#!/usr/bin/env bash

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=wp13-common.sh
source "${SCRIPT_DIR}/wp13-common.sh"

usage() {
  cat <<'EOF'
Usage: preflight.sh [options]

Validate an offline bundle or an existing Compose project before install/upgrade.

Options:
  --bundle-root PATH    Bundle or repository root.
  --compose-file PATH   Compose file (default: <root>/deploy/docker/docker-compose.yml).
  --env-file PATH       Optional Compose environment file.
  --environment-profile PATH
                        Validated JSON profile; selects matching .env and project.
  --project-name NAME   Compose project (default: dataops-test).
  --checksums-only      Verify checksums and exit before Docker access.
  --skip-checksums      Repository development mode only.
  --help                Show this help.
EOF
}

BUNDLE_ROOT="$(wp13_default_root)"
COMPOSE_FILE=""
ENV_FILE=""
ENVIRONMENT_PROFILE=""
PROJECT_NAME=""
CHECKSUMS_ONLY=0
SKIP_CHECKSUMS=0

while [[ $# -gt 0 ]]; do
  case "$1" in
    --bundle-root) BUNDLE_ROOT="$2"; shift 2 ;;
    --compose-file) COMPOSE_FILE="$2"; shift 2 ;;
    --env-file) ENV_FILE="$2"; shift 2 ;;
    --environment-profile) ENVIRONMENT_PROFILE="$2"; shift 2 ;;
    --project-name) PROJECT_NAME="$2"; shift 2 ;;
    --checksums-only) CHECKSUMS_ONLY=1; shift ;;
    --skip-checksums) SKIP_CHECKSUMS=1; shift ;;
    --help|-h) usage; exit 0 ;;
    *) wp13_die "unknown argument: $1" ;;
  esac
done

BUNDLE_ROOT="$(cd "${BUNDLE_ROOT}" && pwd)"
COMPOSE_FILE="${COMPOSE_FILE:-${BUNDLE_ROOT}/deploy/docker/docker-compose.yml}"

if [[ "${SKIP_CHECKSUMS}" -eq 0 ]]; then
  wp13_verify_checksums "${BUNDLE_ROOT}"
fi
if [[ "${CHECKSUMS_ONLY}" -eq 1 ]]; then
  exit 0
fi

if [[ -n "${ENVIRONMENT_PROFILE}" ]]; then
  if [[ "${ENVIRONMENT_PROFILE}" != /* ]]; then
    ENVIRONMENT_PROFILE="${BUNDLE_ROOT}/${ENVIRONMENT_PROFILE}"
  fi
  [[ -r "${ENVIRONMENT_PROFILE}" ]] \
    || wp13_die "environment profile is not readable: ${ENVIRONMENT_PROFILE}"
  wp13_require_command python3
  python3 "${SCRIPT_DIR}/product_engineering.py" validate-environments \
    --profiles-dir "$(dirname "${ENVIRONMENT_PROFILE}")" >/dev/null
  PROFILE_PROJECT="$(python3 -c 'import json,sys; print(json.load(open(sys.argv[1], encoding="utf-8"))["project_name"])' "${ENVIRONMENT_PROFILE}")"
  PROFILE_ENV_FILE="${ENVIRONMENT_PROFILE%.json}.env"
  [[ -r "${PROFILE_ENV_FILE}" ]] \
    || wp13_die "matching environment file is not readable: ${PROFILE_ENV_FILE}"
  if [[ -n "${PROJECT_NAME}" && "${PROJECT_NAME}" != "${PROFILE_PROJECT}" ]]; then
    wp13_die "project name does not match environment profile: ${PROJECT_NAME} != ${PROFILE_PROJECT}"
  fi
  PROJECT_NAME="${PROFILE_PROJECT}"
  if [[ -n "${ENV_FILE}" && "$(cd "$(dirname "${ENV_FILE}")" && pwd)/$(basename "${ENV_FILE}")" != "$(cd "$(dirname "${PROFILE_ENV_FILE}")" && pwd)/$(basename "${PROFILE_ENV_FILE}")" ]]; then
    wp13_die "--env-file must match --environment-profile"
  fi
  ENV_FILE="${PROFILE_ENV_FILE}"
  wp13_log "environment profile validated: $(basename "${ENVIRONMENT_PROFILE}")"
fi
PROJECT_NAME="${PROJECT_NAME:-dataops-test}"

wp13_require_command docker
docker version >/dev/null
docker compose version >/dev/null
[[ -f "${COMPOSE_FILE}" ]] || wp13_die "compose file not found: ${COMPOSE_FILE}"
if [[ -n "${ENV_FILE}" ]]; then
  [[ -r "${ENV_FILE}" ]] || wp13_die "environment file is not readable: ${ENV_FILE}"
fi

wp13_compose "${COMPOSE_FILE}" "${PROJECT_NAME}" "${ENV_FILE}" config --quiet
wp13_log "Compose configuration resolved"

while IFS= read -r image; do
  [[ -n "${image}" ]] || continue
  docker image inspect "${image}" >/dev/null 2>&1 \
    || wp13_die "required offline image is missing: ${image}"
done < <(
  wp13_compose "${COMPOSE_FILE}" "${PROJECT_NAME}" "${ENV_FILE}" \
    config --images | LC_ALL=C sort -u
)
wp13_log "all default-profile images are available locally"

expected_head="$(wp13_expected_migration_head "${BUNDLE_ROOT}")"
if [[ -n "${expected_head}" ]]; then
  wp13_require_command python3
  backend_image="$(
    wp13_compose "${COMPOSE_FILE}" "${PROJECT_NAME}" "${ENV_FILE}" \
      config --format json \
      | python3 -c 'import json,sys; print(json.load(sys.stdin)["services"]["backend"]["image"])'
  )"
  image_head="$(
    docker run --rm --network none --read-only --entrypoint alembic "${backend_image}" \
      -c alembic.ini heads \
      | awk 'NF {print $1; exit}'
  )"
  [[ -n "${image_head}" && "${image_head}" == "${expected_head}" ]] \
    || wp13_die "image migration head does not match release manifest: image=${image_head:-unknown}, release=${expected_head}"
  wp13_log "target image migration head matches release: ${image_head}"
fi

if [[ -n "$(wp13_project_running_ids "${PROJECT_NAME}")" ]]; then
  current="$(
    wp13_compose "${COMPOSE_FILE}" "${PROJECT_NAME}" "${ENV_FILE}" \
      exec -T backend alembic -c alembic.ini current \
      | awk 'NF {print $1; exit}'
  )"
  head="$(
    wp13_compose "${COMPOSE_FILE}" "${PROJECT_NAME}" "${ENV_FILE}" \
      exec -T backend alembic -c alembic.ini heads \
      | awk 'NF {print $1; exit}'
  )"
  [[ -n "${current}" && "${current}" == "${head}" ]] \
    || wp13_die "database migration is not at head: current=${current:-unknown}, head=${head:-unknown}"
  wp13_log "running database is self-consistent at migration: ${current}; target=${expected_head:-unversioned}"
else
  wp13_log "project is not running; migration will be checked after first start"
fi

available_kb="$(df -Pk "${BUNDLE_ROOT}" | awk 'NR==2 {print $4}')"
[[ "${available_kb:-0}" -ge 10485760 ]] \
  || wp13_die "less than 10 GiB free space is available"
wp13_log "preflight passed for project ${PROJECT_NAME}"