// Example 2.2. See page 9 of the FG tutorial.

#include "FG.h"
#include <iostream>
using namespace std;

int func1(FG_stage, FG_stage_params);
int func2(FG_stage, FG_stage_params);
int func3(FG_stage, FG_stage_params);

int main() 
{
  // Declare the pipeline variables.
  int buffer_size = sizeof(int);
  int num_rounds = 1;

  // Declare the stages.
  FG_pipeline_stage_helper
    stage1 = new FG_pipeline_stage_helper_info(),
    stage2 = new FG_pipeline_stage_helper_info(),
    stage3 = new FG_pipeline_stage_helper_info();

  // Assign a function to each stage.
  stage1->set_func(func1, NULL);
  stage2->set_func(func2, NULL);
  stage3->set_func(func3, NULL);

  // Store the stages in a NULL-terminated array.
  FG_pipeline_stage_helper stages[] = {stage1, stage2, stage3, NULL};

  // Instantiate the pipeline.
  FG_pipeline my_pipeline = FG_pipeline_info::create(stages);

  // Set the pipeline variables.
  my_pipeline->set_buff_size(buffer_size);
  my_pipeline->set_num_rounds(num_rounds);

  // Fix the pipeline, which also runs it, and store the return code.
  int error = my_pipeline->fix();

  // Display the return code.
  cout << "FINISHED PIPELINE WITH ERROR CODE " << error << endl;

  // Dismantle the pipeline.
  my_pipeline->dismantle();

  return 0;
}

// func1, run by stage 1.
int func1(FG_stage my_stage, FG_stage_params my_params)
{
  // Accept a thumbnail from the preceding stage (the source).
  FG_pipeline_thumbnail thumb = my_stage->accept_thumbnail();

  // Store a single int value in the buffer.
  int *buff = (int *) thumb->get_address();
  *buff = 8;

  // Convey the thumbnail to the next stage (stage 2).
  my_stage->convey_thumbnail(thumb);

  return 0;
}

// func2, run by stage 2.
int func2(FG_stage my_stage, FG_stage_params my_params)
{
  // Accept a thumbnail from the preceding stage (stage 1).
  FG_pipeline_thumbnail thumb = my_stage->accept_thumbnail();

  // Change the int value in the buffer.
  int *buff = (int *) thumb->get_address();
  *buff += 20;

  // Convey the thumbnail to the next stage (stage 3).
  my_stage->convey_thumbnail(thumb);

  return 0;
}

// func3, run by stage 3.
int func3(FG_stage my_stage, FG_stage_params my_params)
{
  // Accept a thumbnail from the preceding stage (stage 1).
  FG_pipeline_thumbnail thumb = my_stage->accept_thumbnail();

  // Print the value that is in the buffer.
  int *buff = (int *) thumb->get_address();
  cout << "result: " << *buff << endl;

  // Convey the thumbnail to the next stage (the sink).
  my_stage->convey_thumbnail(thumb);

  return 0;
}