use std::fmt::{Display, Formatter};
use actix_web::error::{JsonPayloadError, PayloadError};
use serde::Serialize;

#[derive(Serialize, Debug)]
pub struct APIErrorResponse {
    pub code: String,
    pub message: String,
    pub path: Option<String>
}

impl Display for APIErrorResponse {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        write!(f, "{:?}", self)
    }
}

impl From<&JsonPayloadError> for APIErrorResponse {
    fn from(value: &JsonPayloadError) -> Self {
        match value {
            JsonPayloadError::OverflowKnownLength { length, limit } => {
                APIErrorResponse {
                    code: "ERR_PAYLOAD_OVERFLOW_KNOWN_LENGTH".to_string(),
                    message: format!("Payload size is bigger than allowed & content length header set. (length: {}, limit: {})", length, limit),
                    path: None,
                }
            },
            JsonPayloadError::Overflow { limit } => {
                APIErrorResponse {
                    code: "ERR_PAYLOAD_OVERFLOW".to_string(),
                    message: format!("Payload size is bigger than allowed but no content-length header is set. (limit: {})", limit),
                    path: None,
                }
            },
            JsonPayloadError::ContentType => {
                APIErrorResponse {
                    code: "ERR_NOT_JSON".to_string(),
                    message: "Content-Type header not set to expected application/json".to_string(),
                    path: None,
                }
            },
            JsonPayloadError::Deserialize(e) => {
                APIErrorResponse {
                    code: "ERR_JSON_DESERIALIZE".to_string(),
                    message: format!("Error deserializing JSON: {}", e),
                    path: None,
                }
            },
            JsonPayloadError::Serialize(e) => {
                APIErrorResponse {
                    code: "ERR_JSON_SERIALIZE".to_string(),
                    message: format!("Error serializing JSON: {}", e),
                    path: None,
                }
            },
            JsonPayloadError::Payload(e) => {
                e.into()
            },
            _ => {
                APIErrorResponse {
                    code: "ERR_UNKNOWN_ERROR".to_string(),
                    message: "An unknown error has occured".to_string(),
                    path: None,
                }
            }
        }
    }
}

impl From<&PayloadError> for APIErrorResponse {
    fn from(value: &PayloadError) -> Self {
        match value {
            PayloadError::Incomplete(e) => APIErrorResponse {
                code: "ERR_UNEXPECTED_EOF".to_string(),
                message: match e {
                    None => "Payload reached EOF but was incomplete".to_string(),
                    Some(e) => format!("Payload reached EOF but was incomplete: {}", e),
                },
                path: None,
            },
            PayloadError::EncodingCorrupted => APIErrorResponse {
                code: "ERR_CORRUPTED_PAYLOAD".to_string(),
                message: "Payload content encoding corrupted".to_string(),
                path: None,
            },
            PayloadError::Overflow => APIErrorResponse {
                code: "ERR_PAYLOAD_OVERFLOW".to_string(),
                message: "Payload reached size limit".to_string(),
                path: None,
            },
            PayloadError::UnknownLength => APIErrorResponse {
                code: "ERR_PAYLOAD_UNKNOWN_LENGTH".to_string(),
                message: "Unable to determine payload length".to_string(),
                path: None,
            },
            PayloadError::Http2Payload(e) => APIErrorResponse {
                code: "ERR_HTTP2_ERROR".to_string(),
                message: format!("HTTP/2 error: {}", e),
                path: None,
            },
            PayloadError::Io(e) => APIErrorResponse {
                code: "ERR_IO_ERROR".to_string(),
                message: format!("I/O error: {}", e),
                path: None,
            },
            _ => APIErrorResponse {
                code: "ERR_UNKNOWN_ERROR".to_string(),
                message: "An unknown error has occured".to_string(),
                path: None,
            },
        }
    }
}