Cargo.lock

@@ -17,6 +17,21 @@ version = "0.2.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
 
+[[package]]
+name = "anstream"
+version = "0.6.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43d5b281e737544384e969a5ccad3f1cdd24b48086a0fc1b2a5262a26b8f4f4a"
+dependencies = [
+ "anstyle",
+ "anstyle-parse 0.2.7",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
 [[package]]
 name = "anstream"
 version = "1.0.0"
@@ -24,7 +39,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "824a212faf96e9acacdbd09febd34438f8f711fb84e09a8916013cd7815ca28d"
 dependencies = [
  "anstyle",
- "anstyle-parse",
+ "anstyle-parse 1.0.0",
  "anstyle-query",
  "anstyle-wincon",
  "colorchoice",
@@ -38,6 +53,15 @@ version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "940b3a0ca603d1eade50a4846a2afffd5ef57a9feac2c0e2ec2e14f9ead76000"
 
+[[package]]
+name = "anstyle-parse"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e7644824f0aa2c7b9384579234ef10eb7efb6a0deb83f9630a49594dd9c15c2"
+dependencies = [
+ "utf8parse",
+]
+
 [[package]]
 name = "anstyle-parse"
 version = "1.0.0"
@@ -179,7 +203,7 @@ version = "4.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "714a53001bf66416adb0e2ef5ac857140e7dc3a0c48fb28b2f10762fc4b5069f"
 dependencies = [
- "anstream",
+ "anstream 1.0.0",
  "anstyle",
  "clap_lex",
  "strsim",
@@ -405,6 +429,29 @@ version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
+[[package]]
+name = "env_filter"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a1c3cc8e57274ec99de65301228b537f1e4eedc1b8e0f9411c6caac8ae7308f"
+dependencies = [
+ "log",
+ "regex",
+]
+
+[[package]]
+name = "env_logger"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b2daee4ea451f429a58296525ddf28b45a3b64f1acf6587e2067437bb11e218d"
+dependencies = [
+ "anstream 0.6.21",
+ "anstyle",
+ "env_filter",
+ "jiff",
+ "log",
+]
+
 [[package]]
 name = "equivalent"
 version = "1.0.2"
@@ -632,6 +679,30 @@ version = "1.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "92ecc6618181def0457392ccd0ee51198e065e016d1d527a7ac1b6dc7c1f09d2"
 
+[[package]]
+name = "jiff"
+version = "0.2.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a3546dc96b6d42c5f24902af9e2538e82e39ad350b0c766eb3fbf2d8f3d8359"
+dependencies = [
+ "jiff-static",
+ "log",
+ "portable-atomic",
+ "portable-atomic-util",
+ "serde_core",
+]
+
+[[package]]
+name = "jiff-static"
+version = "0.2.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a8c8b344124222efd714b73bb41f8b5120b27a7cc1c75593a6ff768d9d05aa4"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
 [[package]]
 name = "js-sys"
 version = "0.3.91"
@@ -784,14 +855,18 @@ dependencies = [
 name = "mould"
 version = "0.2.0"
 dependencies = [
+ "anyhow",
  "clap",
  "crossterm",
  "dirs",
+ "env_logger",
+ "log",
  "ratatui",
  "serde",
  "serde_json",
  "serde_yaml",
  "tempfile",
+ "thiserror 2.0.18",
  "toml",
  "tui-input",
 ]
@@ -1005,6 +1080,15 @@ version = "1.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"
 
+[[package]]
+name = "portable-atomic-util"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "091397be61a01d4be58e7841595bd4bfedb15f1cd54977d79b8271e94ed799a3"
+dependencies = [
+ "portable-atomic",
+]
+
 [[package]]
 name = "powerfmt"
 version = "0.2.0"

Cargo.toml

@@ -9,13 +9,17 @@ name = "mould"
 path = "src/main.rs"
 
