<?php
// =============================================================================
// monthly_report_data.php - 월간 보고서 공유 데이터 계층 (단일 출처)
//
// monthly_report.php(HTML 조회 + CSV 다운로드)와 monthly_report_print.php(PDF
// 저장용 A4 문서 뷰)가 함께 require 한다. 집계 로직을 이 한 곳에만 두어 두 뷰가
// 동일한 값을 쓰게 하고(중복 = 회귀 위험), 인쇄 뷰 전용의 일별 추이·누수 사고·
// 판정(verdict) 파생을 여기서 함께 산출한다.
//
// 산출 변수(require 후 호출부에서 사용):
//   $db, $month, $start_at, $end_at, $report_generated_at, $report_scope,
//   $summary, $sensor_rows,
//   $cal_days, $daily_temp, $daily_hum, $daily_metric_alerts, $daily_leak_alerts,
//   $incidents, $has_incident_table, $unrecovered_leak,
//   $verdict, $verdict_label, $verdict_reason
//
// 제공 헬퍼: month_range(), round_or_null(), fmt_num(), csv_cell(),
//            report_table_exists()
// =============================================================================

// include 전용 — 웹 직접 접근 차단(.htaccess 와 이중 방어). 호출부(monthly_report.php)
// 가 세션 인증 후 require 한다. 익명 요청 컨텍스트에서 단독 실행되지 않게 막는다.
if (PHP_SAPI !== 'cli'
    && basename((string)($_SERVER['SCRIPT_FILENAME'] ?? '')) === basename(__FILE__)) {
    http_response_code(404);
    exit;
}

require_once __DIR__ . '/config.php';

// ─── 공용 헬퍼 (기존 monthly_report.php 에서 이관 — 로직 무변경) ────────────────
if (!function_exists('month_range')) {
    function month_range(string $month): array {
        if (!preg_match('/^\d{4}-\d{2}$/', $month)) {
            $month = date('Y-m');
        }
        $start = DateTime::createFromFormat('Y-m-d H:i:s', $month . '-01 00:00:00');
        if (!$start) {
            $start = new DateTime('first day of this month 00:00:00');
        }
        $end = clone $start;
        $end->modify('first day of next month');
        return [$month, $start->format('Y-m-d H:i:s'), $end->format('Y-m-d H:i:s')];
    }
}

if (!function_exists('round_or_null')) {
    function round_or_null($value, int $precision = 1): ?float {
        return $value !== null ? round((float)$value, $precision) : null;
    }
}

if (!function_exists('fmt_num')) {
    function fmt_num(?float $value, string $unit = ''): string {
        if ($value === null) {
            return '-';
        }
        return htmlspecialchars(rtrim(rtrim(number_format($value, 1), '0'), '.')) . $unit;
    }
}

// CSV 수식 주입(formula injection) 방지: 자유 텍스트 셀이 =,+,-,@,탭,CR 로 시작하면
// 선행 작은따옴표로 무력화한다(Excel/Sheets 가 수식으로 실행하지 않도록).
// 숫자 셀(음수 온도 등)은 호출하지 않는다 — 값이 깨지지 않도록.
if (!function_exists('csv_cell')) {
    function csv_cell($value): string {
        $s = (string)$value;
        if ($s !== '' && in_array($s[0], ['=', '+', '-', '@', "\t", "\r"], true)) {
            return "'" . $s;
        }
        return $s;
    }
}

// 테이블 존재 확인(정보스키마) — dashboard_data.php 의 table_exists() 와 동일 취지지만
// 그 파일은 include 시 부작용(전역 쿼리) 위험이 있어 결합을 피한다. 부재 시 graceful
// degrade(누수 사고 섹션·판정 폴백). 요청 내 static 캐시로 재조회 방지.
if (!function_exists('report_table_exists')) {
    function report_table_exists(PDO $db, string $table): bool {
        static $cache = [];
        if (array_key_exists($table, $cache)) {
            return $cache[$table];
        }
        try {
            $stmt = $db->prepare("
                SELECT COUNT(*) FROM information_schema.TABLES
                WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = :table
            ");
            $stmt->execute([':table' => $table]);
            return $cache[$table] = (int)$stmt->fetchColumn() > 0;
        } catch (Throwable $e) {
            return $cache[$table] = false;
        }
    }
}

