import { CommonModule } from '@angular/common';
import { Component, computed, effect, inject, signal } from '@angular/core';
import { toSignal } from '@angular/core/rxjs-interop';
import { FormsModule } from '@angular/forms';
import { ActivatedRoute, Router, RouterLink } from '@angular/router';

import { PeerVideoModalComponent } from './peer-video-modal.component';
import { ChatSessionService } from './chat-session.service';
import { JsonFileViewerComponent } from './json-file-viewer.component';
import type { ChatEntry, ConnectionState, PeerSummary } from './models';

@Component({
  selector: 'app-chat-page',
  imports: [CommonModule, FormsModule, RouterLink, JsonFileViewerComponent, PeerVideoModalComponent],
  templateUrl: './chat-page.component.html',
  styleUrl: './chat-page.component.scss',
})
export class ChatPageComponent {
  private readonly route = inject(ActivatedRoute);
  private readonly router = inject(Router);
  private readonly routeParamMap = toSignal(this.route.paramMap, {
    initialValue: this.route.snapshot.paramMap,
  });
  private composerSelectionStart = 0;
  private composerSelectionEnd = 0;

  messageText = '';
  readonly forwardingEntryId = signal<string | null>(null);
  readonly emojiPickerOpen = signal(false);
  readonly emojiOptions = [
    '😀', '😁', '😂', '🤣', '😊',
    '😉', '😍', '😘', '😎', '🤔',
    '😅', '😭', '😡', '😴', '🙃',
    '👍', '👎', '👏', '🙏', '🤝',
    '🎉', '🔥', '❤️', '💡', '✅',
    '🚀', '👀', '📹', '📎', '💬',
    '🌍', '⚡', '⭐', '🎵', '📷',
    '🗑️', '⏩', '🛑', '🙌', '👌',
  ];
  readonly peerId = computed(() => this.routeParamMap().get('peerId') ?? '');
  readonly peer = computed(() => this.session.peers().find((item) => item.id === this.peerId()) ?? null);
  readonly currentUser = computed(() => this.session.currentUser());
  readonly conversation = computed(() =>
    this.session
      .messages()
      .filter((entry) => entry.peerId === this.peerId()),
  );
  readonly remoteVideoStream = computed(() => this.session.remoteVideoStreamForPeer(this.peerId()));
  readonly remoteVideoModalVisible = computed(
    () => this.session.remoteVideoModalPeerId() === this.peerId() && !!this.remoteVideoStream(),
  );
  readonly webRtcState = computed<ConnectionState>(() => {
    const selectedPeer = this.peer();

    if (!selectedPeer) {
      return 'disconnected';
    }

    if (selectedPeer.channelState === 'open' || selectedPeer.connectionState === 'connected') {
      return 'connected';
    }

    if (selectedPeer.channelState === 'connecting' || selectedPeer.connectionState === 'connecting') {
      return 'connecting';
    }

    return 'disconnected';
  });

  constructor(readonly session: ChatSessionService) {
    if (!this.session.currentUser()) {
      void this.router.navigateByUrl('/');
    }

    effect(() => {
      const peerId = this.peerId();

      if (!peerId) {
        return;
      }

      this.session.selectPeer(peerId);
      void this.session.connectToPeer(peerId);
    });
  }

  async ensureConnection(): Promise<void> {
    const peerId = this.peerId();

    if (!peerId) {
      return;
    }

    this.session.selectPeer(peerId);
    await this.session.connectToPeer(peerId);
  }

  async sendMessage(): Promise<void> {
    const peerId = this.peerId();

    if (!peerId) {
      return;
    }

    await this.session.sendText(peerId, this.messageText);
    this.messageText = '';
    this.emojiPickerOpen.set(false);
    this.composerSelectionStart = 0;
    this.composerSelectionEnd = 0;
  }

  async requestGeneratedImage(): Promise<void> {
    const peerId = this.peerId();

    if (!peerId) {
      return;
    }

    await this.session.requestGeneratedImage(peerId, this.messageText);
  }

  handleComposerEnter(event: Event): void {
    if (!(event instanceof KeyboardEvent) || event.shiftKey) {
      return;
    }

    event.preventDefault();
    void this.sendMessage();
  }

  handleMessageTextChange(text: string): void {
    const peerId = this.peerId();

    if (!peerId) {
      return;
    }

    this.session.notifyTypingActivity(peerId, text);
  }

  trackComposerSelection(textarea: HTMLTextAreaElement): void {
    this.composerSelectionStart = textarea.selectionStart ?? this.messageText.length;
    this.composerSelectionEnd = textarea.selectionEnd ?? this.composerSelectionStart;
  }

  toggleEmojiPicker(event?: Event): void {
    event?.stopPropagation();
    this.emojiPickerOpen.update((open) => !open);
  }

