add timezone engine

Cargo.lock

@@ -289,6 +289,30 @@ dependencies = [
  "windows-targets 0.48.5",
 ]
 
+[[package]]
+name = "chrono-tz"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91d7b79e99bfaa0d47da0687c43aa3b7381938a62ad3a6498599039321f660b7"
+dependencies = [
+ "chrono",
+ "chrono-tz-build",
+ "phf 0.11.2",
+ "uncased",
+]
+
+[[package]]
+name = "chrono-tz-build"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "433e39f13c9a060046954e0592a8d0a4bcb1040125cbf91cb8ee58964cfb350f"
+dependencies = [
+ "parse-zoneinfo",
+ "phf 0.11.2",
+ "phf_codegen 0.11.2",
+ "uncased",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.9.4"
@@ -881,7 +905,7 @@ checksum = "7a2629bb1404f3d34c2e921f21fd34ba00b206124c81f65c50b43b6aaefeb016"
 dependencies = [
  "log",
  "phf 0.10.1",
- "phf_codegen",
+ "phf_codegen 0.10.0",
  "string_cache",
  "string_cache_codegen",
  "tendril",
@@ -909,6 +933,7 @@ dependencies = [
  "base64",
  "bytes",
  "chrono",
+ "chrono-tz",
  "eyre",
  "fend-core",
  "futures",
@@ -1004,6 +1029,15 @@ dependencies = [
  "windows-targets 0.48.5",
 ]
 
+[[package]]
+name = "parse-zoneinfo"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c705f256449c60da65e11ff6626e0c16a0a0b96aaa348de61376b249bc340f41"
+dependencies = [
+ "regex",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.1"
@@ -1039,6 +1073,16 @@ dependencies = [
  "phf_shared 0.10.0",
 ]
 
+[[package]]
+name = "phf_codegen"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8d39688d359e6b34654d328e262234662d16cc0f60ec8dcbe5e718709342a5a"
+dependencies = [
+ "phf_generator 0.11.2",
+ "phf_shared 0.11.2",
+]
+
 [[package]]
 name = "phf_generator"
 version = "0.10.0"
@@ -1088,6 +1132,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "90fcb95eef784c2ac79119d1dd819e162b5da872ce6f3c3abe1e8ca1c082f72b"
 dependencies = [
  "siphasher",
+ "uncased",
 ]
 
 [[package]]
@@ -1370,7 +1415,7 @@ dependencies = [
  "log",
  "new_debug_unreachable",
  "phf 0.10.1",
- "phf_codegen",
+ "phf_codegen 0.10.0",
  "precomputed-hash",
  "servo_arc",
  "smallvec",
@@ -1696,6 +1741,15 @@ version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e421abadd41a4225275504ea4d6566923418b7f05506fbc9c0fe86ba7396114b"
 
+[[package]]
+name = "uncased"
+version = "0.9.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b9bc53168a4be7402ab86c3aad243a84dd7381d09be0eddc81280c1da95ca68"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.14"

Cargo.toml

@@ -18,6 +18,7 @@ axum = { version = "0.7.2", default-features = false, features = [
 base64 = "0.21.5"
 bytes = "1.5.0"
 chrono = "0.4.31"
+chrono-tz = { version = "0.8.5", features = ["case-insensitive"] }
 eyre = "0.6.11"
 fend-core = "1.3.3"
 futures = "0.3.29"

src/engines/answer.rs

@@ -1,6 +1,7 @@
 pub mod calc;
 pub mod dictionary;
 pub mod ip;
+pub mod timezone;
 pub mod useragent;
 pub mod wikipedia;
 

src/engines/answer/calc.rs

@@ -14,7 +14,7 @@ pub fn request(query: &str) -> EngineResponse {
     };
 
