Problem

SlackLite stores chat messages in order. Implement a function that processes a sequence of user actions and returns the copied text after each action while keeping message state consistent.

Each message has a unique integer id and a string text. An action is one of:

• "long_press": if the message exists, copy its text and mark only that message as copied
• "delete": remove the message; if it was the copied message, clear the copied state
• "edit": update the message text; if it is currently copied, the clipboard should immediately reflect the new text

Return a list of clipboard values after every action. Use null when nothing is copied.

Formal Specification

• Input: messages as a list of objects with keys id and text; actions as a list of objects with keys type, id, and optional text
• Output: A list where each element is the current clipboard text after the corresponding action, or null

Examples

Example 1 Input: messages = [{"id": 1, "text": "hi"}, {"id": 2, "text": "bye"}], actions = [{"type": "long_press", "id": 1}, {"type": "long_press", "id": 2}] Output: ["hi", "bye"] Explanation: The first long press copies message 1. The second long press replaces the copied state with message 2.

Example 2 Input: messages = [{"id": 1, "text": "draft"}], actions = [{"type": "long_press", "id": 1}, {"type": "edit", "id": 1, "text": "final"}, {"type": "delete", "id": 1}] Output: ["draft", "final", null] Explanation: Editing a copied message updates the clipboard. Deleting it clears the copied state.

Constraints

• 1 <= len(messages) <= 10^5
• 1 <= len(actions) <= 10^5
• 1 <= id <= 10^9
• 0 <= len(text) <= 10^4
• Message IDs in messages are unique