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

# Разрешение upstream-версии Hysteria и compatibility gate.
#
# Ключевой инвариант: "latest" вычисляется на build machine и замораживается
# в metadata пакета. Target-сервер никогда не обращается к moving "latest".

HYSTERIA_LOCK_FILE="tools/build/hysteria-lock.env"
HYSTERIA_WORK_DIR="tools/build/output/hysteria"

# stable  — определить последнюю стабильную версию через upstream API (default);
# pinned  — использовать закоммиченный tools/build/hysteria-lock.env без сети.
HYSTERIA_CHANNEL="${HYSTERIA_CHANNEL:-stable}"
# Явный пин конкретной версии вида v2.12.2. Побеждает автоматический выбор.
HYSTERIA_VERSION_OVERRIDE="${HYSTERIA_VERSION_OVERRIDE:-}"
# Обновлять ли tools/build/hysteria-lock.env резолвнутыми значениями.
HYSTERIA_WRITE_LOCK="${HYSTERIA_WRITE_LOCK:-false}"
# Compatibility gate обязателен для production-сборки.
HYSTERIA_COMPAT_GATE="${HYSTERIA_COMPAT_GATE:-true}"
# Сверка скачанного бинарника с upstream hashes.txt. Отключается только
# break-glass: без неё SHA-256 считается от уже скачанного файла и является
# trust-on-first-use, а не проверкой происхождения артефакта.
HYSTERIA_VERIFY_UPSTREAM_HASHES="${HYSTERIA_VERIFY_UPSTREAM_HASHES:-true}"
HYSTERIA_LINUX_AMD64_ASSET="hysteria-linux-amd64"

HYSTERIA_GATE_PORT="${HYSTERIA_GATE_PORT:-34443}"
HYSTERIA_GATE_STATS_PORT="${HYSTERIA_GATE_STATS_PORT:-34712}"
HYSTERIA_GATE_TIMEOUT_SECONDS="${HYSTERIA_GATE_TIMEOUT_SECONDS:-15}"

validate_hysteria_version_format() {
  local value="$1"
  grep -Eq '^v[0-9]+\.[0-9]+\.[0-9]+$' <<<"$value" \
    || fail "invalid Hysteria version format: $value (expected vX.Y.Z)"
}

validate_hysteria_sha256_format() {
  local value="$1"
  case "$value" in
    replace-with-*|"")
      fail "HYSTERIA_ARTIFACT_SHA256 must be a real release sha256"
      ;;
  esac
  grep -Eq '^[a-fA-F0-9]{64}$' <<<"$value" \
    || fail "HYSTERIA_ARTIFACT_SHA256 must be a 64-char hex SHA256, got: $value"
}

load_pinned_hysteria_lock() {
  [ -f "$HYSTERIA_LOCK_FILE" ] || fail "missing Hysteria lock file: $HYSTERIA_LOCK_FILE"

  # shellcheck disable=SC1090
  . "$HYSTERIA_LOCK_FILE"

  [ -n "${HYSTERIA_VERSION:-}" ] || fail "HYSTERIA_VERSION is required in $HYSTERIA_LOCK_FILE"
  [ -n "${HYSTERIA_ARTIFACT_URL:-}" ] || fail "HYSTERIA_ARTIFACT_URL is required in $HYSTERIA_LOCK_FILE"
  [ -n "${HYSTERIA_ARTIFACT_SHA256:-}" ] || fail "HYSTERIA_ARTIFACT_SHA256 is required in $HYSTERIA_LOCK_FILE"

  validate_hysteria_version_format "$HYSTERIA_VERSION"
  validate_hysteria_sha256_format "$HYSTERIA_ARTIFACT_SHA256"

  HYSTERIA_RESOLUTION="pinned"
  HYSTERIA_RESOLVED_AT="${HYSTERIA_RESOLVED_AT:-unknown}"
  # Сумма в lock-файле уже была проверена против upstream hashes.txt в тот
  # момент, когда lock записывался.
  HYSTERIA_SHA_SOURCE="hy2xs-lock"

  export HYSTERIA_VERSION HYSTERIA_ARTIFACT_URL HYSTERIA_ARTIFACT_SHA256
  export HYSTERIA_RESOLUTION HYSTERIA_RESOLVED_AT HYSTERIA_SHA_SOURCE
}

resolve_hysteria_from_upstream() {
  local resolver_args=(--channel stable)
  if [ -n "$HYSTERIA_VERSION_OVERRIDE" ]; then
    validate_hysteria_version_format "$HYSTERIA_VERSION_OVERRIDE"
    resolver_args+=(--version "$HYSTERIA_VERSION_OVERRIDE")
    log_info "Resolving pinned Hysteria version override: $HYSTERIA_VERSION_OVERRIDE"
  else
    log_info "Resolving latest stable Hysteria release from upstream"
  fi

