#!/usr/bin/env bash
# Validate the contracts-v1 PostgreSQL migration without touching any schema
# other than th_hotel_booking. This script is safe by default: it refuses a
# schema containing objects outside the booking_contract_* namespace.
set -euo pipefail

readonly BOOKING_SCHEMA='th_hotel_booking'
readonly MIGRATION_FILES=(
  'server/src/main/resources/db/booking-postgresql/migration/V1__booking_contracts_v1.sql'
  'server/src/main/resources/db/booking-postgresql/migration/V2__booking_sender_mapping_direction.sql'
)

database_url="${BOOKING_PG_VERIFY_URL:-${TH_HOTEL_BOOKING_PG_URL:-}}"
if [[ -z "${database_url}" ]]; then
  echo 'BOOKING_PG_VERIFY_URL (or TH_HOTEL_BOOKING_PG_URL) is required.' >&2
  exit 64
fi
if [[ "${BOOKING_PG_VERIFY_SCHEMA:-${BOOKING_SCHEMA}}" != "${BOOKING_SCHEMA}" ]]; then
  echo "Only ${BOOKING_SCHEMA} may be verified by this script." >&2
  exit 64
fi
for migration_file in "${MIGRATION_FILES[@]}"; do
  if [[ ! -f "${migration_file}" ]]; then
    echo "Canonical booking migration was not found: ${migration_file}" >&2
    exit 66
  fi
done
if ! command -v psql >/dev/null 2>&1; then
  echo 'psql is required to run PostgreSQL migration verification.' >&2
  exit 69
fi

psql_query() {
  psql -X -qAt -v ON_ERROR_STOP=1 -d "${database_url}" -c "$1"
}

schema_exists="$(psql_query "SELECT EXISTS (SELECT 1 FROM pg_namespace WHERE nspname = '${BOOKING_SCHEMA}');")"
if [[ "${schema_exists}" == 't' ]]; then
  unexpected_objects="$(psql_query "
    SELECT count(*)
    FROM pg_class relation
    JOIN pg_namespace namespace ON namespace.oid = relation.relnamespace
    WHERE namespace.nspname = '${BOOKING_SCHEMA}'
      AND relation.relkind IN ('r', 'p', 'S', 'v', 'm')
      AND relation.relname NOT LIKE 'booking_contract_%'
      AND relation.relname <> 'flyway_schema_history';")"
  if [[ "${unexpected_objects}" != '0' ]]; then
    echo "Refusing to use ${BOOKING_SCHEMA}: it contains ${unexpected_objects} non-contract object(s)." >&2
    exit 65
  fi
fi

# Count user objects outside the project schema. The migration is allowed to
# create only th_hotel_booking objects; a count change is a hard failure.
other_objects_before="$(psql_query "
  SELECT count(*)
  FROM pg_class relation
  JOIN pg_namespace namespace ON namespace.oid = relation.relnamespace
  WHERE namespace.nspname NOT IN ('pg_catalog', 'information_schema', '${BOOKING_SCHEMA}')
    AND namespace.nspname NOT LIKE 'pg_toast%'
    AND relation.relkind IN ('r', 'p', 'S', 'v', 'm');")"

psql -X -q --single-transaction -v ON_ERROR_STOP=1 -d "${database_url}" \
  -f "${MIGRATION_FILES[0]}" \
  -f "${MIGRATION_FILES[1]}"

other_objects_after="$(psql_query "
  SELECT count(*)
  FROM pg_class relation
  JOIN pg_namespace namespace ON namespace.oid = relation.relnamespace
  WHERE namespace.nspname NOT IN ('pg_catalog', 'information_schema', '${BOOKING_SCHEMA}')
    AND namespace.nspname NOT LIKE 'pg_toast%'
    AND relation.relkind IN ('r', 'p', 'S', 'v', 'm');")"
if [[ "${other_objects_before}" != "${other_objects_after}" ]]; then
  echo 'PostgreSQL migration verification detected a non-booking schema object change.' >&2
  exit 70
fi

required_tables=(
  booking_contract_source_message
  booking_contract_source_attachment
  booking_contract_processing_run
  booking_contract_processing_attempt
  booking_contract_evidence_reference
  booking_contract_artifact
  booking_contract_parsed_fact
  booking_contract_candidate_target
  booking_contract_confirmation_action
  booking_contract_channel_profile
  booking_contract_sender_mapping
  booking_contract_rate_code_mapping
)
for table_name in "${required_tables[@]}"; do
  present="$(psql_query "SELECT to_regclass('${BOOKING_SCHEMA}.${table_name}') IS NOT NULL;")"
  if [[ "${present}" != 't' ]]; then
    echo "Missing required booking table: ${BOOKING_SCHEMA}.${table_name}" >&2
    exit 71
  fi
done

cross_schema_fk_count="$(psql_query "
  SELECT count(*)
  FROM pg_constraint constraint
  JOIN pg_class source_relation ON source_relation.oid = constraint.conrelid
  JOIN pg_namespace source_namespace ON source_namespace.oid = source_relation.relnamespace
  JOIN pg_class target_relation ON target_relation.oid = constraint.confrelid
  JOIN pg_namespace target_namespace ON target_namespace.oid = target_relation.relnamespace
  WHERE constraint.contype = 'f'
    AND (source_namespace.nspname = '${BOOKING_SCHEMA}' OR target_namespace.nspname = '${BOOKING_SCHEMA}')
    AND source_namespace.nspname <> target_namespace.nspname;")"
if [[ "${cross_schema_fk_count}" != '0' ]]; then
  echo 'Booking PostgreSQL migration created or found a cross-schema foreign key.' >&2
  exit 72
fi

echo "Booking PostgreSQL migration verified in ${BOOKING_SCHEMA}; other schema object count unchanged (${other_objects_after})."