path: root/src/birka-web.rs

// Copyright © 2020 Jakob L. Kreuze <zerodaysfordays@sdf.org>
//
// This file is part of бирка-тян.
//
// бирка-тян is free software; you can redistribute it and/or modify it
// under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// бирка-тян is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public
// License along with бирка-тян. If not, see <http://www.gnu.org/licenses/>.

#![feature(proc_macro_hygiene, decl_macro)]

#[macro_use]
extern crate anyhow;
extern crate image;
#[macro_use]
extern crate rocket;
extern crate rocket_contrib;
#[macro_use]
extern crate rusqlite;
#[macro_use]
extern crate serde_derive;

mod database;

use anyhow::Result;
use database::{Image, Query, TagDatabase};
use image::ImageFormat;
use multipart::{MultipartFormData, MultipartFormDataField, MultipartFormDataOptions};
use rand::distributions::Alphanumeric;
use rand::{thread_rng, Rng};
use rocket::http::ContentType;
use rocket::{Data, State};
use rocket_contrib::json::Json;
use rocket_contrib::serve::StaticFiles;
use rocket_contrib::templates::Template;

use std::fs;
use std::fs::File;
use std::io::Write;
use std::os::unix::fs::symlink;
use std::path::Path;
use std::sync::Mutex;

/// Maximum number of results returned by any API endpoint.
const RESULTS_PER_QUERY: i64 = 50;

/// Shorthand for the state that is passed to all handlers.
type SiteState<'a> = State<'a, Mutex<DatabaseConnection>>;

/// Everything necessary to serve images from the tag database.
struct DatabaseConnection {
    tb: TagDatabase,
    image_dir: String,
}

impl DatabaseConnection {
    fn new() -> Result<Self> {
        // FIXME: It is somewhat of an arbitrary choice that the directory
        // containing symbolic links and thumbnails be relative to the binary.
        let bin = std::env::current_exe()?.canonicalize()?;
        let bin_dir = bin.parent().unwrap();
        let image_dir = bin_dir.join("image/").to_str().unwrap().to_string();
        let tb = TagDatabase::new(&bin_dir.join("birka.db"))?;
        Ok(DatabaseConnection { tb, image_dir })
    }
}

/// Information about an image, as returned by the 'posts' endpoint.
#[derive(Debug, Serialize)]
struct ImageResult {
    id: i64,
    filename: String,
    thumb_filename: String,
    orig_filename: String,
    tags: Vec<String>,
}

/// Return the store file name of the image at `filename`.
fn image_store_filename(id: i64, filename: &str) -> String {
    if let Some(n) = filename.rfind('.') {
        format!("{id}.{ext}", id = id, ext = &filename[n + 1..])
    } else {
        id.to_string()
    }
}

/// Return the store file name of the thumbnail for the image at `filename`.
fn thumb_filename(id: i64, filename: &str) -> String {
    if let Some(n) = filename.rfind('.') {
        format!("{id}_thumb.{ext}", id = id, ext = &filename[n + 1..])
    } else {
        format!("{id}_thumb", id = id)
    }
}

#[get("/posts?<tags>&<last>")]
fn get_posts(conn: SiteState, tags: String, last: Option<i64>) -> Json<Vec<ImageResult>> {
    let tb = &conn.inner().lock().unwrap().tb;

    // Ensure that an empty vector is passed to `tb.query` if no tags were
    // specified.
    let tags = if !tags.is_empty() {
        tags.split(",").collect::<Vec<&str>>()
    } else {
        vec![]
    };

    let results = tb
        .query(Query::new(&tags[..], last, Some(RESULTS_PER_QUERY)))
        .unwrap();

    Json(
        results
            .iter()
            .map(|image| ImageResult {
                id: image.id,
                filename: image_store_filename(image.id, &image.filename),
                thumb_filename: thumb_filename(image.id, &image.filename),
                orig_filename: image.filename.clone(),
                tags: tb.tags_for_image(image.id).unwrap(),
            })
            .collect(),
    )
}

#[get("/posts/<id>")]
fn get_post(conn: SiteState, id: i64) -> Json<ImageResult> {
    let tb = &conn.inner().lock().unwrap().tb;
    let image = tb.image_by_id(id).unwrap();

    Json(ImageResult {
        id: image.id,
        filename: image_store_filename(image.id, &image.filename),
        thumb_filename: thumb_filename(image.id, &image.filename),
        orig_filename: image.filename.clone(),
        tags: tb.tags_for_image(image.id).unwrap(),
    })
}

