<?php

if (!defined('ABSPATH')) {
    exit;
}

interface ABJ_404_Solution_ViewSnapshotCacheHostInterface {
    /** @param string $sub @param array<string, mixed> $tableOptions @return bool */
    public function viewTableSnapshotAvailable($sub, array $tableOptions): bool;
    /** @param string $sub @param array<string, mixed> $tableOptions @return bool */
    public function viewRowsSnapshotAvailable($sub, array $tableOptions): bool;
    /** @param string $sub @param array<string, mixed> $tableOptions @return array<int|string, mixed> */
    public function getRedirectsForView($sub, $tableOptions);
    /** @param string $sub @param array<string, mixed> $tableOptions @return int */
    public function getRedirectsForViewCount(string $sub, array $tableOptions): int;
}

class ABJ_404_Solution_ViewSnapshotCache {

    /** @var ABJ_404_Solution_DatabaseCore */
    private $dbCore;

    /** @var ABJ_404_Solution_Logging */
    private $logger;

    /** @var ABJ_404_Solution_ViewSnapshotCacheHostInterface|null */
    private $host;

    /** @var ABJ_404_Solution_ViewBuildOrchestratorInterface|null */
    private $viewBuildOrchestrator;

    /** @var bool */
    private static $viewSnapshotTableEnsured = false;

    /**
     * @param ABJ_404_Solution_DatabaseCore $dbCore
     * @param ABJ_404_Solution_Logging $logger
     */
    public function __construct(
        ABJ_404_Solution_DatabaseCore $dbCore,
        $logger
    ) {
        $this->dbCore = $dbCore;
        $this->logger = $logger;
    }

    /**
     * @param ABJ_404_Solution_ViewSnapshotCacheHostInterface $host
     * @return void
     */
    public function setHost(ABJ_404_Solution_ViewSnapshotCacheHostInterface $host): void {
        $this->host = $host;
    }

    /**
     * @param ABJ_404_Solution_ViewBuildOrchestratorInterface $viewBuildOrchestrator
     * @return void
     */
    public function setViewBuildOrchestrator(ABJ_404_Solution_ViewBuildOrchestratorInterface $viewBuildOrchestrator): void {
        $this->viewBuildOrchestrator = $viewBuildOrchestrator;
    }

    /** @return ABJ_404_Solution_ViewBuildOrchestratorInterface */
    private function requireViewBuildOrchestrator(): ABJ_404_Solution_ViewBuildOrchestratorInterface {
        if ($this->viewBuildOrchestrator === null) {
            throw new \RuntimeException('ViewSnapshotCache requires ViewBuildOrchestrator (call setViewBuildOrchestrator first)'); // allow-raw-error: assertion, should never reach user
        }
        return $this->viewBuildOrchestrator;
    }

    /** @param bool $value @return void */
    public static function setViewSnapshotTableEnsured(bool $value): void {
        self::$viewSnapshotTableEnsured = $value;
    }

    /**
     * @param string $prefix
     * @param string $sub
     * @param array<string, mixed> $tableOptions
     * @return string
     */
    public function getViewSnapshotCacheKey($prefix, $sub, $tableOptions) {
        // Cache key intentionally omits the mutation watermark. Including it
        // produced a race on busy sites. getRedirectsForView read watermark
        // value A, wrote the snapshot under key-with-A, then an incoming 404
        // capture bumped the watermark to B before viewRowsSnapshotAvailable
        // ran. The availability check read with key-with-B and missed,
        // throwing "Warmup rows stage completed but the row snapshot was not
        // available afterward." The cache TTL of 120 seconds bounds staleness
        // to two minutes after any mutation, which is acceptable. The next
        // admin page load picks up fresh data automatically.
        $cacheShape = array(
            'sub' => (string)$sub,
            'filter' => is_scalar($tableOptions['filter'] ?? 0) ? (int)($tableOptions['filter'] ?? 0) : 0,
            'orderby' => is_scalar($tableOptions['orderby'] ?? 'url') ? (string)($tableOptions['orderby'] ?? 'url') : 'url',
            'order' => is_scalar($tableOptions['order'] ?? 'ASC') ? (string)($tableOptions['order'] ?? 'ASC') : 'ASC',
            'paged' => is_scalar($tableOptions['paged'] ?? 1) ? (int)($tableOptions['paged'] ?? 1) : 1,
            'perpage' => is_scalar($tableOptions['perpage'] ?? ABJ404_OPTION_DEFAULT_PERPAGE) ? (int)($tableOptions['perpage'] ?? ABJ404_OPTION_DEFAULT_PERPAGE) : ABJ404_OPTION_DEFAULT_PERPAGE,
            'filterText' => is_scalar($tableOptions['filterText'] ?? '') ? (string)($tableOptions['filterText'] ?? '') : '',
            'score_range' => (function ($v) { return is_string($v) ? $v : 'all'; })($tableOptions['score_range'] ?? 'all'),
            'blog' => function_exists('get_current_blog_id') ? (int)get_current_blog_id() : 1,
        );
        $encoded = function_exists('wp_json_encode') ? wp_json_encode($cacheShape) : json_encode($cacheShape);
        return $prefix . '_' . md5((string)$encoded);
    }

