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

required=(
  INCOMING_PATH DEPLOY_PATH WEB_IMAGE DEPLOY_SHA EXPECTED_PREVIOUS_SHA
  RECOVERY_REFERENCE RECOVERY_CREATED_AT RESTORE_VERIFIED DOCKER_CONFIG
)
case "${DOCKER_BIN:-docker}" in
  docker) docker_command=(docker) ;;
  "sudo -n docker") docker_command=(sudo -n docker --config "$DOCKER_CONFIG") ;;
  *) echo "unsafe production Docker command" >&2; exit 1 ;;
esac
for key in "${required[@]}"; do
  if [ -z "${!key:-}" ]; then
    echo "required production migration input is missing: $key" >&2
    exit 1
  fi
done

[[ "$DEPLOY_SHA" =~ ^[0-9a-f]{40}$ ]] || {
  echo "unsafe production migration revision" >&2
  exit 1
}
image_pattern='^crpi-d1feco6itet73spp\.cn-hongkong\.personal\.cr\.aliyuncs\.com/copse/jyotisha@sha256:[0-9a-f]{64}$'
[[ "$WEB_IMAGE" =~ $image_pattern ]] || {
  echo "unsafe production migration image" >&2
  exit 1
}
case "$INCOMING_PATH" in
  /tmp/jyotisha-production-migration.*) ;;
  *) echo "unsafe incoming production migration path" >&2; exit 1 ;;
esac
[ "$DEPLOY_PATH" = "/opt/jyotisha-production" ] || {
  echo "unsafe production deployment path" >&2
  exit 1
}
[ "$DOCKER_CONFIG" = "$INCOMING_PATH/.docker" ] || {
  echo "unsafe production Docker configuration path" >&2
  exit 1
}
[[ "$RECOVERY_REFERENCE" =~ ^[A-Za-z0-9][A-Za-z0-9._:/@+-]{0,199}$ ]] || {
  echo "unsafe production recovery reference" >&2
  exit 1
}
[[ "$RECOVERY_CREATED_AT" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}Z$ ]] || {
  echo "unsafe production recovery creation time" >&2
  exit 1
}
[ "$RESTORE_VERIFIED" = "true" ] || {
  echo "production recovery point must have restore_verified=true" >&2
  exit 1
}
recovery_created_epoch="$(date -u -d "$RECOVERY_CREATED_AT" +%s 2>/dev/null)" || {
  echo "invalid production recovery creation time" >&2
  exit 1
}
recovery_now_epoch="$(date -u +%s)"
recovery_age_seconds=$((recovery_now_epoch - recovery_created_epoch))
(( recovery_age_seconds >= 0 && recovery_age_seconds <= 24 * 60 * 60 )) || {
  echo "production recovery point must be no more than 24 hours old and not in the future" >&2
  exit 1
}
echo "Recovery attested: reference=$RECOVERY_REFERENCE created_at=$RECOVERY_CREATED_AT restore_verified=true"
echo "WARNING: migration files run sequentially and are not atomic as a whole; recovery may be required after a partial migration." >&2

state_directory="$DEPLOY_PATH/.state"
install -d -m 700 "$state_directory"
exec 9>"$state_directory/mutation.lock"
flock -n 9 || {
  echo "another production mutation holds the host lock" >&2
  exit 75
}

current_sha="not-deployed"
if [ -f "$state_directory/deployed-revision" ]; then
  current_sha="$(<"$state_directory/deployed-revision")"
else
  existing_web="$("${docker_command[@]}" ps -aq \
    --filter 'label=com.docker.compose.project=jyotisha-production' \
    --filter 'label=com.docker.compose.service=web' | head -n 1)"
  if [ -n "$existing_web" ]; then
    discovered_sha="$("${docker_command[@]}" inspect --format '{{range .Config.Env}}{{println .}}{{end}}' \
      "$existing_web" | sed -n 's/^GITHUB_SHA=//p' | head -n 1)"
    if [ -n "$discovered_sha" ]; then current_sha="$discovered_sha"; fi
  fi
fi
if [ "$current_sha" != "not-deployed" ] && [[ ! "$current_sha" =~ ^[0-9a-f]{40}$ ]]; then
  echo "invalid deployed production revision state" >&2
  exit 1
fi
[ "$current_sha" = "$EXPECTED_PREVIOUS_SHA" ] || {
  echo "production revision changed while this migration was waiting" >&2
  exit 1
}
[ "$current_sha" = "not-deployed" ] ||
  [ "$current_sha" = "$DEPLOY_SHA" ] ||
  [ "${FORWARD_REVISION_VERIFIED:-false}" = "true" ] || {
    echo "forward production revision was not verified" >&2
    exit 1
  }

