<?php

declare( strict_types=1 );

namespace Rowbot\Idna\Test;

use GuzzleHttp\Client;
use PHPUnit\Framework\TestCase;
use Psr\Http\Message\ResponseInterface;
use Rowbot\Idna\Idna;
use RuntimeException;
use Symfony\Component\Cache\Adapter\FilesystemAdapter;

use function array_map;
use function count;
use function explode;
use function in_array;
use function preg_last_error;
use function preg_match_all;
use function sprintf;

use const DIRECTORY_SEPARATOR;
use const PREG_NO_ERROR;

class IdnaV2TestCase extends TestCase {
	private const ERROR_CODE_MAP = [
		'P1'   => Idna::ERROR_DISALLOWED,
		'P4'   => [
			Idna::ERROR_EMPTY_LABEL,
			Idna::ERROR_DOMAIN_NAME_TOO_LONG,
			Idna::ERROR_LABEL_TOO_LONG,
			Idna::ERROR_PUNYCODE,
		],
		'V1'   => Idna::ERROR_INVALID_ACE_LABEL,
		'V2'   => Idna::ERROR_HYPHEN_3_4,
		'V3'   => [ Idna::ERROR_LEADING_HYPHEN, Idna::ERROR_TRAILING_HYPHEN ],
		'V4'   => Idna::ERROR_LABEL_HAS_DOT,
		'V5'   => Idna::ERROR_LEADING_COMBINING_MARK,
		'V6'   => Idna::ERROR_DISALLOWED,
		// V7 and V8 are handled by C* and B* respectively.
		'A3'   => Idna::ERROR_PUNYCODE,
		'A4_1' => Idna::ERROR_DOMAIN_NAME_TOO_LONG,
		'A4_2' => [ Idna::ERROR_EMPTY_LABEL, Idna::ERROR_LABEL_TOO_LONG ],
		'B1'   => Idna::ERROR_BIDI,
		'B2'   => Idna::ERROR_BIDI,
		'B3'   => Idna::ERROR_BIDI,
		'B4'   => Idna::ERROR_BIDI,
		'B5'   => Idna::ERROR_BIDI,
		'B6'   => Idna::ERROR_BIDI,
		'C1'   => Idna::ERROR_CONTEXTJ,
		'C2'   => Idna::ERROR_CONTEXTJ,
		// ContextO isn't tested here.
		// 'C3' => Idna::ERROR_CONTEXTO_PUNCTUATION,
		// 'C4' => Idna::ERROR_CONTEXTO_PUNCTUATION,
		// 'C5' => Idna::ERROR_CONTEXTO_PUNCTUATION,
		// 'C6' => Idna::ERROR_CONTEXTO_PUNCTUATION,
		// 'C7' => Idna::ERROR_CONTEXTO_PUNCTUATION,
		// 'C8' => Idna::ERROR_CONTEXTO_DIGITS,
		// 'C9' => Idna::ERROR_CONTEXTO_DIGITS,
		'X4_2' => Idna::ERROR_EMPTY_LABEL,
		'X3'   => Idna::ERROR_EMPTY_LABEL,
	];

	private const BASE_URI = 'https://www.unicode.org/Public/idna/';
	private const TEST_FILE = 'IdnaTestV2.txt';
	private const CACHE_TTL = 86400 * 7; // 7 DAYS
	private const TEST_DATA_DIR = __DIR__ . DIRECTORY_SEPARATOR . 'data';

	/**
	 * @return array<int, array<int, string>>
	 */
	public function loadTestData( string $version ): array {
		$cache    = new FilesystemAdapter(
			'unicode-idna-test-data',
			self::CACHE_TTL,
			self::TEST_DATA_DIR
		);
		$testData = $cache->getItem( $version );

		if ( $testData->isHit() ) {
			return $testData->get();
		}

		$client   = new Client( [
			'base_uri' => self::BASE_URI,
		] );
		$response = $client->request( 'GET', $version . '/' . self::TEST_FILE );

		if ( $response->getStatusCode() >= 400 ) {
			throw new RuntimeException( sprintf(
				'Got status code %d trying to retrieve %s for Unicode version %s.',
				$response->getStatusCode(),
				self::TEST_FILE,
				$version
			) );
		}

		$data = $this->processResponse( $response );
		$testData->set( $data );
		$cache->save( $testData );

		return $data;
	}

	/**
	 * @return array<int, array<int, string>>
	 */
	private function processResponse( ResponseInterface $response ): array {
		$output = [];

		foreach ( explode( "\n", (string) $response->getBody() ) as $line ) {
			// Ignore empty lines and comments.
			if ( $line === '' || $line[0] === '#' ) {
				continue;
			}

			[ $data ] = explode( '#', $line );
			$columns = array_map( '\trim', explode( ';', $data ) );
			assert( count( $columns ) === 7 );
			$output[] = $columns;
		}

		return $output;
	}

	/**
	 * @param  array<int, int|array<int, int>>  $inherit
	 *
	 * @return array<int, int|array<int, int>>
	 */
	private function resolveErrorCodes( string $statusCodes, array $inherit, array $ignore ): array {
		if ( $statusCodes === '' ) {
			return $inherit;
		}

		if ( $statusCodes === '[]' ) {
			return [];
		}

		$matchCount = preg_match_all( '/[PVUABCX][0-9](?:_[0-9])?/', $statusCodes, $matches );

		if ( preg_last_error() !== PREG_NO_ERROR ) {
			throw new RuntimeException();
		}

		if ( $matchCount === 0 ) {
			throw new RuntimeException();
		}

		$errors = [];

		foreach ( $matches[0] as $match ) {
			if ( $match[0] === 'U' || in_array( $match, $ignore, true ) ) {
				continue;
			}

			if ( ! isset( self::ERROR_CODE_MAP[ $match ] ) ) {
				throw new RuntimeException( sprintf( 'Unhandled error code %s.', $match ) );
			}

			$errors[] = self::ERROR_CODE_MAP[ $match ];
		}

		return $errors;
	}

	/**
	 * @return array{
	 *      0: string,
	 *      1: array<int, int|array<int, int>>,
	 *      2: string,
	 *      3: array<int, int|array<int, int>>,
	 *      4: string,
	 *      5: array<int, int|array<int, int>>
	 * }
	 */
	public function translate(
		string $source,
		string $toUnicode,
		string $toUnicodeStatus,
		string $toAsciiN,
		string $toAsciiNStatus,
		string $toAsciiT,
		string $toAsciiTStatus,
		array $ignore = []
	): array {
		if ( $toUnicode === '' ) {
			$toUnicode = $source;
		}

		if ( $toAsciiN === '' ) {
			$toAsciiN = $toUnicode;
		}

		if ( $toAsciiT === '' ) {
			$toAsciiT = $toAsciiN;
		}

		$toUnicodeStatus = $this->resolveErrorCodes( $toUnicodeStatus, [], $ignore );
		$toAsciiNStatus  = $this->resolveErrorCodes( $toAsciiNStatus, $toUnicodeStatus, $ignore );
		$toAsciiTStatus  = $this->resolveErrorCodes( $toAsciiTStatus, $toAsciiNStatus, $ignore );

		return [
			$toUnicode,
			$toUnicodeStatus,
			$toAsciiN,
			$toAsciiNStatus,
			$toAsciiT,
			$toAsciiTStatus,
		];
	}
}