  local resolver_output
  resolver_output="$(cd orchestrator && "$BUN_BIN" run tools/resolve-hysteria.ts "${resolver_args[@]}")" \
    || fail "Hysteria release resolution failed"

  local key value line
  HYSTERIA_VERSION=""
  HYSTERIA_TAG=""
  HYSTERIA_ARTIFACT_URL=""
  HYSTERIA_HASHES_URL=""
  HYSTERIA_PUBLISHED_AT=""
  HYSTERIA_RESOLUTION=""

  while IFS= read -r line; do
    [ -n "$line" ] || continue
    key="${line%%=*}"
    value="${line#*=}"
    case "$key" in
      HYSTERIA_VERSION) HYSTERIA_VERSION="$value" ;;
      HYSTERIA_TAG) HYSTERIA_TAG="$value" ;;
      HYSTERIA_ARTIFACT_URL) HYSTERIA_ARTIFACT_URL="$value" ;;
      HYSTERIA_HASHES_URL) HYSTERIA_HASHES_URL="$value" ;;
      HYSTERIA_PUBLISHED_AT) HYSTERIA_PUBLISHED_AT="$value" ;;
      HYSTERIA_RESOLUTION) HYSTERIA_RESOLUTION="$value" ;;
      *) fail "unexpected resolver output line: $line" ;;
    esac
  done <<<"$resolver_output"

  [ -n "$HYSTERIA_VERSION" ] || fail "resolver did not return HYSTERIA_VERSION"
  [ -n "$HYSTERIA_ARTIFACT_URL" ] || fail "resolver did not return HYSTERIA_ARTIFACT_URL"
  [ -n "$HYSTERIA_HASHES_URL" ] || fail "resolver did not return HYSTERIA_HASHES_URL"
  validate_hysteria_version_format "$HYSTERIA_VERSION"

  HYSTERIA_RESOLVED_AT="$(date -u +%Y-%m-%dT%H:%M:%SZ)"

  log_info "Resolved Hysteria $HYSTERIA_VERSION (tag ${HYSTERIA_TAG:-unknown}, published ${HYSTERIA_PUBLISHED_AT:-unknown})"

  export HYSTERIA_VERSION HYSTERIA_TAG HYSTERIA_ARTIFACT_URL HYSTERIA_HASHES_URL
  export HYSTERIA_PUBLISHED_AT HYSTERIA_RESOLUTION HYSTERIA_RESOLVED_AT
}

# Ожидаемый digest берётся из upstream-ассета hashes.txt ДО того, как он
# попадёт в HY2XS lock. Иначе замороженная сумма подтверждает только то, что
# файл не изменился после скачивания.
resolve_expected_sha_from_upstream() {
  [ "$HYSTERIA_VERIFY_UPSTREAM_HASHES" = "true" ] || {
    log_info "WARNING: upstream hashes.txt verification is disabled (HYSTERIA_VERIFY_UPSTREAM_HASHES=$HYSTERIA_VERIFY_UPSTREAM_HASHES)"
    return 0
  }

  [ -n "${HYSTERIA_HASHES_URL:-}" ] || fail "upstream hashes.txt URL is unknown"

  mkdir -p "$HYSTERIA_WORK_DIR"
  local hashes_file="$HYSTERIA_WORK_DIR/hashes.txt"

  log_info "Downloading upstream checksums: $HYSTERIA_HASHES_URL"
  rm -f "$hashes_file"
  curl --proto '=https' --tlsv1.2 --fail --silent --show-error --location \
    "$HYSTERIA_HASHES_URL" -o "$hashes_file" \
    || fail "failed to download upstream hashes.txt: $HYSTERIA_HASHES_URL"
  [ -s "$hashes_file" ] || fail "downloaded upstream hashes.txt is empty"

  local upstream_sha
  upstream_sha="$(cd orchestrator && "$BUN_BIN" run tools/parse-upstream-hashes.ts \
    --file "../$hashes_file" --asset "$HYSTERIA_LINUX_AMD64_ASSET")" \
    || fail "could not read the expected SHA-256 from upstream hashes.txt"

  validate_hysteria_sha256_format "$upstream_sha"

