/** 应用环境仅允许显式的开发或生产态，禁止隐式 test/staging 绕过生产约束。 */
export type AppEnvironment = 'development' | 'production';
/** 四级日志口径由进程入口统一校验，避免基础设施各自解释字符串。 */
export type LogLevel = 'debug' | 'info' | 'warn' | 'error';

/** 每个进程只接收自己的 Redis DB 与连接参数，凭据不得进入安全摘要。 */
export interface RedisRuntimeConfig {
  host: string;
  port: number;
  username: string;
  password: string;
  database: number;
  tls: boolean;
}

/** MySQL 配置固定 5.7.x 兼容口径，启用状态决定凭据是否必填。 */
export interface MysqlRuntimeConfig {
  enabled: boolean;
  host: string;
  port: number;
  database: string;
  username: string;
  password: string;
  charset: 'utf8mb4';
  collation: 'utf8mb4_general_ci';
  timezone: '+08:00';
}

/** OpenAI 兼容接口配置；关闭 AI 时允许凭据为空，且不影响规则分析。 */
export interface AiRuntimeConfig {
  enabled: boolean;
  baseUrl: string;
  apiKey: string;
  model: string;
  timeoutMs: number;
}

/** RocketMQ 公共寻址配置；实际生产/消费参数由相应进程扩展。 */
export interface RocketMqRuntimeConfig {
  enabled: boolean;
  nameServerAddress: string;
  endpoint: string;
  topicPrefix: string;
}

interface CommonRuntimeConfig {
  processName: 'api' | 'scheduler' | 'worker';
  appEnv: AppEnvironment;
  logLevel: LogLevel;
  redis: RedisRuntimeConfig;
}

/** API 仅获得 HTTP、Redis、MySQL 与可选 AI 配置，不读取调度和消费配置。 */
export interface ApiRuntimeConfig extends CommonRuntimeConfig {
  processName: 'api';
  api: Readonly<{ host: string; port: number }>;
  mysql: MysqlRuntimeConfig;
  ai: AiRuntimeConfig;
}

/** Scheduler 只决定何时投递，因此不获得 MySQL、行情源或 AI 凭据。 */
export interface SchedulerRuntimeConfig extends CommonRuntimeConfig {
  processName: 'scheduler';
  scheduler: Readonly<{ enabled: boolean; timezone: 'Asia/Shanghai' }>;
  rocketMq: RocketMqRuntimeConfig & Readonly<{ sendTimeoutMs: number }>;
}

/** Worker 获得执行任务所需配置，但不读取 API 监听或 Scheduler 开关。 */
export interface WorkerRuntimeConfig extends CommonRuntimeConfig {
  processName: 'worker';
  marketData: Readonly<{
    mode: 'mock' | 'live';
    provider: string;
    baseUrl: string;
    apiKey: string;
  }>;
  mysql: MysqlRuntimeConfig;
  rocketMq: RocketMqRuntimeConfig &
    Readonly<{ consumerGroup: string; consumerConcurrency: number }>;
  ai: AiRuntimeConfig;
}

/** 三类配置的联合类型仅用于安全摘要等跨进程基础能力。 */
export type RuntimeConfig = ApiRuntimeConfig | SchedulerRuntimeConfig | WorkerRuntimeConfig;
type EnvironmentSource = Readonly<Record<string, string | undefined>>;

function requireText(env: EnvironmentSource, key: string): string {
  const value = env[key]?.trim();
  if (!value) throw new Error(`${key} 不能为空`);
  return value;
}

function optionalText(env: EnvironmentSource, key: string): string {
  return env[key]?.trim() ?? '';
}

function parseInteger(
  env: EnvironmentSource,
  key: string,
  constraints: Readonly<{ min: number; max: number }>,
): number {
  const raw = requireText(env, key);
  if (!/^\d+$/.test(raw)) throw new Error(`${key} 必须为整数`);
  const value = Number(raw);
  if (!Number.isSafeInteger(value) || value < constraints.min || value > constraints.max) {
    throw new Error(`${key} 必须位于 ${constraints.min}-${constraints.max}`);
  }
  return value;
}

