#!/usr/bin/env bash
# Vinterliste deploy script.
#
# Builds a podman image from the current working tree, tags it with both
# :latest and a UTC timestamp, then atomically replaces the running
# container with `podman run --replace`. Older timestamped images are
# pruned afterwards.
#
# Configurable via deploy.env (gitignored). Every variable has a sensible
# default — running ./deploy.sh on a fresh checkout works without setup.
#
# Usage:
#   ./deploy.sh                  # build + restart
#   ./deploy.sh build            # build image only, no container action
#   ./deploy.sh run              # use the existing :latest image, no rebuild
#   ./deploy.sh prune            # drop old timestamped images only
#
# Anything that would terminate a process verifies container identity by
# name before acting (the global "process safety" rule). Image pruning
# matches by image-name prefix + the :2YYYYMMDD- pattern only — never by
# wildcards that could catch unrelated podman images.

set -euo pipefail

# Resolve the project directory regardless of where the script was invoked
# from. Symlinks are followed so the script can sit anywhere on $PATH.
SCRIPT_DIR=$(cd -- "$(dirname -- "$(readlink -f -- "${BASH_SOURCE[0]}")")" && pwd)
cd "$SCRIPT_DIR"

# --- Configuration ---------------------------------------------------------
# Defaults first; deploy.env (if present) overrides any of them. We don't
# `source` the .env file blindly — it goes through a key=value parser so a
# malformed line can't run arbitrary code.

IMAGE_NAME="vinterliste"
CONTAINER_NAME="vinterliste"
VOLUME_NAME="vinterliste-data"
HOST_PORT="3000"
BIND_ADDR="0.0.0.0"
KEEP_IMAGES="3"
PUBLIC_BASE_URL=""
EXTRA_PODMAN_RUN_ARGS=""

ENV_FILE="${ENV_FILE:-./deploy.env}"
if [[ -f "$ENV_FILE" ]]; then
  while IFS= read -r line || [[ -n "$line" ]]; do
    # Skip blank lines and comments.
    [[ -z "${line// }" || "$line" =~ ^[[:space:]]*# ]] && continue
    # Allowlist parse: VAR=VALUE, VAR must be uppercase + underscores.
    if [[ "$line" =~ ^[[:space:]]*([A-Z_][A-Z0-9_]*)[[:space:]]*=[[:space:]]*(.*)$ ]]; then
      key="${BASH_REMATCH[1]}"
      val="${BASH_REMATCH[2]}"
      # Strip optional surrounding quotes (single OR double).
      val="${val#\"}"; val="${val%\"}"
      val="${val#\'}"; val="${val%\'}"
      case "$key" in
        IMAGE_NAME|CONTAINER_NAME|VOLUME_NAME|HOST_PORT|BIND_ADDR|KEEP_IMAGES|PUBLIC_BASE_URL|EXTRA_PODMAN_RUN_ARGS)
          printf -v "$key" '%s' "$val"
          ;;
        *)
          echo "deploy.env: ignoring unknown setting '$key'" >&2
          ;;
      esac
    else
      echo "deploy.env: ignoring malformed line: $line" >&2
    fi
  done < "$ENV_FILE"
fi

# Validate that HOST_PORT and KEEP_IMAGES are integers — they go straight
# into shell substitution further down.
if ! [[ "$HOST_PORT" =~ ^[0-9]+$ ]]; then
  echo "HOST_PORT must be an integer, got: $HOST_PORT" >&2; exit 2
fi
if ! [[ "$KEEP_IMAGES" =~ ^[0-9]+$ ]]; then
  echo "KEEP_IMAGES must be an integer, got: $KEEP_IMAGES" >&2; exit 2
fi

# Build-time metadata. Same shape as the README documents.
BUILD_DATE=$(date -u +%Y-%m-%dT%H:%M:%SZ)
TIMESTAMP_TAG=$(date -u +%Y%m%d-%H%M%S)
GIT_REVISION=$(git describe --always --dirty 2>/dev/null || echo dev)

# --- Helpers --------------------------------------------------------------
log() { printf '[deploy] %s\n' "$*" >&2; }

require_cmd() {
  if ! command -v "$1" >/dev/null 2>&1; then
    echo "deploy.sh needs '$1' on PATH" >&2; exit 1
  fi
}

