aigitcommit 1.9.0

/*!
 * Copyright (c) 2025-2026 mingcheng <mingcheng@apache.org>
 *
 * This source code is licensed under the MIT License,
 * which is located in the LICENSE file in the source tree's root directory.
 *
 * File: utils.rs
 * Author: mingcheng <mingcheng@apache.org>
 * File Created: 2025-10-21 11:34:11
 *
 * Modified By: mingcheng <mingcheng@apache.org>
 * Last Modified: 2026-05-07 11:29:44
 */

use crate::git::message::GitMessage;
use crate::git::repository::Repository;
use std::fs;
use std::io::Write;
use tracing::trace;

/// Convenience alias for fallible utility functions in this crate.
pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;

/// Environment variables surfaced by `--check-env`.
const CHECKED_ENV_VARS: &[&str] = &[
    "OPENAI_API_BASE",
    "OPENAI_API_TOKEN",
    "OPENAI_MODEL_NAME",
    "OPENAI_API_PROXY",
    "OPENAI_API_TIMEOUT",
    "AIGITCOMMIT_SIGNOFF",
];

/// Environment variable helpers.
pub mod env {
    use std::env;

    use tracing::{debug, warn};

    /// Read an environment variable, returning `default` when unset.
    pub fn get(key: &str, default: &str) -> String {
        env::var(key).unwrap_or_else(|_| default.to_string())
    }

    /// Read a boolean environment variable.
    /// Accepts `1`, `true`, `yes`, `on` (case-insensitive) as true.
    pub fn get_bool(key: &str) -> bool {
        const TRUTHY: [&str; 4] = ["1", "true", "yes", "on"];
        match env::var(key) {
            Ok(v) => TRUTHY.iter().any(|t| v.eq_ignore_ascii_case(t)),
            Err(_) => false,
        }
    }

    /// Log whether `var_name` is set, returning the result.
    pub fn exists(var_name: &str) -> bool {
        match env::var(var_name) {
            Ok(value) => {
                debug!("{} is set to {}", var_name, value);
                true
            }
            Err(_) => {
                warn!("{} is not set", var_name);
                false
            }
        }
    }
}

/// Should the commit be signed off?
/// True when the CLI flag is set, or when the repository / env opts in.
pub fn should_signoff(repository: &Repository, cli_signoff: bool) -> bool {
    cli_signoff || repository.should_signoff()
}

/// Output format for commit messages.
#[derive(Debug, PartialEq, Eq)]
pub enum OutputFormat {
    Stdout,
    Table,
    Json,
}

impl OutputFormat {
    /// Pick a format from CLI flags. `--json` wins over `--no-table`.
    pub fn detect(json: bool, no_table: bool) -> Self {
        match (json, no_table) {
            (true, _) => Self::Json,
            (false, true) => Self::Stdout,
            (false, false) => Self::Table,
        }
    }

    /// Render `message` to stdout in the selected format.
    pub fn write(&self, message: &GitMessage) -> Result<()> {
        let mut out = std::io::stdout().lock();
        match self {
            Self::Stdout => writeln!(out, "{message}")?,
            Self::Json => writeln!(out, "{}", serde_json::to_string_pretty(message)?)?,
            Self::Table => print_table(&message.title, &message.content),
        }
        Ok(())
    }
}

/// Print the commit message in a rounded, wrapped table.
fn print_table(title: &str, content: &str) {
    let table =
        tabled::builder::Builder::from_iter([["Title", title.trim()], ["Content", content.trim()]])
            .build()
            .with(tabled::settings::Style::rounded())
            .with(tabled::settings::Width::wrap(120))
            .with(tabled::settings::Alignment::left())
            .to_string();

    println!("{table}");
}

/// Log presence/absence of every environment variable consulted by the tool.
pub fn check_env_variables() {
    for var in CHECKED_ENV_VARS {
        env::exists(var);
    }
}

/// Save `content` to `path`, truncating any existing file.
pub fn save_to_file(path: &str, content: &dyn std::fmt::Display) -> Result<()> {
    fs::write(path, content.to_string())?;
    Ok(())
}

/// Install the prepare-commit-msg git hook into the target repository.
///
/// If a hook with the same name already exists, it is preserved by renaming
/// it to `<name>.bak` (overwriting any previous backup) before the new hook
/// is written. This prevents silently clobbering a user's existing hook.
pub fn install_hook(path: &str, name: &str, content: &str) -> Result<()> {
    let repo_dir =
        fs::canonicalize(path).map_err(|e| format!("resolve repository path failed: {e}"))?;
    let git_dir = repo_dir.join(".git");
    if !git_dir.is_dir() {
        return Err("not a git repository (missing .git directory)".into());
    }

    let hooks_dir = git_dir.join("hooks");
    fs::create_dir_all(&hooks_dir).map_err(|e| format!("create hooks dir failed: {e}"))?;

    let hook_path = hooks_dir.join(name);

    // Back up any existing hook with the same name to avoid silent overwrite.
    if hook_path.exists() {
        let backup = hooks_dir.join(format!("{name}.bak"));
        if let Err(e) = fs::rename(&hook_path, &backup) {
            return Err(format!(
                "failed to back up existing hook {hook_path:?} -> {backup:?}: {e}"
            )
            .into());
        }
        trace!("backed up existing hook to {:?}", backup);
    }

    fs::write(&hook_path, content).map_err(|e| format!("write hook file failed: {e}"))?;

