/* @tier easy @module vl @transform validation-online */
/*
 * vl_ol_0019.pgc - 이상금액 탐지 서비스 (VL_OL_0019)  [tier=easy]
 *
 * 가맹점의 과거 평균거래금액(AVG vl_ledger) 을 산출하여, 입력금액이
 * 임계배수(기본 5배) 를 초과하면 이상거래로 판정한다.
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

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

EXEC SQL INCLUDE sqlca;

#define VL0019_DEFAULT_MULT  5

TX_SERVICE(VL_OL_0019, ctx)
{
    EXEC SQL BEGIN DECLARE SECTION;
    char h_merch[16];
    long h_avg_amt;
    long h_sample;
    EXEC SQL END DECLARE SECTION;

    char merch[16];
    long amount = 0;
    long mult = 0;
    long threshold;

    tx_log(TX_LOG_INFO, "[VL_OL_0019] 이상금액 탐지 서비스 진입");

    if (tx_buf_get(ctx->in, "MERCHID", merch, sizeof(merch)) != TX_OK) {
        tx_log(TX_LOG_ERROR, "[VL_OL_0019] 가맹점ID(MERCHID) 누락");
        tx_buf_sets(ctx->out, "ERRCODE", "VL1900");
        tx_return(ctx, TX_EINVAL, ctx->out);
        return;
    }
    if (tx_buf_getlong(ctx->in, "AMOUNT", &amount) != TX_OK ||
        !amount_is_valid(amount)) {
        tx_log(TX_LOG_WARN, "[VL_OL_0019] 금액 범위 오류 amount=%ld", amount);
        tx_buf_sets(ctx->out, "ERRCODE", "VL1901");
        tx_return(ctx, TX_EINVAL, ctx->out);
        return;
    }

    /* 임계배수: 요청에 오면 사용, 없거나 비정상이면 기본값 */
    if (tx_buf_getlong(ctx->in, "MULT", &mult) != TX_OK || mult <= 0) {
        mult = VL0019_DEFAULT_MULT;
    }

    strncpy(h_merch, merch, sizeof(h_merch) - 1);
    h_merch[sizeof(h_merch) - 1] = '\0';

    h_avg_amt = 0;
    h_sample  = 0;
    EXEC SQL SELECT COALESCE(AVG(amount), 0), COUNT(*)
          INTO :h_avg_amt, :h_sample
          FROM vl_ledger
         WHERE merch_id = :h_merch
           AND status  IN ('M', 'S');

    if (sqlca.sqlcode != TX_SQL_OK) {
        TX_DBIO_LOG_ERR("SELECT AVG vl_ledger");
        tx_buf_sets(ctx->out, "ERRCODE", "VL1909");
        tx_return(ctx, TX_EDB, ctx->out);
        return;
    }

    tx_buf_reset(ctx->out);
    tx_buf_sets(ctx->out, "MERCHID", merch);
    tx_buf_setlong(ctx->out, "AMOUNT", amount);
    tx_buf_setlong(ctx->out, "AVGAMT", h_avg_amt);
    tx_buf_setlong(ctx->out, "SAMPLE", h_sample);
    tx_buf_setlong(ctx->out, "MULT", mult);

    /* 표본이 없으면 판단 보류(정상 처리) */
    if (h_sample == 0 || h_avg_amt <= 0) {
        tx_log(TX_LOG_INFO, "[VL_OL_0019] 표본부족 merch=%s 판단보류", merch);
        tx_buf_sets(ctx->out, "RESULT", "NODATA");
        tx_buf_sets(ctx->out, "ERRCODE", RESP_OK);
        tx_return(ctx, TX_OK, ctx->out);
        return;
    }

    threshold = h_avg_amt * mult;
    tx_buf_setlong(ctx->out, "THRESHOLD", threshold);

    if (amount > threshold) {
        tx_log(TX_LOG_WARN, "[VL_OL_0019] 이상금액 탐지 merch=%s amt=%ld thr=%ld",
               merch, amount, threshold);
        tx_buf_sets(ctx->out, "RESULT", "ANOMALY");
        tx_buf_sets(ctx->out, "ERRCODE", "VL1902");
        tx_return(ctx, TX_OK, ctx->out);
        return;
    }

    tx_buf_sets(ctx->out, "RESULT", "NORMAL");
    tx_buf_sets(ctx->out, "ERRCODE", RESP_OK);
    tx_log(TX_LOG_INFO, "[VL_OL_0019] 정상 merch=%s amt=%ld avg=%ld",
           merch, amount, h_avg_amt);
    tx_return(ctx, TX_OK, ctx->out);
}