<?php declare(strict_types = 1);

namespace SlevomatCodingStandard\Sniffs\PHP;

use PHP_CodeSniffer\Files\File;
use PHP_CodeSniffer\Sniffs\Sniff;
use PHP_CodeSniffer\Util\Tokens;
use SlevomatCodingStandard\Helpers\IdentificatorHelper;
use SlevomatCodingStandard\Helpers\TokenHelper;
use function array_key_exists;
use function array_map;
use function array_merge;
use function count;
use function defined;
use function in_array;
use const T_ANON_CLASS;
use const T_ARRAY_CAST;
use const T_BITWISE_AND;
use const T_BITWISE_OR;
use const T_BITWISE_XOR;
use const T_BOOL_CAST;
use const T_BOOLEAN_NOT;
use const T_CASE;
use const T_CLONE;
use const T_CLOSE_PARENTHESIS;
use const T_CLOSURE;
use const T_COALESCE;
use const T_COLON;
use const T_CONSTANT_ENCAPSED_STRING;
use const T_DIVIDE;
use const T_DNUMBER;
use const T_DOLLAR;
use const T_DOUBLE_CAST;
use const T_EMPTY;
use const T_EQUAL;
use const T_EVAL;
use const T_EXIT;
use const T_FN;
use const T_INCLUDE;
use const T_INCLUDE_ONCE;
use const T_INLINE_THEN;
use const T_INT_CAST;
use const T_ISSET;
use const T_LIST;
use const T_LNUMBER;
use const T_LOGICAL_AND;
use const T_LOGICAL_OR;
use const T_MATCH;
use const T_MINUS;
use const T_MODULUS;
use const T_MULTIPLY;
use const T_NEW;
use const T_OBJECT_CAST;
use const T_OPEN_PARENTHESIS;
use const T_PARENT;
use const T_PLUS;
use const T_POW;
use const T_REQUIRE;
use const T_REQUIRE_ONCE;
use const T_SELF;
use const T_SEMICOLON;
use const T_STATIC;
use const T_STRING_CAST;
use const T_STRING_CONCAT;
use const T_UNSET;
use const T_UNSET_CAST;
use const T_USE;
use const T_VARIABLE;
use const T_WHITESPACE;
use const T_YIELD;
use const T_YIELD_FROM;

class UselessParenthesesSniff implements Sniff
{

	public const CODE_USELESS_PARENTHESES = 'UselessParentheses';

	private const OPERATORS = [
		T_POW,
		T_MULTIPLY,
		T_DIVIDE,
		T_MODULUS,
		T_PLUS,
		T_MINUS,
		T_STRING_CONCAT,
	];

	private const OPERATOR_GROUPS = [
		T_POW => 1,
		T_MULTIPLY => 2,
		T_DIVIDE => 2,
		T_MODULUS => 3,
		T_PLUS => 4,
		T_MINUS => 4,
		T_STRING_CONCAT => 5,
	];

	/** @var bool */
	public $ignoreComplexTernaryConditions = false;

	/**
	 * @return array<int, (int|string)>
	 */
	public function register(): array
	{
		return [
			T_OPEN_PARENTHESIS,
		];
	}

	/**
	 * @phpcsSuppress SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingNativeTypeHint
	 * @param File $phpcsFile
	 * @param int $parenthesisOpenerPointer
	 */
	public function process(File $phpcsFile, $parenthesisOpenerPointer): void
	{
		$tokens = $phpcsFile->getTokens();

		if (array_key_exists('parenthesis_owner', $tokens[$parenthesisOpenerPointer])) {
			return;
		}

		/** @var int $pointerBeforeParenthesisOpener */
		$pointerBeforeParenthesisOpener = TokenHelper::findPreviousEffective($phpcsFile, $parenthesisOpenerPointer - 1);
		if (in_array($tokens[$pointerBeforeParenthesisOpener]['code'], array_merge(
			TokenHelper::getNameTokenCodes(),
			[
				T_VARIABLE,
				T_ISSET,
				T_UNSET,
				T_EMPTY,
				T_CLOSURE,
				T_FN,
				T_USE,
				T_ANON_CLASS,
				T_SELF,
				T_STATIC,
				T_EXIT,
				T_CLOSE_PARENTHESIS,
				T_EVAL,
				T_LIST,
				T_INCLUDE,
				T_INCLUDE_ONCE,
				T_REQUIRE,
				T_REQUIRE_ONCE,
				T_INT_CAST,
				T_DOUBLE_CAST,
				T_STRING_CAST,
				T_ARRAY_CAST,
				T_OBJECT_CAST,
				T_BOOL_CAST,
				T_UNSET_CAST,
			],
			defined('T_MATCH') ? [T_MATCH] : []
		), true)
		) {
			return;
		}

