/**
 * Identity implementation classes for Mail Manager services
 */

import type {
  ServiceIdentity,
  ServiceIdentityNone,
  ServiceIdentityBasic,
  ServiceIdentityToken,
  ServiceIdentityOAuth,
  ServiceIdentityCertificate
} from '@/types/service';

/**
 * Base Identity class
 */
export abstract class Identity {
  abstract toJson(): ServiceIdentity;
  
  static fromJson(data: ServiceIdentity): Identity {
    switch (data.type) {
      case 'NA':
        return IdentityNone.fromJson(data);
      case 'BA':
        return IdentityBasic.fromJson(data);
      case 'TA':
        return IdentityToken.fromJson(data);
      case 'OA':
        return IdentityOAuth.fromJson(data);
      case 'CC':
        return IdentityCertificate.fromJson(data);
      default:
        throw new Error(`Unknown identity type: ${(data as any).type}`);
    }
  }
}

/**
 * No authentication
 */
export class IdentityNone extends Identity {
  readonly type = 'NA' as const;

  static fromJson(_data: ServiceIdentityNone): IdentityNone {
    return new IdentityNone();
  }

  toJson(): ServiceIdentityNone {
    return {
      type: this.type
    };
  }
}

/**
 * Basic authentication (username/password)
 */
export class IdentityBasic extends Identity {
  readonly type = 'BA' as const;
  identity: string;
  secret: string;

  constructor(identity: string = '', secret: string = '') {
    super();
    this.identity = identity;
    this.secret = secret;
  }

  static fromJson(data: ServiceIdentityBasic): IdentityBasic {
    return new IdentityBasic(data.identity, data.secret);
  }

  toJson(): ServiceIdentityBasic {
    return {
      type: this.type,
      identity: this.identity,
      secret: this.secret
    };
  }
}

/**
 * Token authentication (API key, static token)
 */
export class IdentityToken extends Identity {
  readonly type = 'TA' as const;
  token: string;

  constructor(token: string = '') {
    super();
    this.token = token;
  }

  static fromJson(data: ServiceIdentityToken): IdentityToken {
    return new IdentityToken(data.token);
  }

  toJson(): ServiceIdentityToken {
    return {
      type: this.type,
      token: this.token
    };
  }
}

/**
 * OAuth authentication
 */
export class IdentityOAuth extends Identity {
  readonly type = 'OA' as const;
  accessToken: string;
  accessScope?: string[];
  accessExpiry?: number;
  refreshToken?: string;
  refreshLocation?: string;

  constructor(
    accessToken: string = '',
    accessScope?: string[],
    accessExpiry?: number,
    refreshToken?: string,
    refreshLocation?: string
  ) {
    super();
    this.accessToken = accessToken;
    this.accessScope = accessScope;
    this.accessExpiry = accessExpiry;
    this.refreshToken = refreshToken;
    this.refreshLocation = refreshLocation;
  }

  static fromJson(data: ServiceIdentityOAuth): IdentityOAuth {
    return new IdentityOAuth(
      data.accessToken,
      data.accessScope,
      data.accessExpiry,
      data.refreshToken,
      data.refreshLocation
    );
  }

  toJson(): ServiceIdentityOAuth {
    return {
      type: this.type,
      accessToken: this.accessToken,
      ...(this.accessScope && { accessScope: this.accessScope }),
      ...(this.accessExpiry && { accessExpiry: this.accessExpiry }),
      ...(this.refreshToken && { refreshToken: this.refreshToken }),
      ...(this.refreshLocation && { refreshLocation: this.refreshLocation })
    };
  }

  isExpired(): boolean {
    if (!this.accessExpiry) return false;
    return Date.now() / 1000 >= this.accessExpiry;
  }

  expiresIn(): number {
    if (!this.accessExpiry) return Infinity;
    return Math.max(0, this.accessExpiry - Date.now() / 1000);
  }
}

/**
 * Client certificate authentication (mTLS)
 */
export class IdentityCertificate extends Identity {
  readonly type = 'CC' as const;
  certificate: string;
  privateKey: string;
  passphrase?: string;

  constructor(certificate: string = '', privateKey: string = '', passphrase?: string) {
    super();
    this.certificate = certificate;
    this.privateKey = privateKey;
    this.passphrase = passphrase;
  }

  static fromJson(data: ServiceIdentityCertificate): IdentityCertificate {
    return new IdentityCertificate(
      data.certificate,
      data.privateKey,
      data.passphrase
    );
  }

  toJson(): ServiceIdentityCertificate {
    return {
      type: this.type,
      certificate: this.certificate,
      privateKey: this.privateKey,
      ...(this.passphrase && { passphrase: this.passphrase })
    };
  }
}