    /** @return void */
    private function ensureViewSnapshotTableExists(): void {
        if (self::$viewSnapshotTableEnsured) {
            return;
        }
        self::$viewSnapshotTableEnsured = true;
        $sqlFile = __DIR__ . '/sql/createViewCacheTable.sql';
        $create = ABJ_404_Solution_Functions::readFileContents($sqlFile);
        if (is_string($create) && trim($create) !== '') {
            $this->dbCore->queryAndGetResults($create, array('log_errors' => false));
        }
    }

    /** @param string $cacheKey @return string */
    private function getViewSnapshotLockOptionName(string $cacheKey): string {
        return $this->dbCore->getLowercasePrefix() . 'abj404_view_cache_lock_' . md5((string)$cacheKey);
    }

    /** @return string */
    private function getViewSnapshotWarmupGlobalLockKey(): string {
        return 'abj404_view_table_warmup_global';
    }

    /** @return bool */
    public function acquireViewSnapshotWarmupGlobalLock(): bool {
        return $this->acquireViewSnapshotRefreshLock($this->getViewSnapshotWarmupGlobalLockKey());
    }

    /** @return void */
    public function releaseViewSnapshotWarmupGlobalLock(): void {
        $this->releaseViewSnapshotRefreshLock($this->getViewSnapshotWarmupGlobalLockKey());
    }

    /** @param string $cacheKey @return string */
    private function getViewWarmupStateOptionName(string $cacheKey): string {
        return $this->dbCore->getLowercasePrefix() . 'abj404_view_warmup_' . md5((string)$cacheKey);
    }

    /**
     * @param array<string, mixed> $tableOptions
     * @return bool
     */
    public function canUseViewTableSnapshotCache(array $tableOptions): bool {
        if (!empty($tableOptions['_abj404_force_view_rebuild'])) {
            return false;
        }
        $rawOrderBy = $tableOptions['orderby'] ?? '';
        $orderBy = strtolower(is_string($rawOrderBy) ? $rawOrderBy : '');
        $isLogsMaintenanceSort = ($orderBy === 'logshits' || $orderBy === 'last_used');
        $rawPerpage = $tableOptions['perpage'] ?? 0;
        return absint(is_scalar($rawPerpage) ? $rawPerpage : 0) <= 200 && !$isLogsMaintenanceSort;
    }

    /**
     * @param string $sub
     * @param array<string, mixed> $tableOptions
     * @return string
     */
    private function getViewTableWarmupShapeKey(string $sub, array $tableOptions): string {
        return $this->getViewSnapshotCacheKey('abj404_view_table', $sub, $tableOptions);
    }

    /**
     * @param mixed $state
     * @return array<string, mixed>
     */
    private function normalizeViewWarmupState($state): array {
        $default = array(
            'status' => 'idle',
            'stage' => 'rows',
            'stage_started_at' => 0,
            'stage_completed_at' => 0,
            'attempts_by_stage' => array('rows' => 0, 'count' => 0),
            'timings_by_stage' => array(
                'rows' => array('last_ms' => 0, 'max_ms' => 0, 'last_completed_at' => 0, 'last_error' => ''),
                'count' => array('last_ms' => 0, 'max_ms' => 0, 'last_completed_at' => 0, 'last_error' => ''),
            ),
            'query_label' => 'getRedirectsForView',
            'last_error' => '',
            'logged_stale_by_stage' => array(),
            'build_progress_at_stage_start' => array(),
        );
        if (!is_array($state)) {
            return $default;
        }
        /** @var array<string, mixed> $out */
        $out = array_merge($default, $state);
        $status = is_string($out['status'] ?? null) ? $out['status'] : 'idle';
        if (!in_array($status, array('idle', 'running', 'ready', 'blocked', 'error'), true)) {
            $out['status'] = 'idle';
        } else {
            $out['status'] = $status;
        }
        $stage = is_string($out['stage'] ?? null) ? $out['stage'] : 'rows';
        if (!in_array($stage, array('rows', 'count'), true)) {
            $out['stage'] = 'rows';
        } else {
            $out['stage'] = $stage;
        }
        $stageStartedAt = $out['stage_started_at'] ?? 0;
        $stageCompletedAt = $out['stage_completed_at'] ?? 0;
        $out['stage_started_at'] = is_scalar($stageStartedAt) ? intval($stageStartedAt) : 0;
        $out['stage_completed_at'] = is_scalar($stageCompletedAt) ? intval($stageCompletedAt) : 0;

