import unittest
from unittest.mock import MagicMock, patch, mock_open
import os
import time
import subprocess
import shutil
import disk_cleaner
import sys
import tempfile

def run_test():
    with tempfile.TemporaryDirectory() as temp_dir:
        print(f"Running test in {temp_dir}")
        
        log_file = os.path.join(temp_dir, "test_app.log")
        rotated_logs = [os.path.join(temp_dir, f"test_app.log.{i}") for i in range(1, 4)]
        
        # 1. Create Rotated Logs
        print("Creating rotated logs...")
        for i, path in enumerate(rotated_logs):
            with open(path, "w") as f:
                f.write("Old data " * 1000)
            t = time.time() - (i + 1) * 3600
            os.utime(path, (t, t))
            print(f"Created {os.path.basename(path)} with mtime {t}")

        # 2. Mocking
        usage_calls = 0
        def mock_disk_usage(path):
            nonlocal usage_calls
            # Always return stateful usage for ANY path in this test (since we only care about the one)
            usage_calls += 1
            # Call 1: Init scan
            # Call 2: Loop scan
            # Call 3: Post-Strategy A check
            # Call 4: Pre-Strategy B check (inside cleanup_rotated_logs) -> MUST BE HIGH
            if usage_calls <= 4: 
                return MagicMock(total=1000, used=900, free=100) # 90%
            # Call 5: After delete 1
            elif usage_calls == 5:
                return MagicMock(total=1000, used=850, free=150) # 85%
            # Call 6: After delete 2 -> 75% (Stop)
            else:
                return MagicMock(total=1000, used=750, free=250) # 75%
            
        disk_cleaner.shutil.disk_usage = mock_disk_usage

        # Mock Partitions -> Return our temp_dir as the ONLY partition
        # disk_cleaner.os.path.exists = lambda p: True # REMOVED: Breaks verification!
        # We simulate that the temp_dir IS the mountpoint
        disk_cleaner.get_partitions = MagicMock(return_value=[('/dev/test', temp_dir)])
        disk_cleaner.get_open_files_flat = MagicMock(return_value=[]) 
        
        # We don't need to mock os.walk if we point it to a real dir!
        # We don't need to mock os.stat if we point to a real dir!
        # We just need to make sure disk_cleaner uses the REAL functions.
        # BUT, previous test run might have left disk_cleaner.os.walk mocked?
        # Since we just import disk_cleaner, if it was modified in memory by previous run... 
        # Wait, this is a script execution. `python test_driver.py`. Fresh process.
        # So disk_cleaner is clean.
        
        # However, we DO need os.stat to behave well for the device check.
        # os.stat(temp_dir).st_dev should equal os.stat(root).st_dev.
        # Since they are real directories, this works natively!
        
        # 3. Run Cleaner
        print("Running check_and_clean()...")
        disk_cleaner.check_and_clean()
        
        # 4. Verify
        # Rotated logs are:
        # log.1 (newest)
        # log.2
        # log.3 (oldest)
        
        if not os.path.exists(rotated_logs[2]):
            print("SUCCESS: Oldest log (log.3) was deleted.")
        else:
            print("FAILURE: Oldest log (log.3) still exists.")
            
        if not os.path.exists(rotated_logs[1]):
            print("SUCCESS: 2nd Oldest log (log.2) was deleted.")
        else:
            print("FAILURE: 2nd Oldest log (log.2) still exists.")

        if os.path.exists(rotated_logs[0]):
            print("SUCCESS: Newest log (log.1) was PRESERVED.")
        else:
            print("FAILURE: Newest log (log.1) was unexpectedly deleted.")

if __name__ == "__main__":
    run_test()