use std::fmt::Display;

use poem::{
    error::{ParseMultipartError, ResponseError},
    http::StatusCode,
};
use sqlx::postgres::PgDatabaseError;

#[derive(Debug)]
pub enum Error {
    IOError(std::io::Error),
    TOMLError(toml::de::Error),
    SQLError(String),
    DatabaseError(sqlx::Error),
    NotFound,
    MissingField,
    Unauthorized,
    MultipartError,
    BadRequest,
    UnsupportedFileType(String),
    UploadDirectory(String),
}

impl Display for Error {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Error::SQLError(error) => write!(f, "SQL Error: {}", error),
            Error::IOError(error) => write!(f, "IO Error: {}", error),
            Error::TOMLError(error) => write!(f, "TOML deserialization error: {}", error),
            Error::DatabaseError(error) => write!(f, "database error: {}", error),
            Error::NotFound => write!(f, "not found"),
            Error::MissingField => write!(f, "missing field in row"),
            Error::Unauthorized => write!(f, "user unauthorized"),
            Error::MultipartError => write!(f, "error parsing multipart form data"),
            Error::BadRequest => write!(f, "bad request"),
            Error::UnsupportedFileType(filetype) => {
                write!(f, "unsupported file upload type: {}", filetype)
            }
            Error::UploadDirectory(directory) => {
                write!(f, "invalid uploads directory: {}", directory)
            }
        }
    }
}

impl std::error::Error for Error {}

impl ResponseError for Error {
    fn status(&self) -> poem::http::StatusCode {
        match self {
            Error::IOError(_) => StatusCode::INTERNAL_SERVER_ERROR,
            Error::TOMLError(_) => StatusCode::INTERNAL_SERVER_ERROR,
            Error::DatabaseError(_) => StatusCode::INTERNAL_SERVER_ERROR,
            Error::NotFound => StatusCode::NOT_FOUND,
            Error::SQLError(_) => StatusCode::INTERNAL_SERVER_ERROR,
            Error::MissingField => StatusCode::INTERNAL_SERVER_ERROR,
            Error::Unauthorized => StatusCode::UNAUTHORIZED,
            Error::MultipartError => StatusCode::BAD_REQUEST,
            Error::BadRequest => StatusCode::BAD_REQUEST,
            Error::UnsupportedFileType(_) => StatusCode::BAD_REQUEST,
            Error::UploadDirectory(_) => StatusCode::INTERNAL_SERVER_ERROR,
        }
    }
}

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

impl From<toml::de::Error> for Error {
    fn from(e: toml::de::Error) -> Self {
        Self::TOMLError(e)
    }
}

impl From<sqlx::Error> for Error {
    fn from(e: sqlx::Error) -> Self {
        match e {
            sqlx::Error::Database(database_error) => {
                let error = database_error.downcast::<PgDatabaseError>();
                match error.code() {
                    code => Error::SQLError(code.to_string()),
                }
            }
            sqlx::Error::RowNotFound => Error::NotFound,
            _ => Self::DatabaseError(e),
        }
    }
}

impl From<ParseMultipartError> for Error {
    fn from(e: ParseMultipartError) -> Self {
        Error::MultipartError
    }
}