        $attempts = is_array($out['attempts_by_stage']) ? $out['attempts_by_stage'] : array();
        $attemptsRows = $attempts['rows'] ?? 0;
        $attemptsCount = $attempts['count'] ?? 0;
        $out['attempts_by_stage'] = array(
            'rows' => is_scalar($attemptsRows) ? intval($attemptsRows) : 0,
            'count' => is_scalar($attemptsCount) ? intval($attemptsCount) : 0,
        );

        $timings = is_array($out['timings_by_stage']) ? $out['timings_by_stage'] : array();
        $out['timings_by_stage'] = array(
            'rows' => $this->normalizeStageTiming($timings['rows'] ?? null),
            'count' => $this->normalizeStageTiming($timings['count'] ?? null),
        );

        $out['query_label'] = is_string($out['query_label'] ?? null) ? $out['query_label'] : $this->getViewWarmupStageQueryLabel((string)$out['stage']);
        $out['last_error'] = is_string($out['last_error'] ?? null) ? $out['last_error'] : '';
        $out['logged_stale_by_stage'] = is_array($out['logged_stale_by_stage']) ? $out['logged_stale_by_stage'] : array();
        $out['build_progress_at_stage_start'] = is_array($out['build_progress_at_stage_start'] ?? null)
            ? $out['build_progress_at_stage_start'] : array();
        return $out;
    }

    /**
     * @param mixed $timing
     * @return array<string, mixed>
     */
    private function normalizeStageTiming($timing): array {
        $default = array('last_ms' => 0, 'max_ms' => 0, 'last_completed_at' => 0, 'last_error' => '');
        if (!is_array($timing)) {
            return $default;
        }
        $lastMs = $timing['last_ms'] ?? 0;
        $maxMs = $timing['max_ms'] ?? 0;
        $lastCompletedAt = $timing['last_completed_at'] ?? 0;
        $lastError = $timing['last_error'] ?? '';
        return array(
            'last_ms' => is_scalar($lastMs) ? intval($lastMs) : 0,
            'max_ms' => is_scalar($maxMs) ? intval($maxMs) : 0,
            'last_completed_at' => is_scalar($lastCompletedAt) ? intval($lastCompletedAt) : 0,
            'last_error' => is_string($lastError) ? $lastError : '',
        );
    }

    /** @param string $stage @return string */
    private function getViewWarmupStageQueryLabel(string $stage): string {
        return $stage === 'count' ? 'getRedirectsForViewCount' : 'getRedirectsForView';
    }

    /** @param string $stage @return int */
    private function getViewWarmupStageNumber(string $stage): int {
        return $stage === 'count' ? 2 : 1;
    }

    /** @return array<string, int> */
    public function getViewBuildProgressFingerprint(): array {
        return array(
            'started_at' => $this->requireViewBuildOrchestrator()->readBuildProgressOption('started_at', 0),
            'current_stage' => $this->requireViewBuildOrchestrator()->readBuildProgressOption('current_stage', 0),
            'last_started_stage' => $this->requireViewBuildOrchestrator()->readBuildProgressOption('last_started_stage', 0),
            'last_completed_stage' => $this->requireViewBuildOrchestrator()->readBuildProgressOption('last_completed_stage', 0),
            's2_high_water' => $this->requireViewBuildOrchestrator()->readBuildProgressOption('s2_high_water', 0),
            's4_high_water' => $this->requireViewBuildOrchestrator()->readBuildProgressOption('s4_high_water', 0),
            's5_high_water' => $this->requireViewBuildOrchestrator()->readBuildProgressOption('s5_high_water', 0),
        );
    }

    /**
     * @param mixed $baseline
     * @param array<string, int>|null $current
     * @return bool
     */
    private function viewBuildProgressAdvancedSince($baseline, ?array $current = null): bool {
        if (!is_array($baseline) || empty($baseline)) {
            return false;
        }
        $current = $current ?? $this->getViewBuildProgressFingerprint();
        foreach (array('current_stage', 's2_high_water', 's4_high_water', 's5_high_water') as $key) {
            $before = is_scalar($baseline[$key] ?? null) ? intval($baseline[$key]) : 0;
            $after = is_scalar($current[$key] ?? null) ? intval($current[$key]) : 0;
            if ($after > $before) {
                return true;
            }
        }
        return false;
    }

