<?php
/**
 * Store only validated, masked Finding contracts in plugin-owned tables.
 *
 * @package Px320\SiteAudit
 */

declare(strict_types=1);

namespace Px320\SiteAudit\Storage;

use DateTimeImmutable;
use DateTimeZone;
use InvalidArgumentException;
use Px320\SiteAudit\Domain\FindingContract;
use Px320\SiteAudit\Security\LocalHashKey;
use wpdb;

final class FindingRepository {
	private const MAX_CONTRACT_BYTES = 262144;

	private wpdb $database;
	private FindingContract $contract;
	private string $table;

	public function __construct( wpdb $database, FindingContract $contract ) {
		$this->database = $database;
		$this->contract = $contract;
		$this->table    = Schema::tables( $database )['findings'];
	}

	/**
	 * @param array<string, mixed> $finding Validated and masked Finding.
	 */
	public function save( int $run_id, array $finding ): string {
		if ( $run_id < 1 ) {
			throw new InvalidArgumentException( 'invalid_run_id' );
		}

		$this->contract->validate( $finding );

		$json = wp_json_encode( $finding, JSON_UNESCAPED_SLASHES );
		if ( false === $json || strlen( $json ) > self::MAX_CONTRACT_BYTES ) {
			throw new StorageException( 'finding_contract_too_large' );
		}

		$uuid        = wp_generate_uuid4();
		$references  = wp_json_encode( $finding['affected_objects'], JSON_UNESCAPED_SLASHES );
		$references  = false === $references ? '[]' : $references;
		$object_hash = hash_hmac(
			'sha256',
			(string) $finding['check_id'] . '|' . $references,
			( new LocalHashKey() )->derive()
		);

		// Idempotent chunk retry updates the same run/check/object projection.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		$existing = $this->database->get_row(
			$this->database->prepare(
				"SELECT id, finding_uuid, contract_json FROM {$this->table} WHERE run_id = %d AND check_id = %s AND object_hash = %s LIMIT 1",
				$run_id,
				(string) $finding['check_id'],
				$object_hash
			),
			ARRAY_A
		);

		if ( is_array( $existing ) ) {
			$previous = json_decode( (string) $existing['contract_json'], true, 64 );
			if ( is_array( $previous ) && isset( $previous['first_seen'] ) && is_string( $previous['first_seen'] ) ) {
				$finding['first_seen'] = $previous['first_seen'];
				$this->contract->validate( $finding );
				$json = wp_json_encode( $finding, JSON_UNESCAPED_SLASHES );
			}

			if ( false === $json || strlen( $json ) > self::MAX_CONTRACT_BYTES ) {
				throw new StorageException( 'finding_contract_too_large' );
			}

			$updated = $this->database->update(
				$this->table,
				array(
					'category'      => (string) $finding['category'],
					'status'        => (string) $finding['status'],
					'severity'      => (string) $finding['severity'],
					'confidence'    => (string) $finding['confidence'],
					'contract_json' => $json,
					'last_seen_at'  => $this->mysql_timestamp( (string) $finding['last_seen'] ),
				),
				array( 'id' => (int) $existing['id'] ),
				array( '%s', '%s', '%s', '%s', '%s', '%s' ),
				array( '%d' )
			);

			if ( false === $updated ) {
				throw new StorageException( 'finding_update_failed' );
			}

			return (string) $existing['finding_uuid'];
		}

		$inserted = $this->database->insert(
			$this->table,
			array(
				'run_id'        => $run_id,
				'finding_uuid'  => $uuid,
				'check_id'      => (string) $finding['check_id'],
				'category'      => (string) $finding['category'],
				'status'        => (string) $finding['status'],
				'severity'      => (string) $finding['severity'],
				'confidence'    => (string) $finding['confidence'],
				'object_hash'   => $object_hash,
				'contract_json' => $json,
				'first_seen_at' => $this->mysql_timestamp( (string) $finding['first_seen'] ),
				'last_seen_at'  => $this->mysql_timestamp( (string) $finding['last_seen'] ),
			),
			array( '%d', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s' )
		);

		if ( false === $inserted ) {
			throw new StorageException( 'finding_save_failed' );
		}

		return $uuid;
	}

	public function count_for_run( int $run_id ): int {
		if ( $run_id < 1 ) {
			throw new InvalidArgumentException( 'invalid_run_id' );
		}

