"""验证"插件是可选依赖"这一契约。

这个模块在**有/没有** FastAPI 的两种环境下都会运行：
它断言的是"核心包永远不依赖第三方框架"，以及"缺依赖时的报错要能直接照做"。
"""

import os
import subprocess
import sys
import unittest

import helpers

THIRD_PARTY = ("fastapi", "starlette", "anyio", "pydantic")


class OptionalDependencyTest(unittest.TestCase):
    def run_snippet(self, code):
        env = dict(os.environ)
        env["PYTHONPATH"] = helpers.SRC_DIR + os.pathsep + env.get("PYTHONPATH", "")
        env["PYTHONIOENCODING"] = "utf-8"
        return subprocess.run(
            [sys.executable, "-c", code],
            capture_output=True,
            text=True,
            encoding="utf-8",
            errors="replace",
            env=env,
        )

    def test_third_party_is_installed_or_not(self):
        """只用于在输出里说明当前环境状态，不断言。"""
        result = self.run_snippet(
            "import importlib.util as u;"
            "print({m: bool(u.find_spec(m)) for m in %r})" % (THIRD_PARTY,)
        )
        self.assertEqual(0, result.returncode, result.stderr)

    def test_importing_core_never_pulls_in_third_party(self):
        """import sqlite_vfs 不能顺带把 fastapi/starlette 拖进来。"""
        result = self.run_snippet(
            "import sys\n"
            "import sqlite_vfs, sqlite_vfs.core, sqlite_vfs.contrib\n"
            "leaked = sorted(\n"
            "    m for m in sys.modules if m.split('.')[0] in %r\n"
            ")\n"
            "print(leaked)" % (THIRD_PARTY,)
        )
        self.assertEqual(0, result.returncode, result.stderr)
        self.assertEqual(
            "[]",
            result.stdout.strip(),
            "导入 sqlite_vfs 时连带加载了第三方框架模块",
        )

    def test_plugin_module_is_not_imported_by_the_package(self):
        """contrib 子包不能自动导入插件模块（否则缺依赖时整包不可用）。"""
        result = self.run_snippet(
            "import sys\n"
            "import sqlite_vfs.contrib\n"
            "print('sqlite_vfs.contrib.fastapi_static' in sys.modules)"
        )
        self.assertEqual(0, result.returncode, result.stderr)
        self.assertEqual("False", result.stdout.strip())

    def test_missing_fastapi_gives_actionable_error(self):
        """缺少可选依赖时，报错信息必须能直接照着做。"""
        probe = self.run_snippet(
            "import importlib.util as u; print(bool(u.find_spec('starlette')))"
        )
        if probe.stdout.strip() == "True":
            self.skipTest("当前环境已安装 starlette，无需检查缺失提示")

        result = self.run_snippet("import sqlite_vfs.contrib.fastapi_static")
        self.assertNotEqual(0, result.returncode)
        self.assertIn("sqlite-vfs[fastapi]", result.stderr)
        self.assertIn("pip install", result.stderr)

    def test_missing_database_path_hint(self):
        """未生成资源包时的报错要给出下一步命令。"""
        result = self.run_snippet(
            "import tempfile, os, sys\n"
            "sys.path.insert(0, %r)\n"
            "try:\n"
            "    from sqlite_vfs.contrib.fastapi_static import SVFSStaticFiles\n"
            "except ImportError as e:\n"
            "    print('SKIP', e); raise SystemExit(0)\n"
            "try:\n"
            "    SVFSStaticFiles(os.path.join(tempfile.mkdtemp(), 'nope.svfs'))\n"
            "except RuntimeError as e:\n"
            "    print(e)\n" % helpers.SRC_DIR
        )
        self.assertEqual(0, result.returncode, result.stderr)
        output = result.stdout.strip()
        if output.startswith("SKIP"):
            self.skipTest("当前环境没有 FastAPI")
        self.assertIn("vfspack", output)


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