//! Bridge from route-layer geometry to the standard's address space.

use map_index::volume::TimeTier;
use map_schema::{CellKey, Lod, TimeBucket};

use crate::Coordinate;

/// The [`CellKey`] for a WGS84 coordinate at a horizontal `level`. Uses the
/// coordinate's altitude (if any) for the band, and an atemporal time bucket
/// (use [`coordinate_cell_key_at`] for a timestamped observation).
pub fn coordinate_cell_key(coord: &Coordinate, level: u8) -> CellKey {
    map_index::cell_key(
        coord.lat,
        coord.lng,
        level,
        map_index::alt_band(coord.altitude.unwrap_or(0.0)),
        TimeBucket::ATEMPORAL,
        Lod(0),
    )
}

/// The [`CellKey`] for a coordinate observed at `time_secs` (epoch seconds) at
/// the given time `tier`.
pub fn coordinate_cell_key_at(coord: &Coordinate, level: u8, time_secs: i64, tier: TimeTier) -> CellKey {
    map_index::cell_key(
        coord.lat,
        coord.lng,
        level,
        map_index::alt_band(coord.altitude.unwrap_or(0.0)),
        map_index::time_bucket(time_secs, tier),
        Lod(0),
    )
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn surface_coordinate_maps_to_band_zero() {
        let c = Coordinate::new(37.7749, -122.4194);
        let k = coordinate_cell_key(&c, 14);
        assert_eq!(k.alt, map_schema::AltBand(0));
        assert_eq!(k.s2.level(), Some(14));
        assert!(k.time.is_atemporal());
    }

    #[test]
    fn timestamped_coordinate_gets_time_bucket() {
        let c = Coordinate::new(0.0, 0.0);
        let k = coordinate_cell_key_at(&c, 10, 3_600 + 5, TimeTier::Recent);
        assert_eq!(k.time.width_ms, 3_600_000);
        assert_eq!(k.time.start_tai_ms, 3_600_000);
    }
}