rename crate "cli_helpers" to "aquatic_cli_helpers"

aquatic_cli_helpers/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "aquatic_cli_helpers"
+version = "0.1.0"
+authors = ["Joakim Frostegård <joakim.frostegard@gmail.com>"]
+edition = "2018"
+license = "Apache-2.0"
+
+[dependencies]
+anyhow = "1"
+gumdrop = "0.7"
+serde = { version = "1", features = ["derive"] }
+toml = "0.5"

aquatic_cli_helpers/src/lib.rs

@@ -0,0 +1,99 @@
+use std::fs::File;
+use std::io::Read;
+
+use anyhow::Context;
+use gumdrop::Options;
+use serde::{Serialize, de::DeserializeOwned};
+use toml;
+
+
+#[derive(Debug, Options)]
+struct AppOptions {
+    #[options(help = "run with config file", short = "c", meta = "PATH")]
+    config_file: Option<String>,
+    #[options(help = "print default config file", short = "p")]
+    print_config: bool,
+    #[options(help = "print help message")]
+    help: bool,
+}
+
+
+pub fn run_app_with_cli_and_config<T>(
+    title: &str,
+    // Function that takes config file and runs application
+    app_fn: fn(T) -> anyhow::Result<()>,
+) where T: Default + Serialize + DeserializeOwned {
+    ::std::process::exit(match run_inner(title, app_fn) {
+        Ok(()) => 0,
+        Err(err) => {
+            eprintln!("Error: {:#}", err);
+
+            1
+        },
+    })
+}
+
+
+fn run_inner<T>(
+    title: &str,
+    // Function that takes config file and runs application
+    app_fn: fn(T) -> anyhow::Result<()>,
+) -> anyhow::Result<()> where T: Default + Serialize + DeserializeOwned {
+    let args: Vec<String> = ::std::env::args().collect();
+
+    let opts = AppOptions::parse_args_default(&args[1..])?;
+
+    if opts.help_requested(){
+        print_help(title, None);
+
+        Ok(())
+    } else if opts.print_config {
+        print!("{}", default_config_as_toml::<T>());
+
+        Ok(())
+    } else if let Some(config_file) = opts.config_file {
+        let config = config_from_toml_file(config_file)?;
+
+        app_fn(config)
+    } else {
+        app_fn(T::default())
+    }
+}
+
+
+fn config_from_toml_file<T>(path: String) -> anyhow::Result<T>
+    where T: DeserializeOwned
+{
+    let mut file = File::open(path.clone()).with_context(||
+        format!("Couldn't open config file {}", path.clone())
+    )?;
+
+    let mut data = String::new();
+
+    file.read_to_string(&mut data).with_context(||
+        format!("Couldn't read config file {}", path.clone())
+    )?;
+
+    toml::from_str(&data).with_context(||
+        format!("Couldn't parse config file {}", path.clone())
+    )
+}
+
+
+fn default_config_as_toml<T>() -> String
+    where T: Default + Serialize
+{
+    toml::to_string_pretty(&T::default())
+        .expect("Could not serialize default config to toml")
+}
+
+
+fn print_help(title: &str, opt_error: Option<anyhow::Error>){
+    println!("{}", title);
+
+    if let Some(error) = opt_error {
+        println!("\nError: {:#}.", error);
+    }
+
+    println!("\n{}", AppOptions::usage());
+}