 [dependencies]
+anyhow = "1.0.102"
 clap = { version = "4.6.0", features = ["derive"] }
 crossterm = "0.29.0"
 dirs = "6.0.0"
+env_logger = "0.11.9"
+log = "0.4.29"
 ratatui = "0.30.0"
 serde = { version = "1.0.228", features = ["derive"] }
 serde_json = "1.0.149"
 serde_yaml = "0.9.34"
+thiserror = "2.0.18"
 toml = "1.0.6"
 tui-input = "0.15.0"
 

src/cli.rs

@@ -3,18 +3,29 @@ use std::path::PathBuf;
 
 /// mould: A TUI tool to generate and edit configuration files (.env, json, yaml, toml)
 #[derive(Parser, Debug)]
-#[command(author, version, about)]
+#[command(
+    author, 
+    version, 
+    about = "mould: A TUI tool to generate and edit configuration files (.env, json, yaml, toml)",
+    long_about = "mould allows you to interactively edit and generate configuration files using templates. It supports various formats including .env, JSON, YAML, and TOML. It features a modern TUI with Vim-inspired keybindings and out-of-the-box support for theming.",
+    after_help = "EXAMPLES:\n  mould .env.example\n  mould docker-compose.yml\n  mould config.template.json -o config.json"
+)]
 pub struct Cli {
     /// The input template file (e.g., .env.example, config.json.template, docker-compose.yml)
+    #[arg(required = true, value_name = "INPUT_FILE")]
     pub input: PathBuf,
 
     /// Optional output file. If not provided, it will be inferred.
-    #[arg(short, long)]
+    #[arg(short, long, value_name = "OUTPUT_FILE")]
     pub output: Option<PathBuf>,
 
     /// Override the format detection (env, json, yaml, toml)
-    #[arg(short, long)]
+    #[arg(short, long, value_name = "FORMAT", value_parser = ["env", "json", "yaml", "toml"])]
     pub format: Option<String>,
+
+    /// Increase verbosity for logging (can be used multiple times)
+    #[arg(short, long, action = clap::ArgAction::Count)]
+    pub verbose: u8,
 }
 
 /// Parses and returns the command-line arguments.

src/error.rs

@@ -0,0 +1,18 @@
+use thiserror::Error;
+use std::io;
+
+/// Custom error types for the mould application.
+#[derive(Error, Debug)]
+pub enum MouldError {
+    #[error("IO error: {0}")]
+    Io(#[from] io::Error),
+
+    #[error("Format error: {0}")]
+    Format(String),
+
+    #[error("File not found: {0}")]
+    FileNotFound(String),
+
+    #[error("Terminal error: {0}")]
+    Terminal(String),
+}

src/main.rs

@@ -1,15 +1,17 @@
 mod app;
 mod cli;
 mod config;
+mod error;
 mod format;
 mod runner;
 mod ui;
 
 use app::App;
 use config::load_config;
+use error::MouldError;
 use format::{detect_format, get_handler};
+use log::{error, info, warn};
 use runner::AppRunner;
-use std::error::Error;
 use std::io;
 use std::path::{Path, PathBuf};
 
@@ -24,12 +26,10 @@ use ratatui::{backend::CrosstermBackend, Terminal};
 fn determine_output_path(input: &Path) -> PathBuf {
     let file_name = input.file_name().unwrap_or_default().to_string_lossy();
     
-    // .env.example -> .env
     if file_name == ".env.example" {
         return input.with_file_name(".env");
     }
     
-    // docker-compose.yml -> docker-compose.override.yml
     if file_name == "docker-compose.yml" {
         return input.with_file_name("docker-compose.override.yml");
     }
@@ -37,7 +37,6 @@ fn determine_output_path(input: &Path) -> PathBuf {
         return input.with_file_name("docker-compose.override.yaml");
     }
     
-    // config.example.json -> config.json
     if file_name.ends_with(".example.json") {
         return input.with_file_name(file_name.replace(".example.json", ".json"));
     }
@@ -45,78 +44,88 @@ fn determine_output_path(input: &Path) -> PathBuf {
         return input.with_file_name(file_name.replace(".template.json", ".json"));
     }
     
