1 files changed, 29 insertions, 2 deletions

diff --git a/src/bin/sp-meta.rs b/src/bin/sp-meta.rs
index cc4a7bd..49f6173 100644
--- a/src/bin/sp-meta.rs
+++ b/src/bin/sp-meta.rs
@@ -1,19 +1,43 @@
 use anyhow::Result;
 use std::convert::TryFrom;
 use std::path::{Path, PathBuf};
+use std::str::FromStr;
 
+use serde::Serialize;
 use structopt::StructOpt;
 
 use subplot::Document;
 
+#[derive(Debug)]
+enum OutputFormat {
+    Plain,
+    Json,
+}
+
+impl FromStr for OutputFormat {
+    type Err = String;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        match s.to_ascii_lowercase().as_ref() {
+            "plain" => Ok(OutputFormat::Plain),
+            "json" => Ok(OutputFormat::Json),
+            _ => Err(format!("Unknown output format: `{}`", s)),
+        }
+    }
+}
+
 #[derive(Debug, StructOpt)]
 #[structopt(name = "sp-meta", about = "Show Subplot document metadata.")]
 struct Opt {
-    // Input filename.
+    /// Form that you want the output to take
+    #[structopt(short = "o", default_value = "plain", possible_values=&["plain", "json"])]
+    output_format: OutputFormat,
+    /// Input subplot document filename
     #[structopt(parse(from_os_str))]
     filename: PathBuf,
 }
 
+#[derive(Serialize)]
 struct Metadata {
     sources: Vec<String>,
     title: String,
@@ -87,7 +111,10 @@ fn main() -> Result<()> {
     let mut doc = Document::from_file(&basedir, &opt.filename)?;
     let meta = Metadata::try_from(&mut doc)?;
 
-    meta.write_out();
+    match opt.output_format {
+        OutputFormat::Plain => meta.write_out(),
+        OutputFormat::Json => println!("{}", serde_json::to_string_pretty(&meta)?),
+    }
 
     Ok(())
 }