/*============================================================================
  CMake - Cross Platform Makefile Generator
  Copyright 2000-2009 Kitware, Inc., Insight Software Consortium

  Distributed under the OSI-approved BSD License (the "License");
  see accompanying file Copyright.txt for details.

  This software is distributed WITHOUT ANY WARRANTY; without even the
  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the License for more information.
============================================================================*/
#include "cmCTestMultiProcessHandler.h"
#include "cmProcess.h"
#include "cmStandardIncludes.h"
#include "cmCTest.h"
#include "cmSystemTools.h"
#include <stdlib.h>
#include <stack>
#include <float.h>

class TestComparator
{
public:
  TestComparator(cmCTestMultiProcessHandler* handler) : Handler(handler) {}
  ~TestComparator() {}

  // Sorts tests in descending order of cost
  bool operator() (int index1, int index2) const
    {
    return Handler->Properties[index1]->Cost >
      Handler->Properties[index2]->Cost;
    }

private:
  cmCTestMultiProcessHandler* Handler;
};

cmCTestMultiProcessHandler::cmCTestMultiProcessHandler()
{
  this->ParallelLevel = 1;
  this->Completed = 0;
  this->RunningCount = 0;
  this->StopTimePassed = false;
}

cmCTestMultiProcessHandler::~cmCTestMultiProcessHandler()
{
}

  // Set the tests
void 
cmCTestMultiProcessHandler::SetTests(TestMap& tests,
                                     PropertiesMap& properties)
{
  this->Tests = tests;
  this->Properties = properties;
  this->Total = this->Tests.size();
  // set test run map to false for all
  for(TestMap::iterator i = this->Tests.begin();
      i != this->Tests.end(); ++i)
    {
    this->TestRunningMap[i->first] = false;
    this->TestFinishMap[i->first] = false;
    }
  if(!this->CTest->GetShowOnly())
    {
    this->ReadCostData();
    this->CreateTestCostList();
    }
}

  // Set the max number of tests that can be run at the same time.
void cmCTestMultiProcessHandler::SetParallelLevel(size_t level)
{
  this->ParallelLevel = level < 1 ? 1 : level;
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::RunTests()
{
  this->CheckResume();
  if(!this->CheckCycles())
    {
    return;
    }
  this->TestHandler->SetMaxIndex(this->FindMaxIndex());
  this->StartNextTests();
  while(this->Tests.size() != 0)
    {
    if(this->StopTimePassed)
      {
      return;
      }
    this->CheckOutput();
    this->StartNextTests();
    }
  // let all running tests finish
  while(this->CheckOutput())
    {
    }
  this->MarkFinished();
  this->UpdateCostData();
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::StartTestProcess(int test)
{
  cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT, "test " << test << "\n");
  this->TestRunningMap[test] = true; // mark the test as running
  // now remove the test itself
  this->EraseTest(test);
  this->RunningCount += GetProcessorsUsed(test);

  cmCTestRunTest* testRun = new cmCTestRunTest(this->TestHandler);
  testRun->SetIndex(test);
  testRun->SetTestProperties(this->Properties[test]);

  std::string current_dir = cmSystemTools::GetCurrentWorkingDirectory();
  cmSystemTools::ChangeDirectory(this->Properties[test]->Directory.c_str());

  // Lock the resources we'll be using
  this->LockResources(test);

  if(testRun->StartTest(this->Total))
    {
    this->RunningTests.insert(testRun);
    }
  else if(testRun->IsStopTimePassed())
    {
    this->StopTimePassed = true;
    delete testRun;
    return;
    }
  else
    {
    this->UnlockResources(test);
    this->Completed++;
    this->TestFinishMap[test] = true;
    this->TestRunningMap[test] = false;
    this->RunningCount -= GetProcessorsUsed(test);
    testRun->EndTest(this->Completed, this->Total, false);
    this->Failed->push_back(this->Properties[test]->Name);
    delete testRun;
    }
  cmSystemTools::ChangeDirectory(current_dir.c_str());
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::LockResources(int index)
{
  for(std::set<std::string>::iterator i =
      this->Properties[index]->LockedResources.begin();
      i != this->Properties[index]->LockedResources.end(); ++i)
    {
    this->LockedResources.insert(*i);
    }
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::UnlockResources(int index)
{
  for(std::set<std::string>::iterator i =
      this->Properties[index]->LockedResources.begin();
      i != this->Properties[index]->LockedResources.end(); ++i)
    {
    this->LockedResources.erase(*i);
    }
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::EraseTest(int test)
{
  this->Tests.erase(test);
  this->SortedTests.erase(
    std::find(this->SortedTests.begin(), this->SortedTests.end(), test));
}

