#!/usr/bin/env bash
# Upload this workspace to a Git remote.
#
# Usage:
#   ./upload_git.sh -r <remote-url> [-b branch] [-m "commit message"]
#   ./upload_git.sh --remote <remote-url> --branch main --message "Update README"
#
# Notes:
#   - If origin already exists, -r/--remote can be omitted.
#   - If the working tree has changes, provide -m/--message to commit them.
#   - This repository currently does not require Git LFS on the remote.

set -euo pipefail

REMOTE_NAME="${REMOTE_NAME:-origin}"
REMOTE_URL="http://git.fairylandtech.com/whut/FaRui_Campus_ADS.git"
BRANCH="origin/main"
COMMIT_MESSAGE="Update project"
NO_COMMIT="false"
SET_REMOTE="false"

usage() {
  sed -n '1,12p' "$0"
  cat <<'EOF'

Options:
  -r, --remote <url>       Remote repository URL. Required if origin is absent.
  -b, --branch <name>      Branch to push. Defaults to current branch, then main.
  -m, --message <message>  Commit message for pending local changes.
      --no-commit          Refuse to commit local changes; push only if clean.
      --set-remote         Replace existing origin URL with --remote.
  -h, --help               Show this help.

Examples:
  ./upload_git.sh -r git@github.com:org/farui-campus-ads.git
  ./upload_git.sh -r git@github.com:org/farui-campus-ads.git -m "Update project README"
  ./upload_git.sh --remote https://github.com/org/farui-campus-ads.git --branch main
EOF
}

log() {
  printf '[INFO] %s\n' "$*"
}

warn() {
  printf '[WARN] %s\n' "$*" >&2
}

die() {
  printf '[ERROR] %s\n' "$*" >&2
  exit 1
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    -r|--remote)
      [[ $# -ge 2 ]] || die "Missing value for $1"
      REMOTE_URL="$2"
      shift 2
      ;;
    -b|--branch)
      [[ $# -ge 2 ]] || die "Missing value for $1"
      BRANCH="$2"
      shift 2
      ;;
    -m|--message)
      [[ $# -ge 2 ]] || die "Missing value for $1"
      COMMIT_MESSAGE="$2"
      shift 2
      ;;
    --no-commit)
      NO_COMMIT="true"
      shift
      ;;
    --set-remote)
      SET_REMOTE="true"
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      die "Unknown argument: $1"
      ;;
  esac
done

command -v git >/dev/null 2>&1 || die "git is not installed."

REPO_ROOT="$(git rev-parse --show-toplevel 2>/dev/null)" || die "Not inside a Git repository."
cd "$REPO_ROOT"

LFS_COUNT="0"
if git lfs version >/dev/null 2>&1; then
  git lfs install --local >/dev/null
  LFS_COUNT="$(git lfs ls-files | wc -l | tr -d ' ')"
else
  warn "Git LFS is not installed. This is acceptable only when no LFS files are tracked."
fi

if [[ -z "$BRANCH" ]]; then
  BRANCH="$(git branch --show-current)"
fi
if [[ -z "$BRANCH" ]]; then
  BRANCH="main"
fi

if ! git show-ref --verify --quiet "refs/heads/$BRANCH"; then
  current_branch="$(git branch --show-current)"
  if [[ -n "$current_branch" ]]; then
    log "Renaming current branch '$current_branch' to '$BRANCH'."
    git branch -M "$BRANCH"
  else
    die "Branch '$BRANCH' does not exist and no current branch is active."
  fi
fi

if git remote get-url "$REMOTE_NAME" >/dev/null 2>&1; then
  existing_remote="$(git remote get-url "$REMOTE_NAME")"
  if [[ -n "$REMOTE_URL" && "$REMOTE_URL" != "$existing_remote" ]]; then
    if [[ "$SET_REMOTE" == "true" ]]; then
      log "Updating $REMOTE_NAME remote URL."
      git remote set-url "$REMOTE_NAME" "$REMOTE_URL"
    else
      die "$REMOTE_NAME already points to '$existing_remote'. Use --set-remote to replace it."
    fi
  fi
else
  [[ -n "$REMOTE_URL" ]] || die "Remote '$REMOTE_NAME' is absent. Provide -r <remote-url>."
  log "Adding $REMOTE_NAME remote: $REMOTE_URL"
  git remote add "$REMOTE_NAME" "$REMOTE_URL"
fi

status_output="$(git status --short)"
if [[ -n "$status_output" ]]; then
  warn "Working tree has local changes:"
  printf '%s\n' "$status_output" >&2

  if [[ "$NO_COMMIT" == "true" ]]; then
    die "Working tree is dirty and --no-commit was set."
  fi

  [[ -n "$COMMIT_MESSAGE" ]] || die "Provide -m \"commit message\" to commit pending changes before upload."

  log "Staging local changes."
  git add -A
  log "Creating commit: $COMMIT_MESSAGE"
  git commit -m "$COMMIT_MESSAGE"
else
  log "Working tree is clean."
fi

log "LFS files tracked: $LFS_COUNT"
log "Pushing branch '$BRANCH' to '$REMOTE_NAME'."
git push -u "$REMOTE_NAME" "$BRANCH"

log "Upload finished."