$db = get_db();
[$month, $start_at, $end_at] = month_range($_GET['month'] ?? date('Y-m'));
$report_generated_at = date('Y-m-d H:i:s');
$report_scope = '온습도 임계 경보, 누수 감지, 장비 오프라인, SMS';

// ── 월간 요약: SMS 태그별 건수 + 실패 건수 + 총 발송 건수 ─────────────────────
$stmt = $db->prepare("
    SELECT
        " . sms_summary_select_sql() . ",
        COUNT(*) AS total_sms
    FROM leak_sms_log
    WHERE sent_at >= :start_at AND sent_at < :end_at
");
$stmt->execute([':start_at' => $start_at, ':end_at' => $end_at]);
$row = $stmt->fetch() ?: [];

$summary = [
    'high_temp'      => (int)($row['high_temp'] ?? 0),
    'low_temp'       => (int)($row['low_temp'] ?? 0),
    'high_humidity'  => (int)($row['high_humidity'] ?? 0),
    'low_humidity'   => (int)($row['low_humidity'] ?? 0),
    'recovery'       => (int)($row['recovery'] ?? 0),
    'device_offline' => (int)($row['device_offline'] ?? 0),
    'device_online'  => (int)($row['device_online'] ?? 0),
    'leak_alert'     => (int)($row['leak_alert'] ?? 0),
    'leak_recovery'  => (int)($row['leak_recovery'] ?? 0),
    'sms_fail'       => (int)($row['sms_fail'] ?? 0),
    'total_sms'      => (int)($row['total_sms'] ?? 0),
    'metrics'        => 0,
    'avg_temp'       => null,
    'min_temp'       => null,
    'max_temp'       => null,
    'avg_humidity'   => null,
    'min_humidity'   => null,
    'max_humidity'   => null,
];
$summary['threshold_alerts'] = $summary['high_temp'] + $summary['low_temp']
    + $summary['high_humidity'] + $summary['low_humidity'];

// ── 월간 요약: 측정 건수 + 평균/최저/최고 온도·습도 ───────────────────────────
$stmt = $db->prepare("
    SELECT
        COUNT(*)              AS metrics,
        AVG(temperature_c)    AS avg_temp,
        MIN(temperature_c)    AS min_temp,
        MAX(temperature_c)    AS max_temp,
        AVG(humidity_percent) AS avg_humidity,
        MIN(humidity_percent) AS min_humidity,
        MAX(humidity_percent) AS max_humidity
    FROM leak_sensor_metric
    WHERE measured_at >= :start_at AND measured_at < :end_at
");
$stmt->execute([':start_at' => $start_at, ':end_at' => $end_at]);
$row = $stmt->fetch() ?: [];
$summary['metrics']      = (int)($row['metrics'] ?? 0);
$summary['avg_temp']     = round_or_null($row['avg_temp'] ?? null);
$summary['min_temp']     = round_or_null($row['min_temp'] ?? null);
$summary['max_temp']     = round_or_null($row['max_temp'] ?? null);
$summary['avg_humidity'] = round_or_null($row['avg_humidity'] ?? null);
$summary['min_humidity'] = round_or_null($row['min_humidity'] ?? null);
$summary['max_humidity'] = round_or_null($row['max_humidity'] ?? null);

// SMS 신뢰성(성공률, %) — 총 발송 대비 성공 비율. 발송이 없으면 100%로 본다.
$summary['sms_reliability_pct'] = $summary['total_sms'] > 0
    ? (int)round(($summary['total_sms'] - $summary['sms_fail']) / $summary['total_sms'] * 100)
    : 100;

