1<?php declare(strict_types=1);
2
3namespace PhpParser\Internal;
4
5use PhpParser\Token;
6
7/**
8 * Provides operations on token streams, for use by pretty printer.
9 *
10 * @internal
11 */
12class TokenStream {
13    /** @var Token[] Tokens (in PhpToken::tokenize() format) */
14    private array $tokens;
15    /** @var int[] Map from position to indentation */
16    private array $indentMap;
17
18    /**
19     * Create token stream instance.
20     *
21     * @param Token[] $tokens Tokens in PhpToken::tokenize() format
22     */
23    public function __construct(array $tokens, int $tabWidth) {
24        $this->tokens = $tokens;
25        $this->indentMap = $this->calcIndentMap($tabWidth);
26    }
27
28    /**
29     * Whether the given position is immediately surrounded by parenthesis.
30     *
31     * @param int $startPos Start position
32     * @param int $endPos End position
33     */
34    public function haveParens(int $startPos, int $endPos): bool {
35        return $this->haveTokenImmediatelyBefore($startPos, '(')
36            && $this->haveTokenImmediatelyAfter($endPos, ')');
37    }
38
39    /**
40     * Whether the given position is immediately surrounded by braces.
41     *
42     * @param int $startPos Start position
43     * @param int $endPos End position
44     */
45    public function haveBraces(int $startPos, int $endPos): bool {
46        return ($this->haveTokenImmediatelyBefore($startPos, '{')
47                || $this->haveTokenImmediatelyBefore($startPos, T_CURLY_OPEN))
48            && $this->haveTokenImmediatelyAfter($endPos, '}');
49    }
50
51    /**
52     * Check whether the position is directly preceded by a certain token type.
53     *
54     * During this check whitespace and comments are skipped.
55     *
56     * @param int $pos Position before which the token should occur
57     * @param int|string $expectedTokenType Token to check for
58     *
59     * @return bool Whether the expected token was found
60     */
61    public function haveTokenImmediatelyBefore(int $pos, $expectedTokenType): bool {
62        $tokens = $this->tokens;
63        $pos--;
64        for (; $pos >= 0; $pos--) {
65            $token = $tokens[$pos];
66            if ($token->is($expectedTokenType)) {
67                return true;
68            }
69            if (!$token->isIgnorable()) {
70                break;
71            }
72        }
73        return false;
74    }
75
76    /**
77     * Check whether the position is directly followed by a certain token type.
78     *
79     * During this check whitespace and comments are skipped.
80     *
81     * @param int $pos Position after which the token should occur
82     * @param int|string $expectedTokenType Token to check for
83     *
84     * @return bool Whether the expected token was found
85     */
86    public function haveTokenImmediatelyAfter(int $pos, $expectedTokenType): bool {
87        $tokens = $this->tokens;
88        $pos++;
89        for ($c = \count($tokens); $pos < $c; $pos++) {
90            $token = $tokens[$pos];
91            if ($token->is($expectedTokenType)) {
92                return true;
93            }
94            if (!$token->isIgnorable()) {
95                break;
96            }
97        }
98        return false;
99    }
100
101    /** @param int|string|(int|string)[] $skipTokenType */
102    public function skipLeft(int $pos, $skipTokenType): int {
103        $tokens = $this->tokens;
104
105        $pos = $this->skipLeftWhitespace($pos);
106        if ($skipTokenType === \T_WHITESPACE) {
107            return $pos;
108        }
109
110        if (!$tokens[$pos]->is($skipTokenType)) {
111            // Shouldn't happen. The skip token MUST be there
112            throw new \Exception('Encountered unexpected token');
113        }
114        $pos--;
115
116        return $this->skipLeftWhitespace($pos);
117    }
118
119    /** @param int|string|(int|string)[] $skipTokenType */
120    public function skipRight(int $pos, $skipTokenType): int {
121        $tokens = $this->tokens;
122
123        $pos = $this->skipRightWhitespace($pos);
124        if ($skipTokenType === \T_WHITESPACE) {
125            return $pos;
126        }
127
128        if (!$tokens[$pos]->is($skipTokenType)) {
129            // Shouldn't happen. The skip token MUST be there
130            throw new \Exception('Encountered unexpected token');
131        }
132        $pos++;
133
134        return $this->skipRightWhitespace($pos);
135    }
136
137    /**
138     * Return first non-whitespace token position smaller or equal to passed position.
139     *
140     * @param int $pos Token position
141     * @return int Non-whitespace token position
142     */
143    public function skipLeftWhitespace(int $pos): int {
144        $tokens = $this->tokens;
145        for (; $pos >= 0; $pos--) {
146            if (!$tokens[$pos]->isIgnorable()) {
147                break;
148            }
149        }
150        return $pos;
151    }
152
153    /**
154     * Return first non-whitespace position greater or equal to passed position.
