/**
 * 对话服务
 * 整合 SSE 通信、工具执行、用户交互
 */
import * as vscode from 'vscode';
import { startStreamDialog, generateTaskId, SSEController, SSECallbacks } from './sseHandler';
import { executeToolCall, createToolExecutorContext, ToolExecutorContext } from './toolExecutor';
import { userInteractionManager } from './userInteraction';
import { getConfig } from '../config/settings';
import type { DialogRequest, ToolCallRequest, AskUserEvent } from '../types/api';

/**
 * 消息段落类型
 */
export interface MessageSegment {
  type: 'text' | 'tool' | 'question';
  content?: string;
  toolName?: string;
  toolStatus?: 'running' | 'success' | 'error';
  toolResult?: string;
  askId?: string;
  question?: string;
  options?: string[];
}

/**
 * 对话回调接口
 */
export interface DialogCallbacks {
  /** 收到文本（可能多次调用，流式） */
  onText?: (text: string, isStreaming: boolean) => void;
  /** 工具开始执行 */
  onToolStart?: (toolName: string) => void;
  /** 工具执行完成 */
  onToolComplete?: (toolName: string, result: string) => void;
  /** 工具执行错误 */
  onToolError?: (toolName: string, error: string) => void;
  /** 显示问题（ask_user） */
  onQuestion?: (askId: string, question: string, options: string[]) => void;
  /** 实时更新段落（流式过程中） */
  onSegmentUpdate?: (segments: MessageSegment[]) => void;
  /** 对话完成，返回所有段落 */
  onComplete?: (segments: MessageSegment[]) => void;
  /** 错误 */
  onError?: (message: string) => void;
  /** 通知消息 */
  onNotification?: (message: string) => void;
}

/**
 * 对话会话
 */
export class DialogSession {
  private taskId: string;
  private sseController: SSEController | null = null;
  private toolContext: ToolExecutorContext;
  private accumulatedText = '';
  private isActive = false;
  private segments: MessageSegment[] = [];
  private currentTextSegment: MessageSegment | null = null;

  constructor(extensionPath: string) {
    this.taskId = generateTaskId();
    this.toolContext = createToolExecutorContext(extensionPath);
  }

  /**
   * 添加文本到当前文本段落
   */
  private appendText(text: string): void {
    if (!this.currentTextSegment) {
      this.currentTextSegment = { type: 'text', content: '' };
      this.segments.push(this.currentTextSegment);
    }
    this.currentTextSegment.content = (this.currentTextSegment.content || '') + text;
  }

  /**
   * 结束当前文本段落
   */
  private finalizeTextSegment(): void {
    this.currentTextSegment = null;
  }

  /**
   * 添加工具段落
   */
  private addToolSegment(toolName: string, status: 'running' | 'success' | 'error', result?: string): MessageSegment {
    this.finalizeTextSegment();
    const segment: MessageSegment = {
      type: 'tool',
      toolName,
      toolStatus: status,
      toolResult: result
    };
    this.segments.push(segment);
    return segment;
  }

  /**
   * 更新工具段落状态
   */
  private updateToolSegment(toolName: string, status: 'success' | 'error', result?: string): void {
    // 找到最后一个匹配的工具段落
    for (let i = this.segments.length - 1; i >= 0; i--) {
      const seg = this.segments[i];
      if (seg.type === 'tool' && seg.toolName === toolName && seg.toolStatus === 'running') {
        seg.toolStatus = status;
        seg.toolResult = result;
        break;
      }
    }
  }

  /**
   * 获取任务ID
   */
  getTaskId(): string {
    return this.taskId;
  }

  /**
   * 是否活跃
   */
  get active(): boolean {
    return this.isActive;
  }

  /**
   * 发送消息并开始流式对话
   */
  async sendMessage(
    message: string,
    callbacks: DialogCallbacks
  ): Promise<void> {
    if (this.isActive) {
      callbacks.onError?.('当前有对话正在进行中');
      return;
    }

    this.isActive = true;
    this.accumulatedText = '';
    this.segments = [];
    this.currentTextSegment = null;

    const config = getConfig();
    const request: DialogRequest = {
      taskId: this.taskId,
      message,
      userId: config.userId,
      toolMode: 'AGENT'
    };

    const sseCallbacks: SSECallbacks = {
      onTextDelta: (data) => {
        this.accumulatedText += data.text;
        this.appendText(data.text);
        console.log('[DialogSession] onTextDelta, 累积文本长度:', this.accumulatedText.length);
        callbacks.onText?.(this.accumulatedText, true);
        // 实时发送段落更新
        callbacks.onSegmentUpdate?.(this.segments);
      },

