bin: Add filter support to subplot binary

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

1 files changed, 55 insertions, 3 deletions

diff --git a/src/bin/subplot.rs b/src/bin/subplot.rs
index 38e129e..94c4b53 100644
--- a/src/bin/subplot.rs
+++ b/src/bin/subplot.rs
@@ -4,10 +4,11 @@
 use anyhow::Result;
 
 use structopt::StructOpt;
-use subplot::{resource, DataFile, Style};
+use subplot::{resource, DataFile, Document, Style};
 
-use std::fs::write;
-use std::path::PathBuf;
+use std::fs::{write, File};
+use std::io::{Read, Write};
+use std::path::{Path, PathBuf};
 use std::process;
 
 mod cli;
@@ -30,12 +31,14 @@ impl Toplevel {
 #[derive(Debug, StructOpt)]
 enum Cmd {
     Extract(Extract),
+    Filter(Filter),
 }
 
 impl Cmd {
     fn run(&self) -> Result<()> {
         match self {
             Cmd::Extract(e) => e.run(),
+            Cmd::Filter(f) => f.run(),
         }
     }
 }
@@ -98,6 +101,55 @@ impl Extract {
     }
 }
 
+#[derive(Debug, StructOpt)]
+/// Filter a pandoc JSON document.
+///
+/// This filters a pandoc JSON document, applying Subplot's formatting rules and
+/// image conversion support.
+///
+/// If input/output filename is provided, this operates on STDIN/STDOUT.
+struct Filter {
+    #[structopt(name = "INPUT", long = "input", short = "i", parse(from_os_str))]
+    /// Input file (uses STDIN if omitted)
+    input: Option<PathBuf>,
+
+    #[structopt(name = "OUTPUT", long = "output", short = "o", parse(from_os_str))]
+    /// Output file (uses STDOUT if omitted)
+    output: Option<PathBuf>,
+
+    #[structopt(name = "BASE", long = "base", short = "b", parse(from_os_str))]
+    /// Base directory (defaults to dir of input if given, or '.' if using STDIN)
+    base: Option<PathBuf>,
+}
+
+impl Filter {
+    fn run(&self) -> Result<()> {
+        let mut buffer = String::new();
+        if let Some(filename) = &self.input {
+            File::open(filename)?.read_to_string(&mut buffer)?;
+        } else {
+            std::io::stdin().read_to_string(&mut buffer)?;
+        }
+        let basedir = if let Some(path) = &self.base {
+            path.as_path()
+        } else if let Some(path) = &self.input {
+            path.parent().unwrap_or_else(|| Path::new("."))
+        } else {
+            Path::new(".")
+        };
+        let style = Style::default();
+        let mut doc = Document::from_json(basedir, vec![], &buffer, style)?;
+        doc.typeset();
+        let bytes = doc.ast()?.into_bytes();
+        if let Some(filename) = &self.output {
+            File::create(filename)?.write_all(&bytes)?;
+        } else {
+            std::io::stdout().write_all(&bytes)?;
+        }
+        Ok(())
+    }
+}
+
 fn main() {
     let args = Toplevel::from_args();
     args.resources.handle();