diff --git a/rust/Cargo.lock b/rust/Cargo.lock index ef6394c..eec1825 100644 --- a/rust/Cargo.lock +++ b/rust/Cargo.lock @@ -940,6 +940,7 @@ dependencies = [ "futures-channel", "futures-core", "futures-util", + "h2", "http", "http-body", "httparse", @@ -1019,6 +1020,12 @@ dependencies = [ "serde", ] +[[package]] +name = "ipnet" +version = "2.5.0" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "879d54834c8c76457ef4293a689b2a8c59b076067ad77b15efafbb05f92a592b" + [[package]] name = "itoa" version = "1.0.4" @@ -1421,6 +1428,45 @@ version = "0.6.27" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "a3f87b73ce11b1619a3c6332f45341e0047173771e8b8b73f87bfeefb7b56244" +[[package]] +name = "reqwest" +version = "0.11.12" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "431949c384f4e2ae07605ccaa56d1d9d2ecdb5cadd4f9577ccfab29f2e5149fc" +dependencies = [ + "base64", + "bytes", + "encoding_rs", + "futures-core", + "futures-util", + "h2", + "http", + "http-body", + "hyper", + "hyper-rustls", + "ipnet", + "js-sys", + "log", + "mime", + "once_cell", + "percent-encoding", + "pin-project-lite", + "rustls", + "rustls-pemfile", + "serde", + "serde_json", + "serde_urlencoded", + "tokio", + "tokio-rustls", + "tower-service", + "url", + "wasm-bindgen", + "wasm-bindgen-futures", + "web-sys", + "webpki-roots", + "winreg", +] + [[package]] name = "ring" version = "0.16.20" @@ -1530,6 +1576,7 @@ dependencies = [ "futures", "log", "rand", + "semver", "serde", "serde_json", "serde_urlencoded", @@ -1554,6 +1601,7 @@ dependencies = [ "num", "num-derive", "num-traits", + "reqwest", "rustls", "sea_battle_backend", "serde_json", @@ -2111,6 +2159,18 @@ dependencies = [ "wasm-bindgen-shared", ] +[[package]] +name = "wasm-bindgen-futures" +version = "0.4.33" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "23639446165ca5a5de86ae1d8896b737ae80319560fbaa4c2887b7da6e7ebd7d" +dependencies = [ + "cfg-if", + "js-sys", + "wasm-bindgen", + "web-sys", +] + [[package]] name = "wasm-bindgen-macro" version = "0.2.83" @@ -2160,6 +2220,15 @@ dependencies = [ "untrusted", ] +[[package]] +name = "webpki-roots" +version = "0.22.5" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "368bfe657969fb01238bb756d351dcade285e0f6fcbd36dcb23359a5169975be" +dependencies = [ + "webpki", +] + [[package]] name = "winapi" version = "0.3.9" @@ -2234,6 +2303,15 @@ version = "0.36.1" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "c811ca4a8c853ef420abd8592ba53ddbbac90410fab6903b3e79972a631f7680" +[[package]] +name = "winreg" +version = "0.10.1" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "80d0f4e272c85def139476380b12f9ac60926689dd2e01d4923222f40580869d" +dependencies = [ + "winapi", +] + [[package]] name = "zstd" version = "0.11.2+zstd.1.5.2" diff --git a/rust/sea_battle_backend/Cargo.toml b/rust/sea_battle_backend/Cargo.toml index 61e53dd..a502b7e 100644 --- a/rust/sea_battle_backend/Cargo.toml +++ b/rust/sea_battle_backend/Cargo.toml @@ -26,6 +26,7 @@ uuid = { version = "1.1.2", features = ["v4"] } rand = "0.8.5" serde_with = "2.0.1" tokio = { version = "1", features = ["full"] } +semver = "1.0.14" [dev-dependencies] #reqwest = { version = "0.11.11", default-features = false, features = ["json", "rustls-tls"] } diff --git a/rust/sea_battle_backend/src/consts.rs b/rust/sea_battle_backend/src/consts.rs index 8189baf..74cfe60 100644 --- a/rust/sea_battle_backend/src/consts.rs +++ b/rust/sea_battle_backend/src/consts.rs @@ -1,5 +1,8 @@ //! # Project constants +pub const MIN_REQUIRED_VERSION: &str = "0.1.0"; +pub const CURRENT_VERSION: &str = env!