1use crate::recursive_parser::{Lexer, Token};
2
3pub struct TextNavigator;
6
7impl TextNavigator {
8 #[must_use]
10 pub fn get_cursor_token_position(query: &str, cursor_pos: usize) -> (usize, usize) {
11 if query.is_empty() {
12 return (0, 0);
13 }
14
15 let mut lexer = Lexer::new(query);
17 let tokens = lexer.tokenize_all_with_positions();
18
19 if tokens.is_empty() {
20 return (0, 0);
21 }
22
23 if cursor_pos == 0 {
25 return (0, tokens.len());
26 }
27
28 let mut current_token = 0;
30 for (i, (start, end, _)) in tokens.iter().enumerate() {
31 if cursor_pos >= *start && cursor_pos <= *end {
32 current_token = i + 1;
33 break;
34 } else if cursor_pos < *start {
35 current_token = i;
37 break;
38 }
39 }
40
41 if current_token == 0 && cursor_pos > 0 {
43 current_token = tokens.len();
44 }
45
46 (current_token, tokens.len())
47 }
48
49 #[must_use]
51 pub fn get_token_at_cursor(query: &str, cursor_pos: usize) -> Option<String> {
52 if query.is_empty() {
53 return None;
54 }
55
56 let mut lexer = Lexer::new(query);
58 let tokens = lexer.tokenize_all_with_positions();
59
60 for (start, end, token) in &tokens {
62 if cursor_pos >= *start && cursor_pos <= *end {
63 let token_str = Self::format_token(token);
65 return Some(token_str.to_string());
66 }
67 }
68
69 None
70 }
71
72 #[must_use]
74 pub fn calculate_prev_token_position(query: &str, cursor_pos: usize) -> Option<usize> {
75 if cursor_pos == 0 {
76 return None;
77 }
78
79 let mut lexer = Lexer::new(query);
80 let tokens = lexer.tokenize_all_with_positions();
81
82 let mut in_token = false;
84 let mut current_token_start = 0;
85 for (start, end, _) in &tokens {
86 if cursor_pos > *start && cursor_pos <= *end {
87 in_token = true;
88 current_token_start = *start;
89 break;
90 }
91 }
92
93 let target_pos = if in_token && cursor_pos > current_token_start {
95 current_token_start
97 } else {
98 let mut prev_start = 0;
100 for (start, _, _) in tokens.iter().rev() {
101 if *start < cursor_pos {
102 prev_start = *start;
103 break;
104 }
105 }
106 prev_start
107 };
108
109 if target_pos < cursor_pos {
110 Some(target_pos)
111 } else {
112 None
113 }
114 }
115
116 #[must_use]
118 pub fn calculate_next_token_position(query: &str, cursor_pos: usize) -> Option<usize> {
119 let query_len = query.len();
120 if cursor_pos >= query_len {
121 return None;
122 }
123
124 let mut lexer = Lexer::new(query);
125 let tokens = lexer.tokenize_all_with_positions();
126
127 let mut in_token = false;
129 let mut current_token_end = query_len;
130 for (start, end, _) in &tokens {
131 if cursor_pos >= *start && cursor_pos < *end {
132 in_token = true;
133 current_token_end = *end;
134 break;
135 }
136 }
137
138 let target_pos = if in_token && cursor_pos < current_token_end {
140 let mut next_start = query_len;
142 for (start, _, _) in &tokens {
143 if *start > current_token_end {
144 next_start = *start;
145 break;
146 }
147 }
148 next_start
149 } else {
150 let mut next_start = query_len;
152 for (start, _, _) in &tokens {
153 if *start > cursor_pos {
154 next_start = *start;
155 break;
156 }
157 }
158 next_start
159 };
160
161 if target_pos > cursor_pos && target_pos <= query_len {
162 Some(target_pos)
163 } else {
164 None
165 }
166 }
167
168 fn format_token(token: &Token) -> &str {
170 match token {
171 Token::Select => "SELECT",
172 Token::From => "FROM",
173 Token::Where => "WHERE",
174 Token::With => "WITH",
175 Token::GroupBy => "GROUP BY",
176 Token::OrderBy => "ORDER BY",
177 Token::Having => "HAVING",
178 Token::As => "AS",
179 Token::Asc => "ASC",
180 Token::Desc => "DESC",
181 Token::And => "AND",
182 Token::Or => "OR",
183 Token::In => "IN",
184 Token::DateTime => "DateTime",
185 Token::Case => "CASE",
186 Token::When => "WHEN",
187 Token::Then => "THEN",
188 Token::Else => "ELSE",
189 Token::End => "END",
190 Token::Distinct => "DISTINCT",
191 Token::Over => "OVER",
192 Token::Partition => "PARTITION",
193 Token::By => "BY",
194 Token::Identifier(s) => s,
195 Token::QuotedIdentifier(s) => s,
196 Token::StringLiteral(s) => s,
197 Token::NumberLiteral(s) => s,
198 Token::Star => "*",
199 Token::Comma => ",",
200 Token::Colon => ":",
201 Token::Dot => ".",
202 Token::LeftParen => "(",
203 Token::RightParen => ")",
204 Token::Equal => "=",
205 Token::NotEqual => "!=",
206 Token::LessThan => "<",
207 Token::LessThanOrEqual => "<=",
