<?php
declare(strict_types=1);

header('Content-Type: application/json; charset=utf-8');

if (session_status() === PHP_SESSION_NONE) {
    session_start();
}

require_once __DIR__ . '/../db_conn.php';

function json_exit(array $payload, int $status = 200): void {
    http_response_code($status);
    echo json_encode($payload, JSON_UNESCAPED_UNICODE);
    exit;
}

function resolve_member_and_company(PDO $pdo): array {
    $sessionMemberId = trim((string)($_SESSION['ss_mb_id'] ?? $_SESSION['member_id'] ?? ''));
    $memberId = $sessionMemberId !== '' ? $sessionMemberId : 'U001';

    $stmtUser = $pdo->prepare('SELECT sys_comp_code FROM edu_users WHERE member_id = ? ORDER BY sys_comp_code LIMIT 1');
    $stmtUser->execute([$memberId]);
    $sysCompCode = (string)($stmtUser->fetchColumn() ?: '');

    if ($sysCompCode === '') {
        json_exit([
            'success' => false,
            'message' => 'edu_users에 회원 정보가 없어 마이클래스 상태를 조회할 수 없습니다.',
            'data' => ['member_id' => $memberId],
        ], 400);
    }

    return [$memberId, $sysCompCode];
}

function ensure_goal_contents(PDO $pdo, string $goalCode, string $quarter, string $actor): int {
    $stmtCnt = $pdo->prepare("SELECT COUNT(*) FROM edu_goal_contents WHERE goal_code = ? AND (is_active = '1' OR is_active IS NULL)");
    $stmtCnt->execute([$goalCode]);
    $existing = (int)$stmtCnt->fetchColumn();
    if ($existing >= 6) {
        return $existing;
    }

    $stmtCandidates = $pdo->prepare(
        "SELECT c.content_id
         FROM edu_contents c
         WHERE (c.is_active = '1' OR c.is_active IS NULL)
           AND (c.goal_code = :goal_code OR c.category_group = :quarter)
         ORDER BY
           CASE WHEN c.sort_order IS NULL THEN 1 ELSE 0 END,
           c.sort_order ASC,
           c.content_id ASC
         LIMIT 6"
    );
    $stmtCandidates->execute([
        ':goal_code' => $goalCode,
        ':quarter' => $quarter,
    ]);
    $candidateIds = $stmtCandidates->fetchAll(PDO::FETCH_COLUMN);

    if (count($candidateIds) < 6) {
        $stmtFallback = $pdo->prepare(
            "SELECT c.content_id
             FROM edu_contents c
             WHERE (c.is_active = '1' OR c.is_active IS NULL)
             ORDER BY
               CASE WHEN c.sort_order IS NULL THEN 1 ELSE 0 END,
               c.sort_order ASC,
               c.content_id ASC
             LIMIT 6"
        );
        $stmtFallback->execute();
        $candidateIds = $stmtFallback->fetchAll(PDO::FETCH_COLUMN);
    }

    $candidateIds = array_values(array_unique(array_filter(array_map('strval', $candidateIds))));

    $stmtUpsert = $pdo->prepare(
        "INSERT INTO edu_goal_contents
            (goal_code, content_id, index_id, is_active, sort_order, created_by, created_at, updated_by, updated_at)
         VALUES
            (?, ?, ?, '1', ?, ?, NOW(), ?, NOW())
         ON DUPLICATE KEY UPDATE
            is_active = VALUES(is_active),
            sort_order = VALUES(sort_order),
            updated_by = VALUES(updated_by),
            updated_at = NOW()"
    );

    foreach ($candidateIds as $idx => $contentId) {
        $order = $idx + 1;
        $stmtUpsert->execute([$goalCode, $contentId, $order, $order, $actor, $actor]);
    }

    $stmtCnt->execute([$goalCode]);
    return (int)$stmtCnt->fetchColumn();
}

try {
    $pdo = db_conn();
    [$memberId, $sysCompCode] = resolve_member_and_company($pdo);

    $stmtGoals = $pdo->query(
        "SELECT goal_code, title, quarter, goal_no, sort_order
         FROM edu_learning_goals
         WHERE (is_active = '1' OR is_active IS NULL)
         ORDER BY base_year DESC, quarter ASC, goal_no ASC, goal_code ASC"
    );
    $goals = $stmtGoals->fetchAll(PDO::FETCH_ASSOC);

    if (!$goals) {
        json_exit(['success' => true, 'data' => ['goals' => [], 'videos' => []]]);
    }

    $stmtSelected = $pdo->prepare(
        "SELECT ug.goal_code, ug.quarter, ug.completed_date, ug.updated_at, lg.title
         FROM edu_user_learning_goals ug
         LEFT JOIN edu_learning_goals lg ON lg.goal_code = ug.goal_code
         WHERE ug.member_id = ?
           AND ug.sys_comp_code = ?
           AND (ug.is_active = '1' OR ug.is_active IS NULL)
         ORDER BY ug.updated_at DESC, ug.goal_code DESC"
    );
    $stmtSelected->execute([$memberId, $sysCompCode]);
    $selectedGoals = $stmtSelected->fetchAll(PDO::FETCH_ASSOC);

