//! Local calendar time for the body, weather and the prompt clock.
//!
//! The host converts with the save's `hosting.timeZone`. The browser build
//! reads the device's own clock (`Date`), so a local pet follows its owner's
//! current zone; moving to a host records that zone first.

/// Calendar fields at one instant; `month0` counts from 0 as JavaScript does.
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct Local {
    pub year: i32,
    pub month0: u32,
    pub day: u32,
    pub hour: u32,
    pub minute: u32,
}
impl Local {
    pub fn date_key(&self) -> String {
        format!("{:04}-{:02}-{:02}", self.year, self.month0 + 1, self.day)
    }
}

#[cfg(not(target_arch = "wasm32"))]
pub fn local(time_zone: &str, t: f64) -> Local {
    use chrono::{Datelike, TimeZone, Timelike};
    let tz = time_zone.parse::<chrono_tz::Tz>().unwrap_or(chrono_tz::UTC);
    let d = tz
        .timestamp_millis_opt(t as i64)
        .single()
        .unwrap_or_else(|| tz.timestamp_millis_opt(0).unwrap());
    Local {
        year: d.year(),
        month0: d.month0(),
        day: d.day(),
        hour: d.hour(),
        minute: d.minute(),
    }
}
#[cfg(not(target_arch = "wasm32"))]
pub fn valid_zone(time_zone: &str) -> bool {
    time_zone.parse::<chrono_tz::Tz>().is_ok()
}

#[cfg(target_arch = "wasm32")]
pub fn local(_time_zone: &str, t: f64) -> Local {
    let d = js_sys::Date::new(&t.into());
    Local {
        year: d.get_full_year() as i32,
        month0: d.get_month(),
        day: d.get_date(),
        hour: d.get_hours(),
        minute: d.get_minutes(),
    }
}
/// The browser supplied this zone name itself; check only its shape.
#[cfg(target_arch = "wasm32")]
pub fn valid_zone(time_zone: &str) -> bool {
    !time_zone.is_empty()
        && time_zone.len() <= 64
        && time_zone
            .bytes()
            .all(|b| b.is_ascii_alphanumeric() || b"/_+-".contains(&b))
}