208 Token::GreaterThan => ">",
209 Token::GreaterThanOrEqual => ">=",
210 Token::Like => "LIKE",
211 Token::Not => "NOT",
212 Token::Is => "IS",
213 Token::Null => "NULL",
214 Token::Between => "BETWEEN",
215 Token::Limit => "LIMIT",
216 Token::Offset => "OFFSET",
217 Token::Plus => "+",
218 Token::Minus => "-",
219 Token::Divide => "/",
220 Token::Modulo => "%",
221 Token::Join => "JOIN",
222 Token::Inner => "INNER",
223 Token::Left => "LEFT",
224 Token::Right => "RIGHT",
225 Token::Full => "FULL",
226 Token::Cross => "CROSS",
227 Token::Outer => "OUTER",
228 Token::On => "ON",
229 Token::Eof => "EOF",
230 }
231 }
232}
233
234pub struct TextEditor;
236
237impl TextEditor {
238 #[must_use]
241 pub fn kill_line_backward(text: &str, cursor_pos: usize) -> Option<(String, String)> {
242 if cursor_pos == 0 {
243 return None;
244 }
245
246 let killed_text = text.chars().take(cursor_pos).collect::<String>();
247 let remaining_text = text.chars().skip(cursor_pos).collect::<String>();
248
249 Some((killed_text, remaining_text))
250 }
251
252 #[must_use]
255 pub fn kill_line_forward(text: &str, cursor_pos: usize) -> Option<(String, String)> {
256 if cursor_pos >= text.len() {
257 return None;
258 }
259
260 let remaining_text = text.chars().take(cursor_pos).collect::<String>();
261 let killed_text = text.chars().skip(cursor_pos).collect::<String>();
262
263 Some((killed_text, remaining_text))
264 }
265
266 #[must_use]
269 pub fn delete_word_backward(text: &str, cursor_pos: usize) -> Option<(String, String, usize)> {
270 if cursor_pos == 0 {
271 return None;
272 }
273
274 let before_cursor = &text[..cursor_pos];
275 let after_cursor = &text[cursor_pos..];
276
277 let mut word_start = before_cursor.len();
279 let mut chars = before_cursor.chars().rev().peekable();
280
281 while let Some(&ch) = chars.peek() {
283 if ch.is_whitespace() {
284 word_start -= ch.len_utf8();
285 chars.next();
286 } else {
287 break;
288 }
289 }
290
291 while let Some(&ch) = chars.peek() {
293 if !ch.is_alphanumeric() && ch != '_' {
294 break;
295 }
296 word_start -= ch.len_utf8();
297 chars.next();
298 }
299
300 while let Some(&ch) = chars.peek() {
302 if ch.is_whitespace() {
303 word_start -= ch.len_utf8();
304 chars.next();
305 } else {
306 break;
307 }
308 }
309
310 let deleted_text = text[word_start..cursor_pos].to_string();
311 let remaining_text = format!("{}{}", &text[..word_start], after_cursor);
312
313 Some((deleted_text, remaining_text, word_start))
314 }
315
316 #[must_use]
319 pub fn delete_word_forward(text: &str, cursor_pos: usize) -> Option<(String, String)> {
320 if cursor_pos >= text.len() {
321 return None;
322 }
323
324 let before_cursor = &text[..cursor_pos];
325 let after_cursor = &text[cursor_pos..];
326
327 let mut chars = after_cursor.chars();
329 let mut word_end = 0;
330
331 while let Some(ch) = chars.next() {
333 word_end += ch.len_utf8();
334 if ch.is_alphanumeric() || ch == '_' {
335 for ch in chars.by_ref() {
337 if !ch.is_alphanumeric() && ch != '_' {
338 break;
339 }
340 word_end += ch.len_utf8();
341 }
342 break;
343 }
344 }
345
346 let deleted_text = text[cursor_pos..cursor_pos + word_end].to_string();
347 let remaining_text = format!("{}{}", before_cursor, &after_cursor[word_end..]);
348
349 Some((deleted_text, remaining_text))
350 }
351}
352
353#[cfg(test)]
354mod tests {
355 use super::*;
356
357 #[test]
358 fn test_cursor_token_position() {
359 let query = "SELECT * FROM users WHERE id = 1";
360
361 assert_eq!(TextNavigator::get_cursor_token_position(query, 0), (0, 8));
363
364 assert_eq!(TextNavigator::get_cursor_token_position(query, 3), (1, 8));
366
367 assert_eq!(TextNavigator::get_cursor_token_position(query, 7), (2, 8));
369 }
370
371 #[test]
372 fn test_kill_line_backward() {
373 let text = "SELECT * FROM users";
374
375 let result = TextEditor::kill_line_backward(text, 8);
377 assert_eq!(
378 result,
379 Some(("SELECT *".to_string(), " FROM users".to_string()))
380 );
381
382 let result = TextEditor::kill_line_backward(text, 0);
384 assert_eq!(result, None);
385 }
386
387 #[test]
388 fn test_delete_word_backward() {
389 let text = "SELECT * FROM users";
390
391 let result = TextEditor::delete_word_backward(text, 13);
393 assert_eq!(
394 result,
395 Some((" FROM".to_string(), "SELECT * users".to_string(), 8))
396 );
397 }
398}