/**
 * 智谱AI (GLM系列)适配器
 */

import { BaseLLMAdapter } from '../base-adapter';
import type { LLMRequest, LLMResponse } from '../types';

export class ZhipuAdapter extends BaseLLMAdapter {
  private baseUrl: string;

  constructor(config: any) {
    super(config);
    this.baseUrl = config.baseUrl || 'https://open.bigmodel.cn/api/paas/v4';
  }

  async complete(request: LLMRequest): Promise<LLMResponse> {
    try {
      await this.validateConfig();

      return await this.retry(async () => {
        return await this.withTimeout(this._sendRequest(request));
      });
    } catch (error) {
      this.handleError(error, '智谱AI API调用失败');
    }
  }

  private async _sendRequest(request: LLMRequest): Promise<LLMResponse> {
    // 智谱AI API兼容OpenAI格式
    const response = await fetch(`${this.baseUrl}/chat/completions`, {
      method: 'POST',
      headers: this.buildHeaders({
        'Authorization': `Bearer ${this.config.apiKey}`,
      }),
      body: JSON.stringify({
        model: this.config.model,
        messages: request.messages,
        temperature: request.temperature ?? this.config.temperature,
        max_tokens: request.maxTokens ?? this.config.maxTokens,
        top_p: request.topP ?? this.config.topP,
      }),
    });

    if (!response.ok) {
      const error = await response.json().catch(() => ({}));
      throw {
        statusCode: response.status,
        message: error.error?.message || `HTTP ${response.status}: ${response.statusText}`,
      };
    }

    const data = await response.json();
    const choice = data.choices?.[0];

    if (!choice) {
      throw new Error('API响应格式异常: 缺少choices字段');
    }

    return {
      content: choice.message?.content || '',
      model: data.model,
      usage: data.usage ? {
        promptTokens: data.usage.prompt_tokens,
        completionTokens: data.usage.completion_tokens,
        totalTokens: data.usage.total_tokens,
      } : undefined,
      finishReason: choice.finish_reason,
    };
  }

  async validateConfig(): Promise<boolean> {
    await super.validateConfig();
    
    if (!this.config.model.startsWith('glm-')) {
      throw new Error(`无效的智谱AI模型: ${this.config.model}`);
    }
    
    return true;
  }
}