    /**
     * @param array<string, mixed> $state
     * @param string $stage
     * @param array<string, int>|null $currentProgress
     * @return bool
     */
    private function forgiveWarmupAttemptIfBuildProgressed(array &$state, string $stage, ?array $currentProgress = null): bool {
        if (!$this->viewBuildProgressAdvancedSince($state['build_progress_at_stage_start'] ?? array(), $currentProgress)) {
            return false;
        }
        $attempts = is_array($state['attempts_by_stage'] ?? null) ? $state['attempts_by_stage'] : array('rows' => 0, 'count' => 0);
        $rawAttempt = $attempts[$stage] ?? 0;
        $attempts[$stage] = max(0, (is_scalar($rawAttempt) ? intval($rawAttempt) : 0) - 1);
        $state['attempts_by_stage'] = $attempts;
        $state['build_progress_at_stage_start'] = is_array($currentProgress)
            ? $currentProgress : $this->getViewBuildProgressFingerprint();
        return true;
    }

    /**
     * @param string $optionName
     * @return array<string, mixed>
     */
    private function getViewWarmupState(string $optionName): array {
        if (!function_exists('get_option')) {
            return $this->normalizeViewWarmupState(null);
        }
        return $this->normalizeViewWarmupState(get_option($optionName, array()));
    }

    /**
     * @param string $optionName
     * @param array<string, mixed> $state
     * @return void
     */
    private function setViewWarmupState(string $optionName, array $state): void {
        if (function_exists('update_option')) {
            update_option($optionName, $state, false);
        } else if (function_exists('add_option')) {
            add_option($optionName, $state, '', false);
        }
    }

    /**
     * @param string $sub
     * @param array<string, mixed> $tableOptions
     * @return array<string, mixed>
     */
    public function warmViewTableSnapshotStage(string $sub, array $tableOptions): array {
        if (!$this->canUseViewTableSnapshotCache($tableOptions)) {
            return array(
                'status' => 'ready',
                'ready' => true,
                'uncached' => true,
                'stage' => 'rows',
                'stageNumber' => 1,
                'queryLabel' => 'getRedirectsForView',
                'message' => 'This table shape is not snapshot-cacheable.',
            );
        }

        $host = $this->host;
        if ($host === null) {
            throw new \RuntimeException('ViewSnapshotCache requires host (call setHost first)'); // allow-raw-error: assertion, should never reach user
        }

        $shapeKey = $this->getViewTableWarmupShapeKey($sub, $tableOptions);
        $optionName = $this->getViewWarmupStateOptionName($shapeKey);
        $state = $this->getViewWarmupState($optionName);
        $now = time();

        if ($host->viewTableSnapshotAvailable($sub, $tableOptions)) {
            $state['status'] = 'ready';
            $state['stage'] = 'count';
            $state['query_label'] = 'getRedirectsForViewCount';
            $state['stage_completed_at'] = $now;
            $state['last_error'] = '';
            $this->setViewWarmupState($optionName, $state);
            return $this->formatViewWarmupResponse($state, true);
        }

        if ($host->viewRowsSnapshotAvailable($sub, $tableOptions)) {
            $state['stage'] = 'count';
            $state['query_label'] = 'getRedirectsForViewCount';
        } else {
            $state['stage'] = 'rows';
            $state['query_label'] = 'getRedirectsForView';
        }

        $stage = (string)$state['stage'];
        $attempts = is_array($state['attempts_by_stage']) ? $state['attempts_by_stage'] : array('rows' => 0, 'count' => 0);
        $attemptCountRaw = $attempts[$stage] ?? 0;
        $attemptCount = is_scalar($attemptCountRaw) ? intval($attemptCountRaw) : 0;

