// $Id: injection.cpp 5188 2012-08-30 00:31:31Z dub $

/*
 Copyright (c) 2007-2012, Trustees of The Leland Stanford Junior University
 All rights reserved.

 Redistribution and use in source and binary forms, with or without
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 list of conditions and the following disclaimer in the documentation and/or
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 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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*/

#include <iostream>
#include <vector>
#include <cassert>
#include <limits>
#include "random_utils.hpp"
#include "injection.hpp"

using namespace std;

InjectionProcess::InjectionProcess(int nodes, double rate)
  : _nodes(nodes), _rate(rate)
{
  if(nodes <= 0) {
    cout << "Error: Number of nodes must be greater than zero." << endl;
    exit(-1);
  }
  if((rate < 0.0) || (rate > 1.0)) {
    cout << "Error: Injection process must have load between 0.0 and 1.0."
	 << endl;
    exit(-1);
  }
}

void InjectionProcess::reset()
{

}

InjectionProcess * InjectionProcess::New(string const & inject, int nodes, 
					 double load, 
					 Configuration const * const config)
{
  string process_name;
  string param_str;
  size_t left = inject.find_first_of('(');
  if(left == string::npos) {
    process_name = inject;
  } else {
    process_name = inject.substr(0, left);
    size_t right = inject.find_last_of(')');
    if(right == string::npos) {
      param_str = inject.substr(left+1);
    } else {
      param_str = inject.substr(left+1, right-left-1);
    }
  }
  vector<string> params = tokenize_str(param_str);

  InjectionProcess * result = NULL;
  if(process_name == "bernoulli") {
    result = new BernoulliInjectionProcess(nodes, load);
  } else if(process_name == "on_off") {
    bool missing_params = false;
    double alpha = numeric_limits<double>::quiet_NaN();
    if(params.size() < 1) {
      if(config) {
	alpha = config->GetFloat("burst_alpha");
      } else {
	missing_params = true;
      }
    } else {
      alpha = atof(params[0].c_str());
    }
    double beta = numeric_limits<double>::quiet_NaN();
    if(params.size() < 2) {
      if(config) {
	beta = config->GetFloat("burst_beta");
      } else {
	missing_params = true;
      }
    } else {
      beta = atof(params[1].c_str());
    }
    double r1 = numeric_limits<double>::quiet_NaN();
    if(params.size() < 3) {
      r1 = config ? config->GetFloat("burst_r1") : -1.0;
    } else {
      r1 = atof(params[2].c_str());
    }
    if(missing_params) {
      cout << "Missing parameters for injection process: " << inject << endl;
      exit(-1);
    }
    if((alpha < 0.0 && beta < 0.0) || 
       (alpha < 0.0 && r1 < 0.0) || 
       (beta < 0.0 && r1 < 0.0) || 
       (alpha >= 0.0 && beta >= 0.0 && r1 >= 0.0)) {
      cout << "Invalid parameters for injection process: " << inject << endl;
      exit(-1);
    }
    vector<int> initial(nodes);
    if(params.size() > 3) {
      initial = tokenize_int(params[2]);
      initial.resize(nodes, initial.back());
    } else {
      for(int n = 0; n < nodes; ++n) {
	initial[n] = RandomInt(1);
      }
    }
    result = new OnOffInjectionProcess(nodes, load, alpha, beta, r1, initial);
  } else {
    cout << "Invalid injection process: " << inject << endl;
    exit(-1);
  }
  return result;
}

//=============================================================

BernoulliInjectionProcess::BernoulliInjectionProcess(int nodes, double rate)
  : InjectionProcess(nodes, rate)
{

}

bool BernoulliInjectionProcess::test(int source)
{
  assert((source >= 0) && (source < _nodes));
  return (RandomFloat() < _rate);
}

//=============================================================

OnOffInjectionProcess::OnOffInjectionProcess(int nodes, double rate, 
					     double alpha, double beta, 
					     double r1, vector<int> initial)
  : InjectionProcess(nodes, rate), 
    _alpha(alpha), _beta(beta), _r1(r1), _initial(initial)
{
  assert(alpha <= 1.0);
  assert(beta <= 1.0);
  assert(r1 <= 1.0);
  if(alpha < 0.0) {
    assert(beta >= 0.0);
    assert(r1 >= 0.0);
    _alpha = beta * rate / (r1 - rate);
  } else if(beta < 0.0) {
    assert(alpha >= 0.0);
    assert(r1 >= 0.0);
    _beta = alpha * (r1 - rate) / rate;
  } else {
    assert(r1 < 0.0);
    _r1 = rate * (alpha + beta) / alpha;
  }
  reset();
}

void OnOffInjectionProcess::reset()
{
  _state = _initial;
}

bool OnOffInjectionProcess::test(int source)
{
  assert((source >= 0) && (source < _nodes));

  // advance state
  _state[source] = 
    _state[source] ? (RandomFloat() >= _beta) : (RandomFloat() < _alpha);

  // generate packet
  return _state[source] && (RandomFloat() < _r1);
}