♻️ refactor(cli): move main.rs to cli folder

- move main.rs to cli folder for better structure

src/cli/main.rs

@@ -0,0 +1,106 @@
+use clap::{Parser, Subcommand};
+
+mod config_cli;
+mod label_cli;
+mod message_cli;
+mod trash_cli;
+
+use cull_gmail::{Config, Error};
+
+use config_cli::ConfigCli;
+use label_cli::LabelCli;
+use message_cli::MessageCli;
+use trash_cli::TrashCli;
+
+use std::error::Error as stdError;
+
+#[derive(Parser, Debug)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    #[clap(flatten)]
+    logging: clap_verbosity_flag::Verbosity,
+    #[command(subcommand)]
+    sub_command: Option<SubCmds>,
+}
+
+#[derive(Subcommand, Debug)]
+enum SubCmds {
+    /// List messages
+    #[clap(name = "message")]
+    Message(MessageCli),
+    /// List labels
+    #[clap(name = "label")]
+    Labels(LabelCli),
+    /// Move messages to trash
+    #[clap(name = "trash")]
+    Trash(TrashCli),
+    /// Configure rules and labels
+    #[clap(name = "config")]
+    Config(ConfigCli),
+}
+
+#[tokio::main]
+async fn main() {
+    let args = Cli::parse();
+
+    let mut logging = get_logging(args.logging.log_level_filter());
+    logging.init();
+    log::info!("Logging started.");
+
+    std::process::exit(match run(args).await {
+        Ok(_) => 0,
+        Err(e) => {
+            if let Some(src) = e.source() {
+                log::error!("{e}: {src}");
+                eprintln!("{e}: {src}");
+            } else {
+                log::error!("{e}");
+                eprintln!("{e}");
+            }
+            101
+        }
+    });
+}
+
+async fn run(args: Cli) -> Result<(), Error> {
+    let config = get_config()?;
+    log::trace!("Configuration loaded: {config:#?}");
+    if let Some(cmds) = args.sub_command {
+        match cmds {
+            SubCmds::Message(list_cli) => list_cli.run(config.credential_file()).await?,
+            SubCmds::Labels(label_cli) => label_cli.run(config.credential_file()).await?,
+            SubCmds::Trash(trash_cli) => trash_cli.run(config.credential_file()).await?,
+            SubCmds::Config(config_cli) => config_cli.run(config)?,
+        }
+    }
+    Ok(())
+}
+
+fn get_logging(level: log::LevelFilter) -> env_logger::Builder {
+    let level = if level > log::LevelFilter::Info {
+        level
+    } else {
+        log::LevelFilter::Info
+    };
+
+    let mut builder = env_logger::Builder::new();
+
+    builder.filter(Some("cull_gmail"), level);
+    // TODO: Provide an option to set wider filter allowing all crates to report
+
+    builder.format_timestamp_secs().format_module_path(false);
+
+    builder
+}
+
+fn get_config() -> Result<Config, Error> {
+    match Config::load() {
+        Ok(c) => Ok(c),
+        Err(_) => {
+            log::warn!("Configuration not found, creating default config.");
+            let config = Config::new();
+            config.save()?;
+            Ok(config)
+        }
+    }
+}