Modular output methods

Using a `std::io::BufWriter` to wrap the output should allow more flexibility.

src/args.rs

@@ -1,6 +1,6 @@
 pub mod args {
-    use clap::{Parser, arg, ColorChoice};
     use super::enums::*;
+    use clap::{arg, ColorChoice, Parser};
 
     #[derive(Parser, Debug)]
     #[command(author, version, about, long_about = None, color = ColorChoice::Always)]
@@ -29,7 +29,7 @@ pub mod args {
 
     impl Arguments {
         pub fn validate(&self) -> Result<(), String> {
-            if self.characters.len() == 0 {
+            if self.characters.is_empty() {
                 return Err("No characters provided".to_string());
             } else if self.characters.len() == 1 {
                 if self.mode == Mode::NormalAscii {
@@ -53,7 +53,7 @@ pub mod enums {
         NormalAscii,
         /// Colored ASCII art, the colors are based on the terminal colors
         #[clap(alias = "c")]
-        COLORED,
+        Colored,
     }
 
     #[derive(Copy, Clone, ValueEnum, Debug, PartialOrd, Eq, PartialEq)]

src/ascii_processor.rs

@@ -1,41 +1,50 @@
-use image::{GenericImageView, DynamicImage};
+use crate::args::{args::Arguments, enums::Mode};
 use colored::{ColoredString, Colorize};
-use crate::args::{
-    args::Arguments,
-    enums::Mode,
-};
+use image::{DynamicImage, GenericImageView};
 
-pub fn generate_ascii(image: DynamicImage, args: &Arguments) -> Vec<ColoredString> {
+use std::io::{self, BufWriter, Write};
+
+pub fn generate_ascii<W: Write>(
+    image: DynamicImage,
+    args: &Arguments,
+    mut buffer: BufWriter<W>,
+) -> io::Result<()> {
     let characters = args.characters.chars().collect::<Vec<char>>();
-    trace!("Characters: {:?}, length: {}", characters, characters.len());
-    let mut output = Vec::new();
     let (width, height) = image.dimensions();
 
     for y in 0..height {
         for x in 0..width {
             if y % (args.scale * 2) == 0 && x % args.scale == 0 {
-                output.push(get_character(
+                let element = get_character(
                     image.get_pixel(x, y),
-                    &characters, args.mode,
+                    &characters,
+                    args.mode,
                     &args.background,
-                ));
+                );
+
+                buffer.write_all(format!("{element}").as_bytes())?;
             }
         }
         // Add a new line at the end of each row
         if y % (args.scale * 2) == 0 {
-            output.push("\n".into());
+            buffer.write_all("\n".as_bytes())?;
         }
     }
 
-    output
+    Ok(())
 }
 
 fn get_character(
     pixel: image::Rgba<u8>,
-    characters: &Vec<char>, mode: Mode,
+    characters: &Vec<char>,
+    mode: Mode,
     background: &Option<String>,
 ) -> ColoredString {
-    let intent = if pixel[3] == 0 { 0 } else { pixel[0] / 3 + pixel[1] / 3 + pixel[2] / 3 };
+    let intent = if pixel[3] == 0 {
+        0
+    } else {
+        pixel[0] / 3 + pixel[1] / 3 + pixel[2] / 3
+    };
 
     let ch = characters[(intent / (32 + 7 - (7 + (characters.len() - 7)) as u8)) as usize];
 
@@ -43,14 +52,11 @@ fn get_character(
 
     let ch = match mode {
         Mode::NormalAscii => ColoredString::from(&*ch),
-        Mode::COLORED => {
-            ch.to_string()
-                .truecolor(pixel[0], pixel[1], pixel[2])
-        }
+        Mode::Colored => ch.truecolor(pixel[0], pixel[1], pixel[2]),
     };
 
     match background {
         Some(bg) => ch.on_color(bg.to_string()),
-        None => ch
+        None => ch,
     }
 }

src/main.rs

@@ -1,23 +1,22 @@
-use std::io::Write;
 use clap::Parser;
 use image::GenericImageView;
 
+use std::io::Result;
 
 extern crate pretty_env_logger;
+
 #[macro_use]
 extern crate log;
 
 mod args;
 mod ascii_processor;
+mod output;
 
-use crate::args::{
-    args::Arguments,
-    enums::OutputMethod,
-};
+use crate::args::{args::Arguments, enums::OutputMethod};
 
 use crate::ascii_processor::generate_ascii;
 
-fn main() {
+fn main() -> Result<()> {
     // Initialize the logger
     pretty_env_logger::init();
     info!("Successfully initialized logger");
@@ -51,34 +50,7 @@ fn main() {
     info!("Successfully opened image");
     trace!("Image dimensions: {:?}", image.dimensions());
 
-    // Process the image
-    let output = generate_ascii(image, &arguments);
+    generate_ascii(image, &arguments, output::prepare_output(&arguments)?)?;
     info!("Successfully processed image");
-
-    // Output the image
-    info!("Outputting image");
-    match arguments.output_method {
-        OutputMethod::File => {
-            match std::fs::write(
-                arguments.output.clone(),
-                output.iter()
-                    .map(|s| format!("{}", s))
-                    .collect::<String>(),
-            ) {
-                Ok(_) => info!("Successfully outputted image: {}", arguments.output),
-                Err(e) => {
-                    error!("Failed to output image: {:?}", e);
-                    eprintln!("Failed to output image: {:?}", e);
-                    std::process::exit(1);
-                }
-            }
-        }
-        OutputMethod::Stdout => {
-            for char in output {
-                print!("{}", char);
-                std::io::stdout().flush().unwrap();
-            }
-            info!("Successfully outputted image");
-        }
-    }
+    Ok(())
 }

src/output.rs

@@ -0,0 +1,20 @@
+use std::fs::File;
+use std::io;
+use std::io::BufWriter;
+use std::io::Write;
+
+use super::Arguments;
+use super::OutputMethod;
+
+pub fn prepare_output(arguments: &Arguments) -> io::Result<BufWriter<Box<dyn Write>>> {
+    match arguments.output_method {
+        OutputMethod::File => {
+            let output_file = Box::new(File::create(&arguments.output)?);
+            Ok(BufWriter::with_capacity(1024, output_file))
+        }
+        OutputMethod::Stdout => {
+            let output_wrap = Box::new(std::io::stdout().lock());
+            Ok(BufWriter::with_capacity(1024, output_wrap))
+        }
+    }
+}