"""Redistributable preparation tests; no native builds or GPU execution."""
from pathlib import Path
import tempfile
import unittest

from build_runtime import bundle_windows_crt, WINDOWS_CRT_FILES


class CrtTests(unittest.TestCase):
    def fixture(self, directory):
        root = Path(directory)
        installation = root / "Visual Studio"
        auxiliary = installation / "VC/Auxiliary/Build"
        auxiliary.mkdir(parents=True)
        (auxiliary / "Microsoft.VCRedistVersion.default.txt").write_text("14.44.35112")
        (auxiliary / "Microsoft.VCToolsVersion.default.txt").write_text("14.44.35207")
        source = installation / "VC/Redist/MSVC/14.44.35112/x64/Microsoft.VC143.CRT"
        source.mkdir(parents=True)
        for name in WINDOWS_CRT_FILES:
            (source / name).write_bytes(name.encode())
        (source / "unlisted-debug.dll").write_bytes(b"do not distribute")
        build = root / "build"
        (build / "Release").mkdir(parents=True)
        (build / "CMakeCache.txt").write_text(f"CMAKE_GENERATOR_INSTANCE:INTERNAL={installation}\n")
        return build, source, auxiliary

    def test_copies_only_fixed_unmodified_release_files_and_public_provenance(self):
        with tempfile.TemporaryDirectory() as directory:
            build, source, _ = self.fixture(directory)
            bundle_windows_crt(build)
            for name in WINDOWS_CRT_FILES:
                self.assertEqual((build / "Release" / name).read_bytes(), (source / name).read_bytes())
            self.assertFalse((build / "Release/unlisted-debug.dll").exists())
            notice = (build / "Release/MSVC-REDISTRIBUTION.txt").read_text(encoding="utf-8")
            self.assertIn("14.44.35112", notice)
            self.assertIn("https://learn.microsoft.com/", notice)
            self.assertNotIn(directory, notice)

    def test_missing_or_mismatched_crt_preserves_existing_files(self):
        with tempfile.TemporaryDirectory() as directory:
            build, source, auxiliary = self.fixture(directory)
            existing = build / "Release/msvcp140.dll"
            existing.write_bytes(b"previous CRT")
            (source / "vcruntime140.dll").unlink()
            with self.assertRaisesRegex(RuntimeError, "redistributable is missing"):
                bundle_windows_crt(build)
            self.assertEqual(existing.read_bytes(), b"previous CRT")
            (auxiliary / "Microsoft.VCRedistVersion.default.txt").write_text("14.43.12345")
            with self.assertRaisesRegex(RuntimeError, "does not match"):
                bundle_windows_crt(build)
            self.assertEqual(existing.read_bytes(), b"previous CRT")

    def test_custom_toolset_compiler_mismatch_rejects_before_copy(self):
        with tempfile.TemporaryDirectory() as directory:
            build, _, _ = self.fixture(directory)
            with (build / "CMakeCache.txt").open("a") as stream:
                stream.write("CMAKE_CACHE_MAJOR_VERSION:INTERNAL=4\nCMAKE_CACHE_MINOR_VERSION:INTERNAL=2\nCMAKE_CACHE_PATCH_VERSION:INTERNAL=0\n")
            compiler = build / "CMakeFiles/4.2.0/CMakeCXXCompiler.cmake"
            compiler.parent.mkdir(parents=True)
            compiler.write_text('set(CMAKE_CXX_COMPILER_VERSION "19.45.12345")\n')
            with self.assertRaisesRegex(RuntimeError, "actual selected compiler"):
                bundle_windows_crt(build)
            self.assertFalse((build / "Release/msvcp140.dll").exists())


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