// ── 센서별 SMS 태그별 건수 + 실패 건수 ───────────────────────────────────────
// sensor_id 로만 묶는다(보고명 sensor_name 은 시기별로 다를 수 있어 GROUP 키에서 제외 —
// 한 센서가 여러 행으로 쪼개지는 것 방지). 표시명은 아래에서 sensor_label() 로 결정.
$stmt = $db->prepare("
    SELECT sensor_id, MAX(sensor_name) AS sensor_name,
        " . sms_summary_select_sql() . "
    FROM leak_sms_log
    WHERE sent_at >= :start_at AND sent_at < :end_at
    GROUP BY sensor_id
");
$stmt->execute([':start_at' => $start_at, ':end_at' => $end_at]);
$sms_by_sensor = [];
foreach ($stmt->fetchAll() as $r) {
    $sms_by_sensor[(int)$r['sensor_id']] = $r;
}

// ── 센서별 측정 집계(온습도) ─────────────────────────────────────────────────
// 마찬가지로 sensor_id 로만 묶고, 보고명/위치는 최신 대표값(MAX)만 폴백용으로 가져온다.
$stmt = $db->prepare("
    SELECT sensor_id,
        MAX(sensor_name)      AS sensor_name,
        MAX(device_location)  AS device_location,
        COUNT(*)              AS metrics,
        AVG(temperature_c)    AS avg_temp,
        MIN(temperature_c)    AS min_temp,
        MAX(temperature_c)    AS max_temp,
        AVG(humidity_percent) AS avg_humidity,
        MIN(humidity_percent) AS min_humidity,
        MAX(humidity_percent) AS max_humidity,
        MAX(measured_at)      AS last_measured_at
    FROM leak_sensor_metric
    WHERE measured_at >= :start_at AND measured_at < :end_at
    GROUP BY sensor_id
");
$stmt->execute([':start_at' => $start_at, ':end_at' => $end_at]);
$metric_by_sensor = [];
foreach ($stmt->fetchAll() as $r) {
    $metric_by_sensor[(int)$r['sensor_id']] = $r;
}

// ── 센서별 행 병합(측정 + SMS) ───────────────────────────────────────────────
$sensor_rows = [];
foreach (array_unique(array_merge(array_keys($metric_by_sensor), array_keys($sms_by_sensor))) as $sid) {
    $m = $metric_by_sensor[$sid] ?? [];
    $s = $sms_by_sensor[$sid] ?? [];
    // 표시명/위치: SENSOR_LABELS(현재 관리주체) 우선, 없으면 보고 대표값 폴백 — 대시보드·SMS 와 동일
    [$loc, $name] = sensor_label((int)$sid, $m['device_location'] ?? null, $m['sensor_name'] ?? $s['sensor_name'] ?? null);
    $threshold_alerts = (int)($s['high_temp'] ?? 0) + (int)($s['low_temp'] ?? 0)
                      + (int)($s['high_humidity'] ?? 0) + (int)($s['low_humidity'] ?? 0);
    $leak_alert = (int)($s['leak_alert'] ?? 0);
    $sensor_rows[] = [
        'sensor_id'        => $sid,
        'sensor_name'      => $name,
        'device_location'  => $loc,
        'high_temp'        => (int)($s['high_temp'] ?? 0),
        'low_temp'         => (int)($s['low_temp'] ?? 0),
        'high_humidity'    => (int)($s['high_humidity'] ?? 0),
        'low_humidity'     => (int)($s['low_humidity'] ?? 0),
        'threshold_alerts' => $threshold_alerts,
        'leak_alert'       => $leak_alert,
        'leak_recovery'    => (int)($s['leak_recovery'] ?? 0),
        'recovery'         => (int)($s['recovery'] ?? 0),
        'device_offline'   => (int)($s['device_offline'] ?? 0),
        'device_online'    => (int)($s['device_online'] ?? 0),
        'sms_fail'         => (int)($s['sms_fail'] ?? 0),
        'metrics'          => (int)($m['metrics'] ?? 0),
        'avg_temp'         => round_or_null($m['avg_temp'] ?? null),
        'min_temp'         => round_or_null($m['min_temp'] ?? null),
        'max_temp'         => round_or_null($m['max_temp'] ?? null),
        'avg_humidity'     => round_or_null($m['avg_humidity'] ?? null),
        'min_humidity'     => round_or_null($m['min_humidity'] ?? null),
        'max_humidity'     => round_or_null($m['max_humidity'] ?? null),
        'last_measured_at' => $m['last_measured_at'] ?? '',
        'alert_sort'       => $threshold_alerts + $leak_alert,   // 정렬용(온습도 경보 + 누수 감지)
    ];
}
usort($sensor_rows, function ($a, $b) {
    return [$b['alert_sort'], $a['sensor_id']] <=> [$a['alert_sort'], $b['sensor_id']];
});