		/** @var int $pointerAfterParenthesisOpener */
		$pointerAfterParenthesisOpener = TokenHelper::findNextEffective($phpcsFile, $parenthesisOpenerPointer + 1);
		if (in_array(
			$tokens[$pointerAfterParenthesisOpener]['code'],
			[T_NEW, T_CLONE, T_YIELD, T_YIELD_FROM, T_REQUIRE, T_REQUIRE_ONCE, T_INCLUDE, T_INCLUDE_ONCE, T_ARRAY_CAST],
			true
		)) {
			return;
		}

		if (TokenHelper::findNext(
			$phpcsFile,
			T_EQUAL,
			$parenthesisOpenerPointer + 1,
			$tokens[$parenthesisOpenerPointer]['parenthesis_closer']
		) !== null) {
			return;
		}

		$pointerAfterParenthesisCloser = TokenHelper::findNextEffective(
			$phpcsFile,
			$tokens[$parenthesisOpenerPointer]['parenthesis_closer'] + 1
		);
		if (
			$pointerAfterParenthesisCloser !== null
			&& $tokens[$pointerAfterParenthesisCloser]['code'] === T_OPEN_PARENTHESIS
		) {
			return;
		}

		if (IdentificatorHelper::findStartPointer($phpcsFile, $pointerBeforeParenthesisOpener) !== null) {
			return;
		}

		$this->checkParenthesesAroundConditionInTernaryOperator($phpcsFile, $parenthesisOpenerPointer);
		$this->checkParenthesesAroundCaseInSwitch($phpcsFile, $parenthesisOpenerPointer);
		$this->checkParenthesesAroundVariableOrFunctionCall($phpcsFile, $parenthesisOpenerPointer);
		$this->checkParenthesesAroundString($phpcsFile, $parenthesisOpenerPointer);
		$this->checkParenthesesAroundOperators($phpcsFile, $parenthesisOpenerPointer);
	}

	private function checkParenthesesAroundConditionInTernaryOperator(File $phpcsFile, int $parenthesisOpenerPointer): void
	{
		$tokens = $phpcsFile->getTokens();

		$parenthesisCloserPointer = $tokens[$parenthesisOpenerPointer]['parenthesis_closer'];

		$ternaryOperatorPointer = TokenHelper::findNextEffective($phpcsFile, $parenthesisCloserPointer + 1);
		if ($tokens[$ternaryOperatorPointer]['code'] !== T_INLINE_THEN) {
			return;
		}

		if (TokenHelper::findNext(
			$phpcsFile,
			[T_LOGICAL_AND, T_LOGICAL_OR],
			$parenthesisOpenerPointer + 1,
			$parenthesisCloserPointer
		) !== null) {
			return;
		}

		$pointerBeforeParenthesisOpener = TokenHelper::findPreviousEffective($phpcsFile, $parenthesisOpenerPointer - 1);
		if ($tokens[$pointerBeforeParenthesisOpener]['code'] === T_BOOLEAN_NOT) {
			return;
		}

		if (in_array($tokens[$pointerBeforeParenthesisOpener]['code'], Tokens::$comparisonTokens, true)) {
			return;
		}

		if (in_array($tokens[$pointerBeforeParenthesisOpener]['code'], Tokens::$booleanOperators, true)) {
			return;
		}

		if ($this->ignoreComplexTernaryConditions) {
			if (TokenHelper::findNext(
				$phpcsFile,
				Tokens::$booleanOperators,
				$parenthesisOpenerPointer + 1,
				$parenthesisCloserPointer
			) !== null) {
				return;
			}

			if (TokenHelper::findNextContent(
				$phpcsFile,
				T_WHITESPACE,
				$phpcsFile->eolChar,
				$parenthesisOpenerPointer + 1,
				$parenthesisCloserPointer
			) !== null) {
				return;
			}
		}

		$contentStartPointer = TokenHelper::findNextEffective($phpcsFile, $parenthesisOpenerPointer + 1);
		$contentEndPointer = TokenHelper::findPreviousEffective($phpcsFile, $parenthesisCloserPointer - 1);

		for ($i = $contentStartPointer; $i <= $contentEndPointer; $i++) {
			if ($tokens[$i]['code'] === T_INLINE_THEN) {
				return;
			}
		}

