#!/usr/bin/env bash
set -euo pipefail

# ============================================================================
# build-and-push.sh
#
# Purpose:
# - Build & push Docker images for each service under ./containers/*
# - Two modes:
#     t (test)    = only push :dev
#     r (release) = push :<version>, :dev, :latest
#                   version is read from the top of changelog.md
#
# No git operations: committing and tagging is done manually.
#
# Usage:
#   ./build-and-push.sh [mode]
#   - mode = t   -> test build, push :dev only
#   - mode = r   -> release build, version taken from changelog.md
#   - omitted    -> prompt (default: t)
#
# Requirements:
# - docs/changelog.md (relative to repo root), with the most recent release
#   at the top as:
#     ## vX.Y.Z — YYYY-MM-DD
#   (the version is parsed from the first such line)
# - One Dockerfile per service under ./containers/<service>/Dockerfile
# ============================================================================

DOCKER_REGISTRY="gitea.oskamp.info"
DOCKER_NAMESPACE="ivooskamp"

CHANGELOG_FILE="docs/changelog.md"
CONTAINERS_DIR="containers"

# --- Input: prompt if missing ------------------------------------------------
MODE="${1:-}"
if [[ -z "${MODE}" ]]; then
  echo "Select build type: [t] test build (push :dev only), [r] release build (default: t)"
  read -r MODE
  MODE="${MODE:-t}"
fi

case "$MODE" in
  t|test)    MODE="t" ;;
  r|release) MODE="r" ;;
  *)
    echo "[ERROR] Unknown mode '$MODE' (use 't' for test or 'r' for release)."
    exit 1
    ;;
esac

# --- Helpers -----------------------------------------------------------------
check_docker_ready() {
  if ! docker info >/dev/null 2>&1; then
    echo "[ERROR] Docker daemon not reachable. Is Docker running and do you have permission to use it?"
    exit 1
  fi
}

ensure_registry_login() {
  local cfg="${HOME}/.docker/config.json"
  if [[ ! -f "$cfg" ]]; then
    echo "[ERROR] Docker config not found at $cfg. Please login:  docker login ${DOCKER_REGISTRY}"
    exit 1
  fi
  if ! grep -q "\"${DOCKER_REGISTRY}\"" "$cfg"; then
    echo "[ERROR] No registry auth found for ${DOCKER_REGISTRY}. Please run:  docker login ${DOCKER_REGISTRY}"
    exit 1
  fi
}

validate_repo_component() {
  local comp="$1"
  if [[ ! "$comp" =~ ^[a-z0-9]+([._-][a-z0-9]+)*$ ]]; then
    echo "[ERROR] Invalid repository component '$comp'."
    echo "        Must match: ^[a-z0-9]+([._-][a-z0-9]+)*$ (lowercase, digits, ., _, - as separators)."
    return 1
  fi
}

validate_tag() {
  local tag="$1"
  local len="${#tag}"
  if (( len < 1 || len > 128 )); then
    echo "[ERROR] Invalid tag length ($len). Must be between 1 and 128 characters."
    return 1
  fi
  if [[ ! "$tag" =~ ^[A-Za-z0-9_][A-Za-z0-9_.-]*$ ]]; then
    echo "[ERROR] Invalid tag '$tag'. Allowed: [A-Za-z0-9_.-], must start with alphanumeric or underscore."
    return 1
  fi
}

# Parse the first "## vX.Y.Z ..." heading from changelog.md.
# Accepts:  ## v1.0.3 — 2026-04-24
#           ## v1.0.3 - 2026-04-24
#           ## v1.0.3
read_version_from_changelog() {
  if [[ ! -f "$CHANGELOG_FILE" ]]; then
    echo "[ERROR] $CHANGELOG_FILE not found in $(pwd)." >&2
    exit 1
  fi
  local line
  # Match lines starting with "## v<digits>.<digits>.<digits>"
  line="$(grep -m1 -E '^##[[:space:]]+v[0-9]+\.[0-9]+\.[0-9]+' "$CHANGELOG_FILE" || true)"
  if [[ -z "$line" ]]; then
    echo "[ERROR] No release heading found in $CHANGELOG_FILE (expected e.g. '## v1.0.3 — 2026-04-24' near the top)." >&2
    exit 1
  fi
  # Extract the vX.Y.Z token
  local version
  version="$(echo "$line" | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' | head -n1)"
  if [[ -z "$version" ]]; then
    echo "[ERROR] Could not parse version from line: $line" >&2
    exit 1
  fi
  echo "$version"
}