    $requestedGoalCode = trim((string)($_GET['goal_code'] ?? ''));
    $activeGoalCode = $requestedGoalCode;
    if ($activeGoalCode === '' && !empty($selectedGoals)) {
        $activeGoalCode = (string)$selectedGoals[0]['goal_code'];
    }
    if ($activeGoalCode === '') {
        $activeGoalCode = (string)$goals[0]['goal_code'];
    }

    $goalIndex = [];
    foreach ($goals as $g) {
        $goalIndex[(string)$g['goal_code']] = $g;
    }

    if (!isset($goalIndex[$activeGoalCode])) {
        $activeGoalCode = (string)$goals[0]['goal_code'];
    }

    $activeQuarter = (string)($goalIndex[$activeGoalCode]['quarter'] ?? '');
    ensure_goal_contents($pdo, $activeGoalCode, $activeQuarter, $memberId);

    $stmtVideos = $pdo->prepare(
        "SELECT
            gc.goal_code,
            gc.content_id,
            gc.sort_order,
            gc.index_id,
            c.title,
            c.description,
            c.description2,
            c.content_url,
            c.thumbnail_url,
            c.category_code,
            c.category_group,
            lh.watch_tm,
            lh.content_tm,
            lh.completed_at
         FROM edu_goal_contents gc
         JOIN edu_contents c ON c.content_id = gc.content_id
         LEFT JOIN edu_learning_histories lh
                ON lh.member_id = ?
               AND lh.sys_comp_code = ?
               AND lh.content_id = gc.content_id
         WHERE gc.goal_code = ?
           AND (gc.is_active = '1' OR gc.is_active IS NULL)
         ORDER BY
            CASE WHEN gc.sort_order IS NULL THEN 1 ELSE 0 END,
            gc.sort_order ASC,
            CASE WHEN gc.index_id IS NULL THEN 1 ELSE 0 END,
            gc.index_id ASC,
            gc.content_id ASC
         LIMIT 6"
    );
    $stmtVideos->execute([$memberId, $sysCompCode, $activeGoalCode]);
    $videos = $stmtVideos->fetchAll(PDO::FETCH_ASSOC);

    $contentIds = array_values(array_unique(array_filter(array_map(static function ($r) {
        return (string)($r['content_id'] ?? '');
    }, $videos))));

    $memoMap = [];
    if (!empty($contentIds)) {
        $in = implode(',', array_fill(0, count($contentIds), '?'));
        $stmtMemo = $pdo->prepare(
            "SELECT content_id, seq, title
             FROM edu_content_memos
             WHERE content_id IN ($in)
               AND (is_active = '1' OR is_active IS NULL)
             ORDER BY content_id ASC, seq ASC"
        );
        $stmtMemo->execute($contentIds);
        $memoRows = $stmtMemo->fetchAll(PDO::FETCH_ASSOC);
        foreach ($memoRows as $m) {
            $cid = (string)$m['content_id'];
            if (!isset($memoMap[$cid])) {
                $memoMap[$cid] = [];
            }
            $memoTitle = trim((string)($m['title'] ?? ''));
            if ($memoTitle !== '') {
                $memoMap[$cid][] = $memoTitle;
            }
        }
    }

    foreach ($videos as $idx => $video) {
        $cid = (string)$video['content_id'];
        $videos[$idx]['memos'] = $memoMap[$cid] ?? [];
        $videos[$idx]['is_completed'] = !empty($video['completed_at']);
        $videos[$idx]['slot_no'] = $idx + 1;
    }

    $stmtProgress = $pdo->prepare(
        "SELECT
            ug.goal_code,
            COUNT(gc.content_id) AS total_count,
            SUM(CASE WHEN lh.completed_at IS NOT NULL THEN 1 ELSE 0 END) AS completed_count
         FROM edu_user_learning_goals ug
         LEFT JOIN edu_goal_contents gc
                ON gc.goal_code = ug.goal_code
               AND (gc.is_active = '1' OR gc.is_active IS NULL)
         LEFT JOIN edu_learning_histories lh
                ON lh.member_id = ug.member_id
               AND lh.sys_comp_code = ug.sys_comp_code
               AND lh.content_id = gc.content_id
         WHERE ug.member_id = ?
           AND ug.sys_comp_code = ?
           AND (ug.is_active = '1' OR ug.is_active IS NULL)
         GROUP BY ug.goal_code"
    );
    $stmtProgress->execute([$memberId, $sysCompCode]);
    $progressRows = $stmtProgress->fetchAll(PDO::FETCH_ASSOC);

    $goalProgress = [];
    foreach ($progressRows as $row) {
        $total = (int)($row['total_count'] ?? 0);
        $completed = (int)($row['completed_count'] ?? 0);
        $goalProgress[(string)$row['goal_code']] = [
            'total_count' => $total,
            'completed_count' => $completed,
            'is_completed' => $total > 0 && $completed >= $total,
        ];
    }

    json_exit([
        'success' => true,
        'data' => [
            'member_id' => $memberId,
            'sys_comp_code' => $sysCompCode,
            'active_goal_code' => $activeGoalCode,
            'goals' => $goals,
            'selected_goals' => $selectedGoals,
            'goal_progress' => $goalProgress,
            'videos' => $videos,
        ],
    ]);
} catch (Throwable $e) {
    json_exit([
        'success' => false,
        'message' => $e->getMessage(),
    ], 500);
}