// ─── 인쇄 뷰 전용 파생: 당월 일자 축(cal_days) ────────────────────────────────
// 일별 차트가 28~31 가변 말일을 정확히 다루도록 1일~말일 전체 축을 만든다. 결측일은
// null 로 남겨(추이 라인 끊김) 왜곡을 막는다.
$cal_days = [];
try {
    $cursor = new DateTime($start_at);
    $stop   = new DateTime($end_at);
    while ($cursor < $stop) {
        $cal_days[] = $cursor->format('Y-m-d');
        $cursor->modify('+1 day');
    }
} catch (Throwable $e) {
    $cal_days = [];
}

// ─── 쿼리A: 일별 평균 온·습도 (strip-chart 용) ────────────────────────────────
$daily_temp = array_fill_keys($cal_days, null);
$daily_hum  = array_fill_keys($cal_days, null);
try {
    $stmt = $db->prepare("
        SELECT DATE(measured_at) AS d,
               AVG(temperature_c)    AS avg_t,
               AVG(humidity_percent) AS avg_h,
               COUNT(*)              AS c
        FROM leak_sensor_metric
        WHERE measured_at >= :start_at AND measured_at < :end_at
        GROUP BY DATE(measured_at)
        ORDER BY d
    ");
    $stmt->execute([':start_at' => $start_at, ':end_at' => $end_at]);
    foreach ($stmt->fetchAll() as $r) {
        $d = (string)$r['d'];
        if (!array_key_exists($d, $daily_temp)) { continue; }
        $daily_temp[$d] = $r['avg_t'] !== null ? round((float)$r['avg_t'], 1) : null;
        $daily_hum[$d]  = $r['avg_h'] !== null ? round((float)$r['avg_h'], 1) : null;
    }
} catch (Throwable $e) {
    // 스키마 편차(컬럼 부재 등) → 빈 추이로 graceful degrade
    $daily_temp = array_fill_keys($cal_days, null);
    $daily_hum  = array_fill_keys($cal_days, null);
}

// ─── 쿼리B: 일별 경보 발생(온습도 임계 + 누수 감지) — 스택 막대용 ─────────────
$daily_metric_alerts = array_fill_keys($cal_days, 0);
$daily_leak_alerts   = array_fill_keys($cal_days, 0);
try {
    $stmt = $db->prepare("
        SELECT DATE(measured_at) AS d, COUNT(*) AS c
        FROM leak_sensor_metric
        WHERE measured_at >= :start_at AND measured_at < :end_at
          AND metric_status <> 'normal'
        GROUP BY DATE(measured_at)
    ");
    $stmt->execute([':start_at' => $start_at, ':end_at' => $end_at]);
    foreach ($stmt->fetchAll() as $r) {
        $d = (string)$r['d'];
        if (array_key_exists($d, $daily_metric_alerts)) {
            $daily_metric_alerts[$d] = (int)$r['c'];
        }
    }
} catch (Throwable $e) {
    $daily_metric_alerts = array_fill_keys($cal_days, 0);
}
try {
    $stmt = $db->prepare("
        SELECT DATE(sensor_time) AS d, COUNT(*) AS c
        FROM leak_sensor_log
        WHERE sensor_time >= :start_at AND sensor_time < :end_at
          AND event_type = 'leak_alert'
        GROUP BY DATE(sensor_time)
    ");
    $stmt->execute([':start_at' => $start_at, ':end_at' => $end_at]);
    foreach ($stmt->fetchAll() as $r) {
        $d = (string)$r['d'];
        if (array_key_exists($d, $daily_leak_alerts)) {
            $daily_leak_alerts[$d] = (int)$r['c'];
        }
    }
} catch (Throwable $e) {
    $daily_leak_alerts = array_fill_keys($cal_days, 0);
}

