//! Error types for medical imaging I/O operations.

use thiserror::Error;

/// Errors that can occur when reading or writing medical image files.
#[derive(Error, Debug)]
pub enum MedicalIoError {
    /// IO error during file operations
    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),

    /// Invalid NIfTI header magic bytes
    #[error("Invalid NIfTI magic bytes: expected 'n+1' or 'ni1', got {0:?}")]
    InvalidNiftiMagic(Vec<u8>),

    /// Invalid NIfTI header size
    #[error("Invalid NIfTI header size: expected 348 (NIfTI-1) or 540 (NIfTI-2), got {0}")]
    InvalidHeaderSize(i32),

    /// Unsupported NIfTI data type
    #[error("Unsupported NIfTI data type code: {0}")]
    UnsupportedDataType(i16),

    /// Invalid dimensions
    #[error("Invalid dimensions: {0}")]
    InvalidDimensions(String),

    /// Compression error
    #[error("Compression error: {0}")]
    Compression(String),

    /// Decompression error
    #[error("Decompression error: {0}")]
    Decompression(String),

    /// Data type mismatch
    #[error("Data type mismatch: expected {expected}, got {actual}")]
    DataTypeMismatch { expected: String, actual: String },

    /// File not found
    #[error("File not found: {0}")]
    FileNotFound(String),

    /// Invalid file extension
    #[error("Invalid file extension: expected .nii or .nii.gz, got {0}")]
    InvalidExtension(String),

    /// Memory mapping error
    #[error("Memory mapping error: {0}")]
    MemoryMap(String),

    /// Invalid transform
    #[error("Invalid transform: {0}")]
    InvalidTransform(String),

    /// Parse error
    #[error("Parse error: {0}")]
    Parse(String),
}

/// Result type for medical imaging I/O operations.
pub type Result<T> = std::result::Result<T, MedicalIoError>;