use diesel::result::Error;
use rocket::http::Status;
use rocket::response::status;
use rocket_contrib::json::Json;
use rocket_contrib::templates::Template;
use std::collections::HashMap;
use syntect::highlighting::ThemeSet;
use syntect::html::highlighted_html_for_string;
use syntect::parsing::SyntaxSet;

use crate::connection::DbConn;
use crate::gists;
use crate::gists::{Gist, InsertableGist};

fn error_response(error: Error) -> Status {
    match error {
        Error::NotFound => Status::NotFound,
        _ => Status::InternalServerError,
    }
}

fn format_gist(filetype: Option<String>, body: String) -> String {
    filetype.map_or(
        format!("<pre class='plaintext'>{}</pre>", body),
        |filetype| {
            let ps = SyntaxSet::load_defaults_newlines();
            let ts = ThemeSet::load_defaults();
            ps.find_syntax_by_extension(&filetype).map_or(
                format!("<pre class='plaintext'>{}</pre>", body),
                |syntax| {
                    highlighted_html_for_string(&body, &ps, syntax, &ts.themes["Solarized (light)"])
                },
            )
        },
    )
}

#[get("/")]
pub fn index(connection: DbConn) -> Result<Json<Vec<Gist>>, Status> {
    gists::all(&connection)
        .map(|gists| Json(gists))
        .map_err(|error| error_response(error))
}

#[get("/gists/<id>")]
pub fn show_gist(id: i32, connection: DbConn) -> Template {
    let result = match gists::get(&connection, id) {
        Ok(gist) => Some(gist),
        Err(_) => None,
    };

    let (title, body) = result.map_or(
        (
            String::from("404 - Gist not found"),
            format!("<h3'>{}</h3>", "Gist not found"),
        ),
        |gist| (gist.title, format_gist(gist.filetype, gist.body)),
    );

    let mut context: HashMap<&str, String> = HashMap::new();
    context.insert("title", title);
    context.insert("body", body);

    Template::render("gists/show", &context)
}

#[post("/api/gists", format = "application/json", data = "<gist>")]
pub fn create_gist<'a>(
    gist: Json<InsertableGist>,
    connection: DbConn,
) -> Result<status::Created<Json<Gist>>, Status> {
    gists::insert(gist.into_inner(), &connection)
        .map(|gist| status::Created(String::from(""), Some(Json(gist))))
        .map_err(|error| error_response(error))
}