# --- Actions --------------------------------------------------------------

action_build() {
  require_cmd podman
  require_cmd git
  log "Building ${IMAGE_NAME}:${TIMESTAMP_TAG} (revision ${GIT_REVISION})"
  BUILDAH_FORMAT=docker podman build \
    --build-arg BUILD_DATE="$BUILD_DATE" \
    --build-arg GIT_REVISION="$GIT_REVISION" \
    -t "${IMAGE_NAME}:${TIMESTAMP_TAG}" \
    -t "${IMAGE_NAME}:latest" \
    .
  log "Built ${IMAGE_NAME}:${TIMESTAMP_TAG} and tagged :latest"
}

action_run() {
  require_cmd podman
  # Confirm a :latest image exists before we try to replace the container.
  if ! podman image exists "${IMAGE_NAME}:latest"; then
    echo "No ${IMAGE_NAME}:latest image found. Run './deploy.sh build' first." >&2
    exit 1
  fi
  # Volume creation is idempotent — `podman volume create` errors if it
  # already exists, but `--ignore` makes it a no-op.
  podman volume create --ignore "$VOLUME_NAME" >/dev/null

  log "Replacing container ${CONTAINER_NAME} (image :latest, port ${BIND_ADDR}:${HOST_PORT} → 3000)"
  # shellcheck disable=SC2086  # EXTRA_PODMAN_RUN_ARGS is intentional word-split
  podman run --replace -d \
    --name "$CONTAINER_NAME" \
    --restart=unless-stopped \
    -p "${BIND_ADDR}:${HOST_PORT}:3000" \
    -v "${VOLUME_NAME}:/app/data:Z" \
    ${PUBLIC_BASE_URL:+-e PUBLIC_BASE_URL="$PUBLIC_BASE_URL"} \
    ${EXTRA_PODMAN_RUN_ARGS} \
    "${IMAGE_NAME}:latest" >/dev/null
  log "Container started. Health: podman healthcheck run $CONTAINER_NAME"
}

action_prune() {
  require_cmd podman
  # List timestamped tags only (the YYYYMMDD-HHMMSS pattern). Sort newest
  # first, skip the first KEEP_IMAGES, drop the rest. :latest is never
  # touched. The pattern is strict enough that an arbitrary user-supplied
  # tag (e.g. 'dev') can't be accidentally caught.
  mapfile -t old_tags < <(
    podman image list --format '{{.Tag}}' "$IMAGE_NAME" \
      | grep -E '^[0-9]{8}-[0-9]{6}$' \
      | sort -r \
      | awk -v keep="$KEEP_IMAGES" 'NR > keep'
  )
  if [[ ${#old_tags[@]} -eq 0 ]]; then
    log "Nothing to prune (≤${KEEP_IMAGES} timestamped images present)"
    return
  fi
  log "Pruning ${#old_tags[@]} old image(s) (keeping ${KEEP_IMAGES} most recent)"
  for tag in "${old_tags[@]}"; do
    log "  - ${IMAGE_NAME}:${tag}"
    podman rmi "${IMAGE_NAME}:${tag}" >/dev/null || true
  done
}

usage() {
  cat <<EOF
Usage: $0 [command]

Commands:
  deploy   (default) build → run → prune
  build    Build and tag image only
  run      Run/restart container from :latest (no rebuild)
  prune    Drop old timestamped images
  config   Print resolved configuration and exit

Configuration is read from deploy.env if present. See README.md.
EOF
}

action_config() {
  cat <<EOF
IMAGE_NAME=$IMAGE_NAME
CONTAINER_NAME=$CONTAINER_NAME
VOLUME_NAME=$VOLUME_NAME
HOST_PORT=$HOST_PORT
BIND_ADDR=$BIND_ADDR
KEEP_IMAGES=$KEEP_IMAGES
PUBLIC_BASE_URL=$PUBLIC_BASE_URL
EXTRA_PODMAN_RUN_ARGS=$EXTRA_PODMAN_RUN_ARGS
BUILD_DATE=$BUILD_DATE
TIMESTAMP_TAG=$TIMESTAMP_TAG
GIT_REVISION=$GIT_REVISION
EOF
}

# --- Dispatch -------------------------------------------------------------
cmd="${1:-deploy}"
case "$cmd" in
  build)  action_build ;;
  run)    action_run ;;
  prune)  action_prune ;;
  config) action_config ;;
  deploy) action_build; action_run; action_prune ;;
  -h|--help|help) usage ;;
  *) echo "Unknown command: $cmd" >&2; usage >&2; exit 2 ;;
esac