/* @tier medium @module py @transform payment-online */
/*
 * py_ol_0026.pgc - 지급 상계처리(선지급금 차감) (PY_OL_0026)  [tier=medium]
 *
 * TxCore TX_SERVICE 엔트리. 요청 TXBUF 를 검증하고 임베디드 SQL / 표준
 * DBIO / tx_call 로 처리한 뒤 응답 TXBUF 를 구성한다.
 */
#include <stdio.h>
#include <string.h>

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

EXEC SQL INCLUDE sqlca;

TX_SERVICE(PY_OL_0026, ctx)
{
    char key[16];
    if (tx_buf_get(ctx->in, "KEY", key, sizeof(key)) != TX_OK) {
        tx_log(TX_LOG_ERROR, "[PY_OL_0026] KEY 누락");
        tx_return(ctx, TX_EINVAL, ctx->out);
        return;
    }
    EXEC SQL BEGIN DECLARE SECTION;
    char h_key[16];
    long h_offset, h_amount, h_net;
    EXEC SQL END DECLARE SECTION;

    long offset = 0;

    tx_log(TX_LOG_INFO, "[PY_OL_0026] 지급 상계처리 진입");
    tx_buf_getlong(ctx->in, "OFFSET", &offset);
    if (offset <= 0) { tx_return(ctx, TX_EINVAL, ctx->out); return; }
    strncpy(h_key, key, 15); h_key[15] = '\0';
    h_offset = offset;

    EXEC SQL SELECT amount INTO :h_amount FROM py_ledger WHERE key = :h_key;
    if (sqlca.sqlcode == TX_SQL_NOTFOUND) { tx_return(ctx, TX_ENOENT, ctx->out); return; }
    if (h_offset > h_amount) {
        tx_log(TX_LOG_WARN, "[PY_OL_0026] 상계액 초과 amt=%ld offset=%ld", h_amount, h_offset);
        tx_return(ctx, TX_EINVAL, ctx->out); return;
    }

    if (tx_begin() != TX_OK) tx_log(TX_LOG_WARN, "[PY_OL_0026] tx_begin 경고");
    EXEC SQL UPDATE py_ledger SET amount = amount - :h_offset, upd_ts = now()
        WHERE key = :h_key;
    if (sqlca.sqlcode != TX_SQL_OK) {
        TX_DBIO_LOG_ERR("py_ol_0026 상계"); tx_abort();
        tx_return(ctx, TX_EDB, ctx->out); return;
    }
    EXEC SQL SELECT amount INTO :h_net FROM py_ledger WHERE key = :h_key;
    tx_commit();

    tx_buf_reset(ctx->out);
    tx_buf_setlong(ctx->out, "OFFSET", h_offset);
    tx_buf_setlong(ctx->out, "NETAMT", h_net);
    tx_log(TX_LOG_INFO, "[PY_OL_0026] 상계완료 key=%s net=%ld", key, h_net);
    tx_return(ctx, TX_OK, ctx->out);
}