-    // Fallback: append .out to the extension
     input.with_extension(format!(
         "{}.out",
         input.extension().unwrap_or_default().to_string_lossy()
     ))
 }
 
-fn main() -> Result<(), Box<dyn Error>> {
-    // Parse CLI arguments
+fn main() -> anyhow::Result<()> {
     let args = cli::parse();
 
+    // Initialize logger with verbosity from CLI
+    let log_level = match args.verbose {
+        0 => log::LevelFilter::Warn,
+        1 => log::LevelFilter::Info,
+        _ => log::LevelFilter::Debug,
+    };
+    env_logger::Builder::new()
+        .filter_level(log_level)
+        .format_timestamp(None)
+        .init();
+
     let input_path = args.input;
     if !input_path.exists() {
-        println!("Input file does not exist: {}", input_path.display());
-        return Ok(());
+        error!("Input file not found: {}", input_path.display());
+        return Err(MouldError::FileNotFound(input_path.display().to_string()).into());
     }
 
-    // Detect format and select appropriate handler
+    info!("Input: {}", input_path.display());
+
     let format_type = detect_format(&input_path, args.format);
     let handler = get_handler(format_type);
 
-    // Determine where to save the result
     let output_path = args
         .output
         .unwrap_or_else(|| determine_output_path(&input_path));
 
-    // Initial parsing of the template file
-    let mut vars = handler.parse(&input_path).unwrap_or_else(|err| {
-        println!("Error parsing input file: {}", err);
-        vec![]
-    });
+    info!("Output: {}", output_path.display());
+
+    let mut vars = handler.parse(&input_path).map_err(|e| {
+        error!("Failed to parse input file: {}", e);
+        MouldError::Format(format!("Failed to parse {}: {}", input_path.display(), e))
+    })?;
 
     if vars.is_empty() {
-        println!(
-            "No variables found in {} or file could not be parsed.",
-            input_path.display()
-        );
-        return Ok(());
+        warn!("No variables found in {}", input_path.display());
     }
 
-    // Merge values from an existing output file if it exists
     if let Err(e) = handler.merge(&output_path, &mut vars) {
-        println!("Warning: Could not merge existing output file: {}", e);
+        warn!("Could not merge existing output file: {}", e);
     }
 
-    // Load user configuration and initialize application state
     let config = load_config();
     let mut app = App::new(vars);
 
-    // Initialize terminal into raw mode and enter alternate screen
-    enable_raw_mode()?;
+    // Terminal lifecycle
+    enable_raw_mode().map_err(|e| MouldError::Terminal(format!("Failed to enable raw mode: {}", e)))?;
     let mut stdout = io::stdout();
-    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)
+        .map_err(|e| MouldError::Terminal(format!("Failed to enter alternate screen: {}", e)))?;
     let backend = CrosstermBackend::new(stdout);
-    let mut terminal = Terminal::new(backend)?;
+    let mut terminal = Terminal::new(backend)
+        .map_err(|e| MouldError::Terminal(format!("Failed to create terminal backend: {}", e)))?;
 
-    // Instantiate the runner and start the application loop
     let mut runner = AppRunner::new(&mut terminal, &mut app, &config, &output_path, handler.as_ref());
     let res = runner.run();
 
-    // Clean up terminal state on exit
-    disable_raw_mode()?;
+    // Restoration
+    disable_raw_mode().ok();
     execute!(
         terminal.backend_mut(),
         LeaveAlternateScreen,
         DisableMouseCapture
-    )?;
-    terminal.show_cursor()?;
+    ).ok();
+    terminal.show_cursor().ok();
 
-    if let Err(err) = res {
-        println!("{:?}", err);
+    match res {
+        Ok(_) => {
+            info!("Successfully finished mould session.");
+            Ok(())
+        },
+        Err(e) => {
+            error!("Application error during run: {}", e);
+            Err(e.into())
+        }
     }
-
-    Ok(())
 }