#![feature(proc_macro_hygiene, decl_macro)]

#[macro_use] extern crate rocket;
#[macro_use] extern crate rocket_contrib;
#[macro_use] extern crate serde_derive;
extern crate rocket_cors;
extern crate cookbook;
extern crate planner;

use std::path::{Path, PathBuf};
use rocket::{
    response::{NamedFile, status::NotFound},
    http::Method,
};
use rocket_cors::{AllowedHeaders, AllowedOrigins, Error};

#[get("/")]
fn index() -> Result<NamedFile, NotFound<String>> {
    files(PathBuf::from("index.html"))
}

#[get("/<file..>", rank=6)]
fn files(file: PathBuf) -> Result<NamedFile, NotFound<String>> {
    let path = Path::new("vue/dist/").join(file);
    NamedFile::open(&path)
        .map_err(|_| NotFound(format!("Bad path: {:?}", path)))
}

mod api {
    use cookbook::*;
    use rocket_contrib::{
        json::Json,
        databases::diesel,
    };

    #[database("cookbook_db")]
    pub struct CookbookDbConn(diesel::SqliteConnection);

    /// A serializable wrapper for [`cookbook::recipes::Recipe`]
    #[derive(Serialize)]
    pub struct RecipeObject {
        id: i32,
        title: String,
        category: i16,
        ingredients: String,
        preparation: String,
    }

    impl RecipeObject {
        fn from(conn: &diesel::SqliteConnection, rec: recipes::Recipe) -> Self {
            Self {
                id: rec.id,
                title: rec.title,
                category: rec.category as i16,
                ingredients: rec.ingredients
                                .into_manager(conn)
                                .display_lines(),
                preparation: rec.preparation,
            }
        }
    }

    /// Retrieves data from database and returns all recipes,
    /// transformed into a js friendly [`RecipeObject`].
    #[get("/list")]
    pub fn recipes_list(conn: CookbookDbConn) -> Json<Vec<RecipeObject>> {
        Json( recipes::load_all(&conn)
                       .into_iter()
                       .map(|r| RecipeObject::from(&conn, r))
                       .collect() )
    }

    /// Delete a recipe given it's `id`
    #[get("/delete/<id>")]
    pub fn delete_recipe(conn: CookbookDbConn, id: i32) -> Json<bool> {
        Json( recipes::delete(&conn, id) )
    }

    #[derive(Serialize)]
    pub struct TemplateItems {
        key: (String, String),
        value: Option<RecipeObject>,
    }

    #[derive(Serialize)]
    pub struct TemplateObject {
        items: Vec<TemplateItems>
    }

    #[get("/solver/one")]
    pub fn one_solution(conn: CookbookDbConn) -> Json<TemplateObject> {
        use planner::{
            template,
            solver::{Domain, Problem}
        };

        let possible_values = recipes::load_all(&conn);
        let domain = Domain::new(possible_values);
        let mut problem = Problem::build();
        for (var, dom, ini) in template::Template::generate_variables(&domain) {
            problem = problem.add_variable(var, dom, ini);
        }
        let mut problem = problem
            .add_constraint(|_| true)
            .finish();
        if let Some(one_result) = problem.solve_one() {
            Json(TemplateObject {
                items: one_result
                        .into_iter()
                        .map(|(k,v)| {
                            TemplateItems {
                                key: (format!("{}", k.0), format!("{:?}", k.1)),
                                value: v.map(|r| RecipeObject::from(&conn, r.clone())),
                        }})
                        .collect(),
            })
        } else {
            panic!("No solution at all !");
        }
    }
}

fn main() -> Result<(), Error> {
    let (allowed_origins, failed_origins) = AllowedOrigins::some(&["http://localhost:8080"]);
    assert!(failed_origins.is_empty());

        // You can also deserialize this
    let cors = rocket_cors::CorsOptions {
        allowed_origins: allowed_origins,
        allowed_methods: vec![Method::Get].into_iter().map(From::from).collect(),
        allowed_headers: AllowedHeaders::some(&["Authorization", "Accept"]),
        allow_credentials: true,
        ..Default::default()
    }
    .to_cors()?;

    rocket::ignite()
        .attach(api::CookbookDbConn::fairing())
        .mount("/", routes![index, files])
        .mount("/api", routes![api::recipes_list, api::delete_recipe, api::one_solution])
        .attach(cors)
        .launch();
    Ok(())
}