/* -*- mode: C -*-  */
/*
  Test suite for stochastic imitation via roulette wheel selection.
  Copyright (C) 2011 Minh Van Nguyen <nguyenminh2@gmail.com>

  This program 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 2 of the License, or
  (at your option) any later version.

  This program 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 this program; if not, write to the Free Software
  Foundation, Inc.,  51 Franklin Street, Fifth Floor, Boston, MA
  02110-1301 USA
*/

#include <igraph.h>
#include <stdio.h>
#include <time.h>

#define R_INTEGER(a,b) (igraph_rng_get_integer(igraph_rng_default(), (a), (b)))

/* test parameters structure */
typedef struct {
  igraph_t *graph;
  igraph_integer_t vertex;
  igraph_bool_t islocal;
  igraph_vector_t *quantities;
  igraph_vector_t *strategies;
  igraph_vector_t *known_strats;
  igraph_neimode_t mode;
  int retval;
} strategy_test_t;

/* Error tests. That is, we expect error codes to be returned from such tests.
 */
int error_tests() {
  igraph_t g, gzero, h;
  igraph_vector_t quant, quantzero, strat, stratzero;
  int i, n, nvert, ret;
  strategy_test_t *test;

  /* nonempty graph */
  igraph_small(&g, /*nvert=*/ 0, IGRAPH_UNDIRECTED, 0,1, 1,2, 2,0, -1);
  igraph_empty(&h, 0, 0);         /* empty graph */
  igraph_vector_init(&quant, 1);  /* quantities vector */
  igraph_vector_init(&strat, 2);  /* strategies vector */
  igraph_small(&gzero, /*nvert=*/ 0, IGRAPH_UNDIRECTED,
               0,3, 0,4, 1,2, 1,4, 1,5, 2,3, 2,4, 3,4, -1);
  nvert = igraph_vcount(&gzero);
  igraph_vector_init_real(&stratzero, nvert, 1.0, 0.0, 1.0, 2.0, 0.0, 3.0);
  igraph_vector_init(&quantzero, nvert);  /* vector of zeros */

  /* test parameters */
  /*graph--vert--islocal--quantities--strategies--known_strats--mode--retval*/
  /* null pointer for graph */
  strategy_test_t null_graph = {NULL, 0, 1, NULL, NULL, NULL, IGRAPH_ALL, IGRAPH_EINVAL};
  /* null pointer for quantities vector */
  strategy_test_t null_quant = {&g, 0, 1, NULL, NULL, NULL, IGRAPH_ALL, IGRAPH_EINVAL};
  /* null pointer for strategies vector */
  strategy_test_t null_strat = {&g, 0, 1, &quant, NULL, NULL, IGRAPH_ALL, IGRAPH_EINVAL};
  /* empty graph */
  strategy_test_t empty_graph = {&h, 0, 1, &quant, &strat, NULL, IGRAPH_ALL, IGRAPH_EINVAL};
  /* length of quantities vector different from number of vertices */
  strategy_test_t qdiff_length = {&g, 0, 1, &quant, &strat, NULL, IGRAPH_ALL, IGRAPH_EINVAL};
  /* length of strategies vector different from number of vertices */
  strategy_test_t sdiff_length = {&g, 0, 1, &quant, &strat, NULL, IGRAPH_ALL, IGRAPH_EINVAL};
  /* quantities vector contains all zeros */
  strategy_test_t zero_quant = {&gzero, 4, 1, &quantzero, &stratzero, NULL, IGRAPH_ALL, IGRAPH_EINVAL};
  strategy_test_t *all_checks[] = {/* 1 */ &null_graph,
                                   /* 2 */ &null_quant,
                                   /* 3 */ &null_strat,
                                   /* 4 */ &empty_graph,
                                   /* 5 */ &qdiff_length,
                                   /* 6 */ &sdiff_length,
                                   /* 7 */ &zero_quant};

