text: import { Schema } from 'mongoose';
  
  export default new Schema(
    {
      type: {
        type: String,
        enum: ['minted', 'transferred', 'received', 'burned'],
        required: true,
      },
      token_uri: {
        type: String,
        required: true,
      },
      uriDataIntegrity: {
        type: String,
        required: true,
      },
      token_id: {
        type: String,
        required: true,
      },
      salt: {
        type: String,
        required: true,
      },
      token_commitment: {
        type: String,
        index: true,
        required: true,
      },
      token_commitment_index: {
        type: Number,
        required: true,
      },
  
      // transferee info
      transferee: String,
  
      transferred_salt: String,
      transferred_token_commitment: String,
      transferred_token_commitment_index: Number,
    },
    {
      timestamps: {
        createdAt: 'created_at',
        updatedAt: 'updated_at',
      },
    },
  );
  