("CARGO_PKG_VERSION"); + pub const MIN_BOATS_NUMBER: usize = 1; pub const MAX_BOATS_NUMBER: usize = 10; diff --git a/rust/sea_battle_backend/src/data/mod.rs b/rust/sea_battle_backend/src/data/mod.rs index 2a828e7..781eea6 100644 --- a/rust/sea_battle_backend/src/data/mod.rs +++ b/rust/sea_battle_backend/src/data/mod.rs @@ -4,6 +4,7 @@ pub use game_map::*; pub use game_rules::*; pub use play_config::*; pub use printable_map::*; +pub use version::*; mod boats_layout; mod current_game_status; @@ -11,3 +12,4 @@ mod game_map; mod game_rules; mod play_config; mod printable_map; +mod version; diff --git a/rust/sea_battle_backend/src/data/version.rs b/rust/sea_battle_backend/src/data/version.rs new file mode 100644 index 0000000..eae183c --- /dev/null +++ b/rust/sea_battle_backend/src/data/version.rs @@ -0,0 +1,32 @@ +//! # Version Info +//! +//! Contains server version requirements information + +use crate::consts; +use crate::utils::res_utils::Res; +use semver::Version; + +#[derive(serde::Serialize, serde::Deserialize)] +pub struct VersionInfo { + current: String, + min_required: String, +} + +impl VersionInfo { + pub fn load_static() -> Self { + Self { + current: consts::CURRENT_VERSION.to_string(), + min_required: consts::MIN_REQUIRED_VERSION.to_string(), + } + } + + /// Check if builtin version is compatible with a remote version or not + pub fn is_compatible_with_static_version(&self) -> Res { + let static_version = Self::load_static(); + + let local_current = Version::parse(&static_version.current)?; + let min_required = Version::parse(&self.min_required)?; + + Ok(min_required <= local_current) + } +} diff --git a/rust/sea_battle_backend/src/server.rs b/rust/sea_battle_backend/src/server.rs index b46a6cb..a0e7e25 100644 --- a/rust/sea_battle_backend/src/server.rs +++ b/rust/sea_battle_backend/src/server.rs @@ -4,7 +4,7 @@ use actix_web::{web, App, HttpRequest, HttpResponse, HttpServer, Responder}; use actix_web_actors::ws; use crate::args::Args; -use crate::data::{GameRules, PlayConfiguration}; +use crate::data::{GameRules, PlayConfiguration, VersionInfo}; use crate::dispatcher_actor::DispatcherActor; use crate::human_player_ws::{HumanPlayerWS, StartMode}; @@ -18,7 +18,12 @@ async fn not_found() -> impl Responder { HttpResponse::NotFound().json("You missed your strike lol") } -/// Get bot configuration +/// Get version information +async fn version_information() -> impl Responder { + HttpResponse::Ok().json(VersionInfo::load_static()) +} + +/// Get game configuration async fn game_configuration() -> impl Responder { HttpResponse::Ok().json(PlayConfiguration::default()) } @@ -148,6 +153,7 @@ pub async fn start_server(args: Args) -> std::io::Result<()> { App::new() .app_data(web::Data::new(dispatcher_actor.clone())) .wrap(cors) + .route("/version", web::get().to(version_information)) .route("/config", web::get().to(game_configuration)) .route("/play/bot", web::get().to(start_bot_play)) .route("/play/create_invite", web::get().to(start_create_invite)) diff --git a/rust/sea_battle_cli_player/Cargo.toml b/rust/sea_battle_cli_player/Cargo.toml index 2224075..d434c3f 100644 --- a/rust/sea_battle_cli_player/Cargo.toml +++ b/rust/sea_battle_cli_player/Cargo.toml @@ -31,3 +31,4 @@ serde_json = "1.0.85" hostname = "0.3.1" rustls = "0.20.6" hyper-rustls = { version = "0.23.0", features = ["rustls-native-certs"] } +reqwest = { version = "0.11", features = ["json", "rustls-tls"], default-features = false } \ No newline at end of file diff --git a/rust/sea_battle_cli_player/src/cli_args.rs b/rust/sea_battle_cli_player/src/cli_args.rs index 7bed537..284da4a 100644 --- a/rust/sea_battle_cli_player/src/cli_args.rs +++ b/rust/sea_battle_cli_player/src/cli_args.rs @@ -20,7 +20,7 @@ pub struct CliArgs { value_parser, default_value = "https://seabattleapi.communiquons.org" )] - pub remote_server_uri: String, + pub remote_server: String, /// Local server listen address #[clap(short, long, default_value = "127.0.0.1:5679")] diff --git a/rust/sea_battle_cli_player/src/client.rs b/rust/sea_battle_cli_player/src/client.rs index c189656..b9d94f4 100644 --- a/rust/sea_battle_cli_player/src/client.rs +++ b/rust/sea_battle_cli_player/src/client.rs @@ -3,12 +3,13 @@ use crate::server; use futures::stream::{SplitSink, SplitStream}; use futures::{SinkExt, StreamExt}; use hyper_rustls::ConfigBuilderExt; -use sea_battle_backend::data::GameRules; +use sea_battle_backend::data::*; use sea_battle_backend::human_player_ws::{ClientMessage, ServerMessage}; use sea_battle_backend::server::{ AcceptInviteQuery, BotPlayQuery, CreateInviteQuery, PlayRandomQuery, }; use sea_battle_backend::utils::res_utils::{boxed_error, Res}; +use std::error::Error; use std::fmt::Display; use std::sync::mpsc::TryRecvError; use std::sync::{mpsc, Arc}; @@ -18,6 +19,11 @@ use tokio_tungstenite::{MaybeTlsStream, WebSocketStream}; type WsStream = WebSocketStream>; +pub enum GetRemoteVersionError { + ConnectionFailed, + Other(Box), +} + /// Connection client /// /// This structure acts as a wrapper around websocket connection that handles automatically parsing @@ -28,6 +34,24 @@ pub struct Client { } impl Client { + /// Get remote server version + pub async fn get_server_version() -> Result { + let url = format!("{}/version", cli_args().remote_server); + log::debug!("Getting remote information from {} ...", url); + + let res = match reqwest::get(url).await { + Ok(r) => r, + Err(e) if e.is_timeout() || e.is_connect() => { + return Err(GetRemoteVersionError::ConnectionFailed) + } + Err(e) => return Err(GetRemoteVersionError::Other(Box::new(e))), + }; + + res.json() + .await + .map_err(|e| GetRemoteVersionError::Other(Box::new(e))) + } + /// Start to play against a bot /// /// When playing against a bot, local server is always used @@ -51,7 +75,7 @@ impl Client { /// Start to play against a random player pub async fn start_random_play(player_name: D) -> Res { Self::connect_url( - &cli_args().remote_server_uri, + &cli_args().remote_server, &format!( "/play/random?{}", serde_urlencoded::to_string(&PlayRandomQuery { @@ -66,7 +90,7 @@ impl Client { /// Start a play by creating an invite pub async fn start_create_invite(rules: &GameRules, player_name: D) -> Res { Self::connect_url( - &cli_args().remote_server_uri, + &cli_args().remote_server, &format!( "/play/create_invite?{}", serde_urlencoded::to_string(&CreateInviteQuery { @@ -82,7 +106,7 @@ impl Client { /// Start a play by accepting an invite pub async fn start_accept_invite(code: String, player_name: D) -> Res { Self::connect_url( - &cli_args().remote_server_uri, + &cli_args().remote_server, &format!( "/play/accept_invite?