#!/usr/bin/env python3

from __future__ import annotations

import importlib.util
import sys
import tempfile
import unittest
from pathlib import Path


SCRIPT_PATH = Path(__file__).with_name("check-import-aliases.py")


spec = importlib.util.spec_from_file_location("check_import_aliases", SCRIPT_PATH)
assert spec is not None and spec.loader is not None
check_import_aliases = importlib.util.module_from_spec(spec)
sys.modules[spec.name] = check_import_aliases
spec.loader.exec_module(check_import_aliases)


class CheckImportAliasesTest(unittest.TestCase):
    def test_reports_explicit_alias_without_conflict(self) -> None:
        with tempfile.TemporaryDirectory() as tmp:
            root = Path(tmp)
            source = root / "main.go"
            source.write_text(
                'package main\n\nimport fooalias "example.com/project/foo"\n\nfunc main() { fooalias.Do() }\n'
            )

            findings, retained, explicit = check_import_aliases.audit(
                root,
                {"example.com/project/foo": "foo"},
                ("example.com/project",),
            )

            self.assertEqual(explicit, 1)
            self.assertEqual(len(retained), 0)
            self.assertEqual(len(findings), 1)
            self.assertEqual(findings[0].alias, "fooalias")
            self.assertEqual(findings[0].default_name, "foo")

    def test_scans_first_party_presets_but_ignores_x_snapshots(self) -> None:
        with tempfile.TemporaryDirectory() as tmp:
            root = Path(tmp)
            presets_source = root / "presets" / "locale.go"
            presets_source.parent.mkdir()
            presets_source.write_text(
                "package presets\n\n"
                'import localepkg "example.com/project/presets/internal/locale"\n'
            )
            x_snapshot = root / "x" / "presets" / "locale.go"
            x_snapshot.parent.mkdir(parents=True)
            x_snapshot.write_text(
                "package presets\n\n"
                'import localepkg "example.com/project/presets/internal/locale"\n'
            )

            findings, retained, explicit = check_import_aliases.audit(
                root,
                {"example.com/project/presets/internal/locale": "locale"},
                ("example.com/project",),
            )

            self.assertEqual(explicit, 1)
            self.assertEqual(retained, [])
            self.assertEqual(len(findings), 1)
            self.assertEqual(findings[0].file, Path("presets/locale.go"))
            self.assertEqual(findings[0].alias, "localepkg")
            self.assertEqual(findings[0].default_name, "locale")

    def test_retains_alias_when_another_import_uses_default_name(self) -> None:
        with tempfile.TemporaryDirectory() as tmp:
            root = Path(tmp)
            source = root / "main.go"
            source.write_text(
                "package main\n\n"
                "import (\n"
                '  fooalias "example.com/project/foo"\n'
                '  "example.com/project/otherfoo"\n'
                ")\n"
            )

            findings, retained, explicit = check_import_aliases.audit(
                root,
                {
                    "example.com/project/foo": "foo",
                    "example.com/project/otherfoo": "foo",
                },
                ("example.com/project",),
            )

            self.assertEqual(explicit, 1)
            self.assertEqual(findings, [])
            self.assertEqual(len(retained), 1)
            self.assertEqual(retained[0].conflicts, ("example.com/project/otherfoo",))

    def test_retains_both_aliases_when_two_imports_share_default_name(self) -> None:
        with tempfile.TemporaryDirectory() as tmp:
            root = Path(tmp)
            source = root / "main.go"
            source.write_text(
                "package main\n\n"
                "import (\n"
                '  fooapi "example.com/project/fooapi"\n'
                '  foostore "example.com/project/foostore"\n'
                ")\n"
            )

            findings, retained, explicit = check_import_aliases.audit(
                root,
                {
                    "example.com/project/fooapi": "foo",
                    "example.com/project/foostore": "foo",
                },
                ("example.com/project",),
            )

            self.assertEqual(explicit, 2)
            self.assertEqual(findings, [])
            self.assertEqual(len(retained), 2)
            self.assertEqual(
                {item.alias: item.conflicts for item in retained},
                {
                    "fooapi": ("example.com/project/foostore",),
                    "foostore": ("example.com/project/fooapi",),
                },
            )

    def test_retains_alias_when_file_package_matches_default_name(self) -> None:
        with tempfile.TemporaryDirectory() as tmp:
            root = Path(tmp)
            source = root / "foo" / "ports.go"
            source.parent.mkdir()
            source.write_text(
                'package foo\n\nimport storefoo "example.com/project/foo"\n\ntype Port = storefoo.Port\n'
            )

            findings, retained, explicit = check_import_aliases.audit(
                root,
                {"example.com/project/foo": "foo"},
                ("example.com/project",),
            )

            self.assertEqual(explicit, 1)
            self.assertEqual(findings, [])
            self.assertEqual(len(retained), 1)
            self.assertEqual(retained[0].conflicts, ("file package foo",))

    def test_ignores_dot_blank_x_and_generated_files(self) -> None:
        with tempfile.TemporaryDirectory() as tmp:
            root = Path(tmp)
            (root / "main.go").write_text(
                "package main\n\n"
                "import (\n"
                '  _ "example.com/project/sideeffect"\n'
                '  . "example.com/project/dot"\n'
                ")\n"
            )
            xfile = root / "x" / "external.go"
            xfile.parent.mkdir()
            xfile.write_text(
                'package x\n\nimport fooalias "example.com/project/foo"\n'
            )
            claude_snapshot = root / ".claude" / "snapshot.go"
            claude_snapshot.parent.mkdir()
            claude_snapshot.write_text(
                'package snapshot\n\nimport fooalias "example.com/project/foo"\n'
            )
            data_snapshot = root / "meshx" / ".data" / "snapshot.go"
            data_snapshot.parent.mkdir(parents=True)
            data_snapshot.write_text(
                'package snapshot\n\nimport fooalias "example.com/project/foo"\n'
            )
            generated = root / "generated.pb.go"
            generated.write_text(
                "// Code generated by protoc. DO NOT EDIT.\n"
                "package main\n\n"
                'import fooalias "example.com/project/foo"\n'
            )

            findings, retained, explicit = check_import_aliases.audit(
                root,
                {"example.com/project/foo": "foo"},
                ("example.com/project",),
            )

            self.assertEqual(explicit, 0)
            self.assertEqual(findings, [])
            self.assertEqual(retained, [])


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