        if ($state['status'] === 'running') {
            $stageStartedAt = $state['stage_started_at'] ?? 0;
            $elapsed = $now - (is_scalar($stageStartedAt) ? intval($stageStartedAt) : 0);
            if ($elapsed <= ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_WARMUP_STALE_SECONDS) {
                return $this->formatViewWarmupResponse($state, false);
            }
            $currentBuildProgress = $this->getViewBuildProgressFingerprint();
            if ($this->forgiveWarmupAttemptIfBuildProgressed($state, $stage, $currentBuildProgress)) {
                $attempts = is_array($state['attempts_by_stage']) ? $state['attempts_by_stage'] : array('rows' => 0, 'count' => 0);
                $attemptCountRaw = $attempts[$stage] ?? 0;
                $attemptCount = is_scalar($attemptCountRaw) ? intval($attemptCountRaw) : 0;
            }
            if ($attemptCount >= ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_WARMUP_MAX_ATTEMPTS) {
                $state['status'] = 'blocked';
                $previousLastError = $state['last_error'] ?? '';
                $previousError = is_string($previousLastError) ? trim($previousLastError) : '';
                $state['last_error'] = 'Previous warmup stage was killed or stalled too many times.'
                    . ($this->isViewWarmupErrorDiagnostic($previousError) ? ' Previous error: ' . $previousError : '');
                $this->logViewWarmupFailure($sub, $tableOptions, $state);
                $this->setViewWarmupState($optionName, $state);
                return $this->formatViewWarmupResponse($state, false);
            }
            $loggedKey = $stage . ':' . (is_scalar($stageStartedAt) ? intval($stageStartedAt) : 0);
            $loggedStaleByStage = is_array($state['logged_stale_by_stage'] ?? null) ? $state['logged_stale_by_stage'] : array();
            if (empty($loggedStaleByStage[$loggedKey])) {
                $this->logStaleViewWarmupStage($sub, $tableOptions, $state, $elapsed, $attemptCount);
                $loggedStaleByStage[$loggedKey] = 1;
                $state['logged_stale_by_stage'] = $loggedStaleByStage;
            }
        }

        if ($attemptCount >= ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_WARMUP_MAX_ATTEMPTS) {
            $previousLastError = $state['last_error'] ?? '';
            $previousError = is_string($previousLastError) ? trim($previousLastError) : '';
            if (!$this->isViewWarmupErrorDiagnostic($previousError)) {
                $attempts[$stage] = ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_WARMUP_MAX_ATTEMPTS - 1;
                $state['attempts_by_stage'] = $attempts;
                $attemptCount = is_scalar($attempts[$stage] ?? 0) ? intval($attempts[$stage]) : 0;
            }
        }

        if ($attemptCount >= ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_WARMUP_MAX_ATTEMPTS) {
            $state['status'] = 'blocked';
            $state['last_error'] = 'Warmup stage reached the retry limit.'
                . ($this->isViewWarmupErrorDiagnostic($previousError) ? ' Previous error: ' . $previousError : '');
            $this->logViewWarmupFailure($sub, $tableOptions, $state);
            $this->setViewWarmupState($optionName, $state);
            return $this->formatViewWarmupResponse($state, false);
        }

        if (!$this->acquireViewSnapshotWarmupGlobalLock()) {
            $state['status'] = 'running';
            $state['last_error'] = 'Another table cache warmup is already running for this site.';
            return $this->formatViewWarmupResponse($state, false, array(
                'locked' => true,
                'lockScope' => 'site',
                'retryAfterMs' => 2500,
            ));
        }

        $attempts[$stage] = $attemptCount + 1;
        $state['status'] = 'running';
        $state['stage_started_at'] = $now;
        $state['stage_completed_at'] = 0;
        $state['attempts_by_stage'] = $attempts;
        $state['query_label'] = $this->getViewWarmupStageQueryLabel($stage);
        $state['last_error'] = '';
        $state['build_progress_at_stage_start'] = $this->getViewBuildProgressFingerprint();
        $this->setViewWarmupState($optionName, $state);

        $stageOptions = $tableOptions;
        $stageOptions['_abj404_query_timeout'] = ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_WARMUP_STAGE_TIMEOUT_SECONDS;
        $stageOptions['_abj404_throw_on_view_query_error'] = true;

        $startMs = microtime(true);
        try {
            if ($stage === 'rows') {
                $host->getRedirectsForView($sub, $stageOptions);
                if (!$host->viewRowsSnapshotAvailable($sub, $tableOptions)) {
                    throw new \Exception('Warmup rows stage completed but the row snapshot was not available afterward.'); // allow-raw-error: pre-existing warmup assertion moved from ViewReadService.php
                }
                $state['status'] = 'idle';
                $state['stage'] = 'count';
                $state['query_label'] = 'getRedirectsForViewCount';
            } else {
                $host->getRedirectsForViewCount($sub, $stageOptions);
                if (!$host->viewTableSnapshotAvailable($sub, $tableOptions)) {
                    throw new \Exception('Warmup count stage completed but the full table snapshot was not available afterward.'); // allow-raw-error: pre-existing warmup assertion moved from ViewReadService.php
                }
                $state['status'] = 'ready';
                $state['stage'] = 'count';
                $state['query_label'] = 'getRedirectsForViewCount';
            }
            $elapsedMs = (int)round((microtime(true) - $startMs) * 1000);
            $state['stage_completed_at'] = time();
            $state['last_error'] = '';

