<?php
// phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
declare(strict_types=1);

/**
 * Orchestrates data collection from all enabled source providers.
 *
 * Iterates through enabled sources (Reddit, LLM Research), calls their
 * collect_data() method, and stores results in the ab_source_data table.
 * Handles deduplication via UNIQUE index on (source_type, source_id).
 * Re-seen items get their collected_at timestamp refreshed so the
 * analyzer's 24-hour window picks them up for re-analysis.
 *
 * Triggered by: PRAutoBlogger::run_generation_pipeline() (step 1).
 * Dependencies: Source provider implementations, WordPress $wpdb.
 *
 * @see providers/interface-source-provider.php — Interface providers implement.
 * @see providers/class-reddit-provider.php       — Reddit source provider.
 * @see providers/class-llm-research-provider.php — LLM deep research provider.
 * @see ARCHITECTURE.md                         — Data flow step 1.
 */
class PRAutoBlogger_Source_Collector {

	/**
	 * Pipeline cost tracker — passed to providers that need run_id tagging.
	 * Null when called outside the pipeline (e.g., manual test collection).
	 */
	private ?PRAutoBlogger_Cost_Tracker $cost_tracker = null;

	/**
	 * Inject the pipeline's cost tracker so source providers can log costs
	 * with the correct run_id. Without this, provider costs are orphaned.
	 *
	 * @param PRAutoBlogger_Cost_Tracker $cost_tracker Pipeline cost tracker with run_id set.
	 * @return $this
	 */
	public function set_cost_tracker( PRAutoBlogger_Cost_Tracker $cost_tracker ): self {
		$this->cost_tracker = $cost_tracker;
		return $this;
	}

	/**
	 * Collect data from all enabled source providers and store in database.
	 *
	 * Side effects: HTTP requests to source APIs, database inserts.
	 *
	 * @return int Total number of new records inserted.
	 */
	public function collect_from_all_sources(): int {
		$raw     = get_option( 'prautoblogger_enabled_sources', '["reddit"]' );
		$enabled = json_decode( (string) $raw, true );
		// Only fall back to reddit if the option is corrupt (non-JSON).
		// An empty array '[]' is a valid choice — the user disabled all sources.
		if ( ! is_array( $enabled ) ) {
			$enabled = array( 'reddit' );
		}

		$total_inserted = 0;

		foreach ( $enabled as $source_type ) {
			$provider = $this->get_provider( $source_type );
			if ( null === $provider ) {
				PRAutoBlogger_Logger::instance()->warning( "No provider found for source type: {$source_type}", 'collector' );
				continue;
			}

			try {
				$data            = $provider->collect_data( $this->get_config_for_source( $source_type ) );
				$inserted        = $this->store_data( $data );
				$refreshed       = count( $data ) - $inserted;
				$total_inserted += $inserted;

				PRAutoBlogger_Logger::instance()->info(
					sprintf( 'Collected %d items from %s (%d new, %d refreshed).', count( $data ), $source_type, $inserted, $refreshed ),
					'collector'
				);
			} catch ( \Throwable $e ) {
				PRAutoBlogger_Logger::instance()->error( sprintf( 'Collection %s from %s: %s', get_class( $e ), $source_type, $e->getMessage() ), 'collector' );
				// Continue with other sources — one failure shouldn't stop everything.
			}
		}

		return $total_inserted;
	}

	/**
	 * Retrieve source data rows by their database IDs.
	 *
	 * Used by the image pipeline to build Image B's source-driven prompt from
	 * the source_ids stored on the Article_Idea. Returns the first matching
	 * row's title and content; these map directly to what
	 * Image_Prompt_Builder::build_source_prompt() expects.
	 *
	 * Side effects: one SELECT query.
	 *
	 * @param int[] $ids Database row IDs from the source_data table.
	 * @return array{title: string, selftext: string}|null First source row, or null if none found.
	 */
	public function get_source_data_for_image( array $ids ): ?array {
		if ( empty( $ids ) ) {
			return null;
		}

		global $wpdb;
		$table        = $wpdb->prefix . 'prautoblogger_source_data';
		$placeholders = implode( ',', array_fill( 0, count( $ids ), '%d' ) );

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare
		$row = $wpdb->get_row(
			$wpdb->prepare(  // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
				"SELECT title, content, subreddit FROM {$table} WHERE id IN ({$placeholders}) ORDER BY score DESC LIMIT 1",
				...$ids
			),
			ARRAY_A
		);

		if ( null === $row ) {
			return null;
		}

		return array(
			'title'    => $row['title'] ?? 'Reddit Discussion',
			'selftext' => $row['content'] ?? '',
		);
	}

