#!/bin/bash
# Push LMS images to GitHub Container Registry (GHCR)
# Auto-bumps the patch version in VERSION file on every successful push.
#
# Usage:
#   ./push-ghcr.sh              # auto-bump patch:  1.2.3 → 1.2.4
#   ./push-ghcr.sh minor        # bump minor:       1.2.3 → 1.3.0
#   ./push-ghcr.sh major        # bump major:       1.2.3 → 2.0.0
#   ./push-ghcr.sh 2.5.1        # use exact version (no auto-bump)
#   ./push-ghcr.sh --no-cache   # force full Docker rebuild
#
# Reads GITHUB_USER and GITHUB_TOKEN from .env
# Version is stored in ./VERSION

set -euo pipefail

cd "$(dirname "$0")"

# ── Colour helpers ────────────────────────────────────────────────────────────
GREEN='\033[0;32m'; YELLOW='\033[1;33m'; CYAN='\033[0;36m'; BOLD='\033[1m'; RESET='\033[0m'
ok()   { echo -e "${GREEN}✔${RESET}  $*"; }
info() { echo -e "${CYAN}▶${RESET}  $*"; }
warn() { echo -e "${YELLOW}⚠${RESET}  $*"; }
fail() { echo -e "\033[0;31m✘${RESET}  $*" >&2; exit 1; }
step() { echo -e "\n${BOLD}${CYAN}══ $* ══${RESET}"; }

# ── Parse arguments ───────────────────────────────────────────────────────────
BUMP_TYPE="patch"
EXPLICIT_TAG=""
NO_CACHE=""

for arg in "$@"; do
  case $arg in
    major|minor|patch) BUMP_TYPE=$arg ;;
    --no-cache)        NO_CACHE="--no-cache" ;;
    [0-9]*.[0-9]*.[0-9]*)  EXPLICIT_TAG=$arg ;;  # exact semver passed
    *) fail "Unknown argument: $arg" ;;
  esac
done

# ── Load .env ─────────────────────────────────────────────────────────────────
[ -f .env ] || fail ".env not found. Copy .env.example → .env first."
# shellcheck disable=SC2046
export $(grep -v '^#' .env | grep -E 'GITHUB_USER|GITHUB_TOKEN' | xargs)

GITHUB_USER="${GITHUB_USER:?GITHUB_USER not set in .env}"
GITHUB_TOKEN="${GITHUB_TOKEN:?GITHUB_TOKEN not set in .env}"

# ── Read current version ──────────────────────────────────────────────────────
VERSION_FILE="VERSION"
[ -f "$VERSION_FILE" ] || echo "1.0.0" > "$VERSION_FILE"

CURRENT=$(cat "$VERSION_FILE" | tr -d '[:space:]')
if ! [[ $CURRENT =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
  fail "VERSION file contains invalid semver: '$CURRENT'. Expected format: X.Y.Z"
fi

IFS='.' read -r V_MAJOR V_MINOR V_PATCH <<< "$CURRENT"

# ── Compute new version ───────────────────────────────────────────────────────
if [ -n "$EXPLICIT_TAG" ]; then
  NEW_VERSION="$EXPLICIT_TAG"
  info "Using explicit version: ${BOLD}$NEW_VERSION${RESET}"
else
  case $BUMP_TYPE in
    major) NEW_VERSION="$((V_MAJOR+1)).0.0" ;;
    minor) NEW_VERSION="${V_MAJOR}.$((V_MINOR+1)).0" ;;
    patch) NEW_VERSION="${V_MAJOR}.${V_MINOR}.$((V_PATCH+1))" ;;
  esac
  info "Bumping ${BUMP_TYPE}: ${BOLD}${CURRENT}${RESET} → ${BOLD}${NEW_VERSION}${RESET}"
fi

# ── Image names ───────────────────────────────────────────────────────────────
REGISTRY="ghcr.io/${GITHUB_USER}"
BACKEND_VERSIONED="${REGISTRY}/lms-backend:${NEW_VERSION}"
FRONTEND_VERSIONED="${REGISTRY}/lms-frontend:${NEW_VERSION}"
BACKEND_LATEST="${REGISTRY}/lms-backend:latest"
FRONTEND_LATEST="${REGISTRY}/lms-frontend:latest"

step "LMS → GHCR Push"
echo -e "  Version  : ${BOLD}${NEW_VERSION}${RESET}"
echo -e "  Backend  : ${BACKEND_VERSIONED}"
echo -e "  Frontend : ${FRONTEND_VERSIONED}"

# ── 1. Login to GHCR ─────────────────────────────────────────────────────────
step "Login to ghcr.io"
echo "$GITHUB_TOKEN" | docker login ghcr.io -u "$GITHUB_USER" --password-stdin
ok "Logged in"

# ── 2. Build images ───────────────────────────────────────────────────────────
step "Building images"
[ -n "$NO_CACHE" ] && warn "Building without layer cache"
# shellcheck disable=SC2086
docker compose build $NO_CACHE
ok "Build complete"

# ── 3. Tag versioned + latest ─────────────────────────────────────────────────
step "Tagging images"
docker tag lms-backend:latest  "$BACKEND_VERSIONED"
docker tag lms-frontend:latest "$FRONTEND_VERSIONED"
docker tag lms-backend:latest  "$BACKEND_LATEST"
docker tag lms-frontend:latest "$FRONTEND_LATEST"
ok "Tagged ${NEW_VERSION} + latest"

# ── 4. Push versioned + latest ────────────────────────────────────────────────
step "Pushing to GHCR"
docker push "$BACKEND_VERSIONED"
docker push "$FRONTEND_VERSIONED"
docker push "$BACKEND_LATEST"
docker push "$FRONTEND_LATEST"
ok "Push complete"

# ── 5. Save new version (only after successful push) ─────────────────────────
if [ -z "$EXPLICIT_TAG" ]; then
  echo "$NEW_VERSION" > "$VERSION_FILE"

  # Commit VERSION bump if inside a git repo
  if git rev-parse --git-dir &>/dev/null; then
    git add "$VERSION_FILE"
    git commit -m "chore: bump version ${CURRENT} → ${NEW_VERSION}" --no-verify 2>/dev/null \
      && ok "Committed VERSION bump to git" \
      || warn "VERSION updated locally but git commit skipped (nothing to commit or no git user configured)"
  else
    ok "VERSION file updated to ${NEW_VERSION}"
  fi
fi

# ── Summary ───────────────────────────────────────────────────────────────────
echo ""
echo -e "${BOLD}${GREEN}══════════════════════════════════════════════════════${RESET}"
echo -e "${BOLD}${GREEN}  ✅  Images pushed successfully — v${NEW_VERSION}${RESET}"
echo -e "${BOLD}${GREEN}══════════════════════════════════════════════════════${RESET}"
echo -e "  ${BOLD}Versioned tags:${RESET}"
echo "    $BACKEND_VERSIONED"
echo "    $FRONTEND_VERSIONED"
echo -e "  ${BOLD}Latest tags also updated:${RESET}"
echo "    $BACKEND_LATEST"
echo "    $FRONTEND_LATEST"
echo ""
echo -e "  ${BOLD}📋 Add to .env on target machine:${RESET}"
echo "    BACKEND_IMAGE=${BACKEND_VERSIONED}"
echo "    FRONTEND_IMAGE=${FRONTEND_VERSIONED}"
echo ""
echo -e "  ${BOLD}🚀 Deploy on target machine:${RESET}"
echo "    docker compose pull && docker compose up -d"