// ─── 쿼리C: 월중 누수 사고 로그(leak_incident, 존재 시) ───────────────────────
$has_incident_table = report_table_exists($db, 'leak_incident');
$incidents = [];
if ($has_incident_table) {
    try {
        $stmt = $db->prepare("
            SELECT id, sensor_id, sensor_name, device_location, started_at, recovered_at
            FROM leak_incident
            WHERE started_at >= :start_at AND started_at < :end_at
            ORDER BY started_at ASC
        ");
        $stmt->execute([':start_at' => $start_at, ':end_at' => $end_at]);
        foreach ($stmt->fetchAll() as $r) {
            [$loc, $name] = sensor_label((int)$r['sensor_id'], $r['device_location'] ?? null, $r['sensor_name'] ?? null);
            $started   = $r['started_at'] ?? null;
            $recovered = $r['recovered_at'] ?? null;
            // 지속시간(분) — 미복구(null)는 진행중
            $duration_min = null;
            if ($started !== null && $recovered !== null) {
                $ds = strtotime($started); $de = strtotime($recovered);
                if ($ds !== false && $de !== false && $de >= $ds) {
                    $duration_min = (int)round(($de - $ds) / 60);
                }
            }
            $incidents[] = [
                'id'              => (int)$r['id'],
                'sensor_id'       => (int)$r['sensor_id'],
                'sensor_name'     => $name,
                'device_location' => $loc,
                'started_at'      => $started,
                'recovered_at'    => $recovered,
                'duration_min'    => $duration_min,
                'ongoing'         => $recovered === null,
            ];
        }
    } catch (Throwable $e) {
        $incidents = [];
    }
}

// ─── 판정(verdict) 파생 — 씰·경영 요약이 공유하는 결정론적 규칙 ───────────────
// 미복구 누수: leak_incident 가 있으면 당월 사고 중 recovered_at IS NULL 개수,
// 없으면 [누수감지] SMS − [누수복구] SMS 차이로 폴백(일관성).
if ($has_incident_table) {
    $unrecovered_leak = 0;
    foreach ($incidents as $inc) {
        if ($inc['ongoing']) { $unrecovered_leak++; }
    }
} else {
    $unrecovered_leak = max(0, $summary['leak_alert'] - $summary['leak_recovery']);
}

if ($unrecovered_leak > 0 || $summary['sms_fail'] > 0) {
    $verdict = 'alert';
    $verdict_label = '경보';
    $bits = [];
    if ($unrecovered_leak > 0) { $bits[] = "미복구 누수 {$unrecovered_leak}건"; }
    if ($summary['sms_fail'] > 0) { $bits[] = "SMS 실패 {$summary['sms_fail']}건"; }
    $verdict_reason = implode(' · ', $bits);
} elseif ($summary['threshold_alerts'] > 0 || $summary['device_offline'] > 0) {
    $verdict = 'warn';
    $verdict_label = '주의';
    $bits = [];
    if ($summary['threshold_alerts'] > 0) { $bits[] = "임계 경보 {$summary['threshold_alerts']}건"; }
    if ($summary['device_offline'] > 0) { $bits[] = "오프라인 {$summary['device_offline']}건"; }
    $verdict_reason = implode(' · ', $bits);
} else {
    $verdict = 'ok';
    $verdict_label = '안정';
    $verdict_reason = '미복구 누수·SMS 실패·임계 경보·오프라인 없음';
}