	/**
	 * Store collected source data in the database.
	 *
	 * Uses INSERT … ON DUPLICATE KEY UPDATE so that re-seen items refresh
	 * their collected_at timestamp (plus score/comment_count which change
	 * on Reddit over time). Without this, items that age past the
	 * analyzer's 24-hour window would never be re-analyzed even though
	 * they keep appearing in the RSS feed.
	 *
	 * Side effects: database inserts/updates.
	 *
	 * @param PRAutoBlogger_Source_Data[] $items
	 *
	 * @return int Number of new records inserted (updates not counted).
	 */
	private function store_data( array $items ): int {
		global $wpdb;
		$table    = $wpdb->prefix . 'prautoblogger_source_data';
		$inserted = 0;

		foreach ( $items as $item ) {
			$row = $item->to_db_row();

			// Upsert: insert new items, refresh timestamps on duplicates so
			// the analyzer's 24-hour window picks them up again.
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery
			$result = $wpdb->query(
				$wpdb->prepare(  // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
					"INSERT INTO {$table}
					(source_type, source_id, subreddit, title, content, author, score, comment_count, permalink, collected_at, metadata_json)
					VALUES (%s, %s, %s, %s, %s, %s, %d, %d, %s, %s, %s)
					ON DUPLICATE KEY UPDATE
						collected_at  = VALUES(collected_at),
						score         = VALUES(score),
						comment_count = VALUES(comment_count)",
					$row['source_type'],
					$row['source_id'],
					$row['subreddit'],
					$row['title'],
					$row['content'],
					$row['author'],
					$row['score'],
					$row['comment_count'],
					$row['permalink'],
					$row['collected_at'],
					$row['metadata_json']
				)
			);

			// ON DUPLICATE KEY UPDATE returns 2 for updates, 1 for inserts.
			// Only count genuine inserts toward the "new" tally.
			if ( false !== $result && 1 === (int) $result ) {
				++$inserted;
			}
		}

		return $inserted;
	}

	/**
	 * Get the provider instance for a given source type.
	 *
	 * @param string $source_type Source type identifier.
	 *
	 * @return PRAutoBlogger_Source_Provider_Interface|null
	 */
	private function get_provider( string $source_type ): ?PRAutoBlogger_Source_Provider_Interface {
		$providers = array(
			'reddit'       => PRAutoBlogger_Reddit_Provider::class,
			'llm_research' => PRAutoBlogger_LLM_Research_Provider::class,
		);

		/**
		 * Filter the registered source providers.
		 *
		 * @param array<string, string> $providers Map of source_type => class name.
		 */
		$providers = apply_filters( 'prautoblogger_filter_source_providers', $providers );

		if ( ! isset( $providers[ $source_type ] ) ) {
			return null;
		}

		$class = $providers[ $source_type ];

		// Guard against unloadable provider classes (e.g. stub providers not yet
		// autoloadable, or classes removed during development).
		if ( ! class_exists( $class ) ) {
			PRAutoBlogger_Logger::instance()->error(
				sprintf( 'Provider class "%s" for source type "%s" does not exist.', $class, $source_type ),
				'collector'
			);
			return null;
		}

		return new $class();
	}

	/**
	 * Build the configuration array for a specific source type from plugin settings.
	 *
	 * @param string $source_type Source type identifier.
	 *
	 * @return array<string, mixed> Configuration for the provider.
	 */
	private function get_config_for_source( string $source_type ): array {
		if ( 'reddit' === $source_type ) {
			return array(
				'subreddits'        => json_decode( get_option( 'prautoblogger_target_subreddits', '[]' ), true ) ?: array(),
				'limit'             => 25,
				'time_filter'       => 'day',
				'include_comments'  => true,
				'comments_per_post' => 10,
			);
		}

		if ( 'llm_research' === $source_type ) {
			$config = array(
				'model'  => get_option( 'prautoblogger_research_model', PRAUTOBLOGGER_DEFAULT_ANALYSIS_MODEL ),
				'prompt' => get_option( 'prautoblogger_research_prompt', '' ),
			);
			// Pass the pipeline's cost tracker so research costs get tagged
			// with the run_id for post-pipeline amortization across articles.
			if ( null !== $this->cost_tracker ) {
				$config['cost_tracker'] = $this->cost_tracker;
			}
			return $config;
		}

		return array();
	}
}