    #[cfg(unix)]
    {
        use std::os::unix::fs::PermissionsExt;
        let mut perms = fs::metadata(&hook_path)
            .map_err(|e| format!("get hook metadata failed: {e}"))?
            .permissions();
        perms.set_mode(0o755);
        fs::set_permissions(&hook_path, perms)
            .map_err(|e| format!("set executable permission failed: {e}"))?;
    }

    trace!("hook installed at {:?}", hook_path);
    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_print_table_simple() {
        print_table(
            "Test Title",
            "This is a test content for the commit message.",
        );
    }

    #[test]
    fn test_print_table_with_message() {
        const TITLE: &str = r#"feat: bump version to 1.4.0 and update system template 🚀"#;
        const CONTENT: &str = r#"
- Update version from 1.3.3 to 1.4.0 in Cargo.toml
- Enhance system template with additional instructions
- Simplify and clarify template content for better usability
- Remove redundant information to streamline template
- Ensure template aligns with latest commit message standards

Signed-off-by: mingcheng <mingcheng@apache.org>
        "#;
        print_table(TITLE, CONTENT);
    }

    #[test]
    fn test_get_env() {
        let result = env::get("NONEXISTENT_VAR_XYZ", "default_value");
        assert_eq!(result, "default_value");
    }

    #[test]
    fn test_get_bool_truthy_and_falsy() {
        // SAFETY: tests run in the same process; use uniquely-named keys.
        unsafe {
            std::env::set_var("AIGC_TEST_BOOL_T1", "1");
            std::env::set_var("AIGC_TEST_BOOL_T2", "TRUE");
            std::env::set_var("AIGC_TEST_BOOL_T3", "Yes");
            std::env::set_var("AIGC_TEST_BOOL_T4", "on");
            std::env::set_var("AIGC_TEST_BOOL_F1", "0");
            std::env::set_var("AIGC_TEST_BOOL_F2", "no");
        }
        assert!(env::get_bool("AIGC_TEST_BOOL_T1"));
        assert!(env::get_bool("AIGC_TEST_BOOL_T2"));
        assert!(env::get_bool("AIGC_TEST_BOOL_T3"));
        assert!(env::get_bool("AIGC_TEST_BOOL_T4"));
        assert!(!env::get_bool("AIGC_TEST_BOOL_F1"));
        assert!(!env::get_bool("AIGC_TEST_BOOL_F2"));
        assert!(!env::get_bool("AIGC_TEST_BOOL_MISSING"));
    }

    #[test]
    fn test_output_format_detect() {
        assert_eq!(OutputFormat::detect(true, false), OutputFormat::Json);
        assert_eq!(OutputFormat::detect(true, true), OutputFormat::Json);
        assert_eq!(OutputFormat::detect(false, true), OutputFormat::Stdout);
        assert_eq!(OutputFormat::detect(false, false), OutputFormat::Table);
    }

    #[test]
    fn test_save_to_file_roundtrip() {
        let path =
            std::env::temp_dir().join(format!("aigitcommit-save-{}.txt", std::process::id()));
        let path_str = path.to_string_lossy().into_owned();
        save_to_file(&path_str, &"hello world").unwrap();
        let read = std::fs::read_to_string(&path).unwrap();
        assert_eq!(read, "hello world");
        let _ = std::fs::remove_file(&path);
    }

    #[test]
    fn test_install_hook() {
        // Use an isolated temp directory containing a fake `.git` so the test
        // does not pollute the workspace's real `.git/hooks/`.
        let tmp =
            std::env::temp_dir().join(format!("aigitcommit-install-hook-{}", std::process::id()));
        let _ = std::fs::remove_dir_all(&tmp);
        std::fs::create_dir_all(tmp.join(".git")).unwrap();

        let path = tmp.to_str().unwrap();
        install_hook(path, "prepare-commit-msg", "#!/bin/sh\necho a\n").unwrap();
        let hook = tmp.join(".git/hooks/prepare-commit-msg");
        assert_eq!(
            std::fs::read_to_string(&hook).unwrap(),
            "#!/bin/sh\necho a\n"
        );

        // Re-install: existing hook should be backed up, not silently lost.
        install_hook(path, "prepare-commit-msg", "#!/bin/sh\necho b\n").unwrap();
        let backup = tmp.join(".git/hooks/prepare-commit-msg.bak");
        assert!(backup.exists(), "backup file should exist after reinstall");
        assert_eq!(
            std::fs::read_to_string(&backup).unwrap(),
            "#!/bin/sh\necho a\n"
        );
        assert_eq!(
            std::fs::read_to_string(&hook).unwrap(),
            "#!/bin/sh\necho b\n"
        );

        let _ = std::fs::remove_dir_all(&tmp);
    }

    #[test]
    fn test_install_hook_rejects_non_git_dir() {
        let tmp =
            std::env::temp_dir().join(format!("aigitcommit-not-a-repo-{}", std::process::id()));
        let _ = std::fs::remove_dir_all(&tmp);
        std::fs::create_dir_all(&tmp).unwrap();
        let result = install_hook(tmp.to_str().unwrap(), "x", "#!/bin/sh\n");
        assert!(result.is_err());
        let _ = std::fs::remove_dir_all(&tmp);
    }
}