155     *
156     * @param int $pos Token position
157     * @return int Non-whitespace token position
158     */
159    public function skipRightWhitespace(int $pos): int {
160        $tokens = $this->tokens;
161        for ($count = \count($tokens); $pos < $count; $pos++) {
162            if (!$tokens[$pos]->isIgnorable()) {
163                break;
164            }
165        }
166        return $pos;
167    }
168
169    /** @param int|string|(int|string)[] $findTokenType */
170    public function findRight(int $pos, $findTokenType): int {
171        $tokens = $this->tokens;
172        for ($count = \count($tokens); $pos < $count; $pos++) {
173            if ($tokens[$pos]->is($findTokenType)) {
174                return $pos;
175            }
176        }
177        return -1;
178    }
179
180    /**
181     * Whether the given position range contains a certain token type.
182     *
183     * @param int $startPos Starting position (inclusive)
184     * @param int $endPos Ending position (exclusive)
185     * @param int|string $tokenType Token type to look for
186     * @return bool Whether the token occurs in the given range
187     */
188    public function haveTokenInRange(int $startPos, int $endPos, $tokenType): bool {
189        $tokens = $this->tokens;
190        for ($pos = $startPos; $pos < $endPos; $pos++) {
191            if ($tokens[$pos]->is($tokenType)) {
192                return true;
193            }
194        }
195        return false;
196    }
197
198    public function haveTagInRange(int $startPos, int $endPos): bool {
199        return $this->haveTokenInRange($startPos, $endPos, \T_OPEN_TAG)
200            || $this->haveTokenInRange($startPos, $endPos, \T_CLOSE_TAG);
201    }
202
203    /**
204     * Get indentation before token position.
205     *
206     * @param int $pos Token position
207     *
208     * @return int Indentation depth (in spaces)
209     */
210    public function getIndentationBefore(int $pos): int {
211        return $this->indentMap[$pos];
212    }
213
214    /**
215     * Get the code corresponding to a token offset range, optionally adjusted for indentation.
216     *
217     * @param int $from Token start position (inclusive)
218     * @param int $to Token end position (exclusive)
219     * @param int $indent By how much the code should be indented (can be negative as well)
220     *
221     * @return string Code corresponding to token range, adjusted for indentation
222     */
223    public function getTokenCode(int $from, int $to, int $indent): string {
224        $tokens = $this->tokens;
225        $result = '';
226        for ($pos = $from; $pos < $to; $pos++) {
227            $token = $tokens[$pos];
228            $id = $token->id;
229            $text = $token->text;
230            if ($id === \T_CONSTANT_ENCAPSED_STRING || $id === \T_ENCAPSED_AND_WHITESPACE) {
231                $result .= $text;
232            } else {
233                // TODO Handle non-space indentation
234                if ($indent < 0) {
235                    $result .= str_replace("\n" . str_repeat(" ", -$indent), "\n", $text);
236                } elseif ($indent > 0) {
237                    $result .= str_replace("\n", "\n" . str_repeat(" ", $indent), $text);
238                } else {
239                    $result .= $text;
240                }
241            }
242        }
243        return $result;
244    }
245
246    /**
247     * Precalculate the indentation at every token position.
248     *
249     * @return int[] Token position to indentation map
250     */
251    private function calcIndentMap(int $tabWidth): array {
252        $indentMap = [];
253        $indent = 0;
254        foreach ($this->tokens as $i => $token) {
255            $indentMap[] = $indent;
256
257            if ($token->id === \T_WHITESPACE) {
258                $content = $token->text;
259                $newlinePos = \strrpos($content, "\n");
260                if (false !== $newlinePos) {
261                    $indent = $this->getIndent(\substr($content, $newlinePos + 1), $tabWidth);
262                } elseif ($i === 1 && $this->tokens[0]->id === \T_OPEN_TAG &&
263                          $this->tokens[0]->text[\strlen($this->tokens[0]->text) - 1] === "\n") {
264                    // Special case: Newline at the end of opening tag followed by whitespace.
265                    $indent = $this->getIndent($content, $tabWidth);
266                }
267            }
268        }
269
270        // Add a sentinel for one past end of the file
271        $indentMap[] = $indent;
272
273        return $indentMap;
274    }
275
276    private function getIndent(string $ws, int $tabWidth): int {
277        $spaces = \substr_count($ws, " ");
278        $tabs = \substr_count($ws, "\t");
279        assert(\strlen($ws) === $spaces + $tabs);
280        return $spaces + $tabs * $tabWidth;
281    }
282}
283