		// Table name is selected from the compiled Schema allowlist.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		return (int) $this->database->get_var(
			$this->database->prepare(
				"SELECT COUNT(*) FROM {$this->table} WHERE run_id = %d",
				$run_id
			)
		);
	}

	/**
	 * Return storage identities plus validated contracts for local report projection.
	 *
	 * @return list<array{id:int,finding_uuid:string,object_hash:string,finding:array<string,mixed>}>
	 */
	public function records_for_run( int $run_id, int $limit = 200 ): array {
		if ( $run_id < 1 || $limit < 1 || $limit > 200 ) {
			throw new InvalidArgumentException( 'invalid_finding_query' );
		}

		// Table name is selected from the compiled Schema allowlist; LIMIT is validated.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		$rows = $this->database->get_results(
			$this->database->prepare(
				"SELECT id, finding_uuid, object_hash, contract_json FROM {$this->table} WHERE run_id = %d ORDER BY id ASC LIMIT %d",
				$run_id,
				$limit
			),
			ARRAY_A
		);
		if ( ! is_array( $rows ) ) {
			throw new StorageException( 'invalid_finding_contract' );
		}

		$records = array();
		foreach ( $rows as $row ) {
			$records[] = $this->record_from_row( $row );
		}

		return $records;
	}

	/**
	 * Resolve a report-local opaque Finding identity inside one run.
	 *
	 * @return array{id:int,finding_uuid:string,object_hash:string,finding:array<string,mixed>}|null
	 */
	public function record_for_run( int $run_id, string $finding_uuid ): ?array {
		if ( $run_id < 1 || ! wp_is_uuid( $finding_uuid, 4 ) ) {
			return null;
		}

		// Table name is selected from the compiled Schema allowlist and values are parameterized.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		$row = $this->database->get_row(
			$this->database->prepare(
				"SELECT id, finding_uuid, object_hash, contract_json FROM {$this->table} WHERE run_id = %d AND finding_uuid = %s LIMIT 1",
				$run_id,
				$finding_uuid
			),
			ARRAY_A
		);

		return is_array( $row ) ? $this->record_from_row( $row ) : null;
	}

	/**
	 * Return validated Finding contracts for an authorized report view.
	 *
	 * @return list<array<string, mixed>>
	 */
	public function list_for_run( int $run_id, int $limit = 200 ): array {
		$findings = array();
		foreach ( $this->records_for_run( $run_id, $limit ) as $record ) {
			$findings[] = $record['finding'];
		}

		return $findings;
	}

	/**
	 * @param mixed $row Database row.
	 * @return array{id:int,finding_uuid:string,object_hash:string,finding:array<string,mixed>}
	 */
	private function record_from_row( $row ): array {
		if ( ! is_array( $row ) || ! isset( $row['id'], $row['finding_uuid'], $row['object_hash'], $row['contract_json'] ) || (int) $row['id'] < 1 || ! is_string( $row['finding_uuid'] ) || ! wp_is_uuid( $row['finding_uuid'], 4 ) || ! is_string( $row['object_hash'] ) || 1 !== preg_match( '/^[a-f0-9]{64}$/D', $row['object_hash'] ) || ! is_string( $row['contract_json'] ) ) {
			throw new StorageException( 'invalid_finding_contract' );
		}

		$finding = json_decode( $row['contract_json'], true, 64 );
		if ( ! is_array( $finding ) ) {
			throw new StorageException( 'invalid_finding_contract' );
		}
		$this->contract->validate( $finding );

		return array(
			'id'           => (int) $row['id'],
			'finding_uuid' => $row['finding_uuid'],
			'object_hash'  => $row['object_hash'],
			'finding'      => $finding,
		);
	}

	private function mysql_timestamp( string $timestamp ): string {
		try {
			$date = new DateTimeImmutable( $timestamp );
		} catch ( \Exception $exception ) {
			// The previous exception is retained for local debugging, never rendered.
			// phpcs:ignore WordPress.Security.EscapeOutput.ExceptionNotEscaped
			throw new InvalidArgumentException( 'invalid_finding_timestamp', 0, $exception );
		}

		return $date->setTimezone( new DateTimeZone( 'UTC' ) )->format( 'Y-m-d H:i:s' );
	}
}