  HYSTERIA_ARTIFACT_SHA256="$upstream_sha"
  HYSTERIA_SHA_SOURCE="upstream-hashes"
  export HYSTERIA_ARTIFACT_SHA256 HYSTERIA_SHA_SOURCE

  log_info "Expected Hysteria SHA-256 from upstream hashes.txt: $upstream_sha"
}

download_hysteria_artifact() {
  mkdir -p "$HYSTERIA_WORK_DIR"
  HYSTERIA_BINARY="$HYSTERIA_WORK_DIR/hysteria-linux-amd64"

  log_info "Downloading $HYSTERIA_ARTIFACT_URL"
  rm -f "$HYSTERIA_BINARY"
  curl --proto '=https' --tlsv1.2 --fail --silent --show-error --location \
    "$HYSTERIA_ARTIFACT_URL" -o "$HYSTERIA_BINARY" \
    || fail "failed to download Hysteria artifact: $HYSTERIA_ARTIFACT_URL"
  [ -s "$HYSTERIA_BINARY" ] || fail "downloaded Hysteria artifact is empty"

  local actual_sha
  actual_sha="$(sha256sum "$HYSTERIA_BINARY" | awk '{print $1}')"

  if [ -n "${HYSTERIA_ARTIFACT_SHA256:-}" ]; then
    validate_hysteria_sha256_format "$HYSTERIA_ARTIFACT_SHA256"
    [ "$actual_sha" = "$HYSTERIA_ARTIFACT_SHA256" ] \
      || fail "Hysteria artifact sha256 mismatch: expected $HYSTERIA_ARTIFACT_SHA256 (${HYSTERIA_SHA_SOURCE:-unknown source}), got $actual_sha"
    log_info "Hysteria artifact verified against ${HYSTERIA_SHA_SOURCE:-unknown source}: $actual_sha"
  else
    # Сюда попадаем только при выключенной сверке с upstream: сумма
    # фиксируется как локальный fingerprint пакета, без проверки происхождения.
    HYSTERIA_ARTIFACT_SHA256="$actual_sha"
    HYSTERIA_SHA_SOURCE="local-download"
    log_info "Computed Hysteria artifact sha256 without upstream verification: $HYSTERIA_ARTIFACT_SHA256"
  fi

  export HYSTERIA_ARTIFACT_SHA256 HYSTERIA_BINARY HYSTERIA_SHA_SOURCE

  chmod 0755 "$HYSTERIA_BINARY"

  local reported_version
  reported_version="$("$HYSTERIA_BINARY" version 2>/dev/null | grep -Eo 'v[0-9]+\.[0-9]+\.[0-9]+' | head -n1 || true)"
  [ -n "$reported_version" ] || fail "unable to read version from downloaded Hysteria binary"
  [ "$reported_version" = "$HYSTERIA_VERSION" ] \
    || fail "downloaded Hysteria binary reports $reported_version, expected $HYSTERIA_VERSION"

  log_info "Verified Hysteria binary: $HYSTERIA_VERSION ($HYSTERIA_ARTIFACT_SHA256)"
}

assert_gate_port_is_free() {
  local port="$1"
  local proto_flag="$2"

  if command -v ss >/dev/null 2>&1; then
    # Вывод собирается ДО поиска: `grep -q` обрывает чтение на первом совпадении,
    # и под `pipefail` SIGPIPE у продюсера превратил бы найденный занятый порт в
    # ненулевой статус, то есть в вывод «порт свободен».
    local sockets
    sockets="$(ss -H "$proto_flag" 2>/dev/null | awk '{print $4}')" || sockets=""
    if grep -Eq "[:.]${port}$" <<<"$sockets"; then
      fail "compatibility gate port $port is already in use; override HYSTERIA_GATE_PORT/HYSTERIA_GATE_STATS_PORT"
    fi
  fi
}

gate_generate_self_signed_cert() {
  local dir="$1"
  openssl req -x509 -newkey rsa:2048 -nodes -days 1 \
    -subj /CN=hy2xs-compat-gate \
    -keyout "$dir/gate.key" -out "$dir/gate.crt" >/dev/null 2>&1 \
    || fail "compatibility gate could not generate a self-signed certificate"
}

gate_run_single_profile() {
  local obfs_type="$1"
  local gate_dir="$2"
  local config_path="$gate_dir/config-$obfs_type.yaml"
  local log_path="$gate_dir/hysteria-$obfs_type.log"

  log_info "Compatibility gate: rendering canonical config (obfs=$obfs_type)"
  (
    cd orchestrator
    "$BUN_BIN" run tools/render-canonical-config.ts \
      --package-dir ../package \
      --obfs "$obfs_type" \
      --tls-mode file \
      --cert "$gate_dir/gate.crt" \
      --key "$gate_dir/gate.key" \
      --port "$HYSTERIA_GATE_PORT" \
      --traffic-stats-port "$HYSTERIA_GATE_STATS_PORT" \
      --out "$config_path"
  ) || fail "BUILD FAILED: HY2XS could not render canonical config for obfs=$obfs_type"

  grep -q "type: $obfs_type" "$config_path" \
    || fail "compatibility gate rendered a config without obfs type $obfs_type"

  log_info "Compatibility gate: starting Hysteria $HYSTERIA_VERSION with generated config (obfs=$obfs_type)"

