#!/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;

/// Git commit message format check util
///
/// Commit format MUST be <type>(<scope>): subject
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 == "force_install" || arg1 == "FORCE_INSTALL";
    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 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: {}<type>{}(<scope>){}: <subject>{}
               <scope> is optional

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

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

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

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");
    if !commit_msg_crs.exists() {
        exit_with_error_message(&format!("File {:?} NOT exists!", 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));
    }

    let commit_msg_crs_content = fs::read_to_string(&commit_msg_crs).unwrap_or_else(|e| {
        exit_with_error_message(&format!("Read file: {:?} failed: {}.", commit_msg_crs, e));
    });
    fs::write(&git_hooks_commit_msg, commit_msg_crs_content).unwrap_or_else(|e| {
        exit_with_error_message(&format!("Write file: {:?} failed: {}.", git_hooks_commit_msg, e));
    });
    Command::new("chmod").args(&["+x", git_hooks_commit_msg.to_str().unwrap()]).output().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!("{}[INFO ]{} {}", BOLD, END, msg); }
fn print_ok(msg: &str)    { println!("{}{}[OK   ]{} {}{}{}", GREEN, BOLD, END, GREEN, msg, END); }
fn print_error(msg: &str) { println!("{}{}[ERROR]{} {}{}{}", RED, BOLD, END, RED, msg, END); }