#!/usr/bin/env sh
#
# 这个脚本用于一键提交并推送当前 Git 仓库。
#
# 使用命令案例：
#   sh push-git.sh "提交说明"
#   chmod +x push-git.sh && ./push-git.sh "提交说明"
#   ./push-git.sh -m "提交说明" --pull-rebase
#   ./push-git.sh -m "提交说明" --dry-run
#
# 这个脚本做的事情：
# 1. 自动进入脚本所在 Git 仓库根目录，并检查当前分支和远程仓库。
# 2. 如果存在本地改动，执行 git add -A 和 git commit -m "提交说明"。
# 3. 按当前分支推送到远程仓库；首次推送会自动设置 upstream。

set -eu

SCRIPT_DIR="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)"
REMOTE="origin"
MESSAGE=""
PULL_REBASE=0
NO_VERIFY=0
DRY_RUN=0

usage() {
    cat <<'EOF'
Usage:
  ./push-git.sh "commit message"
  ./push-git.sh -m "commit message" [--pull-rebase] [--dry-run]

Options:
  -m, --message MESSAGE  Commit message.
  -r, --remote REMOTE    Git remote name. Default: origin.
  --pull-rebase          Run git pull --rebase before pushing.
  --no-verify            Skip git commit hooks.
  --dry-run              Print commands without running them.
  -h, --help             Show this help.
EOF
}

die() {
    echo "Error: $*" >&2
    exit 1
}

run() {
    echo "git $*"
    if [ "$DRY_RUN" -eq 1 ]; then
        return 0
    fi

    git "$@"
}

while [ "$#" -gt 0 ]; do
    case "$1" in
        -m|--message)
            [ "$#" -ge 2 ] || die "$1 requires a value"
            MESSAGE="$2"
            shift 2
            ;;
        -r|--remote)
            [ "$#" -ge 2 ] || die "$1 requires a value"
            REMOTE="$2"
            shift 2
            ;;
        --pull-rebase)
            PULL_REBASE=1
            shift
            ;;
        --no-verify)
            NO_VERIFY=1
            shift
            ;;
        --dry-run)
            DRY_RUN=1
            shift
            ;;
        -h|--help)
            usage
            exit 0
            ;;
        --)
            shift
            break
            ;;
        -*)
            die "unknown option: $1"
            ;;
        *)
            if [ -z "$MESSAGE" ]; then
                MESSAGE="$1"
            else
                MESSAGE="$MESSAGE $1"
            fi
            shift
            ;;
    esac
done

REPO_ROOT="$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel)"
cd "$REPO_ROOT"

BRANCH="$(git rev-parse --abbrev-ref HEAD)"
[ -n "$BRANCH" ] && [ "$BRANCH" != "HEAD" ] || die "detached HEAD detected; checkout a branch before pushing"

git remote get-url "$REMOTE" >/dev/null || die "remote not found: $REMOTE"

STATUS="$(git status --porcelain)"
if [ -n "$STATUS" ]; then
    if [ -z "$MESSAGE" ]; then
        if [ "$DRY_RUN" -eq 1 ]; then
            MESSAGE="<commit message>"
        else
            printf "Commit message: "
            IFS= read -r MESSAGE
        fi
    fi

    [ -n "$MESSAGE" ] || die "commit message is required when there are local changes"

    run add -A

    if [ "$NO_VERIFY" -eq 1 ]; then
        run commit -m "$MESSAGE" --no-verify
    else
        run commit -m "$MESSAGE"
    fi
else
    echo "No local file changes to commit."
fi

if [ "$PULL_REBASE" -eq 1 ]; then
    run fetch "$REMOTE"
    run pull --rebase "$REMOTE" "$BRANCH"
fi

if git rev-parse --abbrev-ref --symbolic-full-name '@{u}' >/dev/null 2>&1; then
    run push "$REMOTE" "$BRANCH"
else
    run push -u "$REMOTE" "$BRANCH"
fi