#[post("/posts", data = "<data>")]
fn put_post(conn: SiteState, content_type: &ContentType, data: Data) -> Json<String> {
    let conn = conn.inner().lock().unwrap();
    let options = MultipartFormDataOptions::with_multipart_form_data_fields(vec![
        MultipartFormDataField::text("tags"),
        MultipartFormDataField::raw("image")
            .size_limit(32 * 1024 * 1024)
            .content_type_by_string(Some(multipart::mime::IMAGE_STAR))
            .unwrap(),
    ]);

    let mut data = MultipartFormData::parse(content_type, data, options).unwrap();
    let raw = data.raw.remove("image").unwrap().remove(0);

    let filename = raw
        .file_name
        .unwrap_or(thread_rng().sample_iter(&Alphanumeric).take(30).collect());
    let path = Path::new(&conn.image_dir).join(&filename);
    let mut f = File::create(&path).unwrap();
    f.write_all(&raw.raw).unwrap();

    let hash = database::hash_file(&path).unwrap();
    let id = conn.tb.import_image(&path, &hash).unwrap();
    add_to_store(
        &Image {
            id,
            blake2: hash,
            filename: filename.clone(),
            orig_dir: conn.image_dir.clone(),
        },
        &conn.image_dir,
    );

    let tags = data.texts.remove("tags").unwrap().remove(0).text;
    for tag in tags.split(",") {
        conn.tb.add_tag(tag).unwrap();
        conn.tb.tag_image(id, tag).unwrap();
    }

    Json("Uploaded!".into())
}

#[get("/")]
fn index(conn: SiteState) -> Template {
    display_posts(conn, String::from(""), None)
}

#[get("/upload")]
fn upload() -> Template {
    Template::render("upload", None::<()>)
}

#[get("/posts?<tags>&<last>")]
fn display_posts(conn: SiteState, tags: String, last: Option<i64>) -> Template {
    #[derive(Serialize)]
    struct TagResult {
        name: String,
        count: i64,
    }

    #[derive(Serialize)]
    struct Context {
        tags: Vec<TagResult>,
        images: Vec<ImageResult>,
        next_page: String,
    }

    let base_params = format!("/posts?tags={}", tags);
    let tag_results = {
        // This is done in a block because `tb` needs to go out of scope before
        // calling out to `get_posts` to perform the query. Otherwise, we
        // deadlock because the mutex is locked for the entirety of
        // `display_posts`.
        let tb = &conn.inner().lock().unwrap().tb;
        tb.top_tags(20)
            .unwrap()
            .iter()
            .map(|tup| TagResult {
                name: tup.1.clone(),
                count: tup.0,
            })
            .collect()
    };
    let images = get_posts(conn, tags, last).into_inner();
    let context = Context {
        tags: tag_results,
        next_page: if images.len() as i64 == RESULTS_PER_QUERY {
            let last_image = images.last().unwrap();
            format!("{}&last={}", base_params, last_image.id)
        } else {
            String::from("")
        },
        images,
    };
    Template::render("index", context)
}

#[get("/posts/<id>")]
fn display_post(conn: SiteState, id: i64) -> Template {
    #[derive(Serialize)]
    struct Context {
        tags: Vec<String>,
        filename: String,
        orig_filename: String,
    }

    let tb = &conn.inner().lock().unwrap().tb;
    let image = tb.image_by_id(id).unwrap();

    Template::render(
        "image",
        Context {
            tags: tb.tags_for_image(image.id).unwrap(),
            filename: image_store_filename(image.id, &image.filename),
            orig_filename: image.filename,
        },
    )
}

/// Create a thumbnail for `image` in the store at `image_dir`.
fn add_to_store(image: &Image, image_dir: &str) {
    let orig_path = Path::new(&image.orig_dir).join(&image.filename);
    let store_path = image_store_filename(image.id, &image.filename);
    let store_path = Path::new(image_dir).join(store_path);
    symlink(orig_path, &store_path).ok();
    let thumb_path = thumb_filename(image.id, &image.filename);
    let thumb_path = Path::new(image_dir).join(&thumb_path);
    if !thumb_path.exists() {
        let im = image::open(store_path).unwrap();
        let out = &mut File::create(&thumb_path).unwrap();
        im.thumbnail(100, 100)
            .write_to(out, ImageFormat::Png)
            .unwrap();
    }
}

/// Maybe initialize the directory for storing image symlinks and thumbnails.
fn create_image_directory(conn: &DatabaseConnection) {
    fs::create_dir(&conn.image_dir).ok();
    for image in conn.tb.images_by_tags(&vec![][..]).unwrap() {
        add_to_store(&image, &conn.image_dir);
    }
}

fn main() {
    let conn = DatabaseConnection::new().unwrap();
    create_image_directory(&conn);
    rocket::ignite()
        .mount("/public", StaticFiles::from("./static/"))
        .mount("/image", StaticFiles::from(&conn.image_dir))
        .mount("/", routes![index, upload, display_posts, display_post])
        .mount("/api", routes![get_posts, get_post, put_post])
        .attach(Template::fairing())
        .manage(Mutex::new(conn))
        .launch();
}