From c13c5574309e05144f75d4c137f6f07a22cc393b Mon Sep 17 00:00:00 2001
From: Mohammad Banisaeid <smbl64@gmail.com>
Date: Mon, 25 Dec 2023 11:13:04 +0100
Subject: [PATCH] Add `completion` command (#33)

This PR adds `completion` command to generate shell completion for Bash, zsh, and other shell types.
---
 Cargo.lock  | 12 +++++++++++-
 Cargo.toml  |  3 ++-
 README.md   |  4 +++-
 src/main.rs | 28 +++++++++++++++++++++++++---
 4 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index bdbd0ad..ea8ce33 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -215,6 +215,15 @@ dependencies = [
  "textwrap",
 ]
 
+[[package]]
+name = "clap_complete"
+version = "3.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f7a2e0a962c45ce25afce14220bc24f9dade0a1787f185cecf96bfba7847cd8"
+dependencies = [
+ "clap",
+]
+
 [[package]]
 name = "clap_derive"
 version = "3.2.25"
@@ -676,13 +685,14 @@ checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
 
 [[package]]
 name = "humble-cli"
-version = "0.13.1"
+version = "0.14.0"
 dependencies = [
  "anyhow",
  "assert_cmd",
  "byte-unit",
  "chrono",
  "clap",
+ "clap_complete",
  "dirs",
  "futures-util",
  "indicatif",
diff --git a/Cargo.toml b/Cargo.toml
index ebb0d92..2e84ff4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "humble-cli"
 authors = ["Mohammad Banisaeid <smbl64@gmail.com>"]
-version = "0.13.1"
+version = "0.14.0"
 license = "MIT"
 description = "The missing CLI for downloading your Humble Bundle purchases"
 documentation = "https://github.com/smbl64/humble-cli"
@@ -26,6 +26,7 @@ anyhow = "1.0"
 byte-unit = { version = "4.0", default-features = false }
 chrono = { version = "0.4", features = ["serde"] }
 clap = { version = "3.1", features = ["cargo", "derive"] }
+clap_complete = "3.2"
 dirs = "4.0.0"
 futures-util = "0.3"
 indicatif = "0.16"
diff --git a/README.md b/README.md
index 80f7457..96e57e2 100644
--- a/README.md
+++ b/README.md
@@ -36,7 +36,8 @@ Use `humble-cli auth "<YOUR SESSION KEY>"` to store the authentication key local
 After that you will have access to the following sub-commands:
 
 ```
-$ humble-cli 0.13.1
+$ humble-cli --help
+humble-cli 0.14.0
 The missing Humble Bundle CLI
 
 USAGE:
@@ -48,6 +49,7 @@ OPTIONS:
 
 SUBCOMMANDS:
     auth            Set the authentication session key
+    completion      Generate shell completions
     details         Print details of a certain bundle [aliases: info]
     download        Selectively download items from a bundle [aliases: d]
     help            Print this message or the help of the given subcommand(s)
diff --git a/src/main.rs b/src/main.rs
index 22ddccb..520bb21 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,8 @@
+use std::io;
+
 use anyhow::Context;
 use clap::{builder::ValueParser, value_parser, Arg, Command};
+use clap_complete::Shell;
 use humble_cli::prelude::*;
 
 fn main() {
@@ -44,6 +47,17 @@ fn run() -> Result<(), anyhow::Error> {
             )
     );
 
+    let completion_subcommand = Command::new("completion")
+        .about("Generate shell completions")
+        .arg(
+            Arg::new("SHELL")
+                .help("Shell type to generate completions for")
+                .possible_values(&["bash", "elvish", "fish", "powershell", "zsh"])
+                .takes_value(true)
+                .required(true)
+                .value_parser(value_parser!(Shell)),
+        );
+
     let list_choices_subcommand = Command::new("list-choices")
         .about("List your current Humble Choices")
         .arg(
@@ -164,20 +178,28 @@ fn run() -> Result<(), anyhow::Error> {
         details_subcommand,
         download_subcommand,
         search_subcommand,
+        completion_subcommand,
     ];
 
     let crate_name = clap::crate_name!();
 
-    let matches = clap::Command::new(crate_name)
+    let mut root = clap::Command::new(crate_name)
         .about("The missing Humble Bundle CLI")
         .version(clap::crate_version!())
         .after_help("Note: `humble-cli -h` prints a short and concise overview while `humble-cli --help` gives all details.")
         .subcommand_required(true)
         .arg_required_else_help(true)
-        .subcommands(sub_commands)
-        .get_matches();
+        .subcommands(sub_commands);
 
+    let matches = root.clone().get_matches();
     return match matches.subcommand() {
+        Some(("completion", sub_matches)) => {
+            if let Some(g) = sub_matches.get_one::<Shell>("SHELL").copied() {
+                let crate_name = clap::crate_name!();
+                clap_complete::generate(g, &mut root, crate_name, &mut io::stdout());
+            }
+            Ok(())
+        }
         Some(("auth", sub_matches)) => {
             let session_key = sub_matches.value_of("SESSION-KEY").unwrap();
             auth(session_key)