            $timingsByStage = is_array($state['timings_by_stage'] ?? null) ? $state['timings_by_stage'] : array();
            $timings = $this->normalizeStageTiming($timingsByStage[$stage] ?? null);
            $timings['last_ms'] = $elapsedMs;
            $timings['max_ms'] = max($timings['max_ms'], $elapsedMs);
            $timings['last_completed_at'] = $state['stage_completed_at'];
            $timings['last_error'] = '';
            $timingsByStage[$stage] = $timings;
            $state['timings_by_stage'] = $timingsByStage;

            $this->logger->debugMessage(sprintf(
                "[warmup] shape=%s stage=%s ms=%d attempts=%d error=",
                substr($shapeKey, 0, 8),
                $stage,
                $elapsedMs,
                $attemptCount + 1
            ));

            $this->setViewWarmupState($optionName, $state);
            return $this->formatViewWarmupResponse($state, $state['status'] === 'ready');
        } catch (Throwable $e) {
            $elapsedMs = (int)round((microtime(true) - $startMs) * 1000);
            $errorMessage = $e->getMessage();
            $state['last_error'] = $errorMessage;
            $state['stage_completed_at'] = time();
            $currentAttempts = $attempts[$stage] ?? 0;
            if ($this->forgiveWarmupAttemptIfBuildProgressed($state, $stage)) {
                $attempts = is_array($state['attempts_by_stage']) ? $state['attempts_by_stage'] : $attempts;
                $rawAttemptCount = $attempts[$stage] ?? 0;
                $currentAttempts = is_scalar($rawAttemptCount) ? intval($rawAttemptCount) : 0;
            }
            $state['status'] = ($currentAttempts >= ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_WARMUP_MAX_ATTEMPTS) ? 'blocked' : 'idle';

            $timingsByStage = is_array($state['timings_by_stage'] ?? null) ? $state['timings_by_stage'] : array();
            $timings = $this->normalizeStageTiming($timingsByStage[$stage] ?? null);
            $timings['last_error'] = $errorMessage;
            $timingsByStage[$stage] = $timings;
            $state['timings_by_stage'] = $timingsByStage;

            $this->logger->debugMessage(sprintf(
                "[warmup] shape=%s stage=%s ms=%d attempts=%d error=%s",
                substr($shapeKey, 0, 8),
                $stage,
                $elapsedMs,
                $attemptCount + 1,
                $errorMessage
            ));

            $this->logViewWarmupFailure($sub, $tableOptions, $state);
            $this->setViewWarmupState($optionName, $state);
            return $this->formatViewWarmupResponse($state, false);
        } finally {
            $this->releaseViewSnapshotWarmupGlobalLock();
        }
    }

    /**
     * @param array<string, mixed> $state
     * @param bool $ready
     * @param array<string, mixed> $extra
     * @return array<string, mixed>
     */
    private function formatViewWarmupResponse(array $state, bool $ready, array $extra = array()): array {
        $stageValue = $state['stage'] ?? 'rows';
        $stage = is_string($stageValue) ? $stageValue : 'rows';
        $statusValue = $state['status'] ?? 'idle';
        $status = is_string($statusValue) ? $statusValue : 'idle';
        $stageStartedAt = $state['stage_started_at'] ?? 0;
        $stageCompletedAt = $state['stage_completed_at'] ?? 0;
        $lastError = $state['last_error'] ?? '';
        $response = array(
            'status' => $status,
            'ready' => $ready || $status === 'ready',
            'stage' => $stage,
            'stageNumber' => $this->getViewWarmupStageNumber($stage),
            'queryLabel' => $this->getViewWarmupStageQueryLabel($stage),
            'stageStartedAt' => is_scalar($stageStartedAt) ? intval($stageStartedAt) : 0,
            'stageCompletedAt' => is_scalar($stageCompletedAt) ? intval($stageCompletedAt) : 0,
            'attemptsByStage' => is_array($state['attempts_by_stage'] ?? null) ? $state['attempts_by_stage'] : array(),
            'timingsByStage' => is_array($state['timings_by_stage'] ?? null) ? $state['timings_by_stage'] : array(),
            'lastError' => is_string($lastError) ? $lastError : '',
        );
        foreach ($extra as $key => $value) {
            if (is_string($key)) {
                $response[$key] = $value;
            }
        }
        return $response;
    }

