import { Component, OnInit, OnDestroy, Input, OnChanges, SimpleChanges } from '@angular/core';
import { CommonModule } from '@angular/common';
import { MatListModule } from '@angular/material/list';
import { MatButtonModule } from '@angular/material/button';
import { MatIconModule } from '@angular/material/icon';
import { MatInputModule } from '@angular/material/input';
import { MatFormFieldModule } from '@angular/material/form-field';
import { FormsModule } from '@angular/forms';
import { Subscription } from 'rxjs';
import { SessionService } from '../services/session.service';
import { AuthService } from '../services/auth.service';
import { MenuService } from '../services/menu.service';
import { InstanceService } from '../services/instance.service';
import { Session } from '../models/session.model';

@Component({
  selector: 'app-session-list',
  standalone: true,
  imports: [
    CommonModule,
    MatListModule,
    MatButtonModule,
    MatIconModule,
    MatInputModule,
    MatFormFieldModule,
    FormsModule
  ],
  templateUrl: './session-list.component.html',
  styleUrl: './session-list.component.scss'
})
export class SessionListComponent implements OnInit, OnDestroy {
  sessions: Session[] = [];
  activeSessionId: string | null = null;
  showCreateForm = false;
  newSessionTitle = '';
  @Input() instanceId: string | undefined;
  menuItemId: string | null = null;
  
  private authSubscription?: Subscription;

  constructor(
    private sessionService: SessionService,
    private authService: AuthService,
    private menuService: MenuService,
    private instanceService: InstanceService
  ) {}

  ngOnInit() {
    // 初始检查认证状态
    if (this.authService.isAuthenticated()) {
      this.loadMenuAndSessions();
    } else {
      // 订阅认证状态变化，登录后加载会话
      this.authSubscription = this.authService.authState$.subscribe(authState => {
        if (authState.isAuthenticated) {
          console.log('用户已认证，加载会话列表');
          this.loadMenuAndSessions();
        }
      });
    }
  }

  ngOnChanges(changes: SimpleChanges) {
    // 如果instanceId变化，重新加载会话
    if (changes['instanceId'] && !changes['instanceId'].firstChange) {
      console.log('实例ID变化，重新加载会话:', this.instanceId);
      this.loadMenuAndSessions();
    }
  }
  
  ngOnDestroy() {
    if (this.authSubscription) {
      this.authSubscription.unsubscribe();
    }
  }

  loadMenuAndSessions() {
    if (this.instanceId) {
      // 通过实例ID加载
      const instance = this.instanceService.getInstanceById(this.instanceId);
      if (instance) {
        this.menuItemId = instance.menuItemId;
        console.log('使用实例菜单项ID:', this.menuItemId);
        this.loadSessionsForInstance();
      } else {
        console.error('实例不存在:', this.instanceId);
        this.loadSessions(); // 回退到普通加载
      }
    } else {
      // 没有实例ID，使用旧逻辑：加载菜单，获取第一个菜单项ID
      this.menuService.getTopMenu().subscribe({
        next: (menuItems) => {
          if (menuItems.length > 0) {
            this.menuItemId = menuItems[0].id;
            console.log('使用第一个菜单项ID:', this.menuItemId);
            this.loadSessions();
          } else {
            console.error('没有可用的菜单项');
            this.loadSessions(); // 仍然尝试加载会话，但创建会话时会失败
          }
        },
        error: (error) => {
          console.error('加载菜单失败:', error);
          // 仍然尝试加载会话
          this.loadSessions();
        }
      });
    }
  }

  loadSessions() {
    this.sessionService.getSessions().subscribe({
      next: (sessions) => {
        // 如果没有实例ID，显示所有会话
        this.sessions = sessions;
        if (sessions.length > 0 && !this.activeSessionId) {
          this.selectSession(sessions[0]);
        }
      },
      error: (error) => {
        console.error('加载会话列表失败:', error);
      }
    });
  }

  loadSessionsForInstance() {
    if (!this.instanceId) {
      this.loadSessions();
      return;
    }

    this.instanceService.getInstanceSessions(this.instanceId).subscribe({
      next: (sessions) => {
        this.sessions = sessions;
        if (sessions.length > 0 && !this.activeSessionId) {
          this.selectSession(sessions[0]);
        }
      },
      error: (error) => {
        console.error('加载实例会话失败:', error);
      }
    });
  }

  createNewSession() {
    this.showCreateForm = true;
  }

  cancelCreate() {
    this.showCreateForm = false;
    this.newSessionTitle = '';
  }

  confirmCreate() {
    if (!this.newSessionTitle.trim()) return;
    
    if (!this.menuItemId) {
      console.error('无法创建会话：未找到菜单项ID');
      // 尝试重新加载菜单
      this.loadMenuAndSessions();
      return;
    }
    
    this.sessionService.createSession(this.newSessionTitle, this.menuItemId!).subscribe({
      next: (session) => {
        this.sessions.unshift(session);
        this.selectSession(session);
        this.showCreateForm = false;
        this.newSessionTitle = '';
      },
      error: (error) => {
        console.error('创建会话失败:', error);
      }
    });
  }

  selectSession(session: Session) {
    this.activeSessionId = session.id;
    // 触发会话切换事件（通过服务）
    this.sessionService.setActiveSession(session);
  }
}