import { logger } from '../../utils/logger';
import { FeatureGovernanceService } from '../governance/FeatureGovernanceService';
import * as fs from 'fs';
import * as path from 'path';

/**
 * [CORE_DEV_17] 基于 WASM 的轻量级边缘计算算子 (Edge WASM)
 * @description 核心逻辑：支持在边缘节点或浏览器端下沉执行高性能逻辑（如图像处理、加密计算、复杂规则引擎）。
 * 模拟 WASM 运行环境，支持动态加载与热更新。
 */
export class EdgeWASMService {
  private static readonly MODULE_CACHE = new Map<string, any>();

  /**
   * 加载并执行 WASM 算子
   */
  static async executeOperator(operatorId: string, input: any, tenantId?: string): Promise<any> {
    // Feature Flag Check
    if (!(await FeatureGovernanceService.isEnabled('CORE_DEV_EDGE_WASM', tenantId))) {
      logger.warn(`[EdgeWASM] Operator ${operatorId} execution skipped: Feature disabled.`);
      return input;
    }

    logger.info(`[EdgeWASM] Executing operator: ${operatorId} for Tenant: ${tenantId}`);

    try {
      // 1. 模拟 WASM 模块加载 (实际场景使用 WebAssembly.instantiate)
      const module = await this.loadModule(operatorId);
      
      // 2. 模拟沙箱执行
      const result = module.run(input);
      
      return result;
    } catch (err: any) {
      logger.error(`[EdgeWASM] Execution failed: ${err.message}`);
      throw err;
    }
  }

  /**
   * 模拟 WASM 模块热加载
   */
  private static async loadModule(id: string): Promise<any> {
    if (this.MODULE_CACHE.has(id)) return this.MODULE_CACHE.get(id);

    // 模拟不同类型的算子
    const operators: Record<string, any> = {
      'IMG_RESIZER': {
        run: (input: any) => ({ ...input, processed: true, engine: 'WASM_SIMD' })
      },
      'PRICE_CALCULATOR': {
        run: (input: any) => ({ ...input, finalPrice: input.base * 1.15, status: 'VERIFIED_BY_WASM' })
      },
      'ZKP_GENERATOR': {
        run: (input: any) => ({ proof: 'WASM_PROOF_0xABC', verified: true })
      }
    };

    const op = operators[id] || operators['PRICE_CALCULATOR'];
    this.MODULE_CACHE.set(id, op);
    return op;
  }

  /**
   * 部署新算子 (热更新)
   */
  static async deployOperator(id: string, wasmBinary: Buffer) {
    logger.info(`[EdgeWASM] Deploying new binary for operator: ${id}, size: ${wasmBinary.length} bytes`);
    this.MODULE_CACHE.delete(id);
    // 实际应写入文件系统或对象存储
  }
}
