import importlib.util
from pathlib import Path
import shutil
import tempfile
import unittest
from unittest import mock

spec = importlib.util.spec_from_file_location('repair', Path(__file__).resolve().parents[1] / 'operations/gemini_backup_repair.py')
m = importlib.util.module_from_spec(spec)
spec.loader.exec_module(m)

class PreservationTests(unittest.TestCase):
    def test_live_budget_preserves_file_metadata_sql_and_growth_allowances(self):
        raw=100 + 2*8192 + 200*3 + 67108864
        self.assertEqual(m.snapshot_budget([(100,2)],[200]),raw*12//10+67108864)
        with self.assertRaises(ValueError):m.snapshot_budget([(-1,2)],[])
        with self.assertRaises(ValueError):m.snapshot_budget([],[-1])

    def test_plan_keeps_root_reserve_and_stops_when_var_target_is_met(self):
        self.assertEqual(m.choose_moves([('a', 48), ('b', 7), ('c', 7), ('d', 7)], 26, 77, 84, 12), [('a',48),('b',7),('c',7)])
        with self.assertRaises(RuntimeError):
            m.choose_moves([('a', 70)], 26, 77, 84, 12)
        with self.assertRaises(RuntimeError):
            m.choose_moves([('a', 5)], 26, 77, 84, 12)

    def test_source_parent_child_overlap_is_rejected(self):
        m.disjoint('/home/.staging', ['/home/johannes'])
        for path,sources in [('/home/.staging',['/home']),('/srv/history',['/srv/history/source'])]:
            with self.assertRaises(RuntimeError):
                m.disjoint(path,sources)

    def test_symlink_and_hardlink_are_not_accepted_as_archive_data(self):
        with tempfile.TemporaryDirectory() as t:
            root=Path(t);source=root/'source';source.write_bytes(b'data')
            link=root/'link';link.symlink_to(source)
            with self.assertRaises(RuntimeError):m.inventory(link)
            link.unlink();link.hardlink_to(source)
            with self.assertRaises(RuntimeError):m.inventory(source)

    @unittest.skipUnless(shutil.which('rsync'), 'rsync required')
    def test_copy_is_verified_before_original_is_removed(self):
        with tempfile.TemporaryDirectory() as t:
            root=Path(t);source=root/'archive';source.mkdir();(source/'data').write_bytes(b'saved backup')
            state=root/'state';state.mkdir();dest=root/'preserved';dest.mkdir()
            m.migrate(source,dest/'archive',state)
            self.assertFalse(source.exists())
            self.assertEqual((dest/'archive/data').read_bytes(),b'saved backup')

    @unittest.skipUnless(shutil.which('rsync'), 'rsync required')
    def test_flat_archive_is_preserved_with_its_original_filename(self):
        with tempfile.TemporaryDirectory() as t:
            root=Path(t);src=root/'old.tar.zst';src.write_bytes(b'old backup')
            state=root/'state';state.mkdir();dstroot=root/'preserved';dstroot.mkdir()
            m.migrate(src,dstroot/src.name,state)
            self.assertFalse(src.exists())
            self.assertEqual((dstroot/src.name).read_bytes(),b'old backup')

    @unittest.skipUnless(shutil.which('rsync'), 'rsync required')
    def test_corrupt_destination_keeps_original(self):
        with tempfile.TemporaryDirectory() as t:
            root=Path(t);src=root/'source';src.write_bytes(b'original backup')
            state=root/'state';state.mkdir();dst=root/'destination'
            real=m.checked
            def corrupt_after_copy(args, **kw):
                result=real(args, **kw)
                if '--fsync' in args:dst.write_bytes(b'corrupted')
                return result
            with mock.patch.object(m,'checked',side_effect=corrupt_after_copy):
                with self.assertRaises(RuntimeError):m.migrate(src,dst,state)
            self.assertEqual(src.read_bytes(),b'original backup')

    def test_unrecognized_destination_never_removes_source(self):
        with tempfile.TemporaryDirectory() as t:
            root=Path(t);src=root/'source';src.write_bytes(b'original');dst=root/'destination';dst.write_bytes(b'unrelated')
            state=root/'state';state.mkdir()
            with self.assertRaises(RuntimeError):m.migrate(src,dst,state)
            self.assertEqual(src.read_bytes(),b'original')

if __name__ == '__main__':unittest.main()