//---------------------------------------------------------
inline size_t cmCTestMultiProcessHandler::GetProcessorsUsed(int test)
{
  size_t processors = 
    static_cast<int>(this->Properties[test]->Processors);
  //If this is set to run serially, it must run alone.
  //Also, if processors setting is set higher than the -j
  //setting, we default to using all of the process slots.
  if(this->Properties[test]->RunSerial
     || processors > this->ParallelLevel)
    {
    processors = this->ParallelLevel;
    }
  return processors;
}

//---------------------------------------------------------
bool cmCTestMultiProcessHandler::StartTest(int test)
{
  //Check for locked resources
  for(std::set<std::string>::iterator i =
      this->Properties[test]->LockedResources.begin();
      i != this->Properties[test]->LockedResources.end(); ++i)
    {
    if(this->LockedResources.find(*i) != this->LockedResources.end())
      {
      return false;
      }
    }

  // copy the depend tests locally because when 
  // a test is finished it will be removed from the depend list
  // and we don't want to be iterating a list while removing from it
  TestSet depends = this->Tests[test];
  size_t totalDepends = depends.size();
  if(totalDepends)
    {
    for(TestSet::const_iterator i = depends.begin();
        i != depends.end(); ++i)
      {
      // if the test is not already running then start it
      if(!this->TestRunningMap[*i])
        {
        // this test might be finished, but since
        // this is a copy of the depend map we might
        // still have it
        if(!this->TestFinishMap[*i])
          {
          // only start one test in this function
          return this->StartTest(*i);
          }
        else
          {
          // the depend has been and finished
          totalDepends--;
          }
        }
      }
    }
  // if there are no depends left then run this test
  if(totalDepends == 0)
    {
    this->StartTestProcess(test);
    return true;
    }
  // This test was not able to start because it is waiting 
  // on depends to run
  return false;
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::StartNextTests()
{
  size_t numToStart = this->ParallelLevel - this->RunningCount;
  if(numToStart == 0)
    {
    return;
    }

  TestList copy = this->SortedTests;
  for(TestList::iterator test = copy.begin(); test != copy.end(); ++test)
    {
    //in case this test has already been started due to dependency
    if(this->TestRunningMap[*test] || this->TestFinishMap[*test])
      {
      continue;
      }
    size_t processors = GetProcessorsUsed(*test);
    if(processors > numToStart)
      {
      return;
      }
    if(this->StartTest(*test))
      {
      if(this->StopTimePassed)
        {
        return;
        }
      numToStart -= processors;
      }
    else
      {
      cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT, std::endl
                 << "Test did not start waiting on depends to finish: "
                 << *test << "\n");
      }
    if(numToStart == 0)
      {
      return;
      }
    }
}

//---------------------------------------------------------
bool cmCTestMultiProcessHandler::CheckOutput()
{
  // no more output we are done
  if(this->RunningTests.size() == 0)
    {
    return false;
    }
  std::vector<cmCTestRunTest*> finished;
  std::string out, err;
  for(std::set<cmCTestRunTest*>::const_iterator i = this->RunningTests.begin();
      i != this->RunningTests.end(); ++i)
    {
    cmCTestRunTest* p = *i;
    if(!p->CheckOutput())
      {
      finished.push_back(p);
      }
    }
  for( std::vector<cmCTestRunTest*>::iterator i = finished.begin();
       i != finished.end(); ++i)
    {
    this->Completed++;
    cmCTestRunTest* p = *i;
    int test = p->GetIndex();

    if(p->EndTest(this->Completed, this->Total, true))
      {
      this->Passed->push_back(p->GetTestProperties()->Name);
      }
    else
      {
      this->Failed->push_back(p->GetTestProperties()->Name);
      }
    for(TestMap::iterator j = this->Tests.begin();
        j != this->Tests.end(); ++j)
      {
      j->second.erase(test);
      }
    this->TestFinishMap[test] = true;
    this->TestRunningMap[test] = false;
    this->RunningTests.erase(p);
    this->WriteCheckpoint(test);
    this->UnlockResources(test);
    this->RunningCount -= GetProcessorsUsed(test);
    delete p;
    }
  return true;
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::UpdateCostData()
{
  std::string fname = this->CTest->GetCostDataFile();
  std::string tmpout = fname + ".tmp";
  std::fstream fout;
  fout.open(tmpout.c_str(), std::ios::out);

