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

#include <strings.h>
#include <stdio.h>
#include <inttypes.h>

int main(int argc, const char *argv[])
{
	if(argc < 2) {
		fprintf(stderr, "Rank argument required.\n");
		return 1;
	}
	int rank = atoi(argv[1]);
	if(rank <= 0 || rank > 1000) {
		fprintf(stderr, "Rank must be a small positive integer.\n");
		return 1;
	}
	if(rank % 2) {
		fprintf(stderr, "Rank must be even.\n"); // opposition involution not trivial otherwise
		return 1;
	}

	doublequotient_t *dq = (doublequotient_t*)malloc(sizeof(doublequotient_t));
	simple_type_t type;
	type.series = 'D';
	type.rank = rank;
	dq->type.n = 1;
	dq->type.factors = &type;
	dq->left_invariance = (1<<rank) - 2;
	dq->right_invariance = 0;
	dq->group = 0;
	dq->grouplists = 0;
	dq->groupletters = 0;
	dq->count = 1 << (rank - 1);
	dq->cosets = (doublecoset_t*)malloc(dq->count*sizeof(doublecoset_t));
	dq->lists = (doublecoset_list_t*)malloc(2*dq->count*rank*sizeof(doublecoset_list_t)); // conservative estimate
	int nlists = 0;

	int *bitmask = malloc((1<<(rank-1)) * sizeof(int));
	int *bitmask_reverse = malloc((1<<rank) * sizeof(int));
	int index = 0;

	LOG("Prepare.\n");

	for(int i = 0; i < dq->count; i++) {
		dq->cosets[i].index = i;
		dq->cosets[i].bruhat_lower = (doublecoset_list_t*)0;
		dq->cosets[i].bruhat_higher = (doublecoset_list_t*)0;
		dq->cosets[i].min = (weylgroup_element_t*)0;
		dq->cosets[i].max = (weylgroup_element_t*)0;
	}

	LOG("Create bitmasks.\n");

	for(uint64_t i = 0; i < (1 << rank); i++) {
		if(__builtin_popcountll(i) % 2 == 1)
			bitmask_reverse[i] = -1;
		else {
			bitmask[index] = i;
			bitmask_reverse[i] = index++;
		}
	}

	LOG("Generate bruhat order.\n");

	for(int i = 0; i < dq->count; i++) {
		for(int j = 0; j < rank - 1; j++) {
			if(!(bitmask[i] & BIT(j)) && (bitmask[i] & BIT(j+1))) {
				int lowerind = bitmask_reverse[bitmask[i] ^ (BIT(j) | BIT(j+1))];
				dq->lists[nlists].next = dq->cosets[i].bruhat_lower;
				dq->cosets[i].bruhat_lower = &dq->lists[nlists];
				dq->cosets[i].bruhat_lower->to = &dq->cosets[lowerind];
				nlists++;
			}
		}
		if((bitmask[i] & BIT(0)) && (bitmask[i] & BIT(1))) {
			int lowerind = bitmask_reverse[bitmask[i] & ~(BIT(0) | BIT(1))];
			dq->lists[nlists].next = dq->cosets[i].bruhat_lower;
			dq->cosets[i].bruhat_lower = &dq->lists[nlists];
			dq->cosets[i].bruhat_lower->to = &dq->cosets[lowerind];
			nlists++;
		}
	}

	LOG("Revert bruhat order.\n");

	for(int i = 0; i < dq->count; i++) {
		for(doublecoset_list_t *cur = dq->cosets[i].bruhat_lower; cur; cur = cur->next) {
			dq->lists[nlists].next = cur->to->bruhat_higher;
			cur->to->bruhat_higher = &dq->lists[nlists];
			cur->to->bruhat_higher->to = &dq->cosets[i];
			nlists++;
		}
	}

	LOG("Find opposites.\n");

	for(int i = 0; i < dq->count; i++) {
		int oppind = bitmask_reverse[~bitmask[i] & ((1<<rank) - 1)];
		dq->cosets[i].opposite = &dq->cosets[oppind];
	}

	/*
	printf("\n");
	printf("digraph test123 {\n");

	for(int i = 0; i < dq->count; i++) {
		for(doublecoset_list_t *cur = dq->cosets[i].bruhat_lower; cur; cur = cur->next) {
			printf("\"0x%02x\" -> \"0x%02x\";\n", bitmask[i], bitmask[cur->to->index]);
		}
	}

	printf("}\n\n");

	printf("Opposites:\n");
	for(int i = 0; i < dq->count; i++)
		printf("0x%02x <-> %d 0x%02x\n", bitmask[i], dq->cosets[i].opposite->index, bitmask[dq->cosets[i].opposite->index]);
	printf("\n");
	*/

	long count = enumerate_balanced_thickenings(dq, 0, 0);
	printf("Found %ld balanced ideals.\n", count);

	free(bitmask);
	free(bitmask_reverse);
	free(dq->lists);
	free(dq->cosets);
	free(dq);

	return 0;
}