{}", serde_urlencoded::to_string(&AcceptInviteQuery { diff --git a/rust/sea_battle_cli_player/src/constants.rs b/rust/sea_battle_cli_player/src/consts.rs similarity index 100% rename from rust/sea_battle_cli_player/src/constants.rs rename to rust/sea_battle_cli_player/src/consts.rs diff --git a/rust/sea_battle_cli_player/src/lib.rs b/rust/sea_battle_cli_player/src/lib.rs index d290538..d3d0df6 100644 --- a/rust/sea_battle_cli_player/src/lib.rs +++ b/rust/sea_battle_cli_player/src/lib.rs @@ -2,7 +2,7 @@ extern crate core; pub mod cli_args; pub mod client; -pub mod constants; +pub mod consts; pub mod server; pub mod ui_screens; pub mod ui_widgets; diff --git a/rust/sea_battle_cli_player/src/main.rs b/rust/sea_battle_cli_player/src/main.rs index 8d0ae0f..b3ef9b2 100644 --- a/rust/sea_battle_cli_player/src/main.rs +++ b/rust/sea_battle_cli_player/src/main.rs @@ -18,7 +18,7 @@ use sea_battle_backend::consts::{ use sea_battle_backend::data::GameRules; use sea_battle_backend::utils::res_utils::Res; use sea_battle_cli_player::cli_args::{cli_args, TestDevScreen}; -use sea_battle_cli_player::client::Client; +use sea_battle_cli_player::client::{Client, GetRemoteVersionError}; use sea_battle_cli_player::server::run_server; use sea_battle_cli_player::ui_screens::configure_game_rules::GameRulesConfigurationScreen; use sea_battle_cli_player::ui_screens::game_screen::GameScreen; @@ -35,10 +35,10 @@ async fn run_dev( d: TestDevScreen, ) -> Result<(), Box> { let res = match d { - TestDevScreen::Popup => popup_screen::PopupScreen::new("Welcome there!!") + TestDevScreen::Popup => PopupScreen::new("Welcome there!!") .show(terminal)? .as_string(), - TestDevScreen::Input => input_screen::InputScreen::new("What it your name ?") + TestDevScreen::Input => InputScreen::new("What it your name ?") .set_title("A custom title") .show(terminal)? .as_string(), @@ -50,9 +50,9 @@ async fn run_dev( TestDevScreen::SelectBotType => select_bot_type_screen::SelectBotTypeScreen::default() .show(terminal)? .as_string(), - TestDevScreen::SelectPlayMode => select_play_mode_screen::SelectPlayModeScreen::default() - .show(terminal)? - .as_string(), + TestDevScreen::SelectPlayMode => { + SelectPlayModeScreen::default().show(terminal)?.as_string() + } TestDevScreen::SetBoatsLayout => { let rules = GameRules { boats_can_touch: true, @@ -64,7 +64,7 @@ async fn run_dev( .as_string() } TestDevScreen::ConfigureGameRules => { - configure_game_rules::GameRulesConfigurationScreen::new(GameRules::default()) + GameRulesConfigurationScreen::new(GameRules::default()) .show(terminal)? .as_string() } @@ -99,6 +99,8 @@ async fn run_app(terminal: &mut Terminal) -> Res { return run_dev(terminal, d).await; } + let mut checked_online_compatibility = false; + let mut rules = GameRules::default(); let mut username = "".to_string(); @@ -107,6 +109,30 @@ async fn run_app(terminal: &mut Terminal) -> Res { let choice = SelectPlayModeScreen::default().show(terminal)?; if let ScreenResult::Ok(c) = choice { + // Check compatibility + if c.is_online_play_mode() && !checked_online_compatibility { + PopupScreen::new("🖥 Checking remote server version...").show_once(terminal)?; + let valid_version = match Client::get_server_version().await { + Ok(v) => v.is_compatible_with_static_version().unwrap_or(false), + Err(GetRemoteVersionError::ConnectionFailed) => { + PopupScreen::new("❌ Could not connect to remote server!") + .show(terminal)?; + continue; + } + Err(GetRemoteVersionError::Other(e)) => { + log::error!("Could not load remote server information! {:?}", e); + false + } + }; + + if !valid_version { + PopupScreen::new("❌ Unfortunately, it seems that your version of Sea Battle Cli player is too old to be used online...