  /* Run the error tests. We expect error to be raised for each test. */
  igraph_set_error_handler(igraph_error_handler_ignore);
  n = 7;
  i = 0;
  while (i < n) {
    test = all_checks[i];
    ret = igraph_roulette_wheel_imitation(test->graph, test->vertex,
                                          test->islocal, test->quantities,
                                          test->strategies, test->mode);
    if (ret != test->retval) {
      printf("Error test no. %d failed.\n", (int)(i + 1));
      return IGRAPH_FAILURE;
    }
    i++;
  }
  /* clean up */
  igraph_destroy(&g);
  igraph_destroy(&gzero);
  igraph_destroy(&h);
  igraph_vector_destroy(&quant);
  igraph_vector_destroy(&quantzero);
  igraph_vector_destroy(&strat);
  igraph_vector_destroy(&stratzero);

  return IGRAPH_SUCCESS;
}

/* A game on a graph with 5 vertices and 7 edges. Use roulette wheel selection
 * to update strategies. This example also illustrates how a choice of
 * perspective (whether local or global) could affect the range of
 * possible strategies a vertex could adopt.
 */
int roulette_test() {
  igraph_t g;
  igraph_bool_t success;
  igraph_vector_t *known, quant, strat, stratcopy;
  igraph_vector_t known0, known1, known2, known3, known4, known5;
  int i, k, n, nvert, ret;;
  strategy_test_t *test;

  /* the game network */
  igraph_small(&g, /*nvert=*/ 0, IGRAPH_UNDIRECTED,
               0,3, 0,4, 1,2, 1,4, 1,5, 2,3, 2,4, 3,4, -1);
  nvert = igraph_vcount(&g);
  /* strategies vector; the strategy space is {0, 1, 2, 3} */
  /* V[i] is strategy of vertex i */
  igraph_vector_init_real(&strat, nvert, 1.0, 0.0, 1.0, 2.0, 0.0, 3.0);
  /* quantities vector; V[i] is quantity of vertex i */
  igraph_vector_init_real(&quant, nvert, 0.56, 0.13, 0.26, 0.73, 0.67, 0.82);
  /* possible strategies each vertex can adopt */
  igraph_vector_init_real(&known0, /*n=*/ 3, 0.0, 1.0, 2.0);       /* local */
  igraph_vector_init_real(&known1, /*n=*/ 3, 0.0, 1.0, 3.0);       /* local */
  igraph_vector_init_real(&known2, /*n=*/ 3, 0.0, 1.0, 2.0);       /* local */
  igraph_vector_init_real(&known3, /*n=*/ 3, 0.0, 1.0, 2.0);       /* local */
  igraph_vector_init_real(&known4, /*n=*/ 3, 0.0, 1.0, 2.0);       /* local */
  igraph_vector_init_real(&known5, /*n=*/ 4, 0.0, 1.0, 2.0, 3.0);  /* global */

  /* test parameters */
  /*graph--vert--islocal--quantities--strategies--known_strats--mode-retval*/
  strategy_test_t game0 = {&g, 0, 1, &quant, NULL, &known0, IGRAPH_ALL, IGRAPH_SUCCESS};
  strategy_test_t game1 = {&g, 1, 1, &quant, NULL, &known1, IGRAPH_ALL, IGRAPH_SUCCESS};
  strategy_test_t game2 = {&g, 2, 1, &quant, NULL, &known2, IGRAPH_ALL, IGRAPH_SUCCESS};
  strategy_test_t game3 = {&g, 3, 1, &quant, NULL, &known3, IGRAPH_ALL, IGRAPH_SUCCESS};
  strategy_test_t game4 = {&g, 4, 1, &quant, NULL, &known4, IGRAPH_ALL, IGRAPH_SUCCESS};
  strategy_test_t game5 = {&g, 5, 0, &quant, NULL, &known5, IGRAPH_ALL, IGRAPH_SUCCESS};
  strategy_test_t *all_checks[] = {/* 1 */ &game0,
                                   /* 2 */ &game1,
                                   /* 3 */ &game2,
                                   /* 4 */ &game3,
                                   /* 5 */ &game4,
                                   /* 6 */ &game5};