		$fix = $phpcsFile->addFixableError('Useless parentheses.', $parenthesisOpenerPointer, self::CODE_USELESS_PARENTHESES);

		if (!$fix) {
			return;
		}

		$phpcsFile->fixer->beginChangeset();
		for ($i = $parenthesisOpenerPointer; $i < $contentStartPointer; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		for ($i = $contentEndPointer + 1; $i <= $parenthesisCloserPointer; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		$phpcsFile->fixer->endChangeset();
	}

	private function checkParenthesesAroundCaseInSwitch(File $phpcsFile, int $parenthesisOpenerPointer): void
	{
		$tokens = $phpcsFile->getTokens();

		$pointerBeforeParenthesisOpener = TokenHelper::findPreviousEffective($phpcsFile, $parenthesisOpenerPointer - 1);
		if ($tokens[$pointerBeforeParenthesisOpener]['code'] !== T_CASE) {
			return;
		}

		$pointerAfterParenthesisCloser = TokenHelper::findNextEffective(
			$phpcsFile,
			$tokens[$parenthesisOpenerPointer]['parenthesis_closer'] + 1
		);
		if ($tokens[$pointerAfterParenthesisCloser]['code'] !== T_COLON) {
			return;
		}

		$fix = $phpcsFile->addFixableError('Useless parentheses.', $parenthesisOpenerPointer, self::CODE_USELESS_PARENTHESES);

		if (!$fix) {
			return;
		}

		$contentStartPointer = TokenHelper::findNextEffective($phpcsFile, $parenthesisOpenerPointer + 1);
		$contentEndPointer = TokenHelper::findPreviousEffective($phpcsFile, $tokens[$parenthesisOpenerPointer]['parenthesis_closer'] - 1);

		$phpcsFile->fixer->beginChangeset();
		for ($i = $parenthesisOpenerPointer; $i < $contentStartPointer; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		for ($i = $contentEndPointer + 1; $i <= $tokens[$parenthesisOpenerPointer]['parenthesis_closer']; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		$phpcsFile->fixer->endChangeset();
	}

	private function checkParenthesesAroundVariableOrFunctionCall(File $phpcsFile, int $parenthesisOpenerPointer): void
	{
		$tokens = $phpcsFile->getTokens();

		$operatorsPointers = TokenHelper::findNextAll(
			$phpcsFile,
			self::OPERATORS,
			$parenthesisOpenerPointer + 1,
			$tokens[$parenthesisOpenerPointer]['parenthesis_closer']
		);
		if (count($operatorsPointers) !== 0) {
			return;
		}

		$casePointer = TokenHelper::findPreviousEffective($phpcsFile, $parenthesisOpenerPointer - 1);
		if ($tokens[$casePointer]['code'] === T_CASE) {
			return;
		}

		$pointerBeforeParenthesisOpener = TokenHelper::findPreviousEffective($phpcsFile, $parenthesisOpenerPointer - 1);
		if (in_array($tokens[$pointerBeforeParenthesisOpener]['code'], Tokens::$booleanOperators, true)) {
			return;
		}

		$pointerAfterParenthesisCloser = TokenHelper::findNextEffective(
			$phpcsFile,
			$tokens[$parenthesisOpenerPointer]['parenthesis_closer'] + 1
		);
		if (in_array($tokens[$pointerAfterParenthesisCloser]['code'], [T_INLINE_THEN, T_OPEN_PARENTHESIS], true)) {
			return;
		}

		/** @var int $contentStartPointer */
		$contentStartPointer = TokenHelper::findNextEffective($phpcsFile, $parenthesisOpenerPointer + 1);

		if ($tokens[$contentStartPointer]['code'] === T_CONSTANT_ENCAPSED_STRING) {
			return;
		}

