//! Error types for orbital mechanics operations.

use serde::{Deserialize, Serialize};

/// Errors that can occur during orbital mechanics operations.
#[derive(Debug, Clone, thiserror::Error, Serialize, Deserialize)]
pub enum OrbitalError {
    /// TLE parsing failed.
    #[error("TLE parse error: {0}")]
    TleParseError(String),

    /// TLE checksum verification failed.
    #[error("TLE checksum error on line {line}: expected {expected}, got {got}")]
    TleChecksumError {
        /// Which line (1 or 2).
        line: u8,
        /// Expected checksum digit.
        expected: u8,
        /// Computed checksum digit.
        got: u8,
    },

    /// Propagation failed (satellite may have decayed or eccentricity diverged).
    #[error("propagation error: {0}")]
    PropagationError(String),

    /// Satellite orbit has decayed (perigee below Earth surface).
    #[error("satellite has decayed")]
    SatelliteDecayed,

    /// Eccentricity outside valid range [0, 1).
    #[error("invalid eccentricity: {0}")]
    InvalidEccentricity(f64),

    /// Kepler's equation or other iterative solver did not converge.
    #[error("iterative solver did not converge")]
    ConvergenceError,
}

/// Convenience alias for orbital results.
pub type OrbitalResult<T> = Result<T, OrbitalError>;