bash "$INCOMING_PATH/deploy/sync-production-tree.sh" \
  "$INCOMING_PATH" "$DEPLOY_PATH"

cd "$DEPLOY_PATH"
EXPECTED_PRODUCTION_ENV_OWNER_UID="$(stat -c '%u' "$DEPLOY_PATH" 2>/dev/null || stat -f '%u' "$DEPLOY_PATH")"
[[ "$EXPECTED_PRODUCTION_ENV_OWNER_UID" =~ ^[0-9]+$ ]] || {
  echo "production deployment owner is invalid" >&2
  exit 1
}
export EXPECTED_PRODUCTION_ENV_OWNER_UID
bash deploy/validate-production-env.sh .env.production
bash deploy/validate-production-database-env.sh .env.production.database

export DATABASE_ENV_FILE='../.env.production.database'
compose=("${docker_command[@]}" compose -p jyotisha-production -f deploy/docker-compose.postgres.yml)
"${docker_command[@]}" pull "$WEB_IMAGE"
"${compose[@]}" config --quiet
"${compose[@]}" up -d --no-build --pull never --wait postgres

membership="$("${compose[@]}" exec -T postgres psql -v ON_ERROR_STOP=1 -U postgres -d jyotisha -Atc \
  "select pg_has_role('migration_runner', 'schema_owner', 'member')")"
[ "$membership" = "t" ] || {
  echo "migration_runner must be allowed to SET ROLE schema_owner before production migration" >&2
  exit 1
}

environment_value() {
  local key="$1"
  local value
  value="$(sed -n -E "s/^[[:space:]]*(export[[:space:]]+)?${key}[[:space:]]*=[[:space:]]*(.*)$/\\2/p" .env.production.database)"
  case "$value" in
    \"*\") value="${value:1:${#value}-2}" ;;
    \'*\') value="${value:1:${#value}-2}" ;;
  esac
  printf '%s' "$value"
}

percent_encode() {
  local value="$1"
  local encoded=""
  local character hex index
  LC_ALL=C
  for ((index = 0; index < ${#value}; index += 1)); do
    character="${value:index:1}"
    case "$character" in
      [a-zA-Z0-9.~_-]) encoded+="$character" ;;
      *)
        printf -v hex '%%%02X' "'$character"
        encoded+="$hex"
        ;;
    esac
  done
  printf '%s' "$encoded"
}

migration_runner_password="$(environment_value MIGRATION_RUNNER_PASSWORD)"
[ -n "$migration_runner_password" ] || {
  echo "production migration runner password is missing" >&2
  exit 1
}
encoded_migration_runner_password="$(percent_encode "$migration_runner_password")"
unset migration_runner_password
migration_runner_database_url="postgresql://migration_runner:${encoded_migration_runner_password}@postgres:5432/jyotisha?options=-c%20role%3Dschema_owner"
unset encoded_migration_runner_password

migration_environment="$(mktemp "$state_directory/production-migration-env.XXXXXXXXXX")"
cleanup_migration_environment() {
  rm -f -- "$migration_environment"
}
trap cleanup_migration_environment EXIT
chmod 600 "$migration_environment"
printf 'SCHEMA_DATABASE_URL=%s\n' "$migration_runner_database_url" >"$migration_environment"
unset migration_runner_database_url

set +e
DATABASE_ENV_FILE="$migration_environment" \
  "${compose[@]}" --profile migration-check run --rm migration-checker
precheck_status=$?
set -e
if [ "$precheck_status" -ne 0 ] && [ "$precheck_status" -ne 3 ]; then
  echo "production migration precheck failed safely" >&2
  exit "$precheck_status"
fi

DATABASE_ENV_FILE="$migration_environment" \
  "${compose[@]}" --profile migration run --rm migrator

set +e
DATABASE_ENV_FILE="$migration_environment" \
  "${compose[@]}" --profile migration-check run --rm migration-checker
postcheck_status=$?
set -e
if [ "$postcheck_status" -ne 0 ]; then
  echo "production migration postcheck did not converge" >&2
  exit "$postcheck_status"
fi

echo "production schema migration verified for $DEPLOY_SHA"