      onToolCall: async (data: ToolCallRequest) => {
        const toolName = data.params.name;
        console.log('[DialogSession] onToolCall:', toolName);
        // 检查是否已经有相同的工具段落（可能由 onToolStart 添加）
        const lastToolSegment = this.segments.filter(s => s.type === 'tool').pop();
        if (lastToolSegment && lastToolSegment.toolName === toolName && lastToolSegment.toolStatus === 'running') {
          console.log('[DialogSession] onToolCall: 跳过重复的工具段落:', toolName);
        } else {
          this.addToolSegment(toolName, 'running');
          // 实时发送段落更新
          callbacks.onSegmentUpdate?.(this.segments);
        }
        // 注意：不在这里调用 callbacks.onToolStart，避免与 onToolStart 事件重复
        try {
          await executeToolCall(data, this.toolContext);
          this.updateToolSegment(toolName, 'success', '执行完成');
          // 实时发送段落更新
          callbacks.onSegmentUpdate?.(this.segments);
          // 也不调用 callbacks.onToolComplete，避免重复
        } catch (error) {
          const errorMsg = error instanceof Error ? error.message : '未知错误';
          this.updateToolSegment(toolName, 'error', errorMsg);
          callbacks.onToolError?.(toolName, errorMsg);
          // 实时发送段落更新
          callbacks.onSegmentUpdate?.(this.segments);
        }
      },

      onToolStart: (data) => {
        console.log('[DialogSession] onToolStart:', data.tool_name);
        // 检查是否已经有相同的工具段落（可能由 onToolCall 添加）
        const lastToolSegment = this.segments.filter(s => s.type === 'tool').pop();
        if (lastToolSegment && lastToolSegment.toolName === data.tool_name && lastToolSegment.toolStatus === 'running') {
          console.log('[DialogSession] 跳过重复的工具段落:', data.tool_name);
        } else {
          this.addToolSegment(data.tool_name, 'running');
          // 实时发送段落更新
          callbacks.onSegmentUpdate?.(this.segments);
        }
        console.log('[DialogSession] segments 数量:', this.segments.length);
        callbacks.onToolStart?.(data.tool_name);
      },

      onToolComplete: (data) => {
        this.updateToolSegment(data.tool_name, 'success', data.result);
        callbacks.onToolComplete?.(data.tool_name, data.result);
        // 实时发送段落更新
        callbacks.onSegmentUpdate?.(this.segments);
      },

      onToolError: (data) => {
        this.updateToolSegment(data.tool_name, 'error', data.error);
        callbacks.onToolError?.(data.tool_name, data.error);
        // 实时发送段落更新
        callbacks.onSegmentUpdate?.(this.segments);
      },

      onAskUser: async (data: AskUserEvent) => {
        this.finalizeTextSegment();
        this.segments.push({
          type: 'question',
          askId: data.askId,
          question: data.question,
          options: data.options
        });
        // 实时发送段落更新（包含问题）
        callbacks.onSegmentUpdate?.(this.segments);
        // 同时调用 onQuestion 用于更新状态栏等
        callbacks.onQuestion?.(data.askId, data.question, data.options);
        try {
          await userInteractionManager.handleAskUser(data, this.taskId);
        } catch (error) {
          console.error('[DialogSession] 处理用户问题失败:', error);
        }
      },

      onComplete: (data) => {
        this.isActive = false;
        this.finalizeTextSegment();
        // 发送所有段落
        callbacks.onComplete?.(this.segments);
      },

      onError: (data) => {
        this.isActive = false;
        callbacks.onError?.(data.message);
      },

      onWarning: (data) => {
        callbacks.onNotification?.(`⚠️ ${data.message}`);
      },

      onNotification: (data) => {
        callbacks.onNotification?.(data.message);
      },

      onOpen: () => {
        console.log('[DialogSession] SSE 连接已建立');
      },

      onClose: () => {
        console.log('[DialogSession] SSE 连接已关闭');
        this.isActive = false;
      }
    };

    try {
      this.sseController = await startStreamDialog(request, sseCallbacks);
    } catch (error) {
      this.isActive = false;
      const errorMsg = error instanceof Error ? error.message : '连接失败';
      callbacks.onError?.(errorMsg);
      throw error;
    }
  }

  /**
   * 中止当前对话
   */
  abort(): void {
    if (this.sseController) {
      this.sseController.abort();
      this.sseController = null;
    }
    this.isActive = false;
    userInteractionManager.cancelAll();
  }

  /**
   * 提交用户回答
   */
  async submitAnswer(
    askId: string,
    selected?: string[],
    customInput?: string
  ): Promise<void> {
    await userInteractionManager.receiveAnswer(askId, selected, customInput);
  }
}

/**
 * 全局对话会话管理
 */
class DialogManager {
  private currentSession: DialogSession | null = null;

  /**
   * 创建新会话
   */
  createSession(extensionPath: string): DialogSession {
    // 如果有活跃会话，先中止
    if (this.currentSession?.active) {
      this.currentSession.abort();
    }
    this.currentSession = new DialogSession(extensionPath);
    return this.currentSession;
  }

  /**
   * 获取当前会话
   */
  getCurrentSession(): DialogSession | null {
    return this.currentSession;
  }

  /**
   * 中止当前会话
   */
  abortCurrentSession(): void {
    this.currentSession?.abort();
  }
}

export const dialogManager = new DialogManager();