  HYSTERIA_DISABLE_UPDATE_CHECK=1 "$HYSTERIA_BINARY" server -c "$config_path" >"$log_path" 2>&1 &
  local gate_pid=$!

  local ready="false"
  local waited=0
  while [ "$waited" -lt "$HYSTERIA_GATE_TIMEOUT_SECONDS" ]; do
    if ! kill -0 "$gate_pid" 2>/dev/null; then
      break
    fi
    if command -v ss >/dev/null 2>&1; then
      local udp_sockets
      udp_sockets="$(ss -H -lun 2>/dev/null | awk '{print $4}')" || udp_sockets=""
      if grep -Eq "[:.]${HYSTERIA_GATE_PORT}$" <<<"$udp_sockets"; then
        ready="true"
        break
      fi
    fi
    sleep 1
    waited=$((waited + 1))
  done

  if [ "$ready" != "true" ]; then
    kill "$gate_pid" 2>/dev/null || true
    wait "$gate_pid" 2>/dev/null || true
    log_info "--- Hysteria compatibility gate output (obfs=$obfs_type) ---"
    cat "$log_path" >&2 || true
    fail "BUILD FAILED: unsupported Hysteria stable $HYSTERIA_VERSION (obfs=$obfs_type config was rejected)"
  fi

  kill "$gate_pid" 2>/dev/null || true
  wait "$gate_pid" 2>/dev/null || true

  log_info "Compatibility gate passed for obfs=$obfs_type"
}

run_hysteria_compatibility_gate() {
  if [ "$HYSTERIA_COMPAT_GATE" != "true" ]; then
    log_info "WARNING: Hysteria compatibility gate is disabled (HYSTERIA_COMPAT_GATE=$HYSTERIA_COMPAT_GATE)"
    return 0
  fi

  require_tool openssl
  [ -x "${HYSTERIA_BINARY:-}" ] || fail "compatibility gate requires a verified Hysteria binary"

  assert_gate_port_is_free "$HYSTERIA_GATE_PORT" "-lun"
  assert_gate_port_is_free "$HYSTERIA_GATE_STATS_PORT" "-ltn"

  local gate_dir
  gate_dir="$(mktemp -d)"
  # shellcheck disable=SC2064
  trap "rm -rf '$gate_dir'" RETURN

  gate_generate_self_signed_cert "$gate_dir"

  gate_run_single_profile "gecko" "$gate_dir"
  gate_run_single_profile "salamander" "$gate_dir"

  log_info "Compatibility gate: Hysteria $HYSTERIA_VERSION accepts the HY2XS production config"
}

write_hysteria_lock_file() {
  if [ "$HYSTERIA_WRITE_LOCK" != "true" ]; then
    return 0
  fi

  log_info "Updating $HYSTERIA_LOCK_FILE with resolved values"
  cat >"$HYSTERIA_LOCK_FILE" <<EOF
# Файл генерируется tools/build/lib/hysteria.sh.
# HYSTERIA_CHANNEL=pinned использует эти значения без обращения к сети.
HYSTERIA_VERSION=$HYSTERIA_VERSION
HYSTERIA_ARTIFACT_URL=$HYSTERIA_ARTIFACT_URL
HYSTERIA_ARTIFACT_SHA256=$HYSTERIA_ARTIFACT_SHA256
HYSTERIA_SHA_SOURCE=${HYSTERIA_SHA_SOURCE:-unknown}
HYSTERIA_RESOLUTION=$HYSTERIA_RESOLUTION
HYSTERIA_RESOLVED_AT=$HYSTERIA_RESOLVED_AT
EOF
}

resolve_and_verify_hysteria() {
  case "$HYSTERIA_CHANNEL" in
    stable)
      resolve_hysteria_from_upstream
      # Ожидаемая сумма приходит из upstream hashes.txt, а не из локального
      # файла: проверяется происхождение артефакта, а не только целостность.
      HYSTERIA_ARTIFACT_SHA256=""
      HYSTERIA_SHA_SOURCE=""
      resolve_expected_sha_from_upstream
      ;;
    pinned)
      log_info "Using pinned Hysteria lock file (offline): $HYSTERIA_LOCK_FILE"
      load_pinned_hysteria_lock
      ;;
    *)
      fail "unsupported HYSTERIA_CHANNEL: $HYSTERIA_CHANNEL (use stable or pinned)"
      ;;
  esac

  download_hysteria_artifact
  run_hysteria_compatibility_gate
  write_hysteria_lock_file
}