#include <stdio.h>
#include <memory.h>

#include "thickenings.h"
#include "queue.h"

#define SWAP(t, a, b) do {t tmp = a; a = b; b = tmp;} while(0)

int edgelist_contains(edgelist_t *list, int needle) {
  while(list) {
    if(list->to == needle)
      return 1;
    list = list->next;
  }
  return 0;
}

edgelist_t *edgelist_add(edgelist_t *list, int new, edgelist_t *storage, int *storage_index)
{
  edgelist_t *new_link = &storage[*storage_index];
  new_link->next = list;
  new_link->to = new;
  (*storage_index)++;
  return new_link;
}

int main(int argc, const char *argv[])
{
  unsigned long left_invariance = atoi(argv[2]);
  unsigned long right_invariance = atoi(argv[3]);
  semisimple_type_t type;
  type.n = 1;
  type.factors = (simple_type_t*)malloc(type.n*sizeof(simple_type_t));
  type.factors[0].series = 'B';
  type.factors[0].rank = atoi(argv[1]);

  char alphabet[] = "abcdefghijklmnopqrstuvwxyz";
  char buffer[1024], buffer2[1024];

  node_t *graph;
  int *leftbuf, *rightbuf;
  edgelist_t *edgelists;
  int *words;
  int rank, order, hyperplanes, cosets;

  // initialize

  rank = coxeter_rank(type);
  order = coxeter_order(type);
  hyperplanes = coxeter_hyperplanes(type);

  graph = (node_t*)malloc(order*sizeof(node_t));
  leftbuf = (int*)malloc(order*rank*sizeof(int));
  rightbuf = (int*)malloc(order*rank*sizeof(int));
  edgelists = (edgelist_t*)malloc(4*order*hyperplanes*sizeof(edgelist_t));
  words = (int*)malloc(order*hyperplanes*sizeof(int));

  for(int i = 0; i < order; i++) {
    graph[i].left = &leftbuf[rank*i];
    graph[i].right = &rightbuf[rank*i];
  }

  // generate graph

  cosets = prepare_simplified_graph(type, left_invariance, right_invariance, graph, edgelists, words);

  // do something

  fprintf(stderr, "There are %d double cosets.\n", cosets);

  // cleanup

  free(leftbuf);
  free(rightbuf);
  free(graph);
  free(edgelists);
  free(words);
}

/*
int main(int argc, const char *argv[])
{
  semisimple_type_t type;
  node_t *graph;
  int *leftbuf, *rightbuf;
  edgelist_t *edgelists;
  edgelist_t *edgelists_simplified;
  int edgelists_simplified_used;
  int *words;
  int rank, order, max_wordlength;
  int *reduced, *group, *simplified;
  int *seen;
  int current;
  edgelist_t *edge, *previous;
  queue_t queue;

  char alphabet[] = "abcdefghijklmnopqrstuvwxyz";
  char buffer[1024], buffer2[1024];

  int ncosets;
  node_t *simplified_graph;

  // left and right invariances as bitmasks
  //  int left = ~(1 << (atoi(argv[1]) - atoi(argv[3])));
  //  int right = ~(1 << (atoi(argv[1]) - atoi(argv[2])));
  int left = atoi(argv[2]);
  int right = atoi(argv[3]);

  type.n = 1;
  type.factors = (simple_type_t*)malloc(type.n*sizeof(simple_type_t));
  type.factors[0].series = 'B';
  type.factors[0].rank = atoi(argv[1]);

  rank = coxeter_rank(type);
  order = coxeter_order(type);
  graph = (node_t*)malloc(order*sizeof(node_t));
  leftbuf = (int*)malloc(rank*order*sizeof(int));
  rightbuf = (int*)malloc(rank*order*sizeof(int));
  for(int i = 0; i < order; i++) {
    graph[i].left = &leftbuf[i*rank];
    graph[i].right = &rightbuf[i*rank];
  }

  prepare_graph(type, graph, &edgelists, &words);

  reduced = (int*)malloc(order*sizeof(int));
  group = (int*)malloc(order*sizeof(int));
  simplified = (int*)malloc(order*sizeof(int));
  for(int i = 0; i < order; i++) {
    group[i] = -1;
    reduced[i] = i;
  }

  // step 1: group
  for(int i = 0; i < order; i++) {
    if(group[i] != -1)
      continue;

    queue_init(&queue);
    queue_put(&queue, i);
    while((current = queue_get(&queue)) != -1) {
      if(group[current] != -1)
        continue;
      group[current] = i;

      for(int j = 0; j < rank; j++) {
        if(left & (1 << j))
          queue_put(&queue, graph[current].left[j]);
        if(right & (1 << j))
          queue_put(&queue, graph[current].right[j]);
      }
    }
  }

  // step 2: find minimum
  for(int i = 0; i < order; i++)
    if(graph[i].wordlength < graph[reduced[group[i]]].wordlength)
      reduced[group[i]] = i;

  // step 3: assign minimum to all
  for(int i = 0; i < order; i++)
    reduced[i] = reduced[group[i]];

