import { CommonModule } from '@angular/common';
import { Component } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { Router } from '@angular/router';
import { finalize } from 'rxjs';
import { getErrorMessage } from '../../core/http/error-message.util';
import { GameApiService } from '../../services/game-api.service';

@Component({
  selector: 'app-welcome',
  standalone: true,
  imports: [CommonModule, FormsModule],
  templateUrl: './welcome.component.html',
  styleUrl: './welcome.component.css'
})
export class WelcomeComponent {
  creating = false;
  errorMessage = '';
  showDifficultySelector = false;
  showJoinGameForm = false;
  showImportGameForm = false;
  gameIdInput = '';
  joiningGame = false;
  importing = false;
  importMode: 'fen' | 'pgn' = 'fen';
  importText = '';

  constructor(
    private readonly router: Router,
    private readonly gameApi: GameApiService
  ) {
    this.initTheme();
  }

  private initTheme(): void {
    const savedTheme = localStorage.getItem('theme');
    if (savedTheme === 'dark') {
      document.documentElement.setAttribute('data-theme', 'dark');
    }
  }

  startOneVsOne(): void {
    if (this.creating) {
      return;
    }

    this.errorMessage = '';
    this.creating = true;

    this.gameApi
      .createGame()
      .pipe(finalize(() => (this.creating = false)))
      .subscribe({
        next: (game) => {
          void this.router.navigate(['/game', game.gameId]);
        },
        error: (error) => {
          this.errorMessage = getErrorMessage(error, 'Unable to create a game.');
        }
      });
  }

  startVsBot(difficulty: 'easy' | 'medium' | 'hard'): void {
    if (this.creating) {
      return;
    }

    this.errorMessage = '';
    this.creating = true;
    this.showDifficultySelector = false;

    this.gameApi
      .createGameVsBot(difficulty)
      .pipe(finalize(() => (this.creating = false)))
      .subscribe({
        next: (game) => {
          void this.router.navigate(['/game', game.gameId]);
        },
        error: (error) => {
          this.errorMessage = getErrorMessage(error, 'Unable to create a game against bot.');
        }
      });
  }

  toggleDifficultySelector(): void {
    this.showDifficultySelector = !this.showDifficultySelector;
    this.showJoinGameForm = false;
    this.showImportGameForm = false;
    this.errorMessage = '';
  }

  toggleJoinGameForm(): void {
    this.showJoinGameForm = !this.showJoinGameForm;
    this.showDifficultySelector = false;
    this.showImportGameForm = false;
    this.errorMessage = '';
    this.gameIdInput = '';
  }

  toggleImportGameForm(): void {
    this.showImportGameForm = !this.showImportGameForm;
    this.showDifficultySelector = false;
    this.showJoinGameForm = false;
    this.errorMessage = '';

    if (!this.showImportGameForm) {
      this.importText = '';
      this.importMode = 'fen';
    }
  }

  setImportMode(mode: 'fen' | 'pgn'): void {
    this.importMode = mode;
    this.errorMessage = '';
  }

  submitImportedGame(): void {
    const trimmedImport = this.importText.trim();
    if (this.importing || !trimmedImport) {
      return;
    }

    this.errorMessage = '';
    this.importing = true;

    const importRequest =
      this.importMode === 'fen' ? this.gameApi.importFen(trimmedImport) : this.gameApi.importPgn(trimmedImport);

    importRequest.pipe(finalize(() => (this.importing = false))).subscribe({
      next: (game) => {
        this.importText = '';
        this.showImportGameForm = false;
        void this.router.navigate(['/game', game.gameId]);
      },
      error: (error) => {
        const defaultMessage = this.importMode === 'fen' ? 'Unable to import FEN.' : 'Unable to import PGN.';
        this.errorMessage = getErrorMessage(error, defaultMessage);
      }
    });
  }

  joinGame(): void {
    if (this.joiningGame || !this.gameIdInput.trim()) {
      return;
    }

    this.errorMessage = '';
    this.joiningGame = true;

    this.gameApi
      .getGame(this.gameIdInput.trim())
      .pipe(finalize(() => (this.joiningGame = false)))
      .subscribe({
        next: (game) => {
          void this.router.navigate(['/game', game.gameId]);
        },
        error: (error) => {
          this.errorMessage = getErrorMessage(error, 'Unable to find or join the game.');
        }
      });
  }

  clearJoinGameForm(): void {
    this.showJoinGameForm = false;
    this.gameIdInput = '';
    this.errorMessage = '';
  }

  toggleDarkMode(): void {
    const htmlElement = document.documentElement;
    const isDarkMode = htmlElement.getAttribute('data-theme') === 'dark';
    
    if (isDarkMode) {
      htmlElement.removeAttribute('data-theme');
      localStorage.removeItem('theme');
    } else {
      htmlElement.setAttribute('data-theme', 'dark');
      localStorage.setItem('theme', 'dark');
    }
  }

  isDarkMode(): boolean {
    return document.documentElement.getAttribute('data-theme') === 'dark';
  }
}