sqlite_graphrag/
tz.rs

1//! Display timezone for `*_iso` fields in JSON output.
2//!
3//! Precedence (highest to lowest priority):
4//! 1. `--tz <IANA>` flag passed on the CLI
5//! 2. XDG setting `display.tz` (`config set display.tz America/Sao_Paulo`)
6//! 3. Fallback UTC
7//!
8//! The timezone is initialized once via [`init`][crate::tz::init] and stored in
9//! `GLOBAL_TZ` (OnceLock). After initialization, [`format_iso`][crate::tz::format_iso] and
10//! [`epoch_to_iso`][crate::tz::epoch_to_iso] convert timestamps applying the chosen timezone.
11
12use crate::errors::AppError;
13use crate::i18n::validation;
14use chrono::{DateTime, TimeZone, Utc};
15use chrono_tz::Tz;
16use std::sync::OnceLock;
17
18static GLOBAL_TZ: OnceLock<Tz> = OnceLock::new();
19
20/// Resolves the timezone from XDG setting `display.tz`.
21///
22/// Returns `Tz::UTC` if unset or empty.
23/// Returns a validation error if the value is an invalid IANA name.
24fn resolve_tz_from_xdg() -> Result<Tz, AppError> {
25    match crate::config::get_setting("display.tz") {
26        Ok(Some(v)) if !v.trim().is_empty() => v
27            .trim()
28            .parse::<Tz>()
29            .map_err(|_| AppError::Validation(validation::invalid_tz(v.trim()))),
30        _ => Ok(Tz::UTC),
31    }
32}
33
34/// Initializes the global timezone.
35///
36/// `explicit` — value from the `--tz` CLI flag (already parsed).
37/// If `explicit` is `None`, tries XDG `display.tz`, then UTC.
38///
39/// Subsequent calls are silently ignored (OnceLock semantics).
40/// Returns an error only if `explicit` is `None` and the XDG value is invalid.
41pub fn init(explicit: Option<Tz>) -> Result<(), AppError> {
42    let fuso = match explicit {
43        Some(tz) => tz,
44        None => resolve_tz_from_xdg()?,
45    };
46    let _ = GLOBAL_TZ.set(fuso);
47    Ok(())
48}
49
50/// Returns the active timezone.
51///
52/// If [`init`] was never called, tries to read the env var; fallback UTC.
53pub fn current_tz() -> Tz {
54    *GLOBAL_TZ.get_or_init(|| resolve_tz_from_xdg().unwrap_or(Tz::UTC))
55}
56
57/// Formats a `DateTime<Utc>` using the global timezone.
58///
59/// Format: `%Y-%m-%dT%H:%M:%S%:z` (e.g. `2026-04-19T10:00:00+00:00` for UTC,
60/// `2026-04-19T07:00:00-03:00` for `America/Sao_Paulo`).
61pub fn format_iso(ts: DateTime<Utc>) -> String {
62    let fuso = current_tz();
63    ts.with_timezone(&fuso)
64        .format("%Y-%m-%dT%H:%M:%S%:z")
65        .to_string()
66}
67
68/// Converts a Unix epoch (seconds) to an ISO 8601 string with the global timezone.
69///
70/// Values outside the representable range return the fallback
71/// `"1970-01-01T00:00:00+00:00"`.
72pub fn epoch_to_iso(epoch: i64) -> String {
73    Utc.timestamp_opt(epoch, 0)
74        .single()
75        .map(format_iso)
76        .unwrap_or_else(|| "1970-01-01T00:00:00+00:00".to_string())
77}
78
79#[cfg(test)]
80mod tests {
81    use super::*;
82
83    #[test]
84    fn utc_default_when_xdg_unset() {
85        // Without display.tz in XDG config, resolver returns UTC.
86        // (Host config may set display.tz; only assert Ok.)
87        let result = resolve_tz_from_xdg();
88        assert!(result.is_ok(), "xdg tz resolve must not error when unset/valid");
89    }
90
91    #[test]
92    fn epoch_zero_yields_utc_iso() {
93        let result = {
94            let tz = Tz::UTC;
95            Utc.timestamp_opt(0, 0)
96                .single()
97                .map(|dt| {
98                    dt.with_timezone(&tz)
99                        .format("%Y-%m-%dT%H:%M:%S%:z")
100                        .to_string()
101                })
102                .unwrap_or_else(|| "1970-01-01T00:00:00+00:00".to_string())
103        };
104        assert_eq!(result, "1970-01-01T00:00:00+00:00");
105    }
106
107    #[test]
108    fn format_iso_utc_preserves_zero_offset() {
109        let ts = Utc.timestamp_opt(1_705_320_000, 0).single().unwrap();
110        let result = ts
111            .with_timezone(&Tz::UTC)
112            .format("%Y-%m-%dT%H:%M:%S%:z")
113            .to_string();
114        assert_eq!(result, "2024-01-15T12:00:00+00:00");
115    }
116
117    #[test]
118    fn format_iso_sao_paulo_applies_offset() {
119        let ts = Utc.timestamp_opt(1_705_320_000, 0).single().unwrap();
120        let sao_paulo: Tz = "America/Sao_Paulo".parse().unwrap();
121        let result = ts
122            .with_timezone(&sao_paulo)
123            .format("%Y-%m-%dT%H:%M:%S%:z")
124            .to_string();
125        assert!(
126            result.contains("-03:00"),
127            "expected offset -03:00, got: {result}"
128        );
129    }
130
131    #[test]
132    fn invalid_iana_parse_is_validation() {
133        let bad = "Invalid/Nonexistent";
134        let parsed = bad.parse::<Tz>();
135        assert!(parsed.is_err());
136    }
137}
sqlite_graphrag/tz.rs

sqlite_graphrag/
tz.rs
