use crate::pict::{Extension, Images};
use actix_web::{
    body::BodyStream, client::Client, http::StatusCode, web, HttpRequest, HttpResponse,
    ResponseError,
};
use url::Url;

pub(crate) static VALID_SIZES: &[u16] = &[80, 160, 320, 640, 1080, 2160];

pub(crate) struct Connection {
    upstream: Url,
    client: Client,
}

impl Connection {
    pub(crate) fn new(upstream: Url, client: Client) -> Self {
        Connection { upstream, client }
    }

    pub(crate) async fn thumbnail(
        &self,
        size: u16,
        file: &str,
        extension: Extension,
        req: &HttpRequest,
    ) -> Result<HttpResponse, actix_web::Error> {
        if !VALID_SIZES.contains(&size) {
            return Err(SizeError(size).into());
        }

        self.proxy(self.thumbnail_url(size, file, extension), req)
            .await
    }

    pub(crate) async fn image(
        &self,
        file: &str,
        req: &HttpRequest,
    ) -> Result<HttpResponse, actix_web::Error> {
        self.proxy(self.image_url(file), req).await
    }

    pub(crate) async fn upload(
        &self,
        req: &HttpRequest,
        body: web::Payload,
    ) -> Result<Images, UploadError> {
        let client_request = self.client.request_from(self.upload_url(), req.head());

        let client_request = if let Some(addr) = req.head().peer_addr {
            client_request.header("X-Forwareded-For", addr.to_string())
        } else {
            client_request
        };

        let mut res = client_request
            .send_stream(body)
            .await
            .map_err(|_| UploadError::Request)?;

        let images = res.json::<Images>().await.map_err(|_| UploadError::Json)?;

        Ok(images)
    }

    pub(crate) async fn delete(&self, file: &str, token: &str) -> Result<(), UploadError> {
        let res = self
            .client
            .delete(self.delete_url(file, token))
            .send()
            .await
            .map_err(|_| UploadError::Request)?;

        if !res.status().is_success() {
            return Err(UploadError::Status);
        }

        Ok(())
    }

    fn upload_url(&self) -> String {
        let mut url = self.upstream.clone();
        url.set_path("/image");

        url.to_string()
    }

    fn thumbnail_url(&self, size: u16, file: &str, extension: Extension) -> String {
        let mut url = self.upstream.clone();
        url.set_path(&format!("/image/process.{}", extension));
        url.set_query(Some(&format!("src={}&thumbnail={}", file, size)));

        url.to_string()
    }

    fn image_url(&self, file: &str) -> String {
        let mut url = self.upstream.clone();
        url.set_path(&format!("/image/original/{}", file,));

        url.to_string()
    }

    fn delete_url(&self, file: &str, token: &str) -> String {
        let mut url = self.upstream.clone();
        url.set_path(&format!("/image/delete/{}/{}", token, file));

        url.to_string()
    }

    async fn proxy(
        &self,
        url: String,
        req: &HttpRequest,
    ) -> Result<HttpResponse, actix_web::Error> {
        let client_request = self.client.request_from(url, req.head());
        let client_request = if let Some(addr) = req.head().peer_addr {
            client_request.header("X-Forwarded-For", addr.to_string())
        } else {
            client_request
        };

        let res = client_request.no_decompress().send().await?;

        let mut client_res = HttpResponse::build(res.status());

        for (name, value) in res.headers().iter().filter(|(h, _)| *h != "connection") {
            client_res.header(name.clone(), value.clone());
        }

        Ok(client_res.body(BodyStream::new(res)))
    }
}

#[derive(Clone, Debug, thiserror::Error)]
pub(crate) enum UploadError {
    #[error("There was an error uploading the image")]
    Request,

    #[error("There was an error parsing the image response")]
    Json,

    #[error("Request returned bad HTTP status")]
    Status,
}

impl ResponseError for UploadError {
    fn status_code(&self) -> StatusCode {
        StatusCode::INTERNAL_SERVER_ERROR
    }

    fn error_response(&self) -> HttpResponse {
        HttpResponse::build(self.status_code())
            .content_type(mime::TEXT_PLAIN.essence_str())
            .body(self.to_string())
    }
}

#[derive(Clone, Debug, thiserror::Error)]
#[error("The requested size is invalid, {0}")]
struct SizeError(u16);

impl ResponseError for SizeError {
    fn status_code(&self) -> StatusCode {
        StatusCode::BAD_REQUEST
    }

    fn error_response(&self) -> HttpResponse {
        HttpResponse::build(self.status_code())
            .content_type(mime::TEXT_PLAIN.essence_str())
            .body(self.to_string())
    }
}