Problem

At Acme Analytics, an internal service returns REST API results as a JSON string. Write a function that parses the JSON response and returns the id values of all users whose active field is true.

Formal Specification

Implement extract_active_user_ids(response).

• Input: A string response containing valid JSON.
• The JSON object has the shape:
  • {"users": [ ... ]}
• Each user object may contain:
  • id: integer
  • active: boolean
• Output: A list of integers containing the IDs of active users, in the same order they appear in the input.
• If the users field is missing or empty, return an empty list.
• Ignore user objects missing either id or active.

Examples

Example 1

Input: response = '{"users": [{"id": 1, "active": true}, {"id": 2, "active": false}, {"id": 3, "active": true}]}'
Output: [1, 3]

Active users are the first and third entries.

Example 2

Input: response = '{"users": [{"id": 10}, {"id": 20, "active": true}, {"active": true}]}'
Output: [20]

Only the second object has both required fields and is active.

Constraints

• 1 <= len(response) <= 10^5
• response is valid JSON
• users contains at most 10^4 objects
• id values are integers in the range [-10^9, 10^9]