  insertEmoji(emoji: string, textarea: HTMLTextAreaElement): void {
    const selectionStart = textarea.selectionStart ?? this.composerSelectionStart;
    const selectionEnd = textarea.selectionEnd ?? this.composerSelectionEnd;
    const before = this.messageText.slice(0, selectionStart);
    const after = this.messageText.slice(selectionEnd);

    this.messageText = `${before}${emoji}${after}`;
    this.emojiPickerOpen.set(false);
    this.handleMessageTextChange(this.messageText);

    const nextSelection = selectionStart + emoji.length;
    this.composerSelectionStart = nextSelection;
    this.composerSelectionEnd = nextSelection;

    queueMicrotask(() => {
      textarea.focus();
      textarea.setSelectionRange(nextSelection, nextSelection);
      this.trackComposerSelection(textarea);
    });
  }

  async sendFile(peerId: string, input: HTMLInputElement): Promise<void> {
    const file = input.files?.item(0);

    if (!file) {
      return;
    }

    await this.session.sendFile(peerId, file);
    input.value = '';
  }

  async deleteMessage(entry: ChatEntry): Promise<void> {
    await this.session.deleteMessage(entry);
  }

  async deleteConversation(peerId: string, event?: Event): Promise<void> {
    event?.stopPropagation();
    await this.session.deleteConversation(peerId);
  }

  toggleForwardMenu(entry: ChatEntry, event?: Event): void {
    event?.stopPropagation();

    if (entry.kind === 'system' || entry.direction === 'system' || this.forwardTargets(entry).length === 0) {
      this.forwardingEntryId.set(null);
      return;
    }

    this.forwardingEntryId.update((currentEntryId) => (currentEntryId === entry.id ? null : entry.id));
  }

  isForwardMenuOpen(entryId: string): boolean {
    return this.forwardingEntryId() === entryId;
  }

  forwardTargets(entry: ChatEntry): PeerSummary[] {
    if (entry.kind === 'system' || entry.direction === 'system') {
      return [];
    }

    return this.session.peers().filter((peer) => peer.id !== entry.peerId);
  }

  async forwardEntry(entry: ChatEntry, targetPeerId: string, select: HTMLSelectElement): Promise<void> {
    if (!targetPeerId) {
      return;
    }

    await this.session.forwardMessage(targetPeerId, entry);
    select.value = '';
    this.forwardingEntryId.set(null);
  }

  async toggleCameraStream(peerId: string): Promise<void> {
    if (this.session.isStreamingCameraToPeer(peerId)) {
      await this.session.stopCameraStream(peerId);
      return;
    }

    await this.session.startCameraStream(peerId);
  }

  isImageEntry(entry: ChatEntry): boolean {
    return entry.kind === 'file' && !!entry.downloadUrl && (entry.fileMimeType?.startsWith('image/') ?? false);
  }

  isVideoEntry(entry: ChatEntry): boolean {
    if (entry.kind !== 'file' || !entry.downloadUrl) {
      return false;
    }

    if (entry.fileMimeType?.startsWith('video/')) {
      return true;
    }

    return /\.(mp4|webm|ogg|ogv|mov|m4v)$/i.test(entry.fileName ?? '');
  }

  isIncomingJsonFileEntry(entry: ChatEntry): boolean {
    return (
      entry.kind === 'file' &&
      entry.direction === 'incoming' &&
      !!entry.downloadUrl &&
      !!entry.fileName &&
      entry.fileName.toLowerCase().endsWith('.json')
    );
  }

  isPeerTyping(peerId: string): boolean {
    return this.session.typingPeerIds().includes(peerId);
  }

  indicatorTone(state: ConnectionState): 'ok' | 'connecting' | 'offline' {
    if (state === 'connected') {
      return 'ok';
    }

    if (state === 'connecting') {
      return 'connecting';
    }

    return 'offline';
  }

  canReconnectWebRtc(): boolean {
    return this.indicatorTone(this.webRtcState()) === 'offline';
  }

  isStreamingCameraToSelectedPeer(): boolean {
    const peerId = this.peerId();

    return !!peerId && this.session.isStreamingCameraToPeer(peerId);
  }

  closeRemoteVideoModal(): void {
    const peerId = this.peerId();

    if (!peerId) {
      return;
    }

    this.session.dismissRemoteVideoModal(peerId);
  }

  async switchPeer(peerId: string): Promise<void> {
    if (!peerId || peerId === this.peerId()) {
      return;
    }

    this.forwardingEntryId.set(null);
    this.emojiPickerOpen.set(false);
    this.session.selectPeer(peerId);
    await this.router.navigate(['/chat', peerId]);
  }
}