from pathlib import Path
import random
import unittest

from govoplan_campaign.backend.services.filenames import FilenameAllocator
from govoplan_campaign.backend.services.zip_service import _normalized_members


def legacy_names(names):
    used = set()
    result = []
    for name in names:
        path = Path(name)
        candidate = name
        counter = 2
        while candidate.casefold() in used:
            candidate = f"{path.stem} ({counter}){path.suffix}"
            counter += 1
        used.add(candidate.casefold())
        result.append(candidate)
    return result


class FilenameAllocatorTests(unittest.TestCase):
    def test_exact_equivalence_with_colliding_suffixes_case_unicode_and_multiple_dots(
        self,
    ):
        choices = [
            "report.pdf",
            "REPORT.PDF",
            "report (2).pdf",
            "report (3).pdf",
            "report (2) (2).pdf",
            ".hidden",
            "a.tar.gz",
            "A.TAR.GZ",
            "Straße.txt",
            "STRASSE.txt",
            "readme",
        ]
        rng = random.Random(42)
        for _ in range(30):
            names = [rng.choice(choices) for _ in range(200)]
            allocator = FilenameAllocator()
            self.assertEqual(
                legacy_names(names), [allocator.allocate(name) for name in names]
            )

    def test_zip_and_message_names_preserve_every_input_and_sequence(self):
        names = ["a.pdf", "A.pdf", "a (2).pdf", "a.pdf"]
        paths = [Path(f"/synthetic/{index}/source") for index in range(len(names))]
        members = _normalized_members(list(zip(paths, names)))
        self.assertEqual(paths, [path for path, _ in members])
        self.assertEqual(legacy_names(names), [name for _, name in members])
        self.assertEqual("a.pdf", FilenameAllocator().allocate("a.pdf"))

    def test_many_collisions_have_linear_membership_work(self):
        class CountingSet(set):
            probes = 0

            def __contains__(self, item):
                self.probes += 1
                return super().__contains__(item)

        allocator = FilenameAllocator()
        allocator.used = CountingSet()
        for _ in range(10000):
            last = allocator.allocate("report.pdf")
        self.assertEqual("report (10000).pdf", last)
        self.assertEqual(10000, len(allocator.used))
        self.assertEqual(19999, allocator.used.probes)


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