Sure, I can help you write a test case generator for the given problem statement "Special Chat". Here's a Python function that generates random test cases for this problem:

```python
import random

def tcgen():
    # Constraint for P: 1 ≤ P ≤ 10^5
    P = random.randint(1, 100000)
    return P

# Example of using the test case generator
if __name__ == "__main__":
    print(tcgen())
```

This function generates a random integer \( P \) within the given constraints, which represents the total amount of points you currently have. You can call this function to generate multiple test cases for the "Special Chat" problem. Here's how you might use it to generate and print several test cases:

```python
if __name__ == "__main__":
    for _ in range(10):  # Generate 10 test cases
        print(tcgen())
```

Feel free to modify the number of test cases or any other parameters as needed.