/*
 * src/test/isolation/isolationtester.c
 *
 * isolationtester.c
 *		Runs an isolation test specified by a spec file.
 */

#ifdef WIN32
#include <windows.h>
#endif

#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libpq-fe.h"

#include "isolationtester.h"

static PGconn  **conns = NULL;
static int	   nconns = 0;

static void run_all_permutations(TestSpec *testspec);
static void run_all_permutations_recurse(TestSpec *testspec, int nsteps, Step **steps);
static void run_named_permutations(TestSpec *testspec);
static void run_permutation(TestSpec *testspec, int nsteps, Step **steps);

static int step_qsort_cmp(const void *a, const void *b);
static int step_bsearch_cmp(const void *a, const void *b);

static void printResultSet(PGresult *res);

/* close all connections and exit */
static void
exit_nicely(void)
{
	int			i;
	for (i = 0; i < nconns; i++)
		PQfinish(conns[i]);
	exit(1);
}

int
main(int argc, char **argv)
{
	const char *conninfo;
	TestSpec   *testspec;
	int			i;

	/*
	 * If the user supplies a parameter on the command line, use it as the
	 * conninfo string; otherwise default to setting dbname=postgres and
	 * using environment variables or defaults for all other connection
	 * parameters.
	 */
	if (argc > 1)
		conninfo = argv[1];
	else
		conninfo = "dbname = postgres";

	/* Read the test spec from stdin */
	spec_yyparse();
	testspec = &parseresult;
	printf("Parsed test spec with %d sessions\n", testspec->nsessions);

	/* Establish connections to the database, one for each session */
	nconns = testspec->nsessions;
	conns = calloc(nconns, sizeof(PGconn *));
	for (i = 0; i < testspec->nsessions; i++)
	{
		PGresult *res;

		conns[i] = PQconnectdb(conninfo);
		if (PQstatus(conns[i]) != CONNECTION_OK)
		{
			fprintf(stderr, "Connection %d to database failed: %s",
					i, PQerrorMessage(conns[i]));
			exit_nicely();
		}

		/*
		 * Suppress NOTIFY messages, which otherwise pop into results at odd
		 * places.
		 */
		res = PQexec(conns[i], "SET client_min_messages = warning;");
		if (PQresultStatus(res) != PGRES_COMMAND_OK)
		{
			fprintf(stderr, "message level setup failed: %s", PQerrorMessage(conns[i]));
			exit_nicely();
		}
		PQclear(res);
	}

	/* Set the session index fields in steps. */
	for (i = 0; i < testspec->nsessions; i++)
	{
		Session *session = testspec->sessions[i];
		int		stepindex;
		for (stepindex = 0; stepindex < session->nsteps; stepindex++)
			session->steps[stepindex]->session = i;
	}

	/*
	 * Run the permutations specified in the spec, or all if none were
	 * explicitly specified.
	 */
	if (testspec->permutations)
		run_named_permutations(testspec);
	else
		run_all_permutations(testspec);

	/* Clean up and exit */
	for (i = 0; i < nconns; i++)
		PQfinish(conns[i]);
	return 0;
}

static int *piles;

/*
 * Run all permutations of the steps and sessions.
 */
static void
run_all_permutations(TestSpec *testspec)
{
	int			nsteps;
	int			i;
	Step	  **steps;

	/* Count the total number of steps in all sessions */
	nsteps = 0;
	for (i = 0; i < testspec->nsessions; i++)
		nsteps += testspec->sessions[i]->nsteps;

	steps = malloc(sizeof(Step *) * nsteps);

	/*
	 * To generate the permutations, we conceptually put the steps of
	 * each session on a pile. To generate a permuation, we pick steps
	 * from the piles until all piles are empty. By picking steps from
	 * piles in different order, we get different permutations.
	 *
	 * A pile is actually just an integer which tells how many steps
	 * we've already picked from this pile.
	 */
	piles = malloc(sizeof(int) * testspec->nsessions);
	for (i = 0; i < testspec->nsessions; i++)
		piles[i] = 0;

	run_all_permutations_recurse(testspec, 0, steps);
}

static void
run_all_permutations_recurse(TestSpec *testspec, int nsteps, Step **steps)
{
	int i;
	int found = 0;

	for (i = 0; i < testspec->nsessions; i++)
	{
		/* If there's any more steps in this pile, pick it and recurse */
		if (piles[i] < testspec->sessions[i]->nsteps)
		{
			steps[nsteps] = testspec->sessions[i]->steps[piles[i]];
			piles[i]++;

			run_all_permutations_recurse(testspec, nsteps + 1, steps);

			piles[i]--;

			found = 1;
		}
	}

	/* If all the piles were empty, this permutation is completed. Run it */
	if (!found)
		run_permutation(testspec, nsteps, steps);
}

/*
 * Run permutations given in the test spec
 */
static void
run_named_permutations(TestSpec *testspec)
{
	int		i, j;
	int		n;
	int		nallsteps;
	Step  **allsteps;

