whichtime_sys/parsers/ru/
weekday.rs

1//! Russian weekday parser
2//!
3//! Handles Russian weekday expressions like:
4//! - "понедельник", "в пятницу"
5//! - "следующая среда", "прошлый вторник"
6//! - "через 2 пятницы" (future)
7
8use crate::components::Component;
9use crate::context::ParsingContext;
10use crate::dictionaries::RelativeModifier;
11use crate::dictionaries::ru::{get_relative_modifier, get_weekday};
12use crate::error::Result;
13use crate::parsers::Parser;
14use crate::results::ParsedResult;
15use chrono::{Datelike, Duration};
16use fancy_regex::Regex;
17use std::sync::LazyLock;
18
19static PATTERN: LazyLock<Regex> = LazyLock::new(|| {
20    Regex::new(
21        r"(?ix)
22        (?<![a-zA-Zа-яА-Я])
23        (?:(?:в|во|на|к)\s+)?
24        (?:
25            (?P<prefix>этот|эта|это|эту|следующий|следующая|следующее|следующую|будущий|будущая|будущее|прошлый|прошлая|прошлое|прошлую|предыдущий|предыдущая|предыдущее|последний|последняя)\s+
26        )?
27        (?P<weekday>понедельник|понедельника|пн|вторник|вторника|вт|среда|среды|среду|ср|четверг|четверга|чт|пятница|пятницу|пятницы|пт|суббота|субботу|субботы|сб|воскресенье|воскресенья|вс|вск)
28        (?:\.|,)?
29        (?:
30            \s+
31            (?P<suffix>прошлый|прошлая|прошлое|прошлую|следующий|следующая|следующее|следующую)
32        )?
33        (?=\W|$)"
34    ).unwrap()
35});
36
37/// Russian weekday parser
38pub struct RUWeekdayParser;
39
40impl RUWeekdayParser {
41    pub fn new() -> Self {
42        Self
43    }
44}
45
46impl Default for RUWeekdayParser {
47    fn default() -> Self {
48        Self::new()
49    }
50}
51
52impl Parser for RUWeekdayParser {
53    fn name(&self) -> &'static str {
54        "RUWeekdayParser"
55    }
56
57    fn should_apply(&self, _context: &ParsingContext) -> bool {
58        true
59    }
60
61    fn parse(&self, context: &ParsingContext) -> Result<Vec<ParsedResult>> {
62        let mut results = Vec::new();
63        let ref_date = context.reference.instant;
64        let ref_weekday = ref_date.weekday().num_days_from_sunday() as i64;
65
66        let mut start = 0;
67        while start < context.text.len() {
68            let search_text = &context.text[start..];
69            let captures = match PATTERN.captures(search_text) {
70                Ok(Some(caps)) => caps,
71                Ok(None) => break,
72                Err(_) => break,
73            };
74
75            let full_match = match captures.get(0) {
76                Some(m) => m,
77                None => break,
78            };
79
80            let match_start = start + full_match.start();
81            let match_end = start + full_match.end();
82            let matched_text = full_match.as_str();
83
84            let weekday_str = captures
85                .name("weekday")
86                .map(|m| m.as_str().to_lowercase())
87                .unwrap_or_default();
88            let prefix_str = captures.name("prefix").map(|m| m.as_str().to_lowercase());
89            let suffix_str = captures.name("suffix").map(|m| m.as_str().to_lowercase());
90
91            let clean_wd = weekday_str.trim_end_matches('.').trim_end_matches(',');
92            let Some(weekday) = get_weekday(clean_wd) else {
93                start = match_end;
94                continue;
95            };
96
97            let target_weekday = weekday as i64;
98
99            // Determine modifier from prefix or suffix
100            let modifier = prefix_str
101                .as_ref()
102                .and_then(|s| get_relative_modifier(s))
103                .or_else(|| suffix_str.as_ref().and_then(|s| get_relative_modifier(s)));
104
105            // Calculate days offset
106            let days_offset = match modifier {
107                Some(RelativeModifier::Next) => {
108                    let diff = target_weekday - ref_weekday;
109                    if diff <= 0 { diff + 7 } else { diff }
110                }
111                Some(RelativeModifier::Last) => {
112                    let diff = target_weekday - ref_weekday;
113                    if diff >= 0 { diff - 7 } else { diff }
114                }
115                Some(RelativeModifier::This) | None => {
116                    // Default behavior: find closest day
117                    let diff = target_weekday - ref_weekday;
118                    if diff == 0 {
119                        0
120                    } else if diff > 0 {
121                        if diff <= 3 { diff } else { diff - 7 }
122                    } else if diff >= -3 {
123                        diff
124                    } else {
125                        diff + 7
126                    }
127                }
128            };
129
130            let target_date = ref_date + Duration::days(days_offset);
131
132            let mut components = context.create_components();
133            components.assign(Component::Year, target_date.year());
134            components.assign(Component::Month, target_date.month() as i32);
135            components.assign(Component::Day, target_date.day() as i32);
136            components.assign(Component::Weekday, target_weekday as i32);
137
138            // Find actual text bounds (trim leading/trailing non-alphanumeric)
139            let actual_start = matched_text
140                .find(|c: char| c.is_alphanumeric())
141                .unwrap_or(0);
142            let actual_end = matched_text
143                .rfind(|c: char| c.is_alphanumeric())
144                .map(|i| i + matched_text[i..].chars().next().map_or(1, char::len_utf8))
145                .unwrap_or(matched_text.len());
146
147            results.push(context.create_result(
148                match_start + actual_start,
149                match_start + actual_end,
150                components,
151                None,
152            ));
153
154            start = match_end;
155        }
156
157        Ok(results)
158    }
159}
whichtime_sys/parsers/ru/weekday.rs

whichtime_sys/parsers/ru/
weekday.rs
