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/*
 * DMNTK - Decision Model and Notation Toolkit
 *
 * MIT license
 *
 * Copyright (c) 2015-2023 Dariusz Depta
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Apache license, Version 2.0
 *
 * Copyright (c) 2015-2023 Dariusz Depta
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//! # Definition of the common error type

use std::{any, fmt};

/// Common result type.
pub type Result<T, E = DmntkError> = std::result::Result<T, E>;

/// Common trait to be implemented by structs defining a specific error.
pub trait ToErrorMessage {
  /// Convert error definition to message string.
  fn message(self) -> String;
}

/// Error definition used by all components of **DMNTK** project.
#[derive(Debug, PartialEq, Eq)]
pub struct DmntkError(String);

impl fmt::Display for DmntkError {
  /// Implementation of [Display](fmt::Display) trait for [DmntkError].
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
    write!(f, "{}", self.0)
  }
}

impl DmntkError {
  /// Creates a new [DmntkError] with specified source name and error message.
  pub fn new(source: &str, message: &str) -> Self {
    Self(format!("<{source}> {message}"))
  }
}

impl<T> From<T> for DmntkError
where
  T: ToErrorMessage,
{
  /// Converts any type that implements [ToErrorMessage] trait to [DmntkError].
  fn from(value: T) -> Self {
    let error_type_name = any::type_name::<T>().split("::").last().unwrap_or("UnknownError");
    DmntkError::new(error_type_name, &value.message())
  }
}

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

  #[test]
  fn test_new() {
    assert_eq!("<TestError> unexpected", format!("{}", DmntkError::new("TestError", "unexpected")));
  }

  #[test]
  fn test_debug() {
    assert_eq!(r#"DmntkError("<TestError> unexpected")"#, format!("{:?}", DmntkError::new("TestError", "unexpected")));
  }

  #[test]
  fn test_equal() {
    let err1 = DmntkError::new("TestError", "unexpected");
    let err2 = DmntkError::new("TestError", "unexpected");
    assert!((err1 == err2));
  }

  #[test]
  fn test_not_equal() {
    let err1 = DmntkError::new("TestError", "expected");
    let err2 = DmntkError::new("TestError", "unexpected");
    assert!((err1 != err2));
  }

  #[test]
  fn test_total_eq() {
    DmntkError::new("TestError", "unexpected").assert_receiver_is_total_eq();
  }
}