import { Component, EventEmitter, Output, inject, OnInit } from '@angular/core';
import { CommonModule } from '@angular/common';
import { HttpClient } from '@angular/common/http';
import { MatProgressSpinnerModule } from '@angular/material/progress-spinner';
import { MatButtonModule } from '@angular/material/button';
import { MatIconModule } from '@angular/material/icon';
import { MatPaginatorModule, PageEvent } from '@angular/material/paginator';

interface ActivityLog {
  id: number;
  timestamp: string;
  user: string;
  action: string;
  entity_type: string;
  entity_id: any;
  entity_name: string;
  details?: string;
}

interface ActivityLogResponse {
  items: ActivityLog[];
  total: number;
  page: number;
  limit: number;
  pages: number;
}

@Component({
  selector: 'app-activity-log',
  standalone: true,
  imports: [
    CommonModule, 
    MatProgressSpinnerModule,
    MatButtonModule,
    MatIconModule,
    MatPaginatorModule
  ],
  template: `
    <div class="activity-log-dropdown" (click)="$event.stopPropagation()">
      <div class="activity-header">
        <h3>🔔 Recent Activities</h3>
        <button class="close-btn" (click)="close.emit()">×</button>
      </div>
      
      <div class="activity-content">
        @if (loading && activities.length === 0) {
          <div class="loading">
            <mat-spinner diameter="30"></mat-spinner>
          </div>
        } @else if (activities.length === 0) {
          <div class="empty">No activities found</div>
        } @else {
          <div class="activity-list">
            @for (activity of activities; track activity.id) {
              <div class="activity-item">
                <div class="activity-time">{{ getRelativeTime(activity.timestamp) }}</div>
                <div class="activity-content">
                  <strong>{{ activity.user }}</strong> {{ getActionText(activity) }}
                  <em>{{ activity.entity_name }}</em>
                  @if (activity.details) {
                    <span class="details">• {{ activity.details }}</span>
                  }
                </div>
              </div>
            }
          </div>
        }
      </div>
      
      <div class="activity-footer">
        @if (totalItems > pageSize) {
          <mat-paginator
            [length]="totalItems"
            [pageSize]="pageSize"
            [pageIndex]="currentPage - 1"
            [pageSizeOptions]="[10, 25, 50]"
            (page)="onPageChange($event)"
            showFirstLastButtons>
          </mat-paginator>
        } @else {
          <button mat-button (click)="openFullView()">
            <mat-icon>open_in_new</mat-icon>
            View All Activities
          </button>
        }
      </div>
    </div>
  `,
  styles: [`
    .activity-log-dropdown {
      position: absolute;
      top: 100%;
      right: 0;
      width: 400px;
      background: white;
      border: 1px solid #dee2e6;
      border-radius: 8px;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
      z-index: 1000;
      margin-top: 0.5rem;
      display: flex;
      flex-direction: column;
      max-height: 600px;
    }

    .activity-header {
      padding: 1rem;
      border-bottom: 1px solid #dee2e6;
      display: flex;
      justify-content: space-between;
      align-items: center;

      h3 {
        margin: 0;
        font-size: 1.1rem;
      }

      .close-btn {
        background: none;
        border: none;
        font-size: 1.5rem;
        cursor: pointer;
        color: #6c757d;
        line-height: 1;
        padding: 0;
        width: 24px;
        height: 24px;
        display: flex;
        align-items: center;
        justify-content: center;

        &:hover {
          color: #333;
        }
      }
    }

    .activity-content {
      flex: 1;
      overflow-y: auto;
      min-height: 200px;
      max-height: 400px;
    }

    .activity-list {
      .activity-item {
        padding: 0.75rem 1rem;
        border-bottom: 1px solid #f0f0f0;
        transition: background-color 0.2s;

        &:hover {
          background-color: #f8f9fa;
        }

        &:last-child {
          border-bottom: none;
        }

        .activity-time {
          font-size: 0.85rem;
          color: #6c757d;
          margin-bottom: 0.25rem;
        }

        .activity-content {
          font-size: 0.9rem;

          em {
            color: #007bff;
            font-style: normal;
            font-weight: 500;
          }

          .details {
            color: #6c757d;
            font-size: 0.85rem;
          }
        }
      }
    }

    .activity-footer {
      padding: 0.5rem;
      border-top: 1px solid #dee2e6;
      display: flex;
      justify-content: center;
      align-items: center;

      button {
        width: 100%;
      }

      ::ng-deep .mat-paginator {
        background: transparent;
        width: 100%;

        .mat-paginator-container {
          padding: 0;
          justify-content: center;
        }

        .mat-paginator-range-label {
          margin: 0 8px;
        }
      }
    }

    .loading {
      padding: 3rem;
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .empty {
      padding: 3rem;
      text-align: center;
      color: #6c757d;
    }
  `]
})
export class ActivityLogComponent implements OnInit {
  @Output() close = new EventEmitter<void>();

  private http = inject(HttpClient);

  activities: ActivityLog[] = [];
  loading = false;
  currentPage = 1;
  pageSize = 10;
  totalItems = 0;
  totalPages = 0;

  ngOnInit() {
    this.loadActivities();
  }

  loadActivities(page: number = 1) {
    this.loading = true;
    this.currentPage = page;
    
    this.http.get<ActivityLogResponse>(
      `/api/activity-log?page=${page}&limit=${this.pageSize}`
    ).subscribe({
      next: (response) => {
        this.activities = response.items;
        this.totalItems = response.total;
        this.totalPages = response.pages;
        this.loading = false;
      },
      error: (error) => {
        console.error('Failed to load activities:', error);
        this.loading = false;
      }
    });
  }

  onPageChange(event: PageEvent) {
    this.pageSize = event.pageSize;
    this.loadActivities(event.pageIndex + 1);
  }

  openFullView() {
    // TODO: Implement full activity log view
    console.log('Open full activity log view');
    this.close.emit();
  }

  getRelativeTime(timestamp: string): string {
    const date = new Date(timestamp);
    const now = new Date();
    const diff = now.getTime() - date.getTime();

    const minutes = Math.floor(diff / 60000);
    const hours = Math.floor(diff / 3600000);
    const days = Math.floor(diff / 86400000);

    if (minutes < 1) return 'just now';
    if (minutes < 60) return `${minutes} min ago`;
    if (hours < 24) return `${hours} hour${hours > 1 ? 's' : ''} ago`;
    if (days < 7) return `${days} day${days > 1 ? 's' : ''} ago`;

    return date.toLocaleDateString();
  }

  getActionText(activity: ActivityLog): string {
    const actions: Record<string, string> = {
      'CREATE_PROJECT': 'created project',
      'UPDATE_PROJECT': 'updated project',
      'DELETE_PROJECT': 'deleted project',
      'ENABLE_PROJECT': 'enabled project',
      'DISABLE_PROJECT': 'disabled project',
      'PUBLISH_VERSION': 'published version of',
      'CREATE_VERSION': 'created version for',
      'UPDATE_VERSION': 'updated version of',
      'DELETE_VERSION': 'deleted version from',
      'CREATE_API': 'created API',
      'UPDATE_API': 'updated API',
      'DELETE_API': 'deleted API',
      'UPDATE_ENVIRONMENT': 'updated environment',
      'IMPORT_PROJECT': 'imported project',
      'CHANGE_PASSWORD': 'changed password'
    };

    return actions[activity.action] || activity.action.toLowerCase().replace(/_/g, ' ');
  }
}