  PropertiesMap temp = this->Properties;

  if(cmSystemTools::FileExists(fname.c_str()))
    {
    std::ifstream fin;
    fin.open(fname.c_str());

    std::string line;
    while(std::getline(fin, line))
      {
      if(line == "---") break;
      std::vector<cmsys::String> parts = 
        cmSystemTools::SplitString(line.c_str(), ' ');
      //Format: <name> <previous_runs> <avg_cost>
      if(parts.size() < 3) break;

      std::string name = parts[0];
      int prev = atoi(parts[1].c_str());
      float cost = static_cast<float>(atof(parts[2].c_str()));

      int index = this->SearchByName(name);
      if(index == -1)
        {
        // This test is not in memory. We just rewrite the entry
        fout << name << " " << prev << " " << cost << "\n";
        }
      else
        {
        // Update with our new average cost
        fout << name << " " << this->Properties[index]->PreviousRuns << " "
          << this->Properties[index]->Cost << "\n";
        temp.erase(index);
        }
      }
    fin.close();
    cmSystemTools::RemoveFile(fname.c_str());
    }

  // Add all tests not previously listed in the file
  for(PropertiesMap::iterator i = temp.begin(); i != temp.end(); ++i)
    {
    fout << i->second->Name << " " << i->second->PreviousRuns << " "
      << i->second->Cost << "\n";
    }

  // Write list of failed tests
  fout << "---\n";
  for(std::vector<cmStdString>::iterator i = this->Failed->begin();
      i != this->Failed->end(); ++i)
    {
    fout << i->c_str() << "\n";
    }
  fout.close();
  cmSystemTools::RenameFile(tmpout.c_str(), fname.c_str());
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::ReadCostData()
{
  std::string fname = this->CTest->GetCostDataFile();

  if(cmSystemTools::FileExists(fname.c_str(), true))
    {
    std::ifstream fin;
    fin.open(fname.c_str());
    std::string line;
    while(std::getline(fin, line))
      {
      if(line == "---") break;

      std::vector<cmsys::String> parts =
        cmSystemTools::SplitString(line.c_str(), ' ');

      // Probably an older version of the file, will be fixed next run
      if(parts.size() < 3)
        {
        fin.close();
        return;
        }

      std::string name = parts[0];
      int prev = atoi(parts[1].c_str());
      float cost = static_cast<float>(atof(parts[2].c_str()));

      int index = this->SearchByName(name);
      if(index == -1) continue;

      this->Properties[index]->PreviousRuns = prev;
      if(this->Properties[index] && this->Properties[index]->Cost == 0)
        {
        this->Properties[index]->Cost = cost;
        }
      }
    // Next part of the file is the failed tests
    while(std::getline(fin, line))
      {
      if(line != "")
        {
        this->LastTestsFailed.push_back(line);
        }
      }
    fin.close();
    }
}

//---------------------------------------------------------
int cmCTestMultiProcessHandler::SearchByName(std::string name)
{
  int index = -1;

  for(PropertiesMap::iterator i = this->Properties.begin();
      i != this->Properties.end(); ++i)
    {
    if(i->second->Name == name)
      {
      index = i->first;
      }
    }
  return index;
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::CreateTestCostList()
{
  for(TestMap::iterator i = this->Tests.begin();
      i != this->Tests.end(); ++i)
    {
    SortedTests.push_back(i->first);

    //If the test failed last time, it should be run first, so max the cost
    if(std::find(this->LastTestsFailed.begin(),
                 this->LastTestsFailed.end(),
                 this->Properties[i->first]->Name)
       != this->LastTestsFailed.end())
      {
      this->Properties[i->first]->Cost = FLT_MAX;
      }
    }
  if(this->ParallelLevel > 1)
    {
    TestComparator comp(this);
    std::sort(SortedTests.begin(), SortedTests.end(), comp);
    }
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::WriteCheckpoint(int index)
{
  std::string fname = this->CTest->GetBinaryDir()
    + "/Testing/Temporary/CTestCheckpoint.txt";
  std::fstream fout;
  fout.open(fname.c_str(), std::ios::app | std::ios::out);
  fout << index << "\n";
  fout.close();
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::MarkFinished()
{
  std::string fname = this->CTest->GetBinaryDir()
    + "/Testing/Temporary/CTestCheckpoint.txt";
  cmSystemTools::RemoveFile(fname.c_str());
}

