junk>
         //
         *obuf << spaces(2) << NoCommandExpl << token1 << CRLF;
         return nullptr;
      }

      inIncr = false;
      stack_->Push(*incr);
   }

   if(ibuf->GetStr(tag, token2) != CliParm::Ok)
   {
      //  <increment>
      //
      if(inIncr) *obuf << AlreadyInIncrement << token1 << '.' << CRLF;
      return nullptr;
   }

   if(!tag.empty()) return nullptr;
   comm = incr->FindCommand(token2);

   if(comm == nullptr)
   {
      //  <increment> <junk>
      //
      *obuf << spaces(2) << NoCommandExpl << token1;
      *obuf << CliCommand::CommandSeparator << token2 << CRLF;
   }

   if(!inIncr) stack_->Pop();
   return comm;
}

//------------------------------------------------------------------------------

void CliThread::Patch(sel_t selector, void* arguments)
{
   Thread::Patch(selector, arguments);
}

//------------------------------------------------------------------------------

bool CliThread::PopOutputFile(bool all)
{
   Debug::ft("CliThread.PopOutputFile");

   if(outFiles_.empty()) return false;

   SendAckToOutputFile();

   while(!outFiles_.empty())
   {
      outFiles_.pop_back();
      if(!all) return true;
   }

   return true;
}

//------------------------------------------------------------------------------

bool CliThread::PushOutputFile(const string& file)
{
   Debug::ft("CliThread.PushOutputFile");

   if(outFiles_.size() >= MaxOutputDepth) return false;

   SendAckToOutputFile();
   outFiles_.push_back(file);
   return true;
}

//------------------------------------------------------------------------------

fn_name CliThread_ReadCommands = "CliThread.ReadCommands";

void CliThread::ReadCommands()
{
   Debug::ft(CliThread_ReadCommands);

   auto skip = false;  // suppresses the CLI prompt if set

   while(true)
   {
      //  Print the CLI prompt, which contains the name of the
      //  most recently entered increment (if any).
      //
      string prompt(stack_->Top()->Name());
      prompt.push_back(CliPrompt);
      prompt_ = prompt;

      if(!skip)
      {
         CoutThread::Spool(prompt_.c_str());

         if(!outFiles_.empty())
         {
            FileThread::Spool(outFiles_.back(), prompt_, false);
         }
      }

      skip = false;

      //  Read the user's input and parse it.
      //
      auto rc = ibuf->GetLine(*this);

      if(rc > 0)
      {
         auto comm = ParseCommand();
         if(comm != nullptr) InvokeCommand(*comm);
         Flush();
      }
      else
      {
         switch(rc)
         {
         case StreamEmpty:
            //
            //  Redisplay the prompt again only if reading from the console.
            //
            skip = ibuf->ReadingFromFile();
            break;

         case StreamBadChar:
            //
            //  CliBuffer has displayed an error string.  Just loop around and
            //  prompt for new input.
            //
            break;

         case StreamEof:
         case StreamFailure:
            //
            //  CliBuffer has handled the error.  Continue with the next input.
            //
            skip = true;
            break;

         case StreamInterrupt:
         case StreamRestart:
            //
            //  o StreamInterrupt occurs when we plan to exit during a restart.
            //    Pausing causes us to receive SIGCLOSE and exit.
            //  o StreamRestart can occur if InitThread traps during a restart,
            //    after we have been created.  Pausing is also appropriate in
            //    this case, as another restart should occur momentarily.
            //
            Pause(msecs_t(1 * ONE_SEC));
            break;

         case StreamInUse:
         default:
            Debug::SwLog(CliThread_ReadCommands, "unexpected StreamRc", rc);
         }
      }
   }
}

//------------------------------------------------------------------------------

bool CliThread::Recover()
{
   Debug::ft("CliThread.Recover");

   auto sig = GetSignal();
   auto reg = Singleton<PosixSignalRegistry>::Instance();

   if(reg->Attrs(sig).test(PosixSignal::Break))
   {
      //  On a break signal, remain in the current increment(s) but
      //  abort whatever work was in progress.
      //
      appsData_.clear();
      outFiles_.clear();
      stream_.reset();
      ibuf->Reset();
   }

   return true;
}

//------------------------------------------------------------------------------

word CliThread::Report(word rc, const string& expl, col_t indent) const
{
   Debug::ft("CliThread.Report");

