input.json

{
  "offers": [
    {
      "id": 1,
      "title": "Offer 1",
      "description": "Offer 1 description",
      "category": 1,
      "merchants": [
        {
          "id": 1,
          "name": "Offer1 Merchant1",
          "distance": 0.5,
          "margin": 2.0
        }
      ],
      "valid_to": "2020-02-01"
    },
    {
      "id": 2,
      "title": "Offer 2",
      "description": "Offer 2 description",
      "category": 2,
      "merchants": [
        {
          "id": 2,
          "name": "Offer2 Merchant1",
          "distance": 0.9,
          "margin": 2.0
        }
      ],
      "valid_to": "2019-12-01"
    },
    {
      "id": 3,
      "title": "Offer 3",
      "description": "Offer 3 description",
      "category": 2,
      "merchants": [
        {
          "id": 3,
          "name": "Offer3 Merchant1",
          "distance": 0.9,
          "margin": 1.2
        },
        {
          "id": 4,
          "name": "Offer3 Merchant2",
          "distance": 0.9,
          "margin": 1.9
        }
      ],
      "valid_to": "2020-01-01"
    }
  ]
}