//---------------------------------------------------------
//For ShowOnly mode
void cmCTestMultiProcessHandler::PrintTestList()
{
  this->TestHandler->SetMaxIndex(this->FindMaxIndex());
  int count = 0;
  for (PropertiesMap::iterator it = this->Properties.begin();
       it != this->Properties.end(); ++it)
    {
    count++;
    cmCTestTestHandler::cmCTestTestProperties& p = *it->second;
    //push working dir
    std::string current_dir = cmSystemTools::GetCurrentWorkingDirectory();
    cmSystemTools::ChangeDirectory(p.Directory.c_str());

    cmCTestRunTest testRun(this->TestHandler);
    testRun.SetIndex(p.Index);
    testRun.SetTestProperties(&p);
    testRun.ComputeArguments(); //logs the command in verbose mode

    if (this->TestHandler->MemCheck)
      {
      cmCTestLog(this->CTest, HANDLER_OUTPUT, "  Memory Check");
      }
     else
      {
      cmCTestLog(this->CTest, HANDLER_OUTPUT, "  Test");
      }
    cmOStringStream indexStr;
    indexStr << " #" << p.Index << ":";
    cmCTestLog(this->CTest, HANDLER_OUTPUT, 
      std::setw(3 + getNumWidth(this->TestHandler->GetMaxIndex()))
      << indexStr.str().c_str());
    cmCTestLog(this->CTest, HANDLER_OUTPUT, " ");
    cmCTestLog(this->CTest, HANDLER_OUTPUT, p.Name.c_str() << std::endl);
    //pop working dir
    cmSystemTools::ChangeDirectory(current_dir.c_str());
    }
  cmCTestLog(this->CTest, HANDLER_OUTPUT, std::endl << "Total Tests: "
    << this->Total << std::endl);
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::CheckResume()
{
  std::string fname = this->CTest->GetBinaryDir()
      + "/Testing/Temporary/CTestCheckpoint.txt";
  if(this->CTest->GetFailover())
    {
    if(cmSystemTools::FileExists(fname.c_str(), true))
      {
      *this->TestHandler->LogFile << "Resuming previously interrupted test set"
        << std::endl
        << "----------------------------------------------------------"
        << std::endl;
        
      std::ifstream fin;
      fin.open(fname.c_str());
      std::string line;
      while(std::getline(fin, line))
        {
        int index = atoi(line.c_str());
        this->RemoveTest(index);
        }
      fin.close();
      }
    }
  else if(cmSystemTools::FileExists(fname.c_str(), true))
    {
    cmSystemTools::RemoveFile(fname.c_str());
    }
}

//---------------------------------------------------------
void cmCTestMultiProcessHandler::RemoveTest(int index)
{
  this->EraseTest(index);
  this->Properties.erase(index);
  this->TestRunningMap[index] = false;
  this->TestFinishMap[index] = true;
  this->Completed++;
}

//---------------------------------------------------------
int cmCTestMultiProcessHandler::FindMaxIndex()
{
  int max = 0;
  cmCTestMultiProcessHandler::TestMap::iterator i = this->Tests.begin();
  for(; i != this->Tests.end(); ++i)
    {
    if(i->first > max)
      {
      max = i->first;
      }
    }
  return max;
}

//Returns true if no cycles exist in the dependency graph
bool cmCTestMultiProcessHandler::CheckCycles()
{
  cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT, 
             "Checking test dependency graph..." << std::endl);
  for(TestMap::iterator it = this->Tests.begin();
      it != this->Tests.end(); ++it)
    {
    //DFS from each element to itself
    std::stack<int> s;
    std::vector<int> visited;
    s.push(it->first);
    visited.push_back(it->first);

    while(!s.empty())
      {
      int test = s.top();
      s.pop();
      
      for(TestSet::iterator d = this->Tests[test].begin();
          d != this->Tests[test].end(); ++d)
        {
        s.push(*d);
        for(std::vector<int>::iterator v = visited.begin();
            v != visited.end(); ++v)
          {
          if(*v == *d)
            {
            //cycle exists
            cmCTestLog(this->CTest, ERROR_MESSAGE, "Error: a cycle exists in "
              "the test dependency graph for the test \""
              << this->Properties[*d]->Name << "\"." << std::endl
              << "Please fix the cycle and run ctest again." << std::endl);
            return false;
            }
          }
        visited.push_back(*d);
        }
      visited.pop_back();
      }
    }
  return true;
}