use hyper::http::response::Builder;
use hyper::StatusCode;
use sputnik::hyper_body::FormError;
use sputnik::request::QueryError;
use sputnik::response::EmptyBuilder;
use std::str::Utf8Error;

use crate::HyperResponse;

/// For convenience this enum also contains nonerroneous variants.
pub enum Error {
    /// A 400 bad request error.
    BadRequest(String),
    /// A 401 unauthorized error.
    Unauthorized(String),
    /// A 403 forbidden error.
    Forbidden(String),
    /// A 404 not found error.
    NotFound(String),
    /// A 500 internal server error.
    Internal(String),
    /// A 304 response.
    NotModified,
    /// A 302 redirect to the given path.
    Redirect(String),

    // TODO: use Redirect instead
    /// Missing trailing slash.
    MissingTrailingSlash(String),
}

impl From<Utf8Error> for Error {
    fn from(_: Utf8Error) -> Self {
        Self::BadRequest("invalid UTF-8".into())
    }
}

impl From<git2::Error> for Error {
    fn from(e: git2::Error) -> Self {
        eprintln!("git error: {}", e);
        Self::Internal("something went wrong with git".into())
    }
}

impl From<FormError> for Error {
    fn from(e: FormError) -> Self {
        Self::BadRequest(e.to_string())
    }
}

impl From<QueryError> for Error {
    fn from(e: QueryError) -> Self {
        Self::BadRequest(e.to_string())
    }
}

impl From<Error> for HyperResponse {
    fn from(err: Error) -> Self {
        let (status, message) = match err {
            Error::BadRequest(msg) => (400, msg),
            Error::Unauthorized(msg) => (401, msg),
            Error::Forbidden(msg) => (403, msg),
            Error::NotFound(msg) => (404, msg),
            Error::Internal(msg) => (500, msg),
            Error::NotModified => {
                return Builder::new()
                    .status(StatusCode::NOT_MODIFIED)
                    .empty()
                    .unwrap();
            }
            Error::MissingTrailingSlash(path) => {
                return Builder::new()
                    .status(StatusCode::FOUND)
                    .header("location", format!("{}/", path))
                    .body("redirecting".into())
                    .unwrap();
            }
            Error::Redirect(target) => {
                return Builder::new()
                    .status(StatusCode::FOUND)
                    .header("location", target)
                    .body("redirecting".into())
                    .unwrap();
            }
        };
        // TODO: use Page
        Builder::new()
            .status(status)
            .header("content-type", "text/html")
            .body(message.into())
            .unwrap()
    }
}