/*PGR-GNU*****************************************************************
File: bipartite.c

Generated with Template by:
Copyright (c) 2015 pgRouting developers
Mail: project@pgrouting.org

Function's developer:
Copyright (c) 2020 Prakash Tiwari
Mail: 85prakash2017@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.

 ********************************************************************PGR-GNU*/


#include <stdbool.h>

#include "c_common/postgres_connection.h"

#include "c_types/ii_t_rt.h"
#include "c_common/debug_macro.h"
#include "c_common/e_report.h"
#include "c_common/time_msg.h"
#include "drivers/coloring/bipartite_driver.h"


PGDLLEXPORT Datum _pgr_bipartite(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(_pgr_bipartite);


static
void
process(char* edges_sql,
        II_t_rt **result_tuples,
        size_t *result_count) {
    pgr_SPI_connect();
    char* log_msg = NULL;
    char* notice_msg = NULL;
    char* err_msg = NULL;

    PGR_DBG("Starting timer");
    clock_t start_t = clock();
    pgr_do_bipartite(
            edges_sql,
            result_tuples, result_count,
            &log_msg,
            &notice_msg,
            &err_msg);
    time_msg("processing pgr_bipartite()", start_t, clock());


    if (err_msg && (*result_tuples)) {
        pfree(*result_tuples);
        (*result_tuples) = NULL;
        (*result_count) = 0;
    }

    pgr_global_report(&log_msg, &notice_msg, &err_msg);

    pgr_SPI_finish();
}

PGDLLEXPORT Datum
_pgr_bipartite(PG_FUNCTION_ARGS) {
    FuncCallContext     *funcctx;
    TupleDesc            tuple_desc;
    II_t_rt *result_tuples = NULL;
    size_t result_count = 0;
    if (SRF_IS_FIRSTCALL()) {
        MemoryContext   oldcontext;
        funcctx = SRF_FIRSTCALL_INIT();
        oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
        process(
                text_to_cstring(PG_GETARG_TEXT_P(0)),
                &result_tuples,
                &result_count);


        funcctx->max_calls = result_count;

        funcctx->user_fctx = result_tuples;
        if (get_call_result_type(fcinfo, NULL, &tuple_desc)
                != TYPEFUNC_COMPOSITE)
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("function returning record called in context "
                         "that cannot accept type record")));
        funcctx->tuple_desc = tuple_desc;
        MemoryContextSwitchTo(oldcontext);
    }

    funcctx = SRF_PERCALL_SETUP();
    tuple_desc = funcctx->tuple_desc;
    result_tuples = (II_t_rt*) funcctx->user_fctx;

    if (funcctx->call_cntr < funcctx->max_calls) {
        HeapTuple   tuple;
        Datum       result;
        Datum       *values;
        bool        *nulls;
        size_t call_cntr = funcctx->call_cntr;

        size_t numb = 2;
        values =(Datum *)palloc(numb * sizeof(Datum));
        nulls = palloc(numb * sizeof(bool));
        size_t i;
        for (i = 0; i < numb; ++i) {
            nulls[i] = false;
        }
            values[0] = Int64GetDatum(result_tuples[call_cntr].d1.id);
            values[1] = Int64GetDatum(result_tuples[call_cntr].d2.value);
            tuple = heap_form_tuple(tuple_desc, values, nulls);
            result = HeapTupleGetDatum(tuple);
            SRF_RETURN_NEXT(funcctx, result);
        } else {
            SRF_RETURN_DONE(funcctx);
        }
}
