use build_html::Html;
use http::{Error, StatusCode};
use std::collections::HashMap;
use warp::http::Response;

use crate::{pages, App, AuthToken, FileId, FileInfo, ReadFileError, SessionToken};

pub async fn handle_index(
    app: App,
    token: Option<SessionToken>,
) -> Result<Response<String>, Error> {
    match token {
        Some(token) => match app.validate_session(token).await {
            Ok(_) => render_gallery_page(app).await,
            Err(err) => render_auth_page(Some(format!("session expired: {:?}", err))),
        },
        None => render_auth_page(None),
    }
}

pub fn render_auth_page(message: Option<String>) -> Result<Response<String>, Error> {
    Response::builder()
        .status(StatusCode::OK)
        .body(pages::auth(message).to_html_string())
}

pub async fn render_gallery_page(app: App) -> Result<Response<String>, Error> {
    match app.list_files().await {
        Ok(ids) => {
            let mut files = vec![];
            for id in ids.into_iter() {
                let file = app.get_file(&id).await;
                files.push(file);
            }
            Response::builder()
                .header("content-type", "text/html")
                .status(StatusCode::OK)
                .body(pages::gallery(files).to_html_string())
        }
        Err(_) => Response::builder()
            .header("content-type", "text/html")
            .status(StatusCode::INTERNAL_SERVER_ERROR)
            .body("".to_owned()),
    }
}

pub async fn thumbnail(
    app: App,
    id: String,
    old_etags: Option<String>,
) -> Result<Response<Vec<u8>>, Error> {
    match app.get_file(&FileId::from(id)).await {
        Ok(file) => serve_file(file.info.clone(), || file.thumbnail(), old_etags),
        Err(_err) => Response::builder()
            .status(StatusCode::NOT_FOUND)
            .body(vec![]),
    }
}

pub async fn file(
    app: App,
    id: String,
    old_etags: Option<String>,
) -> Result<Response<Vec<u8>>, Error> {
    match app.get_file(&FileId::from(id)).await {
        Ok(file) => serve_file(file.info.clone(), || file.thumbnail(), old_etags),
        Err(_err) => Response::builder()
            .status(StatusCode::NOT_FOUND)
            .body(vec![]),
    }
}

pub async fn handle_auth(
    app: App,
    form: HashMap<String, String>,
) -> Result<http::Response<String>, Error> {
    match form.get("token") {
        Some(token) => match app
            .authenticate(AuthToken::from(AuthToken::from(token.clone())))
            .await
        {
            Ok(Some(session_token)) => Response::builder()
                .header("location", "/")
                .header(
                    "set-cookie",
                    format!(
                        "session={}; Secure; HttpOnly; SameSite=Strict",
                        session_token.to_string()
                    ),
                )
                .status(StatusCode::SEE_OTHER)
                .body("".to_owned()),
            Ok(None) => render_auth_page(Some(format!("no user found"))),
            Err(_) => render_auth_page(Some(format!("invalid auth token"))),
        },
        None => render_auth_page(Some(format!("no token available"))),
    }
}

pub async fn handle_upload(app: App, token: SessionToken) -> Result<http::Response<String>, Error> {
    match app.validate_session(token).await {
        Ok(Some(_)) => Response::builder()
            .status(StatusCode::NOT_IMPLEMENTED)
            .body("".to_owned()),
        _ => Response::builder()
            .status(StatusCode::UNAUTHORIZED)
            .body("".to_owned()),
    }
}

fn serve_file<F>(
    info: FileInfo,
    file: F,
    old_etags: Option<String>,
) -> http::Result<http::Response<Vec<u8>>>
where
    F: FnOnce() -> Result<Vec<u8>, ReadFileError>,
{
    match old_etags {
        Some(old_etags) if old_etags != info.hash => Response::builder()
            .header("content-type", info.file_type)
            .status(StatusCode::NOT_MODIFIED)
            .body(vec![]),
        _ => match file() {
            Ok(content) => Response::builder()
                .header("content-type", info.file_type)
                .header("etag", info.hash)
                .status(StatusCode::OK)
                .body(content),
            Err(_) => Response::builder()
                .status(StatusCode::INTERNAL_SERVER_ERROR)
                .body(vec![]),
        },
    }
}