    /**
     * @param string $sub
     * @param array<string, mixed> $tableOptions
     * @param array<string, mixed> $state
     * @param int $elapsed
     * @param int $attemptCount
     * @return void
     */
    private function logStaleViewWarmupStage(string $sub, array $tableOptions, array $state, int $elapsed, int $attemptCount): void {
        $details = array(
            'stage' => is_string($state['stage'] ?? null) ? $state['stage'] : '',
            'query_label' => is_string($state['query_label'] ?? null) ? $state['query_label'] : '',
            'elapsed_seconds' => $elapsed,
            'subpage' => $sub,
            'attempt_count' => $attemptCount,
            'table_shape' => array(
                'filter' => $tableOptions['filter'] ?? null,
                'orderby' => $tableOptions['orderby'] ?? null,
                'order' => $tableOptions['order'] ?? null,
                'paged' => $tableOptions['paged'] ?? null,
                'perpage' => $tableOptions['perpage'] ?? null,
                'filterText_length' => is_string($tableOptions['filterText'] ?? null) ? strlen($tableOptions['filterText']) : 0,
                'score_range' => $tableOptions['score_range'] ?? null,
            ),
        );
        $message = 'Table cache warmup stage appears stalled: ' . json_encode($details);
        $this->logger->warn($message);
    }

    /**
     * @param string $sub
     * @param array<string, mixed> $tableOptions
     * @param array<string, mixed> $state
     * @return void
     */
    private function logViewWarmupFailure(string $sub, array $tableOptions, array $state): void {
        $details = array(
            'status' => is_string($state['status'] ?? null) ? $state['status'] : '',
            'stage' => is_string($state['stage'] ?? null) ? $state['stage'] : '',
            'stage_number' => $this->getViewWarmupStageNumber(is_string($state['stage'] ?? null) ? $state['stage'] : 'rows'),
            'query_label' => is_string($state['query_label'] ?? null) ? $state['query_label'] : '',
            'last_error' => is_string($state['last_error'] ?? null) ? $state['last_error'] : '',
            'subpage' => $sub,
            'attempts_by_stage' => is_array($state['attempts_by_stage'] ?? null) ? $state['attempts_by_stage'] : array(),
            'table_shape' => array(
                'filter' => $tableOptions['filter'] ?? null,
                'orderby' => $tableOptions['orderby'] ?? null,
                'order' => $tableOptions['order'] ?? null,
                'paged' => $tableOptions['paged'] ?? null,
                'perpage' => $tableOptions['perpage'] ?? null,
                'filterText_length' => is_string($tableOptions['filterText'] ?? null) ? strlen($tableOptions['filterText']) : 0,
                'score_range' => $tableOptions['score_range'] ?? null,
            ),
        );
        $message = 'Table cache warmup failed: ' . json_encode($details);
        $this->logger->errorMessage($message);
    }

    /** @param string $lastError @return bool */
    private function isViewWarmupErrorDiagnostic(string $lastError): bool {
        if ($lastError === '') {
            return false;
        }
        return $lastError !== 'Warmup stage reached the retry limit.'
            && $lastError !== 'Previous warmup stage was killed or stalled too many times.';
    }

    /** @param string $cacheKey @return bool */
    private function isViewSnapshotRefreshLocked(string $cacheKey): bool {
        if (!function_exists('get_option')) {
            return false;
        }
        $lockKey = $this->getViewSnapshotLockOptionName($cacheKey);
        $lockValue = get_option($lockKey, false);
        if ($lockValue === false || $lockValue === '' || $lockValue === null) {
            return false;
        }
        $lockTs = is_numeric($lockValue) ? (int)$lockValue : 0;
        if ($lockTs > 0 && (time() - $lockTs) > ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_REFRESH_COOLDOWN_SECONDS) {
            if (function_exists('delete_option')) {
                delete_option($lockKey);
            }
            return false;
        }
        return true;
    }

    /** @param string $cacheKey @return bool */
    private function acquireViewSnapshotRefreshLock(string $cacheKey): bool {
        if (!function_exists('add_option')) {
            return true;
        }
        if ($this->isViewSnapshotRefreshLocked($cacheKey)) {
            return false;
        }
        $lockKey = $this->getViewSnapshotLockOptionName($cacheKey);
        return (bool)add_option($lockKey, time(), '', false);
    }

    /** @param string $cacheKey @return void */
    private function releaseViewSnapshotRefreshLock(string $cacheKey): void {
        if (function_exists('delete_option')) {
            delete_option($this->getViewSnapshotLockOptionName($cacheKey));
        }
    }

    /**
     * @param mixed $payload
     * @return array<string, mixed>|null
     */
    private function decodeSnapshotPayload($payload) {
        if (!is_string($payload) || $payload === '') {
            return null;
        }
        $decoded = json_decode($payload, true);
        return is_array($decoded) ? $decoded : null;
    }

