use axum::{
    http::StatusCode,
    response::{IntoResponse, Response},
};
use std::fmt;

pub struct Error {
    inner: anyhow::Error,
    status: StatusCode,
    message: String,
}

impl Error {
    // Provide a builder method to set the status code
    pub fn with_status(mut self, status: StatusCode) -> Self {
        self.status = status;
        self
    }

    // Provide a builder method to set the custom message
    pub fn with_message(mut self, message: String) -> Self {
        self.message = message;
        self
    }
}

impl Default for Error {
    fn default() -> Self {
        Self {
            inner: anyhow::Error::new(std::fmt::Error),
            status: StatusCode::INTERNAL_SERVER_ERROR,
            message: String::from("An internal error occurred"),
        }
    }
}

impl IntoResponse for Error {
    fn into_response(self) -> Response {
        (self.status, format!("{}: {}", self.message, self.inner)).into_response()
    }
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}: {}", self.message, self.inner)
    }
}

// make it possible to use ? on anyhow::Error Results
impl From<anyhow::Error> for Error {
    fn from(err: anyhow::Error) -> Self {
        Self {
            inner: err,
            status: StatusCode::INTERNAL_SERVER_ERROR,
            message: String::from("An unknown internal error occurred"),
        }
    }
}

impl From<minijinja::Error> for Error {
    fn from(err: minijinja::Error) -> Self {
        Self {
            inner: anyhow::Error::new(err),
            status: StatusCode::INTERNAL_SERVER_ERROR,
            message: String::from("A Templating Error occured"),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use anyhow::anyhow;
    use axum::http::StatusCode;

    #[test]
    fn test_error_with_status_and_message() {
        let error = Error::from(anyhow!("Test error"))
            .with_status(StatusCode::BAD_REQUEST)
            .with_message(String::from("A custom error message"));

        assert_eq!(error.status, StatusCode::BAD_REQUEST);
        assert_eq!(error.message, "A custom error message");
        assert_eq!(format!("{}", error.inner), "Test error");
    }
}