#!/usr/bin/env run-cargo-script
// cargo-deps: regex="1.3.9"
use std::{ env, fs, process };
use std::path::PathBuf;
use std::process::Command;
use std::os::unix::fs::PermissionsExt;

/// Git commit message format check util
///
/// Commit format MUST be <type>(<scope>): subject
///
/// Usage:
/// `commit-msg.crs usage`
///
/// Install:
/// `commit-msg.crs install`
fn main() {
    let arg1 = env::args().nth(1).unwrap_or_else(|| {
        exit_with_error_message("Commit message is EMPTY!");
    });

    if arg1 == "usage" || arg1 == "USAGE" {
        print_usage(); return;
    }

    let is_install = arg1 == "install" || arg1 == "INSTALL";
    let is_force_install = arg1 == "forceinstall" || arg1 == "FORCEINSTALL"
                        || arg1 == "force-install" || arg1 == "FORCE-INSTALL"
                        || arg1 == "installforce" || arg1 == "INSTALLFORCE"
                        || arg1 == "install-force" || arg1 == "INSTALL-FORCE";
    if is_install || is_force_install {
        install_commit_msg(is_force_install); return;
    }

    let commit_message = fs::read_to_string(arg1).unwrap_or_else(|e| {
        exit_with_error_message(&format!("Read commit message failed: {}", e));
    });

    let re = regex::Regex::new("^(feat|fix|docs|style|refactor|test|chore)(\\([\\w\\-_]+\\))?:\\s*.*").unwrap();
    let is_commit_message_matches = re.is_match(&commit_message);

    print_info(&format!("Commit message: {}{}{}", UNDER, commit_message.trim(), END));
    if is_commit_message_matches {
        print_ok("Commit message rule matches");
    } else {
        print_usage();
        exit_with_error_message("Commit message rule is NOT matched");
    }
}

const RED: &str    = "\x1B[91m";
const GREEN: &str  = "\x1B[92m";
const YELLOW: &str = "\x1B[93m";
const BOLD: &str   = "\x1B[1m";
const UNDER: &str  = "\x1B[4m";
const END: &str    = "\x1B[0m";

fn print_usage() {
    print_info(&format!(r#"Please follow the commit spec:
Format: {b}<type>{e}(<scope>){b}: <subject>{e}
               <scope> is optional

{b}feat{e}: add hat wobble
^--^  ^------------^
|     |
|     +-> Summary in present tense.
|
+-------> Type: chore, docs, feat, fix, refactor, style, or test.

{b}feat{e}     : new feature for the user, not a new feature for build script
{b}fix{e}      : bug fix for the user, not a fix to a build script
{b}docs{e}     : changes to the documentation
{b}style{e}    : formatting, missing semi colons, etc; no production code change
{b}refactor{e} : refactoring production code, eg. renaming a variable
{b}test{e}     : adding missing tests, refactoring tests; no production code change
{b}chore{e}    : updating grunt tasks etc; no production code change

Reference: {u}https://gist.github.com/joshbuchea/6f47e86d2510bce28f8e7f42ae84c716{e}
or mirror: {u}https://hatter.ink/wiki/view_raw.action?__access_token=PUBLIC&id=42{e}
"#, b = BOLD, e = END, u = UNDER));
}

fn install_commit_msg(force: bool) {
    let home_path = PathBuf::from(env::var("HOME").unwrap_or_else(|e| {
        exit_with_error_message(&format!("Get env HOME failed: {}!", e));
    }));
    let commit_msg_crs = home_path.join("bin").join("commit-msg.crs");
    let commig_msg_exec_file = if !commit_msg_crs.exists() {
        print_warn(&format!("File {:?} NOT exists!", commit_msg_crs));
        PathBuf::from(env::args().next().unwrap())
    } else {
        commit_msg_crs
    };

    let git_hooks = PathBuf::from(".git").join("hooks");
    if !git_hooks.exists() {
        exit_with_error_message(&format!("Path {:?} NOT exists!", git_hooks));
    }
    let git_hooks_commit_msg = git_hooks.join("commit-msg");
    if git_hooks_commit_msg.exists() && !force {
        exit_with_error_message(&format!("File {:?} exists! or try forceinstall.", git_hooks_commit_msg));
    }

    print_info(&format!("Copy file: {:?} to: {:?}", commig_msg_exec_file, git_hooks_commit_msg));
    let commig_msg_exec_file_content = fs::read(&commig_msg_exec_file).unwrap_or_else(|e| {
        exit_with_error_message(&format!("Read file: {:?} failed: {}.", commig_msg_exec_file, e));
    });
    fs::write(&git_hooks_commit_msg, commig_msg_exec_file_content).unwrap_or_else(|e| {
        exit_with_error_message(&format!("Write file: {:?} failed: {}.", git_hooks_commit_msg, e));
    });
    fs::set_permissions(&git_hooks_commit_msg, PermissionsExt::from_mode(0o755)).unwrap_or_else(|e| {
        exit_with_error_message(&format!("Apply executable permission on file: {:?} failed: {}.", git_hooks_commit_msg, e));
    });

    print_ok("Install commit-msg to repo successed!");
}

fn exit_with_error() -> ! { process::exit(1) }
fn exit_with_error_message(msg: &str) -> ! { print_error(msg); exit_with_error() }

fn print_info(msg: &str)  { println!("{b}[INFO ]{e} {m}", b = BOLD, e = END, m = msg); }
fn print_ok(msg: &str)    { println!("{g}{b}[OK   ]{e} {g}{m}{e}", g = GREEN, b = BOLD, e = END, m = msg); }
fn print_warn(msg: &str)  { println!("{y}{b}[WARN ]{e} {y}{m}{e}", y = YELLOW, b = BOLD, e = END, m = msg); }
fn print_error(msg: &str) { println!("{r}{b}[ERROR]{e} {r}{m}{e}", r = RED, b = BOLD, e = END, m = msg); }