\n\nPlease update it before trying to play online...").show(terminal)?; + continue; + } + + checked_online_compatibility = true; + } + if c.need_player_name() && username.is_empty() { username = query_player_name(terminal)?; } diff --git a/rust/sea_battle_cli_player/src/ui_screens/configure_game_rules.rs b/rust/sea_battle_cli_player/src/ui_screens/configure_game_rules.rs index 7e7e868..683865a 100644 --- a/rust/sea_battle_cli_player/src/ui_screens/configure_game_rules.rs +++ b/rust/sea_battle_cli_player/src/ui_screens/configure_game_rules.rs @@ -16,7 +16,7 @@ use tui::{Frame, Terminal}; use sea_battle_backend::data::GameRules; -use crate::constants::{HIGHLIGHT_COLOR, TICK_RATE}; +use crate::consts::{HIGHLIGHT_COLOR, TICK_RATE}; use crate::ui_screens::popup_screen::show_screen_too_small_popup; use crate::ui_screens::select_bot_type_screen::SelectBotTypeScreen; use crate::ui_screens::utils::centered_rect_size; diff --git a/rust/sea_battle_cli_player/src/ui_screens/confirm_dialog_screen.rs b/rust/sea_battle_cli_player/src/ui_screens/confirm_dialog_screen.rs index 1f9bb4f..34d8acb 100644 --- a/rust/sea_battle_cli_player/src/ui_screens/confirm_dialog_screen.rs +++ b/rust/sea_battle_cli_player/src/ui_screens/confirm_dialog_screen.rs @@ -9,7 +9,7 @@ use tui::text::*; use tui::widgets::*; use tui::{Frame, Terminal}; -use crate::constants::*; +use crate::consts::*; use crate::ui_screens::utils::centered_rect_size; use crate::ui_screens::ScreenResult; use crate::ui_widgets::button_widget::ButtonWidget; diff --git a/rust/sea_battle_cli_player/src/ui_screens/game_screen.rs b/rust/sea_battle_cli_player/src/ui_screens/game_screen.rs index dd1ddb5..eda9dd5 100644 --- a/rust/sea_battle_cli_player/src/ui_screens/game_screen.rs +++ b/rust/sea_battle_cli_player/src/ui_screens/game_screen.rs @@ -16,7 +16,7 @@ use sea_battle_backend::utils::res_utils::Res; use sea_battle_backend::utils::time_utils::time; use crate::client::Client; -use crate::constants::*; +use crate::consts::*; use crate::ui_screens::confirm_dialog_screen::confirm; use crate::ui_screens::popup_screen::{show_screen_too_small_popup, PopupScreen}; use crate::ui_screens::set_boats_layout_screen::SetBoatsLayoutScreen; diff --git a/rust/sea_battle_cli_player/src/ui_screens/input_screen.rs b/rust/sea_battle_cli_player/src/ui_screens/input_screen.rs index d3b02c9..40c1562 100644 --- a/rust/sea_battle_cli_player/src/ui_screens/input_screen.rs +++ b/rust/sea_battle_cli_player/src/ui_screens/input_screen.rs @@ -10,7 +10,7 @@ use tui::layout::*; use tui::widgets::*; use tui::{Frame, Terminal}; -use crate::constants::*; +use crate::consts::*; use crate::ui_screens::utils::*; use crate::ui_screens::ScreenResult; use crate::ui_widgets::button_widget::ButtonWidget; diff --git a/rust/sea_battle_cli_player/src/ui_screens/popup_screen.rs b/rust/sea_battle_cli_player/src/ui_screens/popup_screen.rs index 97914d0..896e1b3 100644 --- a/rust/sea_battle_cli_player/src/ui_screens/popup_screen.rs +++ b/rust/sea_battle_cli_player/src/ui_screens/popup_screen.rs @@ -9,7 +9,7 @@ use tui::text::*; use tui::widgets::*; use tui::{Frame, Terminal}; -use crate::constants::*; +use crate::consts::*; use crate::ui_screens::utils::centered_rect_size; use crate::ui_screens::ScreenResult; use crate::ui_widgets::button_widget::ButtonWidget; diff --git a/rust/sea_battle_cli_player/src/ui_screens/select_bot_type_screen.rs b/rust/sea_battle_cli_player/src/ui_screens/select_bot_type_screen.rs index cd28afd..19caebe 100644 --- a/rust/sea_battle_cli_player/src/ui_screens/select_bot_type_screen.rs +++ b/rust/sea_battle_cli_player/src/ui_screens/select_bot_type_screen.rs @@ -11,7 +11,7 @@ use tui::{Frame, Terminal}; use sea_battle_backend::data::{BotDescription, BotType, PlayConfiguration}; -use crate::constants::{HIGHLIGHT_COLOR, TICK_RATE}; +use crate::consts::{HIGHLIGHT_COLOR, TICK_RATE}; use crate::ui_screens::utils::centered_rect_size; use crate::ui_screens::ScreenResult; diff --git a/rust/sea_battle_cli_player/src/ui_screens/select_play_mode_screen.rs b/rust/sea_battle_cli_player/src/ui_screens/select_play_mode_screen.rs index 519d3de..9b0d8e4 100644 --- a/rust/sea_battle_cli_player/src/ui_screens/select_play_mode_screen.rs +++ b/rust/sea_battle_cli_player/src/ui_screens/select_play_mode_screen.rs @@ -1,7 +1,7 @@ use std::io; use std::time::{Duration, Instant}; -use crate::constants::{HIGHLIGHT_COLOR, TICK_RATE}; +use crate::consts::{HIGHLIGHT_COLOR, TICK_RATE}; use crate::ui_screens::utils::centered_rect_size; use crate::ui_screens::ScreenResult; use crossterm::event; @@ -33,6 +33,11 @@ impl SelectPlayModeResult { pub fn need_custom_rules(&self) -> bool { self == &SelectPlayModeResult::PlayAgainstBot || self == &SelectPlayModeResult::CreateInvite } + + /// Specify whether a play mode is to be played online or not + pub fn is_online_play_mode(&self) -> bool { + self != &SelectPlayModeResult::PlayAgainstBot && self != &SelectPlayModeResult::Exit + } } #[derive(Debug, Clone)] diff --git a/rust/sea_battle_cli_player/src/ui_screens/set_boats_layout_screen.rs b/rust/sea_battle_cli_player/src/ui_screens/set_boats_layout_screen.rs index e8993bc..7456de6 100644 --- a/rust/sea_battle_cli_player/src/ui_screens/set_boats_layout_screen.rs +++ b/rust/sea_battle_cli_player/src/ui_screens/set_boats_layout_screen.rs @@ -12,7 +12,7 @@ use tui::{Frame, Terminal}; use sea_battle_backend::data::*; -use crate::constants::*; +use crate::consts::*; use crate::ui_screens::confirm_dialog_screen::confirm; use crate::ui_screens::popup_screen::show_screen_too_small_popup; use crate::ui_screens::utils::{centered_rect_size, centered_text}; diff --git a/rust/sea_battle_cli_player/src/ui_widgets/button_widget.rs b/rust/sea_battle_cli_player/src/ui_widgets/button_widget.rs index 0e4ff3b..a004999 100644 --- a/rust/sea_battle_cli_player/src/ui_widgets/button_widget.rs +++ b/rust/sea_battle_cli_player/src/ui_widgets/button_widget.rs @@ -1,6 +1,6 @@ use std::fmt::Display; -use crate::constants::HIGHLIGHT_COLOR; +use crate::consts::HIGHLIGHT_COLOR; use tui::buffer::Buffer; use tui::layout::Rect; use tui::style::{Color, Style}; diff --git a/rust/sea_battle_cli_player/src/ui_widgets/checkbox_widget.rs b/rust/sea_battle_cli_player/src/ui_widgets/checkbox_widget.rs index 821c4f4..daaaf71 100644 --- a/rust/sea_battle_cli_player/src/ui_widgets/checkbox_widget.rs +++ b/rust/sea_battle_cli_player/src/ui_widgets/checkbox_widget.rs @@ -1,4 +1,4 @@ -use crate::constants::HIGHLIGHT_COLOR; +use crate::consts::HIGHLIGHT_COLOR; use std::fmt::Display; use tui::buffer::Buffer; use tui::layout::Rect; diff --git a/rust/sea_battle_cli_player/src/ui_widgets/text_editor_widget.rs b/rust/sea_battle_cli_player/src/ui_widgets/text_editor_widget.rs index fea06ec..50b30f3 100644 --- a/rust/sea_battle_cli_player/src/ui_widgets/text_editor_widget.rs +++ b/rust/sea_battle_cli_player/src/ui_widgets/text_editor_widget.rs @@ -1,6 +1,6 @@ use std::fmt::Display; -use crate::constants::HIGHLIGHT_COLOR; +use crate::consts::HIGHLIGHT_COLOR; use tui::buffer::Buffer; use tui::layout::Rect; use tui::style::*;