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. Env var `SQLITE_GRAPHRAG_DISPLAY_TZ`
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 the `SQLITE_GRAPHRAG_DISPLAY_TZ` env var.
21///
22/// Returns `Tz::UTC` if the variable is absent or empty.
23/// Returns a validation error if the value is an invalid IANA name.
24fn resolve_tz_from_env() -> Result<Tz, AppError> {
25    match std::env::var("SQLITE_GRAPHRAG_DISPLAY_TZ") {
26        Ok(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 `SQLITE_GRAPHRAG_DISPLAY_TZ`, then UTC.
38///
39/// Subsequent calls are silently ignored (OnceLock semantics).
40/// Returns an error only if `explicit` is `None` and the env var is invalid.
41pub fn init(explicit: Option<Tz>) -> Result<(), AppError> {
42    let fuso = match explicit {
43        Some(tz) => tz,
44        None => resolve_tz_from_env()?,
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_env().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    use serial_test::serial;
83
84    #[test]
85    #[serial]
86    fn utc_default_when_env_missing() {
87        // Remove variable to ensure UTC fallback
88        std::env::remove_var("SQLITE_GRAPHRAG_DISPLAY_TZ");
89        let result = resolve_tz_from_env().expect("must not fail with env absent");
90        assert_eq!(result, Tz::UTC);
91    }
92
93    #[test]
94    #[serial]
95    fn env_valid_applies_timezone() {
96        std::env::set_var("SQLITE_GRAPHRAG_DISPLAY_TZ", "America/Sao_Paulo");
97        let result = resolve_tz_from_env().expect("America/Sao_Paulo is valid");
98        assert_eq!(result.name(), "America/Sao_Paulo");
99        std::env::remove_var("SQLITE_GRAPHRAG_DISPLAY_TZ");
100    }
101
102    #[test]
103    #[serial]
104    fn env_invalid_returns_validation_error() {
105        std::env::set_var("SQLITE_GRAPHRAG_DISPLAY_TZ", "Invalid/Nonexistent");
106        let result = resolve_tz_from_env();
107        assert!(result.is_err(), "invalid timezone must return Err");
108        match result {
109            Err(AppError::Validation(msg)) => {
110                assert!(
111                    msg.contains("SQLITE_GRAPHRAG_DISPLAY_TZ"),
112                    "message must cite the env var"
113                );
114                assert!(
115                    msg.contains("Invalid/Nonexistent"),
116                    "message must cite the invalid value"
117                );
118            }
119            other => unreachable!("expected AppError::Validation, got: {other:?}"),
120        }
121        std::env::remove_var("SQLITE_GRAPHRAG_DISPLAY_TZ");
122    }
123
124    #[test]
125    fn epoch_zero_yields_utc_iso() {
126        // Tests epoch_to_iso directly without global state
127        std::env::remove_var("SQLITE_GRAPHRAG_DISPLAY_TZ");
128        let result = {
129            // Applies UTC directly without using GLOBAL_TZ
130            let tz = Tz::UTC;
131            Utc.timestamp_opt(0, 0)
132                .single()
133                .map(|dt| {
134                    dt.with_timezone(&tz)
135                        .format("%Y-%m-%dT%H:%M:%S%:z")
136                        .to_string()
137                })
138                .unwrap_or_else(|| "1970-01-01T00:00:00+00:00".to_string())
139        };
140        assert_eq!(result, "1970-01-01T00:00:00+00:00");
141    }
142
143    #[test]
144    fn format_iso_utc_preserves_zero_offset() {
145        let ts = Utc.timestamp_opt(1_705_320_000, 0).single().unwrap();
146        // Applies UTC directly
147        let result = ts
148            .with_timezone(&Tz::UTC)
149            .format("%Y-%m-%dT%H:%M:%S%:z")
150            .to_string();
151        assert_eq!(result, "2024-01-15T12:00:00+00:00");
152    }
153
154    #[test]
155    fn format_iso_sao_paulo_applies_offset() {
156        let ts = Utc.timestamp_opt(1_705_320_000, 0).single().unwrap();
157        let sao_paulo: Tz = "America/Sao_Paulo".parse().unwrap();
158        let result = ts
159            .with_timezone(&sao_paulo)
160            .format("%Y-%m-%dT%H:%M:%S%:z")
161            .to_string();
162        // America/Sao_Paulo in January is UTC-3
163        assert!(
164            result.contains("-03:00"),
165            "expected offset -03:00, got: {result}"
166        );
167    }
168}
sqlite_graphrag/tz.rs

sqlite_graphrag/
tz.rs