  // step 4: assign indices to cosets
  ncosets = 0;
  for(int i = 0; i < order; i++)
    if(reduced[i] == i)
      simplified[i] = ncosets++;

  for(int i = 0; i < order; i++)
    simplified[i] = simplified[reduced[i]];

  fprintf(stderr, "Number of double cosets: %d\n\n", ncosets);

  max_wordlength = coxeter_hyperplanes(type);
  simplified_graph = (node_t*) malloc(ncosets*sizeof(node_t));
  edgelists_simplified = (edgelist_t*) malloc(2*max_wordlength*order*sizeof(edgelist_t));
  seen = (int*) malloc(ncosets*sizeof(int));
  edgelists_simplified_used = 0;

  // step 5: set up nodes from minima
  current = 0;
  for(int i = 0; i < order; i++)
    if(reduced[i] == i) { // is minimum
      simplified_graph[simplified[i]].word = graph[i].word;
      simplified_graph[simplified[i]].wordlength = graph[i].wordlength;
      simplified_graph[simplified[i]].opposite = simplified[graph[i].opposite];
      simplified_graph[simplified[i]].bruhat_lower = (edgelist_t*)0;
      simplified_graph[simplified[i]].bruhat_higher = (edgelist_t*)0;
    }

  // some output
  for(int i = 0; i < ncosets; i++)
    fprintf(stderr, "%s <=> %s\n", simplified_graph[i].wordlength == 0 ? "1" : alphabetize(simplified_graph[i].word, simplified_graph[i].wordlength, alphabet, buffer), simplified_graph[simplified_graph[i].opposite].wordlength == 0 ? "1" : alphabetize(simplified_graph[simplified_graph[i].opposite].word, simplified_graph[simplified_graph[i].opposite].wordlength, alphabet, buffer2));

  // step 6: find order relations
  for(int i = 0; i < order; i++) {
    edge = graph[i].bruhat_lower;
    while(edge) {
      int this = simplified[i];
      int that = simplified[edge->to];
      if(this != that) {
	// found something
	if(!edgelist_contains(simplified_graph[this].bruhat_lower, that))
	  simplified_graph[this].bruhat_lower = edgelist_add(simplified_graph[this].bruhat_lower, that, edgelists_simplified, &edgelists_simplified_used);
	ERROR(simplified_graph[this].wordlength <= simplified_graph[that].wordlength, "The order assumption is being violated!\n");
      }
      edge = edge->next;
    }
  }

  fprintf(stderr, "\nAdded %d edges.\n\n", edgelists_simplified_used);

  // step 7: remove redundant edges
  for(int i = 0; i < ncosets; i++) {
    memset(seen, 0, ncosets*sizeof(int));
    queue_init(&queue);

    for(int len = 1; len <= simplified_graph[i].wordlength; len++) {
      edge = simplified_graph[i].bruhat_lower;
      previous = (edgelist_t*)0;

      while(edge) {
	// only look at edges of this length now
	if(simplified_graph[i].wordlength - simplified_graph[edge->to].wordlength != len) {
	  // we only consider edges of length len in this pass
	  previous = edge;
	} else if(seen[edge->to]) {
	  // this edge is redundant, remove it
	  //	  fprintf(stderr, "removing edge from %d to %d\n", i, edge->to);
	  if(previous)
	    previous->next = edge->next;
	  else
	    simplified_graph[i].bruhat_lower = edge->next;
	} else {
	  // this edge was not redundant, add to seen
	  previous = edge;
	  seen[edge->to] = 1;
	  queue_put(&queue, edge->to);
	}
	edge = edge->next;
      }

      // calculate transitive closure of seen nodes
      while((current = queue_get(&queue)) != -1) {
	edge = simplified_graph[current].bruhat_lower;
	while(edge) {
	  if(!seen[edge->to]) {
	    seen[edge->to] = 1;
	    queue_put(&queue, edge->to);
	  }
	  edge = edge->next;
	}
      }
    }
  }

  // step 8: revert order
  for(int i = 0; i < ncosets; i++) {
    edge = simplified_graph[i].bruhat_lower;
    while(edge) {
      simplified_graph[edge->to].bruhat_higher =
	edgelist_add(simplified_graph[edge->to].bruhat_higher,
		     i, edgelists_simplified, &edgelists_simplified_used);
      edge = edge->next;
    }
  }

  // output as graphviz dot file
  fprintf(stdout, "digraph test123 {\n");
  for(int i = 0; i < ncosets; i++) {
    edge = simplified_graph[i].bruhat_lower;
    while(edge) {
      fprintf(stdout, "%s -> %s;\n",
      	     alphabetize(simplified_graph[i].word, simplified_graph[i].wordlength, alphabet, buffer),
	     alphabetize(simplified_graph[edge->to].word, simplified_graph[edge->to].wordlength, alphabet, buffer2));

      edge = edge->next;
    }
  }
  fprintf(stdout, "}\n");

  long nthickenings = enumerate_balanced_thickenings(type, simplified_graph, ncosets, alphabet, stdout);

  fprintf(stderr, "Found %ld balanced thickenings.\n", nthickenings);

  free(seen);
  free(simplified_graph);
  free(edgelists_simplified);
  free(type.factors);
  free(graph);
  free(edgelists);
  free(words);
  free(reduced);
  free(group);
  free(simplified);
  free(leftbuf);
  free(rightbuf);

  return 0;
}
*/