function parseBoolean(env: EnvironmentSource, key: string): boolean {
  const raw = requireText(env, key);
  if (raw !== 'true' && raw !== 'false') throw new Error(`${key} 必须为 true 或 false`);
  return raw === 'true';
}

function parseEnum<TValue extends string>(
  env: EnvironmentSource,
  key: string,
  allowed: readonly TValue[],
): TValue {
  const value = requireText(env, key);
  if (!allowed.includes(value as TValue)) {
    throw new Error(`${key} 必须为 ${allowed.join('、')}`);
  }
  return value as TValue;
}

function deepFreeze<TValue>(value: TValue): Readonly<TValue> {
  if (value && typeof value === 'object' && !Object.isFrozen(value)) {
    for (const child of Object.values(value as Record<string, unknown>)) deepFreeze(child);
    Object.freeze(value);
  }
  return value;
}

function loadAppEnv(env: EnvironmentSource): AppEnvironment {
  return parseEnum(env, 'APP_ENV', ['development', 'production']);
}

function loadLogLevel(env: EnvironmentSource): LogLevel {
  return parseEnum(env, 'LOG_LEVEL', ['debug', 'info', 'warn', 'error']);
}

function loadRedisConfig(env: EnvironmentSource): RedisRuntimeConfig {
  return {
    host: requireText(env, 'REDIS_HOST'),
    port: parseInteger(env, 'REDIS_PORT', { min: 1, max: 65_535 }),
    username: optionalText(env, 'REDIS_USERNAME'),
    password: optionalText(env, 'REDIS_PASSWORD'),
    database: parseInteger(env, 'REDIS_DATABASE', { min: 0, max: 15 }),
    tls: parseBoolean(env, 'REDIS_TLS'),
  };
}

function loadMysqlConfig(env: EnvironmentSource): MysqlRuntimeConfig {
  const enabled = parseBoolean(env, 'MYSQL_ENABLED');
  const username = optionalText(env, 'MYSQL_USERNAME');
  const password = optionalText(env, 'MYSQL_PASSWORD');
  const charset = parseEnum(env, 'MYSQL_CHARSET', ['utf8mb4']);
  const collation = parseEnum(env, 'MYSQL_COLLATION', ['utf8mb4_general_ci']);
  const timezone = parseEnum(env, 'MYSQL_TIMEZONE', ['+08:00']);

  if (enabled && !username) throw new Error('MYSQL_USERNAME 在 MySQL 启用时不能为空');
  if (enabled && !password) throw new Error('MYSQL_PASSWORD 在 MySQL 启用时不能为空');

  return {
    enabled,
    host: requireText(env, 'MYSQL_HOST'),
    port: parseInteger(env, 'MYSQL_PORT', { min: 1, max: 65_535 }),
    database: requireText(env, 'MYSQL_DATABASE'),
    username,
    password,
    charset,
    collation,
    timezone,
  };
}

function loadAiConfig(env: EnvironmentSource): AiRuntimeConfig {
  const enabled = parseBoolean(env, 'AI_ENABLED');
  const baseUrl = optionalText(env, 'AI_BASE_URL');
  const apiKey = optionalText(env, 'AI_API_KEY');
  const model = optionalText(env, 'AI_MODEL');

  if (enabled && !baseUrl) throw new Error('AI_BASE_URL 在 AI 启用时不能为空');
  if (enabled && !apiKey) throw new Error('AI_API_KEY 在 AI 启用时不能为空');
  if (enabled && !model) throw new Error('AI_MODEL 在 AI 启用时不能为空');

  return {
    enabled,
    baseUrl,
    apiKey,
    model,
    timeoutMs: parseInteger(env, 'AI_TIMEOUT_MS', { min: 1, max: 300_000 }),
  };
}

function loadRocketMqConfig(env: EnvironmentSource): RocketMqRuntimeConfig {
  const enabled = parseBoolean(env, 'ROCKETMQ_ENABLED');
  const nameServerAddress = optionalText(env, 'ROCKETMQ_NAMESRV_ADDR');
  const endpoint = optionalText(env, 'ROCKETMQ_ENDPOINT');

