//! Module containing all the logic for exporting 3D models.

pub mod obj;

use std::io;
use std::io::Write;

use std::fmt;

use parser::Element;
use model::Model;

/// An error occured during export.
pub enum ExportError {
    /// An IO error occured when creating files or directories.
    IoError(io::Error),
}

impl fmt::Display for ExportError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            ExportError::IoError(ref e) =>
                write!(f, "IoError occured: {}", e),
        }
    }
}

impl From<io::Error> for ExportError {
    fn from(e: io::Error) -> Self {
        ExportError::IoError(e)
    }
}

/// Exports a 3D model to a certain format.
pub trait Exporter {
    /// The type of errors the exporter will return in case of errors.
    ///
    /// The errors can be of many things, we can't know everything in this create, so this type
    /// will enable you to use custom errors.
    type Error;

    /// Performs the export in the specified output directory.
    fn export(&self, model: &Model, output_dir: &str) -> Result<(), Self::Error>;
}

/// Serialize a 3D element.
pub trait ElementSerializer {

    /// Performs the serialization.
    ///
    /// Writes the serialization on the output and returns Err if an error occured.
    fn serialize<W: Write>(&self, element: Element, output: &mut W) -> Result<usize, ExportError>;
}