Improve command line options

cli/src/main.rs

@@ -4,6 +4,8 @@ extern crate zecpaperlib;
 use clap::{Arg, App};
 use zecpaperlib::paper::*;
 use zecpaperlib::pdf;
+use std::io;
+use std::io::prelude::*;
 
 fn main() { 
     let matches = App::new("zecpaperwaller")
@@ -19,7 +21,7 @@ fn main() {
                 .help("What format to generate the output in")
                 .takes_value(true)
                 .value_name("FORMAT")
-                .possible_values(&["png", "pdf", "json"])
+                .possible_values(&["pdf", "json"])
                 .default_value("json"))
         .arg(Arg::with_name("output")
                 .short("o")
@@ -40,12 +42,39 @@ fn main() {
 
     let testnet: bool = matches.is_present("testnet");
     if !testnet {
-        eprint!("Mainnet addresses are not supported yet. Please re-run with --testnet\n");
+        eprintln!("Mainnet addresses are not supported yet. Please re-run with --testnet");
+        return;
+    }
+
+    let filename = matches.value_of("output");
+    let format   = matches.value_of("format").unwrap();
+
+    // Writing to PDF requires a filename
+    if format == "pdf" && filename.is_none() {
+        eprintln!("Need an output file name when writing to PDF");
         return;
     }
 
     let num_addresses = matches.value_of("z_addresses").unwrap().parse::<u32>().unwrap();
+
+    print!("Generating {} Sapling addresses.........", num_addresses);
+    io::stdout().flush().ok();
     let addresses = generate_wallet(testnet, num_addresses); 
-    println!("{}", addresses);
-    pdf::save_to_pdf(&addresses, "test_working.pdf");
+    println!("[OK]");
+    
+    // If the default format is present, write to the console if the filename is absent
+    if format == "json" {
+        if filename.is_none() {
+            println!("{}", addresses);
+        } else {
+            std::fs::write(filename.unwrap(), addresses).expect("Couldn't write to file!");
+            println!("Wrote {:?} as a plaintext file", filename);
+        }
+    } else if format == "pdf" {
+        // We already know the output file name was specified
+        print!("Writing {:?} as a PDF file...", filename.unwrap());
+        io::stdout().flush().ok();
+        pdf::save_to_pdf(&addresses, filename.unwrap());
+        println!("[OK]");
+    }    
 }

lib/src/pdf.rs

@@ -225,7 +225,7 @@ mod tests {
 
         // Test random combinations of block size and spaces to ensure that 
         // the string is always preserved
-        for m in 2..100 {
+        for m in 1..100 {
             for b in 1..40 {
                 assert_eq!(split_to_max(addr, m, b).join(" ").replace(" ", ""), addr);
                 assert_eq!(split_to_max(pk, m, b).join(" ").replace(" ", ""), pk);