/* @tier medium @module st @transform settlement-online */
/*
 * st_ol_0018.pgc - 정산 상계(offset) 처리 (ST_OL_0018)  [tier=medium]
 *
 * 가맹점 채권(수취)과 채무(지급)를 상계하여 잔액과 방향을 산출한다.
 * 상계 후 잔여채권/잔여채무를 구분해 반환한다. 채권/채무 미입력 시
 * 원장(st_ledger)의 정산완료(S)=채무, 실패/회수(U)=채권으로 집계한다.
 */
#include <stdio.h>
#include <string.h>

#include "txcore.h"
#include "txcore_dbio.h"
#include "acq_util.h"
#include "st_core.h"

EXEC SQL INCLUDE sqlca;


TX_SERVICE(ST_OL_0018, ctx)
{
    EXEC SQL BEGIN DECLARE SECTION;
    char h_merch[16];
    long h_recv;
    long h_pay;
    EXEC SQL END DECLARE SECTION;

    char merch[16];
    long receivable = 0, payable = 0, offset, residual;
    const char *dir;

    tx_log(TX_LOG_INFO, "[ST_OL_0018] 정산 상계 처리 진입");

    if (tx_buf_get(ctx->in, "MERCHID", merch, sizeof(merch)) != TX_OK) {
        tx_return(ctx, TX_EINVAL, ctx->out);
        return;
    }
    tx_buf_getlong(ctx->in, "RECEIVABLE", &receivable);
    tx_buf_getlong(ctx->in, "PAYABLE",    &payable);

    /* 미입력 시 원장 상태별 합계로 채권/채무 집계 */
    if (receivable <= 0 && payable <= 0) {
        strncpy(h_merch, merch, sizeof(h_merch) - 1);
        h_merch[sizeof(h_merch) - 1] = '\0';
        h_recv = 0;
        h_pay  = 0;
        EXEC SQL SELECT
                coalesce(sum(amount) filter (where status = 'U'), 0),
                coalesce(sum(amount) filter (where status = 'S'), 0)
            INTO :h_recv, :h_pay
            FROM st_ledger
            WHERE merch_id = :h_merch;
        if (sqlca.sqlcode == TX_SQL_OK) {
            receivable = h_recv;
            payable    = h_pay;
        } else if (sqlca.sqlcode != TX_SQL_NOTFOUND) {
            TX_DBIO_LOG_ERR("SELECT 상계집계");
        }
    }

    if (receivable < 0 || payable < 0) {
        tx_buf_reset(ctx->out);
        tx_buf_sets(ctx->out, "RESPCODE", RESP_INVALID);
        tx_return(ctx, TX_EINVAL, ctx->out);
        return;
    }

    offset   = (receivable < payable) ? receivable : payable;
    residual = receivable - payable;
    dir      = (residual > 0) ? "RECV" : (residual < 0 ? "PAY" : "EVEN");

    tx_buf_reset(ctx->out);
    tx_buf_sets(ctx->out, "RESPCODE", RESP_OK);
    tx_buf_sets(ctx->out, "MERCHID", merch);
    tx_buf_setlong(ctx->out, "RECEIVABLE", receivable);
    tx_buf_setlong(ctx->out, "PAYABLE", payable);
    tx_buf_setlong(ctx->out, "OFFSET", offset);
    tx_buf_setlong(ctx->out, "RESIDUAL", residual);
    tx_buf_sets(ctx->out, "DIR", dir);
    tx_log(TX_LOG_INFO, "[ST_OL_0018] 상계 recv=%ld pay=%ld offset=%ld 잔액=%ld(%s)",
           receivable, payable, offset, residual, dir);
    tx_return(ctx, TX_OK, ctx->out);
}
