Implement manpage generation for goose-cli (#6980)

Signed-off-by: Rodolfo Olivieri <rodolfo.olivieri3@gmail.com>

crates/goose-cli/Cargo.toml

@@ -14,7 +14,12 @@ workspace = true
 name = "goose"
 path = "src/main.rs"
 
+[[bin]]
+name = "generate_manpages"
+path = "src/bin/generate_manpages.rs"
+
 [dependencies]
+clap_mangen = "0.2.31"
 goose = { path = "../goose" }
 goose-acp = { path = "../goose-acp" }
 goose-mcp = { path = "../goose-mcp" }
@@ -66,3 +71,4 @@ disable-update = []
 [dev-dependencies]
 tempfile = "3"
 tokio = { workspace = true }
+

crates/goose-cli/src/bin/generate_manpages.rs

@@ -0,0 +1,177 @@
+//! Generate manpages for the goose CLI.
+//!
+//! This binary generates ROFF-formatted manpages from the clap CLI definitions.
+//! Manpages are an essential part of the Linux/Unix ecosystem, providing users with
+//! offline documentation accessible via the `man` command (e.g., `man goose`).
+//!
+//! When goose is packaged for Linux distributions (deb, rpm, etc.), the generated
+//! manpages should be installed to `/usr/share/man/man1/` so users can access help
+//! without an internet connection, following Unix conventions that have existed
+//! since the 1970s.
+//!
+//! Usage:
+//!   cargo run -p goose-cli --bin generate_manpages
+//!   # or
+//!   just generate-manpages
+//!
+//! Output: target/man/goose.1, target/man/goose-session.1, etc.
+
+use clap::CommandFactory;
+use clap_mangen::Man;
+use goose_cli::Cli;
+use std::env;
+use std::fs;
+use std::io::Result;
+use std::path::PathBuf;
+
+fn main() -> Result<()> {
+    // Manpages are a Unix/Linux convention - skip generation on Windows
+    if cfg!(target_os = "windows") {
+        eprintln!("Skipping manpage generation on Windows (manpages are a Unix/Linux convention)");
+        return Ok(());
+    }
+
+    let package_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
+    let output_dir = PathBuf::from(package_dir)
+        .join("..")
+        .join("..")
+        .join("target")
+        .join("man");
+
+    fs::create_dir_all(&output_dir)?;
+
+    let cmd = Cli::command();
+
+    // First pass: collect all command names for SEE ALSO sections
+    let mut all_commands: Vec<String> = Vec::new();
+    collect_command_names(&cmd, &mut all_commands, None);
+
+    // Second pass: generate manpages with SEE ALSO sections
+    generate_manpages(&cmd, &output_dir, None, &all_commands)?;
+
+    let canonical_path = output_dir.canonicalize()?;
+    eprintln!(
+        "Successfully generated manpages at {}",
+        canonical_path.display()
+    );
+
+    Ok(())
+}
+
+fn collect_command_names(cmd: &clap::Command, names: &mut Vec<String>, parent_name: Option<&str>) {
+    let name = match parent_name {
+        Some(parent) => format!("{}-{}", parent, cmd.get_name()),
+        None => cmd.get_name().to_string(),
+    };
+    names.push(name.clone());
+
+    for subcmd in cmd.get_subcommands() {
+        if subcmd.get_name() == "help" || subcmd.is_hide_set() {
+            continue;
+        }
+        collect_command_names(subcmd, names, Some(&name));
+    }
+}
+
+fn generate_manpages(
+    cmd: &clap::Command,
+    dir: &PathBuf,
+    parent_name: Option<&str>,
+    all_commands: &[String],
+) -> Result<()> {
+    let name = match parent_name {
+        Some(parent) => format!("{}-{}", parent, cmd.get_name()),
+        None => cmd.get_name().to_string(),
+    };
+
+    // Generate the base manpage
+    let man = Man::new(cmd.clone());
+    let mut buffer = Vec::new();
+    man.render(&mut buffer)?;
+
+    // Add SEE ALSO section
+    let see_also = generate_see_also(&name, parent_name, cmd, all_commands);
+    buffer.extend_from_slice(see_also.as_bytes());
+
+    let manpage_path = dir.join(format!("{}.1", name));
+    fs::write(&manpage_path, buffer)?;
+    eprintln!("  Generated: {}.1", name);
+
+    for subcmd in cmd.get_subcommands() {
+        if subcmd.get_name() == "help" || subcmd.is_hide_set() {
+            continue;
+        }
+        generate_manpages(subcmd, dir, Some(&name), all_commands)?;
+    }
+
+    Ok(())
+}
+
+fn generate_see_also(
+    current_name: &str,
+    parent_name: Option<&str>,
+    cmd: &clap::Command,
+    all_commands: &[String],
+) -> String {
+    let mut references: Vec<String> = Vec::new();
+
+    // Always reference the main goose command if we're not it
+    if current_name != "goose" {
+        references.push("goose".to_string());
+    }
+
+    // Reference parent command if exists and not already added
+    if let Some(parent) = parent_name {
+        if parent != "goose" && !references.contains(&parent.to_string()) {
+            references.push(parent.to_string());
+        }
+    }
+
+    // For the main command, list immediate subcommands
+    // For subcommands, list sibling commands
+    if current_name == "goose" {
+        // Add all immediate subcommands (skip hidden ones)
+        for subcmd in cmd.get_subcommands() {
+            let subcmd_name = subcmd.get_name();
+            if subcmd_name != "help" && !subcmd.is_hide_set() {
+                let full_name = format!("goose-{}", subcmd_name);
+                if !references.contains(&full_name) {
+                    references.push(full_name);
+                }
+            }
+        }
+    } else if let Some(parent) = parent_name {
+        // Add sibling commands (other commands with same parent)
+        let prefix = format!("{}-", parent);
+        for cmd_name in all_commands {
+            if cmd_name.starts_with(&prefix) && cmd_name != current_name {
+                // Only add immediate siblings, not nested subcommands
+                let suffix = &cmd_name.strip_prefix(&prefix).unwrap_or(cmd_name);
+                if !suffix.contains('-') && !references.contains(cmd_name) {
+                    references.push(cmd_name.clone());
+                }
+            }
+        }
+    }
+
+    // Sort references for consistent output
+    references.sort();
+
+    if references.is_empty() {
+        return String::new();
+    }
+
+    // Format as ROFF
+    let mut roff = String::from("\n.SH \"SEE ALSO\"\n");
+    let formatted_refs: Vec<String> = references
+        .iter()
+        .map(|r| {
+            let escaped = r.replace('-', "\\-");
+            format!(".BR {} (1)", escaped)
+        })
+        .collect();
+    roff.push_str(&formatted_refs.join(",\n"));
+    roff.push('\n');
+
+    roff
+}

crates/goose-cli/src/cli.rs

@@ -35,8 +35,8 @@ use std::path::PathBuf;
 use tracing::warn;
 
 #[derive(Parser)]
-#[command(author, version, display_name = "", about, long_about = None)]
-struct Cli {
+#[command(name = "goose", author, version, display_name = "", about, long_about = None)]
+pub struct Cli {
     #[command(subcommand)]
     command: Option<Command>,
 }

crates/goose-cli/src/lib.rs

@@ -8,4 +8,5 @@ pub mod session;
 pub mod signal;
 
 // Re-export commonly used types
+pub use cli::Cli;
 pub use session::CliSession;