// 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 serde_derive;

mod database;

use anyhow::Result;
use database::{hash_file, Query, TagDatabase};
use image::ImageFormat;
use rocket::{Data, State};
use rocket_contrib::json::Json;
use rocket_contrib::serve::StaticFiles;
use rocket_contrib::templates::Template;
use std::env;
use std::fs;
use std::fs::File;
use std::os::unix::fs::symlink;
use std::path::Path;
use std::sync::Mutex;

type SiteState<'a> = State<'a, Mutex<DatabaseConnection>>;

struct DatabaseConnection {
    tb: TagDatabase,
    image_dir: String,
}

impl DatabaseConnection {
    fn new() -> Result<Self> {
        let bin = env::current_exe()?.canonicalize()?;
        let bin_dir = bin.parent().unwrap();
        let image_dir = String::from(bin_dir.join("image/").to_str().unwrap());
        let tb_path = bin_dir.join("birka.db");
        let tb = TagDatabase::new(tb_path.to_str().unwrap())?;
        Ok(DatabaseConnection { tb, image_dir })
    }
}

#[get("/")]
fn index() -> Template {
    let context = HashMap::<&str, &str>::new();
    Template::render("index", &context)
}

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

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

    let tag_results = {
        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).into_inner();
    let context = Asdf {
        tags: tag_results,
        images,
    };
    Template::render("index", context)
}

#[derive(Serialize)]
struct ImageResult {
    filename: String,
    thumb_filename: String,
    tags: Vec<String>,
}

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

    let tags = tags.split(",").collect::<Vec<&str>>();
    let results = tb
        .query(Query {
            tags: &tags[..],
            last_id: Some(0),
            limit: Some(50),
        })
        .unwrap();

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

#[post("/posts/<filename>", data = "<data>")]
fn put_posts(conn: SiteState, filename: String, data: Data) -> Json<&str> {
    let conn = conn.inner().lock().unwrap();
    let path = Path::new(&conn.image_dir).join(filename);
    data.stream_to_file(&path).unwrap();
    conn.tb
        .import_image(&path, &hash_file(&path).unwrap())
        .unwrap();

    Json("uploaded!")
}

fn thumb_filename(filename: &str) -> String {
    String::from(format!(
        "{}_thumb.png",
        // Strip extension.
        if let Some(n) = filename.rfind('.') {
            &filename[..n]
        } else {
            &filename[..]
        }
    ))
}

/// 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() {
        let src = format!("{}/{}", image.orig_dir, image.filename);
        let dst = format!("{}/{}", conn.image_dir, image.filename);
        symlink(&src, &dst).ok();

        let stem = Path::new(&dst).file_stem().unwrap().to_str().unwrap();
        let thumb_path = format!("{}/{}", conn.image_dir, thumb_filename(&stem));
        let thumb_path = Path::new(&thumb_path);

        if !thumb_path.exists() {
            let im = image::open(&Path::new(&src)).unwrap();
            let fout = &mut File::create(&thumb_path).unwrap();
            im.thumbnail(100, 100)
                .write_to(fout, ImageFormat::Png)
                .unwrap();
        }
    }
}

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