make separate binary crate

jsonformat-cli/src/main.rs

@@ -0,0 +1,79 @@
+use clap::clap_app;
+use jsonformat::{format_json_buffered, Indentation};
+use std::error::Error;
+use std::fs::File;
+use std::io::{BufReader, BufWriter, Read, Write};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let matches = clap_app!(jsonformat =>
+        (version: "1.1")
+        (author: "nilstrieb <nilstrieb@gmail.com>")
+        (about: "Formats json from stdin or from a file")
+        (@arg stdout: -s --stdout "Output the result to stdout instead of the default output file. Windows only.")
+        (@arg indentation: -i --indent +takes_value "Set the indentation used (\\s for space, \\t for tab)")
+        (@arg output: -o --output +takes_value "The output file for the formatted json")
+        (@arg input: "The input file to format")
+    )
+    .get_matches();
+
+    // Note: on-stack dynamic dispatch
+    let (mut file, mut stdin);
+    let reader: &mut dyn Read = match matches.value_of("input") {
+        Some(path) => {
+            file = File::open(path)?;
+            &mut file
+        }
+        None => {
+            stdin = std::io::stdin();
+            &mut stdin
+        }
+    };
+
+    let replaced_indent = matches.value_of("indentation").map(|value| {
+        value
+            .to_lowercase()
+            .chars()
+            .filter(|c| ['s', 't'].contains(c))
+            .collect::<String>()
+            .replace("s", " ")
+            .replace("t", "\t")
+    });
+
+    let indent = match replaced_indent {
+        Some(ref str) => Indentation::Custom(str),
+        None => Indentation::Default,
+    };
+
+    let mut output = matches.value_of("output");
+    let mut windows_output_default_file: Option<String> = None;
+
+    #[cfg(windows)]
+    if !matches.is_present("stdout") {
+        if let Some(file) = matches.value_of("input") {
+            // on windows, set the default output file if no stdout flag is provided
+            // this makes it work with drag and drop in windows explorer
+            windows_output_default_file = Some(file.replace(".json", "_f.json"))
+        }
+    }
+
+    output = windows_output_default_file.as_deref().or(output);
+
+    // Note: on-stack dynamic dispatch
+    let (mut file, mut stdout);
+    let writer: &mut dyn Write = match output {
+        Some(filename) => {
+            file = File::create(filename)?;
+            &mut file
+        },
+        None => {
+            stdout = std::io::stdout();
+            &mut stdout
+        },
+    };
+
+    let mut reader = BufReader::new(reader);
+    let mut writer = BufWriter::new(writer);
+    format_json_buffered(&mut reader, &mut writer, indent)?;
+
+    Ok(())
+}