reorganize folder and cli structure

src/completion/args.rs

@@ -0,0 +1,39 @@
+//! Module related to completion CLI.
+//!
+//! This module provides subcommands and a command matcher related to completion.
+
+use anyhow::Result;
+use clap::{value_parser, Arg, ArgMatches, Command};
+use clap_complete::Shell;
+use log::debug;
+
+const ARG_SHELL: &str = "shell";
+const CMD_COMPLETION: &str = "completion";
+
+type SomeShell = Shell;
+
+/// Completion commands.
+pub enum Cmd {
+    /// Generate completion script for the given shell.
+    Generate(SomeShell),
+}
+
+/// Completion command matcher.
+pub fn matches(m: &ArgMatches) -> Result<Option<Cmd>> {
+    if let Some(m) = m.subcommand_matches(CMD_COMPLETION) {
+        let shell = m.get_one::<Shell>(ARG_SHELL).cloned().unwrap();
+        debug!("shell: {:?}", shell);
+        return Ok(Some(Cmd::Generate(shell)));
+    };
+
+    Ok(None)
+}
+
+/// Completion subcommands.
+pub fn subcmd() -> Command {
+    Command::new(CMD_COMPLETION)
+        .about("Generate the completion script for the given shell")
+        .args(&[Arg::new(ARG_SHELL)
+            .value_parser(value_parser!(Shell))
+            .required(true)])
+}

src/completion/handlers.rs

@@ -0,0 +1,15 @@
+//! Module related to completion handling.
+//!
+//! This module gathers all completion commands.  
+
+use anyhow::Result;
+use clap::Command;
+use clap_complete::Shell;
+use std::io::stdout;
+
+/// Generates completion script from the given [`clap::App`] for the given shell slice.
+pub fn generate<'a>(mut cmd: Command, shell: Shell) -> Result<()> {
+    let name = cmd.get_name().to_string();
+    clap_complete::generate(shell, &mut cmd, name, &mut stdout());
+    Ok(())
+}

src/completion/mod.rs

@@ -0,0 +1,8 @@
+//! Module related to shell completion.
+//!
+//! This module allows users to generate autocompletion scripts for
+//! their shells. You can see the list of available shells directly on
+//! the clap's [docs.rs](https://docs.rs/clap/2.33.3/clap/enum.Shell.html).
+
+pub mod args;
+pub mod handlers;