Break out modules

src/cli.rs

@@ -0,0 +1,31 @@
+use clap::{arg, Parser, Subcommand};
+
+#[derive(Debug, Parser)]
+#[command(author, version, about)]
+
+pub struct Cli {
+    /// Which currencies do you want to fetch rates for?
+    #[arg(long = "currencies", short = 'c')]
+    pub currencies: Vec<String>,
+    /// Which subcommand (output format) we are using
+    #[command(subcommand)]
+    pub command: FormatCommand,
+}
+
+/// Subcommand enum for output format
+#[derive(Debug, Subcommand)]
+pub enum FormatCommand {
+    /// Minimal JSON output
+    JSONMin,
+    /// Pretty-printed JSON output
+    JSONPretty,
+    /// Plain line-by-line output (with extra flags)
+    Plain {
+        /// Show the time in the output
+        #[arg(long = "display-time")]
+        display_time: bool,
+        /// Print currencies in a compact single line
+        #[arg(long = "compact")]
+        compact: bool,
+    },
+}