feat(cli): Add language parameter and parse for supported languages

resources/en-US/cli.ftl

@@ -11,6 +11,9 @@ flags-verbose =
 subcommand-make =
   Executes a make target
 
+flags-language =
+  Set language
+
 subcommand-make-target =
   Target as defined in CaSILE makefile
 

src/main.rs

@@ -1,11 +1,17 @@
+use fluent_langneg::{
+    accepted_languages, convert_vec_str_to_langids_lossy, negotiate_languages, NegotiationStrategy,
+};
+use fluent_resmgr::resource_manager::ResourceManager;
 use git2::Repository;
+use regex::Regex;
 use std::fs;
 use std::io;
 use std::io::{Error, ErrorKind};
 use std::path;
 use std::vec;
 use structopt::clap::AppSettings;
 use structopt::StructOpt;
+use unic_langid::LanguageIdentifier;
 
 /// The command line interface to the CaSILE toolkit, a book publishing
 /// workflow employing SILE and other wizardry
@@ -17,6 +23,10 @@ struct Cli {
     #[structopt(short, long, env = "DEBUG")]
     debug: bool,
 
+    /// Set language
+    #[structopt(short, long, env = "LANG")]
+    language: String,
+
     /// Outputs verbose feedback where possible
     #[structopt(short, long)]
     verbose: bool,
@@ -56,6 +66,23 @@ fn main() -> io::Result<()> {
         println!("User requested verbose output")
     }
 
+    // TODO: scan i18n dir(s) at run time for available languages
+    let available = convert_vec_str_to_langids_lossy(&["en_US", "tr_TR"]);
+
+    let re = Regex::new(r"\..*$").unwrap();
+    let input = re.replace(&args.language, "");
+    let requested = accepted_languages::parse(&input);
+    let default: LanguageIdentifier = "en-US".parse().unwrap();
+
+    let language = negotiate_languages(
+        &requested,
+        &available,
+        Some(&default),
+        NegotiationStrategy::Filtering,
+    );
+
+    println!("Lang ended up {:?}", language[0]);
+
     match args.subcommand {
         Subcommand::Make { target } => make(target),
         Subcommand::Setup { path } => setup(path),