import { Component, ViewEncapsulation, OnInit } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { AuthService } from '../auth/auth.service';
import { firstValueFrom } from 'rxjs';

type Post = {
  id: number;
  userId: number;
  userName: string;
  title?: string;
  category?: string;
  tags?: string;
  body: string;
  createdAt: string;
  likeCount?: number;
  dislikeCount?: number;
  commentCount?: number;
};

@Component({
  selector: 'app-community',
  standalone: true,
  imports: [CommonModule, FormsModule, ReactiveFormsModule],
  templateUrl: './community.component.html',
  styleUrls: ['./community.component.scss'],
  encapsulation: ViewEncapsulation.None
})
export class CommunityComponent implements OnInit {
  showModal = false;

  // modal bound fields
  title = '';
  category = 'General Discussion';
  tags = '';
  tickers = '';
  body = '';

  posts: Post[] = [];
  loading = false;
  loadError = '';

  // reply state per post
  replyDraft: Record<number, string> = {};
  private replyOpen = new Set<number>();

  private readonly baseUrl =
    location.hostname.endsWith('hf.space')
      ? 'https://pykara-pytrade-backend.hf.space'
      : 'http://127.0.0.1:5000';

  constructor(private auth: AuthService) {}

  ngOnInit(): void {
    this.loadPosts();
  }

  async loadPosts() {
    this.loading = true;
    this.loadError = '';
    try {
      const res = await fetch(`${this.baseUrl}/posts?limit=50&offset=0`, {
        method: 'GET',
        credentials: 'omit',
      });
      if (!res.ok) {
        const err = await res.json().catch(() => ({}));
        throw new Error(err.error || err.message || `Failed (${res.status})`);
      }
      const data = await res.json();
      const list = (data?.results as Post[]) ?? [];
      // Ensure counts exist for UI
      this.posts = list.map(p => ({
        likeCount: 0,
        dislikeCount: 0,
        commentCount: 0,
        ...p
      }));
    } catch (e: any) {
      console.error('Load posts failed:', e);
      this.loadError = e?.message || 'Failed to load posts';
    } finally {
      this.loading = false;
    }
  }

  splitTags(tags?: string): string[] {
    return (tags ?? '')
      .split(',')
      .map(t => t.trim())
      .filter(t => t.length > 0);
  }

  toggleModal(show: boolean) {
    this.showModal = show;
    document.body.style.overflow = show ? 'hidden' : '';
  }

  openThread(id: any) {
    const view = document.getElementById('threadView');
    if (view) view.scrollIntoView({ behavior: 'smooth', block: 'start' });
  }

  backToList() {
    const list = document.getElementById('threadList');
    if (list) list.scrollIntoView({ behavior: 'smooth', block: 'start' });
  }

  private async ensureAccessToken(): Promise<string | null> {
    let token = this.auth.getAccessToken();
    if (!token) return null;
    if (this.auth.tokenExpired()) {
      try {
        token = await firstValueFrom(this.auth.refreshAccessToken());
      } catch {
        return null;
      }
    }
    return token || null;
  }

  private parseJwt(token: string): any | null {
    try {
      const base64 = token.split('.')[1].replace(/-/g, '+').replace(/_/g, '/');
      const json = decodeURIComponent(atob(base64).split('').map(c => {
        return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
      }).join(''));
      return JSON.parse(json);
    } catch {
      return null;
    }
  }

  private getUserContextFromToken(token: string): { userId?: number; userName?: string } {
    const payload = this.parseJwt(token);
    if (!payload) return {};
    const userId = payload.sub ? Number(payload.sub) : undefined;
    const userName =
      payload.name ||
      payload.preferred_username ||
      [payload.given_name, payload.family_name].filter(Boolean).join(' ') ||
      undefined;
    return { userId, userName };
  }

  isReplyOpen(postId: number): boolean {
    return this.replyOpen.has(postId);
  }

  toggleReply(postId: number) {
    if (this.replyOpen.has(postId)) {
      this.replyOpen.delete(postId);
    } else {
      this.replyOpen.add(postId);
    }
  }

  async likePost(p: Post) {
    // optimistic UI
    p.likeCount = (p.likeCount ?? 0) + 1;
    const token = await this.ensureAccessToken();
    if (!token) return; // if not signed-in, keep optimistic or revert if you prefer

    try {
      await fetch(`${this.baseUrl}/posts/${p.id}/like`, {
        method: 'POST',
        credentials: 'omit',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${token}`
        }
      });
    } catch {
      // optionally revert UI on failure
      p.likeCount = Math.max(0, (p.likeCount ?? 1) - 1);
    }
  }

  async dislikePost(p: Post) {
    p.dislikeCount = (p.dislikeCount ?? 0) + 1;
    const token = await this.ensureAccessToken();
    if (!token) return;

    try {
      await fetch(`${this.baseUrl}/posts/${p.id}/dislike`, {
        method: 'POST',
        credentials: 'omit',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${token}`
        }
      });
    } catch {
      p.dislikeCount = Math.max(0, (p.dislikeCount ?? 1) - 1);
    }
  }

  async submitReply(postId: number) {
    const draft = (this.replyDraft[postId] || '').trim();
    if (!draft) return;

    const token = await this.ensureAccessToken();
    if (!token) {
      alert('Please sign in to reply.');
      return;
    }

    try {
      const res = await fetch(`${this.baseUrl}/posts/${postId}/comments`, {
        method: 'POST',
        credentials: 'omit',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${token}`
        },
        body: JSON.stringify({ body: draft })
      });
      if (!res.ok) {
        const err = await res.json().catch(() => ({}));
        throw new Error(err.error || err.message || `Failed (${res.status})`);
      }
      // success: clear draft and bump counter
      delete this.replyDraft[postId];
      const post = this.posts.find(x => x.id === postId);
      if (post) post.commentCount = (post.commentCount ?? 0) + 1;
      this.replyOpen.delete(postId);
    } catch (e: any) {
      console.error('Reply failed', e);
      alert(e?.message || 'Failed to post reply');
    }
  }

  async publish() {
    if (!this.body.trim()) {
      alert('Post body is required');
      return;
    }

    const token = await this.ensureAccessToken();
    if (!token) {
      alert('Please sign in to publish.');
      return;
    }

    const { userId, userName } = this.getUserContextFromToken(token);

    try {
      const res = await fetch(`${this.baseUrl}/posts`, {
        method: 'POST',
        credentials: 'omit',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${token}`
        },
        body: JSON.stringify({
          userId,          // optional; backend may ignore and derive from JWT/DB
          userName,        // optional; backend may ignore and derive from DB
          title: this.title,
          category: this.category,
          tags: this.tags,
          body: this.body
        })
      });

      if (res.status === 401) {
        alert('Session expired. Please sign in again.');
        return;
      }
      if (!res.ok) {
        const err = await res.json().catch(() => ({}));
        throw new Error(err.error || err.message || `Failed (${res.status})`);
      }

      // Clear and reload
      this.title = '';
      this.category = 'General Discussion';
      this.tags = '';
      this.tickers = '';
      this.body = '';
      this.toggleModal(false);
      await this.loadPosts();
    } catch (e: any) {
      console.error('Publish error:', e);
      alert(e?.message || 'Failed to publish');
    }
  }
}