     EngineResponse::answer_html(format!(
-        r#"<p class="answer-calc-query">{query} =</p>
+        r#"<p class="answer-query">{query} =</p>
 <h3><b>{result_html}</b></h3>"#,
         query = html_escape::encode_text(&query),
     ))
@@ -87,7 +87,7 @@ fn evaluate(query: &str, html: bool) -> Option<String> {
         let hex = spans[0].text.trim_start_matches("0x");
         if let Ok(num) = u64::from_str_radix(hex, 16) {
             result_html.push_str(&format!(
-                r#" <span class="answer-calc-comment">= {num}</span>"#,
+                r#" <span class="answer-comment">= {num}</span>"#,
                 num = num
             ));
         }

src/engines/answer/timezone.rs

@@ -0,0 +1,157 @@
+use chrono::{DateTime, TimeZone};
+use chrono_tz::{OffsetComponents, OffsetName, Tz};
+
+use crate::engines::EngineResponse;
+
+use super::regex;
+
+pub fn request(query: &str) -> EngineResponse {
+    match evaluate(query) {
+        None => EngineResponse::new(),
+        Some(TimeResponse::Current { time, timezone }) => EngineResponse::answer_html(format!(
+            r#"<p class="answer-query">Current time in {timezone}</p>
+<h3><b>{time}</b> <span class="answer-comment">({date})</span></h3>"#,
+            time = html_escape::encode_text(&time.format("%-I:%M %P").to_string()),
+            date = html_escape::encode_text(&time.format("%B %-d").to_string()),
+            timezone = html_escape::encode_text(&timezone_to_string(&timezone)),
+        )),
+        Some(TimeResponse::Conversion {
+            source_timezone,
+            target_timezone,
+            source_time,
+            target_time,
+            source_offset,
+            target_offset,
+        }) => EngineResponse::answer_html(format!(
+            r#"<p class="answer-query">{source_time} {source_timezone} to {target_timezone}</p>
+<h3><b>{target_time}</b> <span class="answer-comment">{target_timezone} ({delta})</span></h3>"#,
+            source_time = html_escape::encode_text(&source_time.format("%-I:%M %P").to_string()),
+            target_time = html_escape::encode_text(&target_time.format("%-I:%M %P").to_string()),
+            source_timezone = html_escape::encode_text(&timezone_to_string(&source_timezone)),
+            target_timezone = html_escape::encode_text(&timezone_to_string(&target_timezone)),
+            delta = html_escape::encode_text(&{
+                let delta_minutes = (target_offset - source_offset).num_minutes();
+                if delta_minutes % 60 == 0 {
+                    format!("{:+}", delta_minutes / 60)
+                } else {
+                    format!("{:+}:{}", delta_minutes / 60, delta_minutes % 60)
+                }
+            })
+        )),
+    }
+}
+
+enum TimeResponse {
+    Current {
+        time: DateTime<Tz>,
+        timezone: Tz,
+    },
+    Conversion {
+        source_timezone: Tz,
+        target_timezone: Tz,
+        source_time: DateTime<Tz>,
+        target_time: DateTime<Tz>,
+        source_offset: chrono::Duration,
+        target_offset: chrono::Duration,
+    },
+}
+
+fn evaluate(query: &str) -> Option<TimeResponse> {
+    // "4pm utc to cst"
+    let re = regex!(r"(\d{1,2})(?:(\d{1,2}))?\s*(am|pm|) ([\w/+\-]+) (to|as|in) ([\w/+\-]+)");
+    if let Some(captures) = re.captures(query) {
+        if let Some(hour) = captures.get(1).map(|m| m.as_str().parse::<u32>().unwrap()) {
+            let minute = match captures.get(2) {
+                Some(m) => m.as_str().parse::<u32>().ok()?,
+                None => 0,
+            };
+            let ampm = captures.get(3).unwrap().as_str();
+            let timezone1_name = captures.get(4).unwrap().as_str();
+            let timezone2_name = captures.get(6).unwrap().as_str();
+
+            let source_timezone = parse_timezone(timezone1_name)?;
+            let target_timezone = parse_timezone(timezone2_name)?;
+
+            let current_date = chrono::Utc::now().date_naive();
+
+            let source_offset = source_timezone.offset_from_utc_date(&current_date);
+            let target_offset = target_timezone.offset_from_utc_date(&current_date);
+
+            println!(
+                "source_offset: {:?} {:?}",
+                source_offset,
+                source_offset.tz_id()
+            );
+            println!("target_offset: {:?}", target_offset);
+
+            let source_time_naive = current_date.and_hms_opt(
+                if ampm == "pm" && hour != 12 {
+                    hour + 12
+                } else if ampm == "am" && hour == 12 {
+                    0
+                } else {
+                    hour
+                },
+                minute,
+                0,
+            )?;
+            let source_time_utc = chrono::Utc
+                .from_local_datetime(&source_time_naive)
+                .latest()?;
+
+            let source_time = source_time_utc.with_timezone(&source_timezone);
+            let target_time = source_time_utc.with_timezone(&target_timezone);
+
+            return Some(TimeResponse::Conversion {
+                source_timezone,
+                target_timezone,
+                source_time,
+                target_time,
+                // the offsets are wrong for some reason so we have to negate them
+                source_offset: -source_offset.base_utc_offset(),
+                target_offset: -target_offset.base_utc_offset(),
+            });
+        }
+    }
+
+    // "utc time"
+    let re = regex!(r"([\w/+\-]+)(?: current)? time");
+    // "time in utc"
+    let re2 = regex!(r"time (?:in|as) ([\w/+\-]+)");
+    if let Some(timezone_name) = re
+        .captures(query)
+        .and_then(|m| m.get(1))
+        .or_else(|| re2.captures(query).and_then(|m| m.get(1)))
+    {
+        if let Some(timezone) = parse_timezone(timezone_name.as_str()) {
+            let time = chrono::Utc::now().with_timezone(&timezone);
+            return Some(TimeResponse::Current { time, timezone });
+        }
+    }
+
+    None
+}
+
+fn parse_timezone(timezone_name: &str) -> Option<Tz> {
+    match timezone_name.to_lowercase().as_str() {
+        "cst" => Some(Tz::CST6CDT),
+        "cdt" => Some(Tz::CST6CDT),
+        _ => Tz::from_str_insensitive(timezone_name)
+            .ok()
+            .or_else(|| Tz::from_str_insensitive(&format!("etc/{timezone_name}")).ok()),
+    }
+}
+
+fn timezone_to_string(tz: &Tz) -> String {
+    match tz {
+        Tz::CST6CDT => "CST".to_string(),
+        _ => {
+            let tz_string = tz.name();
+            if let Some(tz_string) = tz_string.strip_prefix("Etc/") {
+                tz_string.to_string()
+            } else {
+                tz_string.to_string()
+            }
+        }
+    }
+}