    /**
     * @param string $cacheKey
     * @param bool $allowExpired
     * @param bool $respectCooldown
     * @return array<string, mixed>|null
     */
    public function getViewRowsSnapshotFromTable(string $cacheKey, bool $allowExpired = false, bool $respectCooldown = false) {
        $this->ensureViewSnapshotTableExists();
        $query = "SELECT payload, refreshed_at, expires_at
            FROM {wp_abj404_view_cache}
            WHERE cache_key = %s LIMIT 1";
        $result = $this->dbCore->queryAndGetResults($query, array('query_params' => array($cacheKey), 'log_errors' => true));
        $resultRows = $result['rows'] ?? array();
        if (!is_array($resultRows) || empty($resultRows) || !is_array($resultRows[0])) {
            return null;
        }
        $row = $resultRows[0];
        $expiresAtRaw = $row['expires_at'] ?? 0;
        $refreshedAtRaw = $row['refreshed_at'] ?? 0;
        $expiresAt = is_scalar($expiresAtRaw) ? intval($expiresAtRaw) : 0;
        $refreshedAt = is_scalar($refreshedAtRaw) ? intval($refreshedAtRaw) : 0;
        $now = time();
        $isFresh = ($expiresAt > $now);
        $recentEnough = ($refreshedAt > 0 && ($now - $refreshedAt) <= ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_REFRESH_COOLDOWN_SECONDS);
        if (!$allowExpired && !$isFresh) {
            return null;
        }
        if ($respectCooldown && !$isFresh && !$recentEnough) {
            return null;
        }
        $payload = $row['payload'] ?? '';
        return $this->decodeSnapshotPayload(is_scalar($payload) ? (string)$payload : '');
    }

    /**
     * @param string $cacheKey
     * @param string $sub
     * @param mixed $rows
     * @param int $ttlSeconds
     * @return void
     */
    public function setViewRowsSnapshotToTable(string $cacheKey, string $sub, $rows, int $ttlSeconds): void {
        if (!is_array($rows)) {
            return;
        }
        $this->ensureViewSnapshotTableExists();
        $encoded = function_exists('wp_json_encode') ? wp_json_encode($rows) : json_encode($rows);
        if (!is_string($encoded)) {
            return;
        }
        $bytes = strlen($encoded);
        if ($bytes > ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_MAX_PAYLOAD_BYTES) {
            return;
        }
        $now = time();
        $expiresAt = $now + max(1, intval($ttlSeconds));
        $query = "INSERT INTO {wp_abj404_view_cache}
            (cache_key, subpage, payload, payload_bytes, refreshed_at, expires_at, updated_at)
            VALUES (%s, %s, %s, %d, %d, %d, %d)
            ON DUPLICATE KEY UPDATE
                subpage = VALUES(subpage),
                payload = VALUES(payload),
                payload_bytes = VALUES(payload_bytes),
                refreshed_at = VALUES(refreshed_at),
                expires_at = VALUES(expires_at),
                updated_at = VALUES(updated_at)";
        $this->dbCore->queryAndGetResults($query, array(
            'query_params' => array($cacheKey, (string)$sub, $encoded, $bytes, $now, $expiresAt, $now),
            'log_errors' => false,
        ));
        $this->cleanupExpiredViewSnapshotRowsIfNeeded();
    }

    /**
     * @param string $cacheKey
     * @param int $timeoutMs
     * @return array<string, mixed>|null
     */
    public function waitForViewRowsSnapshotFromTable(string $cacheKey, int $timeoutMs = 4000) {
        $deadline = microtime(true) + (max(100, intval($timeoutMs)) / 1000);
        while (microtime(true) < $deadline) {
            $rows = $this->getViewRowsSnapshotFromTable($cacheKey, false, false);
            if (is_array($rows)) {
                return $rows;
            }
            usleep(100000);
        }
        return null;
    }

    /** @return void */
    private function cleanupExpiredViewSnapshotRowsIfNeeded(): void {
        if (!function_exists('get_transient') || !function_exists('set_transient')) {
            return;
        }
        $marker = get_transient('abj404_view_cache_cleanup_marker');
        if ($marker !== false) {
            return;
        }
        set_transient('abj404_view_cache_cleanup_marker', time(), 1800);
        $query = "DELETE FROM {wp_abj404_view_cache} WHERE expires_at < %d";
        $this->dbCore->queryAndGetResults($query, array(
            'query_params' => array(time() - ABJ_404_Solution_ViewReadRuntimeState::VIEW_SNAPSHOT_REFRESH_COOLDOWN_SECONDS),
            'log_errors' => false,
        ));
    }

}