  // GOV-009 尚未选定通过真实链路验证的 Node 客户端，禁止以内存队列或空实现伪装启用。
  if (enabled) throw new Error('RocketMQ Node 客户端尚未落地验证，当前禁止启用');
  if (enabled && !nameServerAddress && !endpoint) {
    throw new Error('ROCKETMQ_NAMESRV_ADDR 或 ROCKETMQ_ENDPOINT 至少填写一个');
  }

  return {
    enabled,
    nameServerAddress,
    endpoint,
    topicPrefix: requireText(env, 'ROCKETMQ_TOPIC_PREFIX'),
  };
}

/** 从 API 专属环境变量生成深冻结配置，启动后禁止被运行时代码改写。 */
export function loadApiConfig(env: EnvironmentSource): ApiRuntimeConfig {
  return deepFreeze({
    processName: 'api',
    appEnv: loadAppEnv(env),
    logLevel: loadLogLevel(env),
    api: {
      host: requireText(env, 'API_HOST'),
      port: parseInteger(env, 'API_PORT', { min: 1, max: 65_535 }),
    },
    redis: loadRedisConfig(env),
    mysql: loadMysqlConfig(env),
    ai: loadAiConfig(env),
  }) as ApiRuntimeConfig;
}

/** 从 Scheduler 专属变量生成深冻结配置，并保持 RocketMQ 默认禁用边界。 */
export function loadSchedulerConfig(env: EnvironmentSource): SchedulerRuntimeConfig {
  const rocketMq = loadRocketMqConfig(env);
  return deepFreeze({
    processName: 'scheduler',
    appEnv: loadAppEnv(env),
    logLevel: loadLogLevel(env),
    scheduler: {
      enabled: parseBoolean(env, 'SCHEDULER_ENABLED'),
      timezone: parseEnum(env, 'SCHEDULER_TIMEZONE', ['Asia/Shanghai']),
    },
    redis: loadRedisConfig(env),
    rocketMq: {
      ...rocketMq,
      sendTimeoutMs: parseInteger(env, 'ROCKETMQ_SEND_TIMEOUT_MS', {
        min: 1,
        max: 60_000,
      }),
    },
  }) as SchedulerRuntimeConfig;
}

/** 从 Worker 专属变量生成深冻结配置，并阻止生产环境使用模拟行情。 */
export function loadWorkerConfig(env: EnvironmentSource): WorkerRuntimeConfig {
  const appEnv = loadAppEnv(env);
  const mode = parseEnum(env, 'MARKET_DATA_MODE', ['mock', 'live']);
  const provider = requireText(env, 'MARKET_DATA_PROVIDER');
  const rocketMq = loadRocketMqConfig(env);

  if (appEnv === 'production' && mode !== 'live') {
    throw new Error('生产环境 MARKET_DATA_MODE 必须为 live');
  }

  return deepFreeze({
    processName: 'worker',
    appEnv,
    logLevel: loadLogLevel(env),
    marketData: {
      mode,
      provider,
      baseUrl: optionalText(env, 'MARKET_DATA_BASE_URL'),
      apiKey: optionalText(env, 'MARKET_DATA_API_KEY'),
    },
    redis: loadRedisConfig(env),
    mysql: loadMysqlConfig(env),
    rocketMq: {
      ...rocketMq,
      consumerGroup: requireText(env, 'ROCKETMQ_CONSUMER_GROUP'),
      consumerConcurrency: parseInteger(env, 'ROCKETMQ_CONSUMER_CONCURRENCY', {
        min: 1,
        max: 128,
      }),
    },
    ai: loadAiConfig(env),
  }) as WorkerRuntimeConfig;
}

/** 日志只保留诊断所需的非敏感字段，绝不序列化密码、Token 或 API Key。 */
export function toSafeRuntimeSummary(config: RuntimeConfig): Readonly<Record<string, unknown>> {
  const summary: Record<string, unknown> = {
    processName: config.processName,
    appEnv: config.appEnv,
    logLevel: config.logLevel,
    redis: {
      host: config.redis.host,
      port: config.redis.port,
      database: config.redis.database,
      tls: config.redis.tls,
    },
  };

  if (config.processName === 'api') summary.api = config.api;
  if (config.processName === 'scheduler') summary.scheduler = config.scheduler;
  if (config.processName === 'worker') summary.marketData = { mode: config.marketData.mode };

  return deepFreeze(summary);
}