src/engines/mod.rs

@@ -34,6 +34,7 @@ engines! {
     Calc = "calc",
     Wikipedia = "wikipedia",
     Dictionary = "dictionary",
+    Timezone = "timezone",
     // post-search
     StackExchange = "stackexchange",
     GitHub = "github",
@@ -49,15 +50,18 @@ engine_weights! {
 }
 
 engine_requests! {
+    // search
     Google => search::google::request, parse_response,
     Bing => search::bing::request, parse_response,
     Brave => search::brave::request, parse_response,
     Marginalia => search::marginalia::request, parse_response,
+    // answer
     Useragent => answer::useragent::request, None,
     Ip => answer::ip::request, None,
     Calc => answer::calc::request, None,
     Wikipedia => answer::wikipedia::request, parse_response,
     Dictionary => answer::dictionary::request, parse_response,
+    Timezone => answer::timezone::request, None,
 }
 
 engine_autocomplete_requests! {

src/web/assets/style.css

@@ -185,11 +185,17 @@ h1 {
   font-size: 1.2rem;
 }
 
-/* styles for specific answers */
+/* styles that are somewhat answer-specific but get reused across other styles sometimes */
-.answer-calc-query {
+.answer-query {
   margin: 0;
   opacity: 0.5;
 }
+.answer-comment {
+  color: #acb6bf8c;
+  font-weight: normal;
+}
+
+/* styles for specific answers */
 .answer-calc-constant {
   color: #d2a6ff;
   white-space: pre-wrap;
@@ -200,10 +206,6 @@ h1 {
 .answer-calc-special {
   color: #e6b673;
 }
-.answer-calc-comment {
-  color: #acb6bf8c;
-  font-weight: normal;
-}
 
 .answer-dictionary-word {
   margin-top: 0;