<?php
/**
 * Scans repository â€“ persistence layer for accessibility scans.
 *
 * @package WPAG
 */

declare(strict_types=1);

namespace WPAG\Database;

use wpdb;

defined( 'ABSPATH' ) || exit;

final class ScansRepository {

	private wpdb $db;
	private string $scans_table;
	private string $issues_table;

	public function __construct() {
		global $wpdb;
		$this->db           = $wpdb;
		$this->scans_table  = $wpdb->prefix . 'wpag_scans';
		$this->issues_table = $wpdb->prefix . 'wpag_issues';
	}

	/**
	 * Create a new scan row in 'queued' state.
	 *
	 * @return array{id:int,uuid:string}
	 */
	public function create( string $url, string $wcag_level = 'AA' ): array {
		$uuid = wp_generate_uuid4();
		$now  = current_time( 'mysql', true );

		$this->db->insert(
			$this->scans_table,
			[
				'scan_uuid'  => $uuid,
				'url'        => $url,
				'status'     => 'queued',
				'wcag_level' => $wcag_level,
				'created_at' => $now,
			],
			[ '%s', '%s', '%s', '%s', '%s' ]
		);

		return [
			'id'   => (int) $this->db->insert_id,
			'uuid' => $uuid,
		];
	}

	/**
	 * Persist axe-core results for a scan and mark it completed.
	 *
	 * @param array<int,array<string,mixed>> $issues
	 */
	public function complete( int $scan_id, int $score, array $issues, ?array $raw = null ): void {
		$now = current_time( 'mysql', true );

		$this->db->update(
			$this->scans_table,
			[
				'status'       => 'completed',
				'score'        => max( 0, min( 100, $score ) ),
				'issues_count' => count( $issues ),
				'raw_payload'  => $raw ? wp_json_encode( $raw ) : null,
				'completed_at' => $now,
			],
			[ 'id' => $scan_id ],
			[ '%s', '%d', '%d', '%s', '%s' ],
			[ '%d' ]
		);

		// Replace any previous issues for this scan (defensive).
		$this->db->delete( $this->issues_table, [ 'scan_id' => $scan_id ], [ '%d' ] );

		foreach ( $issues as $issue ) {
			$this->db->insert(
				$this->issues_table,
				[
					'scan_id'  => $scan_id,
					'rule_id'  => substr( (string) ( $issue['rule_id'] ?? '' ), 0, 80 ),
					'impact'   => $this->normalize_impact( (string) ( $issue['impact'] ?? 'minor' ) ),
					'selector' => (string) ( $issue['selector'] ?? '' ),
					'html'     => isset( $issue['html'] ) ? substr( (string) $issue['html'], 0, 4000 ) : null,
					'help_url' => isset( $issue['help_url'] ) ? esc_url_raw( (string) $issue['help_url'] ) : null,
				],
				[ '%d', '%s', '%s', '%s', '%s', '%s' ]
			);
		}

		$this->update_summary_cache();
	}

	public function fail( int $scan_id, string $reason = '' ): void {
		$this->db->update(
			$this->scans_table,
			[
				'status'       => 'failed',
				'raw_payload'  => wp_json_encode( [ 'error' => $reason ] ),
				'completed_at' => current_time( 'mysql', true ),
			],
			[ 'id' => $scan_id ],
			[ '%s', '%s', '%s' ],
			[ '%d' ]
		);
	}

	/**
	 * @return list<array<string,mixed>>
	 */
	public function list( int $limit = 20, int $offset = 0 ): array {
		$limit  = max( 1, min( 100, $limit ) );
		$offset = max( 0, $offset );

		$rows = $this->db->get_results(
			$this->db->prepare(
				"SELECT id, scan_uuid, url, status, score, wcag_level, issues_count, created_at, completed_at
				 FROM {$this->scans_table}
				 ORDER BY id DESC
				 LIMIT %d OFFSET %d",
				$limit,
				$offset
			),
			ARRAY_A
		);

		return array_map( [ $this, 'map_scan_row' ], $rows ?: [] );
	}

	public function count(): int {
		return (int) $this->db->get_var( "SELECT COUNT(*) FROM {$this->scans_table}" );
	}

	public function find( int $id ): ?array {
		$row = $this->db->get_row(
			$this->db->prepare( "SELECT * FROM {$this->scans_table} WHERE id = %d", $id ),
			ARRAY_A
		);