		$notBooleanNotOperatorPointer = $contentStartPointer;

		if ($tokens[$contentStartPointer]['code'] === T_BOOLEAN_NOT) {
			/** @var int $notBooleanNotOperatorPointer */
			$notBooleanNotOperatorPointer = TokenHelper::findNextEffective($phpcsFile, $contentStartPointer + 1);
		}

		if (in_array(
			$tokens[$notBooleanNotOperatorPointer]['code'],
			array_merge([T_SELF, T_STATIC, T_PARENT, T_VARIABLE, T_DOLLAR], TokenHelper::getNameTokenCodes()),
			true
		)) {
			$contentEndPointer = IdentificatorHelper::findEndPointer($phpcsFile, $notBooleanNotOperatorPointer);

			if (
				$contentEndPointer === null
				&& in_array($tokens[$notBooleanNotOperatorPointer]['code'], TokenHelper::getNameTokenCodes(), true)
			) {
				$nextPointer = TokenHelper::findNextEffective($phpcsFile, $contentStartPointer + 1);
				if ($tokens[$nextPointer]['code'] === T_OPEN_PARENTHESIS) {
					$contentEndPointer = $contentStartPointer;
				}
			}

			do {
				$nextPointer = TokenHelper::findNextEffective($phpcsFile, $contentEndPointer + 1);
				if ($tokens[$nextPointer]['code'] !== T_OPEN_PARENTHESIS) {
					break;
				}

				$contentEndPointer = $tokens[$nextPointer]['parenthesis_closer'];
			} while (true);
		} else {
			$nextPointer = TokenHelper::findNext($phpcsFile, T_OPEN_PARENTHESIS, $notBooleanNotOperatorPointer + 1);
			if ($nextPointer === null) {
				return;
			}

			$contentEndPointer = $tokens[$nextPointer]['parenthesis_closer'];
		}

		$pointerAfterContent = TokenHelper::findNextEffective($phpcsFile, $contentEndPointer + 1);

		if ($pointerAfterContent !== $tokens[$parenthesisOpenerPointer]['parenthesis_closer']) {
			return;
		}

		$fix = $phpcsFile->addFixableError('Useless parentheses.', $parenthesisOpenerPointer, self::CODE_USELESS_PARENTHESES);

		if (!$fix) {
			return;
		}

		$phpcsFile->fixer->beginChangeset();
		for ($i = $parenthesisOpenerPointer; $i < $contentStartPointer; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		for ($i = $contentEndPointer + 1; $i <= $tokens[$parenthesisOpenerPointer]['parenthesis_closer']; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		$phpcsFile->fixer->endChangeset();
	}

	private function checkParenthesesAroundString(File $phpcsFile, int $parenthesisOpenerPointer): void
	{
		$tokens = $phpcsFile->getTokens();

		/** @var int $stringPointer */
		$stringPointer = TokenHelper::findNextEffective($phpcsFile, $parenthesisOpenerPointer + 1);

		if ($tokens[$stringPointer]['code'] !== T_CONSTANT_ENCAPSED_STRING) {
			return;
		}

		$pointerAfterString = TokenHelper::findNextEffective($phpcsFile, $stringPointer + 1);
		if ($pointerAfterString !== $tokens[$parenthesisOpenerPointer]['parenthesis_closer']) {
			return;
		}

		$fix = $phpcsFile->addFixableError('Useless parentheses.', $parenthesisOpenerPointer, self::CODE_USELESS_PARENTHESES);

		if (!$fix) {
			return;
		}

		$phpcsFile->fixer->beginChangeset();
		for ($i = $parenthesisOpenerPointer; $i < $stringPointer; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		for ($i = $stringPointer + 1; $i <= $tokens[$parenthesisOpenerPointer]['parenthesis_closer']; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		$phpcsFile->fixer->endChangeset();
	}

	private function checkParenthesesAroundOperators(File $phpcsFile, int $parenthesisOpenerPointer): void
	{
		$tokens = $phpcsFile->getTokens();

		$pointerBeforeParenthesisOpener = TokenHelper::findPreviousEffective($phpcsFile, $parenthesisOpenerPointer - 1);
		$pointerAfterParenthesisCloser = TokenHelper::findNextEffective(
			$phpcsFile,
			$tokens[$parenthesisOpenerPointer]['parenthesis_closer'] + 1
		);

		if ($tokens[$pointerBeforeParenthesisOpener]['code'] === T_MINUS) {
			$pointerBeforeMinus = TokenHelper::findPreviousEffective($phpcsFile, $pointerBeforeParenthesisOpener - 1);
			if (!in_array($tokens[$pointerBeforeMinus]['code'], [T_DNUMBER, T_LNUMBER], true)) {
				return;
			}
		}

		if (
			in_array($tokens[$pointerBeforeParenthesisOpener]['code'], Tokens::$booleanOperators, true)
			|| in_array($tokens[$pointerAfterParenthesisCloser]['code'], Tokens::$booleanOperators, true)
		) {
			return;
		}

