/**
 * Domain Entity: AvatarGenerationRequest
 *
 * Represents a request to generate a racing avatar from a face photo.
 */
 
import { Entity } from '@core/shared/domain/Entity';
import type {
    AvatarGenerationRequestProps,
    AvatarGenerationStatus,
    AvatarStyle,
    RacingSuitColor,
} from '../types/AvatarGenerationRequest';
import { MediaUrl } from '../value-objects/MediaUrl';
 
export class AvatarGenerationRequest extends Entity<string> {
  readonly userId: string;
  readonly facePhotoUrl: MediaUrl;
  readonly suitColor: RacingSuitColor;
  readonly style: AvatarStyle;
  private _status: AvatarGenerationStatus;
  private _generatedAvatarUrls: MediaUrl[];
  private _selectedAvatarIndex?: number;
  private _errorMessage?: string;
  readonly createdAt: Date;
  private _updatedAt: Date;

  private constructor(props: AvatarGenerationRequestProps) {
    super(props.id);
    
    this.userId = props.userId;
    this.facePhotoUrl = MediaUrl.create(props.facePhotoUrl);
    this.suitColor = props.suitColor;
    this.style = props.style;
    this._status = props.status;
    this._generatedAvatarUrls = props.generatedAvatarUrls.map(url => MediaUrl.create(url));
    if (props.selectedAvatarIndex !== undefined) {
      this._selectedAvatarIndex = props.selectedAvatarIndex;
    }
    if (props.errorMessage !== undefined) {
      this._errorMessage = props.errorMessage;
    }
    this.createdAt = props.createdAt;
    this._updatedAt = props.updatedAt;
  }

  static create(props: {
    id: string;
    userId: string;
    facePhotoUrl: string;
    suitColor: RacingSuitColor;
    style?: AvatarStyle;
  }): AvatarGenerationRequest {
    if (!props.userId) {
      throw new Error('User ID is required');
    }
    if (!props.facePhotoUrl) {
      throw new Error('Face photo URL is required');
    }

    const now = new Date();
    return new AvatarGenerationRequest({
      id: props.id,
      userId: props.userId,
      facePhotoUrl: props.facePhotoUrl,
      suitColor: props.suitColor,
      style: props.style ?? 'realistic',
      status: 'pending',
      generatedAvatarUrls: [],
      createdAt: now,
      updatedAt: now,
    });
  }

  static reconstitute(props: AvatarGenerationRequestProps): AvatarGenerationRequest {
    return new AvatarGenerationRequest(props);
  }

  get status(): AvatarGenerationStatus {
    return this._status;
  }

  get generatedAvatarUrls(): string[] {
    return this._generatedAvatarUrls.map(url => url.value);
  }

  get selectedAvatarIndex(): number | undefined {
    return this._selectedAvatarIndex;
  }

  get selectedAvatarUrl(): string | undefined {
    const index = this._selectedAvatarIndex;
    if (index === undefined) {
      return undefined;
    }
    const avatar = this._generatedAvatarUrls[index];
    if (!avatar) {
      return undefined;
    }
    return avatar.value;
  }

  get errorMessage(): string | undefined {
    return this._errorMessage;
  }

  get updatedAt(): Date {
    return this._updatedAt;
  }

  markAsValidating(): void {
    if (this._status !== 'pending') {
      throw new Error('Can only start validation from pending status');
    }
    this._status = 'validating';
    this._updatedAt = new Date();
  }

  markAsGenerating(): void {
    if (this._status !== 'validating') {
      throw new Error('Can only start generation from validating status');
    }
    this._status = 'generating';
    this._updatedAt = new Date();
  }

  completeWithAvatars(avatarUrls: string[]): void {
    if (avatarUrls.length === 0) {
      throw new Error('At least one avatar URL is required');
    }
    this._status = 'completed';
    this._generatedAvatarUrls = avatarUrls.map(url => MediaUrl.create(url));
    this._updatedAt = new Date();
  }

  fail(errorMessage: string): void {
    this._status = 'failed';
    this._errorMessage = errorMessage;
    this._updatedAt = new Date();
  }

  selectAvatar(index: number): void {
    if (this._status !== 'completed') {
      throw new Error('Can only select avatar when generation is completed');
    }
    if (index < 0 || index >= this._generatedAvatarUrls.length) {
      throw new Error('Invalid avatar index');
    }
    this._selectedAvatarIndex = index;
    this._updatedAt = new Date();
  }

  /**
   * Build the AI prompt for avatar generation.
   * We control the prompt completely - users cannot enter free text.
   */
  buildPrompt(): string {
    const colorDescriptions: Record<RacingSuitColor, string> = {
      red: 'vibrant racing red',
      blue: 'deep motorsport blue',
      green: 'racing green',
      yellow: 'bright championship yellow',
      orange: 'McLaren-style papaya orange',
      purple: 'royal purple',
      black: 'stealth black',
      white: 'clean white',
      pink: 'hot pink',
      cyan: 'electric cyan',
    };

    const styleDescriptions: Record<AvatarStyle, string> = {
      realistic: 'photorealistic, professional motorsport portrait',
      cartoon: 'stylized cartoon racing character',
      'pixel-art': '8-bit pixel art retro racing avatar',
    };

    const suitColorDesc = colorDescriptions[this.suitColor];
    const styleDesc = styleDescriptions[this.style];

    return `Create a ${styleDesc} of a racing driver wearing a ${suitColorDesc} racing suit with matching helmet. The driver should look professional and confident, as if posing for a team photo. Background should be a subtle racing paddock or garage setting. High quality, well-lit, professional motorsport photography style.`;
  }

  toProps(): AvatarGenerationRequestProps {
    const base: AvatarGenerationRequestProps = {
      id: this.id,
      userId: this.userId,
      facePhotoUrl: this.facePhotoUrl.value,
      suitColor: this.suitColor,
      style: this.style,
      status: this._status,
      generatedAvatarUrls: this._generatedAvatarUrls.map(url => url.value),
      createdAt: this.createdAt,
      updatedAt: this._updatedAt,
    };

    return {
      ...base,
      ...(this._selectedAvatarIndex !== undefined && {
        selectedAvatarIndex: this._selectedAvatarIndex,
      }),
      ...(this._errorMessage !== undefined && {
        errorMessage: this._errorMessage,
      }),
    };
  }
}