//! AssetBundle error types.

use thiserror::Error;

/// AssetBundle parser error.
#[derive(Error, Debug)]
pub enum AssetBundleError {
    /// I/O error.
    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),

    /// Parser reached malformed data while reading a named field.
    #[error("Parse error at offset {offset} while reading {field}: {message}")]
    ParseField {
        /// Field or structure name being read.
        field: String,
        /// Byte offset where parsing failed.
        offset: usize,
        /// Human-readable diagnostic.
        message: String,
    },

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

    /// Unsupported format or compression mode.
    #[error("Unsupported format: {0}")]
    UnsupportedFormat(String),

    /// Other error.
    #[error(transparent)]
    Other(#[from] anyhow::Error),
}

impl AssetBundleError {
    /// Creates a field-scoped parser error with byte offset context.
    pub fn parse_field(
        field: impl Into<String>,
        offset: usize,
        message: impl Into<String>,
    ) -> Self {
        Self::ParseField {
            field: field.into(),
            offset,
            message: message.into(),
        }
    }
}

/// AssetBundle result type.
pub type Result<T> = std::result::Result<T, AssetBundleError>;