	/* First create a lookup table of all steps */
	nallsteps = 0;
	for (i = 0; i < testspec->nsessions; i++)
		nallsteps += testspec->sessions[i]->nsteps;

	allsteps = malloc(nallsteps * sizeof(Step *));

	n = 0;
	for (i = 0; i < testspec->nsessions; i++)
	{
		for (j = 0; j < testspec->sessions[i]->nsteps; j++)
			allsteps[n++] = testspec->sessions[i]->steps[j];
	}

	qsort(allsteps, nallsteps, sizeof(Step *), &step_qsort_cmp);

	for (i = 0; i < testspec->npermutations; i++)
	{
		Permutation *p = testspec->permutations[i];
		Step **steps;

		steps = malloc(p->nsteps * sizeof(Step *));

		/* Find all the named steps from the lookup table */
		for (j = 0; j < p->nsteps; j++)
		{
			steps[j] = *((Step **) bsearch(p->stepnames[j], allsteps, nallsteps,
										   sizeof(Step *), &step_bsearch_cmp));
			if (steps[j] == NULL)
			{
				fprintf(stderr, "undefined step \"%s\" specified in permutation\n", p->stepnames[j]);
				exit_nicely();
			}
		}

		run_permutation(testspec, p->nsteps, steps);
		free(steps);
	}
}

static int
step_qsort_cmp(const void *a, const void *b)
{
	Step *stepa = *((Step **) a);
	Step *stepb = *((Step **) b);

	return strcmp(stepa->name, stepb->name);
}

static int
step_bsearch_cmp(const void *a, const void *b)
{
	char *stepname = (char *) a;
	Step *step = *((Step **) b);

	return strcmp(stepname, step->name);
}

/*
 * Run one permutation
 */
static void
run_permutation(TestSpec *testspec, int nsteps, Step **steps)
{
	PGresult *res;
	int i;

	printf("\nstarting permutation:");
	for (i = 0; i < nsteps; i++)
		printf(" %s", steps[i]->name);
	printf("\n");

	/* Perform setup */
	if (testspec->setupsql)
	{
		res = PQexec(conns[0], testspec->setupsql);
		if (PQresultStatus(res) != PGRES_COMMAND_OK)
		{
			fprintf(stderr, "setup failed: %s", PQerrorMessage(conns[0]));
			exit_nicely();
		}
		PQclear(res);
	}

	/* Perform per-session setup */
	for (i = 0; i < testspec->nsessions; i++)
	{
		if (testspec->sessions[i]->setupsql)
		{
			res = PQexec(conns[i], testspec->sessions[i]->setupsql);
			if (PQresultStatus(res) != PGRES_COMMAND_OK)
			{
				fprintf(stderr, "setup of session %s failed: %s",
						testspec->sessions[i]->name,
						PQerrorMessage(conns[0]));
				exit_nicely();
			}
			PQclear(res);
		}
	}

	/* Perform steps */
	for (i = 0; i < nsteps; i++)
	{
		Step *step = steps[i];
		printf("step %s: %s\n", step->name, step->sql);
		res = PQexec(conns[step->session], step->sql);

		switch(PQresultStatus(res))
		{
			case PGRES_COMMAND_OK:
				break;

			case PGRES_TUPLES_OK:
				printResultSet(res);
				break;

			case PGRES_FATAL_ERROR:
				/* Detail may contain xid values, so just show primary. */
				printf("%s:  %s\n", PQresultErrorField(res, PG_DIAG_SEVERITY),
					   PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY));
				break;

			default:
				printf("unexpected result status: %s\n",
					   PQresStatus(PQresultStatus(res)));
		}
		PQclear(res);
	}

	/* Perform per-session teardown */
	for (i = 0; i < testspec->nsessions; i++)
	{
		if (testspec->sessions[i]->teardownsql)
		{
			res = PQexec(conns[i], testspec->sessions[i]->teardownsql);
			if (PQresultStatus(res) != PGRES_COMMAND_OK)
			{
				fprintf(stderr, "teardown of session %s failed: %s",
						testspec->sessions[i]->name,
						PQerrorMessage(conns[0]));
				/* don't exit on teardown failure */
			}
			PQclear(res);
		}
	}

	/* Perform teardown */
	if (testspec->teardownsql)
	{
		res = PQexec(conns[0], testspec->teardownsql);
		if (PQresultStatus(res) != PGRES_COMMAND_OK)
		{
			fprintf(stderr, "teardown failed: %s",
					PQerrorMessage(conns[0]));
			/* don't exit on teardown failure */

		}
		PQclear(res);
	}
}

static void
printResultSet(PGresult *res)
{
	int		nFields;
	int		i, j;

    /* first, print out the attribute names */
    nFields = PQnfields(res);
    for (i = 0; i < nFields; i++)
        printf("%-15s", PQfname(res, i));
    printf("\n\n");

    /* next, print out the rows */
    for (i = 0; i < PQntuples(res); i++)
    {
        for (j = 0; j < nFields; j++)
            printf("%-15s", PQgetvalue(res, i, j));
        printf("\n");
    }
}