update: add meme help action

Author: Liki4

src/main.rs

@@ -1,7 +1,6 @@
 mod bot;
 mod meme;
 
-use std::env;
 use {
     crate::bot::{
         bot_init,
@@ -15,6 +14,7 @@ use {
         command,
         command::Command,
     },
+    std::env,
     teloxide::{
         prelude::*,
         utils::command::BotCommands,
@@ -43,8 +43,9 @@ async fn main() {
                     dptree::filter(|msg: Message| msg.media_group_id().is_some())
                         .branch(
                             dptree::filter(|msg: Message| {
-                                msg.caption()
-                                    .map_or(false, |caption| Command::parse(caption, &env::var("BOT_NAME").unwrap()).is_ok())
+                                msg.caption().map_or(false, |caption| {
+                                    Command::parse(caption, &env::var("BOT_NAME").unwrap()).is_ok()
+                                })
                             })
                             .endpoint(media_group_with_command_handler),
                         )

src/meme/cmd.rs

@@ -26,10 +26,34 @@ use {
     },
 };
 
+const HELP_MSG: &str = r#"
+`/meme help` \- display this message
+`/meme list` \- list all memes
+`/meme info <key/keyword>` \- display meme information
+`/meme search <keyword>` \- search meme key by keyword
+`/meme random [args]` \- generate a random meme
+`/meme generate <key/keyword> [args]` \- generate a specific meme
+
+args \= `[<text1> <text2>] [<@someone> <@someone_else>]`
+
+**random** & **generate** action can pass photo using `@someone`, append as photo and reply to a media group message
+
+command sender's **first\_name** & **profile\_photo** will append to end of texts\_list and photos\_list
+
+see https://github\.com/Liki4/Liki4TeloxideBot for more details\.
+"#;
+
 pub async fn meme_command_handler(
     bot: &Bot, msg: &Message, action: MemeAction, args: Vec<String>,
 ) -> ResponseResult<Message> {
     let error = match action {
+        MemeAction::Help => {
+            return bot
+                .send_message(msg.chat.id, HELP_MSG)
+                .parse_mode(ParseMode::MarkdownV2)
+                .reply_parameters(ReplyParameters::new(msg.id))
+                .await;
+        }
         MemeAction::Info => match args.first() {
             Some(keyword) => {
                 if let Some(key) = MEME_KEYWORD_KEY_MAPPING.get().unwrap().get(keyword) {

src/meme/mod.rs

@@ -4,22 +4,19 @@ mod utils;
 
 use {
     std::{
-        error::Error,
         fmt::{
             self,
             Display,
             Formatter,
         },
         str::FromStr,
     },
-    teloxide::utils::command::{
-        ParseError,
-        ParseError::IncorrectFormat,
-    },
+    teloxide::utils::command::ParseError,
 };
 
 #[derive(Debug, PartialEq, Clone)]
 pub enum MemeAction {
+    Help,
     List,
     Search,
     Info,
@@ -37,16 +34,15 @@ impl FromStr for MemeAction {
             "search" => Ok(MemeAction::Search),
             "random" => Ok(MemeAction::Random),
             "generate" => Ok(MemeAction::Generate),
-            _ => Err(IncorrectFormat(
-                Box::<dyn Error + Send + Sync + 'static>::from("Unknown MemeAction"),
-            )),
+            _ => Ok(MemeAction::Help),
         }
     }
 }
 
 impl Display for MemeAction {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         match self {
+            MemeAction::Help => write!(f, "help"),
             MemeAction::Info => write!(f, "info"),
             MemeAction::List => write!(f, "list"),
             MemeAction::Search => write!(f, "search"),