   //  If EXPL contains explicit endlines, output each substring
   //  that ends with an endline individually.
   //
   size_t size = expl.size();
   size_t begin = 0;

   while(begin < size)
   {
      auto end = expl.find(CRLF, begin);

      if(end == string::npos)
      {
         Report1(expl, begin, size - 1, indent);
         return rc;
      }

      if(end == begin)
         *obuf << CRLF;
      else
         Report1(expl, begin, end - 1, indent);

      begin = end + 1;
   }

   return rc;
}

//------------------------------------------------------------------------------

void CliThread::Report1
   (const string& expl, size_t begin, size_t end, col_t indent) const
{
   Debug::ft("CliThread.Report1");

   size_t maxlen = 79 - indent;  // maximum line length

   while(begin <= end)
   {
      //  If the rest of EXPL fits on one line, output it and return.
      //
      auto size = end - begin + 1;

      if(size <= maxlen)
      {
         *obuf << spaces(indent) << expl.substr(begin, size) << CRLF;
         return;
      }

      //  Starting at the last character that would fit on a line,
      //  work backwards to find a blank, and insert an endline at
      //  that point.  Then continue with the remaining characters.
      //
      auto stop = std::min(begin + maxlen - 1, end);
      auto blank = expl.rfind(SPACE, stop);

      if(blank != string::npos)
      {
         *obuf << spaces(indent) << expl.substr(begin, blank - begin) << CRLF;
         begin = blank + 1;
      }
      else
      {
         //  There are more characters without intervening blanks than
         //  fit on one line.  Just output the entire substring and let
         //  it wrap wherever.
         //
         *obuf << spaces(indent) << expl.substr(begin, size) << CRLF;
         return;
      }
   }
}

//------------------------------------------------------------------------------

void CliThread::SendAckToOutputFile()
{
   Debug::ft("CliThread.SendAckToOutputFile");

   std::ostringstream ack;

   ack << spaces(2) << SuccessExpl << CRLF;

   if(outFiles_.empty())
      CoutThread::Spool(ack.str().c_str());
   else
      FileThread::Spool(outFiles_.back(), ack.str());
}

//------------------------------------------------------------------------------

void CliThread::SendToFile(const string& name, bool purge)
{
   Debug::ft("CliThread.SendToFile");

   if(stream_->tellp() > 0)
   {
      FileThread::Spool(name, stream_, purge);
   }
}

//------------------------------------------------------------------------------

void CliThread::SetAppData(CliAppData* data, CliAppData::Id aid)
{
   Debug::ft("CliThread.SetAppData");

   if(data == nullptr)
      appsData_.erase(aid);
   else
      appsData_[aid].reset(data);
}

//------------------------------------------------------------------------------

void CliThread::SetResult(word result)
{
   Debug::ft("CliThread.SetResult");

   result_ = result;
   auto reg = Singleton<SymbolRegistry>::Instance();
   auto sym = reg->EnsureSymbol("cli.result");
   if(sym != nullptr) sym->SetValue(std::to_string(result_), false);
}

//------------------------------------------------------------------------------

void CliThread::Shutdown(RestartLevel level)
{
   Debug::ft("CliThread.Shutdown");

   //  Nullify the resources whose heap will be deleted during a restart.
   //
   Restart::Release(ibuf);
   Restart::Release(stack_);

   for(auto a = appsData_.begin(); a != appsData_.end(); ++a)
   {
      Restart::Release(a->second);
   }

   Thread::Shutdown(level);
}

//------------------------------------------------------------------------------

void CliThread::Startup(RestartLevel level)
{
   Debug::ft("CliThread.Startup");

   Thread::Startup(level);
   AllocResources();
}

//------------------------------------------------------------------------------

string CliThread::StrPrompt(const string& prompt)
{
   Debug::ft("CliThread.StrPrompt");

   //  If input is being taken from a file rather than the console,
   //  return an empty string.
   //
   if(ibuf->ReadingFromFile()) return EMPTY_STR;

   auto first = true;
   string text;

   //  Output the query, read the user's input, and echo it to the
   //  console transcript file before returning it.
   //
   while(true)
   {
      ostringstreamPtr stream(new std::ostringstream);

      if(first)
         *stream << prompt;
      else
         *stream << "Please enter a non-empty string";

      Flush();
      CoutThread::Spool(stream);
      first = false;

      if(CinThread::GetLine(text) < 0) return EMPTY_STR;
      text.pop_back();

      if(!text.empty())
      {
         string input(text);
         FileThread::Record(input, true);
         return input;
      }
   }
}
}