# --- Preflight ---------------------------------------------------------------
if [[ ! -d "$CONTAINERS_DIR" ]]; then
  echo "[ERROR] '$CONTAINERS_DIR' directory missing. Expected ./${CONTAINERS_DIR}/<service>/ with a Dockerfile."
  exit 1
fi

check_docker_ready
ensure_registry_login
validate_repo_component "$DOCKER_NAMESPACE"

# Informational: show branch and HEAD if this happens to be a git repo.
BRANCH_INFO=""
HEAD_INFO=""
if [[ -d ".git" ]]; then
  BRANCH_INFO="$(git branch --show-current 2>/dev/null || echo unknown)"
  HEAD_INFO="$(git rev-parse --short HEAD 2>/dev/null || echo unknown)"
  echo "[INFO] Repo:             $(pwd)"
  echo "[INFO] Current branch:   $BRANCH_INFO"
  echo "[INFO] HEAD (sha):       $HEAD_INFO"
else
  echo "[INFO] Repo:             $(pwd) (not a git checkout)"
fi

# --- Determine version (release only) ----------------------------------------
VERSION=""
if [[ "$MODE" == "r" ]]; then
  VERSION="$(read_version_from_changelog)"
  echo "[INFO] Release version (from $CHANGELOG_FILE): $VERSION"
  validate_tag "$VERSION"
  validate_tag "latest"

  # Ask for confirmation so you never accidentally re-push an old version or a wrong one.
  read -r -p "Proceed building & pushing as ${VERSION}? [y/N] " CONFIRM
  CONFIRM="${CONFIRM:-N}"
  if [[ ! "$CONFIRM" =~ ^[Yy]$ ]]; then
    echo "[INFO] Aborted by user."
    exit 0
  fi
else
  echo "[INFO] Test build: only :dev will be pushed."
fi
validate_tag "dev"

# --- Build & push per service ------------------------------------------------
shopt -s nullglob
services=( "$CONTAINERS_DIR"/* )
if [[ ${#services[@]} -eq 0 ]]; then
  echo "[ERROR] No services found under $CONTAINERS_DIR"
  exit 1
fi

BUILT_IMAGES=()

for svc_path in "${services[@]}"; do
  [[ -d "$svc_path" ]] || continue
  svc="$(basename "$svc_path")"
  dockerfile="$svc_path/Dockerfile"

  validate_repo_component "$svc"

  if [[ ! -f "$dockerfile" ]]; then
    echo "[WARNING] Skipping '${svc}': Dockerfile not found in ${svc_path}"
    continue
  fi

  IMAGE_BASE="${DOCKER_REGISTRY}/${DOCKER_NAMESPACE}/${svc}"

  if [[ "$MODE" == "r" ]]; then
    echo "============================================================"
    echo "[INFO] Building ${svc} -> tags: ${VERSION}, dev, latest"
    echo "============================================================"
    docker build \
      -t "${IMAGE_BASE}:${VERSION}" \
      -t "${IMAGE_BASE}:dev" \
      -t "${IMAGE_BASE}:latest" \
      "$svc_path"

    docker push "${IMAGE_BASE}:${VERSION}"
    docker push "${IMAGE_BASE}:dev"
    docker push "${IMAGE_BASE}:latest"

    BUILT_IMAGES+=("${IMAGE_BASE}:${VERSION}" "${IMAGE_BASE}:dev" "${IMAGE_BASE}:latest")
  else
    echo "============================================================"
    echo "[INFO] Test build ${svc} -> tag: dev"
    echo "============================================================"
    docker build -t "${IMAGE_BASE}:dev" "$svc_path"
    docker push "${IMAGE_BASE}:dev"
    BUILT_IMAGES+=("${IMAGE_BASE}:dev")
  fi
done

# --- Summary -----------------------------------------------------------------
echo ""
echo "============================================================"
if [[ "$MODE" == "r" ]]; then
  echo "[SUMMARY] Release build & push complete: $VERSION"
else
  echo "[SUMMARY] Test build & push complete (:dev only)"
fi
if [[ -n "$BRANCH_INFO" ]]; then
  echo "[INFO] Branch: $BRANCH_INFO  HEAD: $HEAD_INFO"
fi
echo "[INFO] Images pushed:"
for img in "${BUILT_IMAGES[@]}"; do
  echo "  - $img"
done
echo "============================================================"
echo ""
echo "[REMINDER] No git operations were performed. If this was a release,"
echo "           commit and tag manually, e.g.:"
if [[ "$MODE" == "r" ]]; then
  echo "             git add -A && git commit -m \"Release ${VERSION}\""
  echo "             git tag -a ${VERSION} -m \"Release ${VERSION}\""
  echo "             git push && git push --tags"
fi