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

	/**
	 * @return list<array<string,mixed>>
	 */
	public function issues_for( int $scan_id ): array {
		$rows = $this->db->get_results(
			$this->db->prepare(
				"SELECT id, rule_id, impact, selector, html, help_url, fixed
				 FROM {$this->issues_table}
				 WHERE scan_id = %d
				 ORDER BY FIELD(impact,'critical','serious','moderate','minor'), id ASC",
				$scan_id
			),
			ARRAY_A
		);

		return array_map(
			static function ( array $row ): array {
				return [
					'id'       => (int) $row['id'],
					'ruleId'   => $row['rule_id'],
					'impact'   => $row['impact'],
					'selector' => $row['selector'],
					'html'     => $row['html'],
					'helpUrl'  => $row['help_url'],
					'fixed'    => (bool) $row['fixed'],
				];
			},
			$rows ?: []
		);
	}

	public function delete( int $id ): bool {
		// Issues are removed by FK-less cascade via explicit delete.
		$this->db->delete( $this->issues_table, [ 'scan_id' => $id ], [ '%d' ] );
		$result = $this->db->delete( $this->scans_table, [ 'id' => $id ], [ '%d' ] );
		$this->update_summary_cache();
		return (bool) $result;
	}

	public function latest_completed(): ?array {
		$row = $this->db->get_row(
			"SELECT id, scan_uuid, url, status, score, issues_count, created_at, completed_at
			 FROM {$this->scans_table}
			 WHERE status = 'completed'
			 ORDER BY id DESC LIMIT 1",
			ARRAY_A
		);

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

	public function previous_completed_for_url( string $url, int $before_id ): ?array {
		$row = $this->db->get_row(
			$this->db->prepare(
				"SELECT id, scan_uuid, url, status, score, issues_count, created_at, completed_at
				 FROM {$this->scans_table}
				 WHERE status = 'completed' AND url = %s AND id < %d
				 ORDER BY id DESC LIMIT 1",
				$url,
				$before_id
			),
			ARRAY_A
		);

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

	/**
	 * Aggregated counts by impact across the latest completed scan.
	 *
	 * @return array<string,int>
	 */
	public function impact_breakdown_for( int $scan_id ): array {
		$rows = $this->db->get_results(
			$this->db->prepare(
				"SELECT impact, COUNT(*) AS c FROM {$this->issues_table} WHERE scan_id = %d GROUP BY impact",
				$scan_id
			),
			ARRAY_A
		) ?: [];

		$out = [ 'critical' => 0, 'serious' => 0, 'moderate' => 0, 'minor' => 0 ];
		foreach ( $rows as $row ) {
			$out[ $row['impact'] ] = (int) $row['c'];
		}
		return $out;
	}

	private function update_summary_cache(): void {
		$latest = $this->latest_completed();
		if ( ! $latest ) {
			delete_option( 'wpag_last_scan_summary' );
			return;
		}

		update_option(
			'wpag_last_scan_summary',
			[
				'scanId'    => $latest['id'],
				'url'       => $latest['url'],
				'score'     => $latest['score'],
				'issues'    => $latest['issuesCount'],
				'breakdown' => $this->impact_breakdown_for( $latest['id'] ),
				'at'        => $latest['completedAt'],
			]
		);
	}

	private function normalize_impact( string $impact ): string {
		$impact = strtolower( $impact );
		return in_array( $impact, [ 'critical', 'serious', 'moderate', 'minor' ], true ) ? $impact : 'minor';
	}

	/**
	 * @param array<string,mixed> $row
	 * @return array<string,mixed>
	 */
	private function map_scan_row( array $row ): array {
		return [
			'id'           => (int) $row['id'],
			'uuid'         => $row['scan_uuid'] ?? null,
			'url'          => $row['url'],
			'status'       => $row['status'],
			'score'        => isset( $row['score'] ) ? (int) $row['score'] : null,
			'wcagLevel'    => $row['wcag_level'] ?? 'AA',
			'issuesCount'  => (int) ( $row['issues_count'] ?? 0 ),
			'createdAt'    => $row['created_at'],
			'completedAt'  => $row['completed_at'] ?? null,
		];
	}
}