  /* play game */
  n = 6;
  i = 0;
  while (i < n) {
    test = all_checks[i];
    igraph_vector_copy(&stratcopy, &strat);
    ret = igraph_roulette_wheel_imitation(test->graph, test->vertex,
                                          test->islocal, test->quantities,
                                          &stratcopy, test->mode);
    if (ret != test->retval) {
      printf("Test no. %d failed.\n", i + 1);
      return IGRAPH_FAILURE;
    }
    /* If the revised strategy s matches one of the candidate strategies, */
    /* then success. If s doesn't match any of the possible strategies, then */
    /* failure. Default to failure. */
    success = 0;
    known = test->known_strats;
    for (k = 0; k < igraph_vector_size(known); k++) {
      if (VECTOR(*known)[k] == VECTOR(stratcopy)[test->vertex]) {
        success = 1;
        break;
      }
    }
    if (!success) {
      printf("Roulette wheel imitation failed for vertex %d.\n",
             (int)test->vertex);
      return IGRAPH_FAILURE;
    }
    igraph_vector_destroy(&stratcopy);
    i++;
  }
  /* game finished; pack up */
  igraph_destroy(&g);
  igraph_vector_destroy(&known0);
  igraph_vector_destroy(&known1);
  igraph_vector_destroy(&known2);
  igraph_vector_destroy(&known3);
  igraph_vector_destroy(&known4);
  igraph_vector_destroy(&known5);
  igraph_vector_destroy(&quant);
  igraph_vector_destroy(&strat);

  return IGRAPH_SUCCESS;
}

/* It is possible for a vertex to retain its current strategy. This can
 * happen both in the local and global perspectives.
 */
int retain_strategy_test() {
  igraph_t g;
  igraph_integer_t max, min, v;
  igraph_vector_t quant, strat, stratcp;
  int i, ntry, nvert;

  /* the game network */
  igraph_small(&g, /*nvert=*/ 0, IGRAPH_UNDIRECTED,
               0,3, 0,4, 1,2, 1,4, 1,5, 2,3, 2,4, 3,4, -1);
  nvert = igraph_vcount(&g);
  /* strategies vector; the strategy space is {0, 1, 2, 3} */
  /* V[i] is strategy of vertex i */
  igraph_vector_init_real(&strat, nvert, 1.0, 0.0, 1.0, 2.0, 0.0, 3.0);
  /* quantities vector; V[i] is quantity of vertex i */
  igraph_vector_init_real(&quant, nvert, 0.56, 0.13, 0.26, 0.73, 0.67, 0.82);

  /* random vertex */
  min = 0;
  max = 5;
  igraph_rng_seed(igraph_rng_default(), time(0));
  v = R_INTEGER(min, max);  /* min <= v <= max */
  /* Ensure that it is possible for v to retain its current strategy. We */
  /* will try to do this at most ntry times. As there are at most 6 vertices */
  /* to choose from, it shouldn't take long before we encounter a strategy */
  /* revision round where v retains its current strategy. */
  /* With local perspective. */
  i = 0;
  ntry = 100;
  igraph_vector_init(&stratcp, 0);
  do {
    i++;
    if (i > ntry)
      return IGRAPH_FAILURE;  /* ideally this should never happen */
    igraph_vector_destroy(&stratcp);
    igraph_vector_copy(&stratcp, &strat);
    igraph_roulette_wheel_imitation(&g, v, /*is local?*/ 1, &quant, &stratcp,
                                    IGRAPH_ALL);
  }
  while (VECTOR(stratcp)[v] != VECTOR(strat)[v]);
  /* If we get to this point, we know that there was an update round */
  /* i <= ntry as a result of which v retains its current strategy. */
  /* Now try again, but this time with the global perspective. */
  i = 0;
  do {
    i++;
    if (i > ntry)
      return IGRAPH_FAILURE;  /* ideally this should never happen */
    igraph_vector_destroy(&stratcp);
    igraph_vector_copy(&stratcp, &strat);
    igraph_roulette_wheel_imitation(&g, v, /*is local?*/ 0, &quant, &stratcp,
                                    IGRAPH_ALL);
  }
  while (VECTOR(stratcp)[v] != VECTOR(strat)[v]);
  /* nothing further to do, but housekeeping */
  igraph_destroy(&g);
  igraph_vector_destroy(&quant);
  igraph_vector_destroy(&strat);
  igraph_vector_destroy(&stratcp);

  return IGRAPH_SUCCESS;
}

int main() {
  int ret;

  ret = error_tests();
  if (ret)
    return IGRAPH_FAILURE;
  ret = roulette_test();
  if (ret)
    return IGRAPH_FAILURE;
  ret = retain_strategy_test();
  if (ret)
    return IGRAPH_FAILURE;

  return IGRAPH_SUCCESS;
}