		$operatorsPointers = [];
		$actualStartPointer = $parenthesisOpenerPointer + 1;
		while (true) {
			$pointer = TokenHelper::findNext(
				$phpcsFile,
				array_merge(
					self::OPERATORS,
					[T_OPEN_PARENTHESIS, T_INLINE_THEN, T_COALESCE, T_BITWISE_AND, T_BITWISE_OR, T_BITWISE_XOR],
					Tokens::$comparisonTokens
				),
				$actualStartPointer,
				$tokens[$parenthesisOpenerPointer]['parenthesis_closer']
			);

			if ($pointer === null) {
				break;
			}

			if (in_array($tokens[$pointer]['code'], [T_INLINE_THEN, T_COALESCE, T_BITWISE_AND, T_BITWISE_OR, T_BITWISE_XOR], true)) {
				return;
			}

			if (in_array($tokens[$pointer]['code'], Tokens::$comparisonTokens, true)) {
				return;
			}

			if ($tokens[$pointer]['code'] === T_OPEN_PARENTHESIS) {
				$actualStartPointer = $tokens[$pointer]['parenthesis_closer'] + 1;
				continue;
			}

			$operatorsPointers[] = $pointer;
			$actualStartPointer = $pointer + 1;
		}

		if (count($operatorsPointers) === 0) {
			return;
		}

		if (
			$tokens[$pointerBeforeParenthesisOpener]['code'] !== T_EQUAL
			|| $tokens[$pointerAfterParenthesisCloser]['code'] !== T_SEMICOLON
		) {
			$operatorsGroups = array_map(static function (int $operatorPointer) use ($tokens): int {
				return self::OPERATOR_GROUPS[$tokens[$operatorPointer]['code']];
			}, $operatorsPointers);

			if (count($operatorsGroups) > 1) {
				return;
			}
		}

		$firstOperatorPointer = $operatorsPointers[0];
		if (in_array($tokens[$pointerBeforeParenthesisOpener]['code'], self::OPERATORS, true)) {
			if (self::OPERATOR_GROUPS[$tokens[$firstOperatorPointer]['code']] !== self::OPERATOR_GROUPS[$tokens[$pointerBeforeParenthesisOpener]['code']]) {
				return;
			}

			if (
				$tokens[$pointerBeforeParenthesisOpener]['code'] === T_MINUS
				&& in_array($tokens[$firstOperatorPointer]['code'], [T_PLUS, T_MINUS], true)
			) {
				return;
			}

			if (
				$tokens[$pointerBeforeParenthesisOpener]['code'] === T_DIVIDE
				&& in_array($tokens[$firstOperatorPointer]['code'], [T_DIVIDE, T_MULTIPLY], true)
			) {
				return;
			}

			if (
				$tokens[$pointerBeforeParenthesisOpener]['code'] === T_MODULUS
				&& $tokens[$firstOperatorPointer]['code'] === T_MODULUS
			) {
				return;
			}
		}

		$lastOperatorPointer = $operatorsPointers[count($operatorsPointers) - 1];
		if (
			in_array($tokens[$pointerAfterParenthesisCloser]['code'], self::OPERATORS, true)
			&& self::OPERATOR_GROUPS[$tokens[$lastOperatorPointer]['code']] !== self::OPERATOR_GROUPS[$tokens[$pointerAfterParenthesisCloser]['code']]
		) {
			return;
		}

		$fix = $phpcsFile->addFixableError('Useless parentheses.', $parenthesisOpenerPointer, self::CODE_USELESS_PARENTHESES);

		if (!$fix) {
			return;
		}

		$contentStartPointer = TokenHelper::findNextEffective($phpcsFile, $parenthesisOpenerPointer + 1);
		$contentEndPointer = TokenHelper::findPreviousEffective($phpcsFile, $tokens[$parenthesisOpenerPointer]['parenthesis_closer'] - 1);

		$phpcsFile->fixer->beginChangeset();
		for ($i = $parenthesisOpenerPointer; $i < $contentStartPointer; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		for ($i = $contentEndPointer + 1; $i <= $tokens[$parenthesisOpenerPointer]['parenthesis_closer']; $i++) {
			$phpcsFile->fixer->replaceToken($i, '');
		}
		$phpcsFile->fixer->endChangeset();
	}

}
