// mtpython: the embedded CPython 2.7.18 starts, every statically linked module imports, and the
// interpreter runs code (docs/PORT-PLAN.md 批次 2P step 1). Started the way CPythonLauncher does
// (no site, no environment), then sys.path is replaced by the host, as tools/py_embed_android/main.c
// does on the device.
//
//   py_embed_test [stdlib dir or python27.zip]
#include <Python.h>

#include <algorithm>
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>

static int g_failures = 0;
#define CHECK(cond)                                                                       \
	do {                                                                                  \
		if (!(cond))                                                                      \
		{                                                                                 \
			std::fprintf(stderr, "%s:%d: CHECK(%s)\n", __FILE__, __LINE__, #cond);        \
			++g_failures;                                                                 \
		}                                                                                 \
	} while (0)

int main(int argc, char** argv)
{
	// CPythonLauncher::Create starts the interpreter without site, without environment variables and
	// without a filesystem prefix; sys.path is handed over by the host afterwards.
	Py_NoSiteFlag = 1;
	Py_IgnoreEnvironmentFlag = 1;
	Py_FrozenFlag = 1;
	Py_DontWriteBytecodeFlag = 1;
	Py_SetProgramName(argv[0]);
	Py_Initialize();
	CHECK(Py_IsInitialized());

	// Without a stdlib on sys.path the interpreter still runs, but anything that imports a .py
	// (cPickle -> copy_reg, the codec registry -> encodings) cannot work; the host always supplies one.
	const std::string stdlib = argc > 1 ? argv[1] : "";
	if (!stdlib.empty())
	{
		// Py_Initialize already ran _PyCodecRegistry_Init against the empty path and 2.7 never retries
		// ("no codec search functions registered"), so the host re-registers encodings.search_function
		// after handing over sys.path. CPythonLauncher will have to do the same.
		const std::string boot = "import sys\nsys.path[:] = ['" + stdlib +
								 "']\nimport codecs, encodings\ncodecs.register(encodings.search_function)\n";
		CHECK(PyRun_SimpleString(boot.c_str()) == 0);
	}

	// The built-in table is what config/config.c (shared by every platform) declares.
	std::vector<std::string> names;
	for (const _inittab* t = PyImport_Inittab; t && t->name; ++t)
		names.push_back(t->name);
	CHECK(names.size() == 39); // config/config.c: 30 from Setup.static + marshal/imp/_ast/gc/_warnings + __main__/__builtin__/sys/exceptions

	size_t imported = 0;
	for (const std::string& name : names)
	{
		if (name == "xxsubtype")   // the reference Setup builds it, nothing imports it
			continue;
		if (name == "__main__")    // importing it re-enters the running module
			continue;
		if (stdlib.empty() && name == "cPickle") // needs copy_reg from the stdlib
			continue;
		if (PyObject* m = PyImport_ImportModule(name.c_str()))
		{
			++imported;
			Py_DECREF(m);
		}
		else
		{
			std::fprintf(stderr, "import %s failed\n", name.c_str());
			PyErr_Print();
			++g_failures;
		}
	}

	// The modules the 40250 scripts reach for first, as the spike measured them.
	for (const char* need : {"posix", "time", "math", "_struct", "operator", "itertools", "_collections",
							 "cStringIO", "cPickle", "_locale", "binascii", "datetime", "zipimport", "_codecs"})
		CHECK(std::find(names.begin(), names.end(), need) != names.end());

	CHECK(PyRun_SimpleString("import sys, time, math, _struct\n"
							 "assert sys.version.startswith('2.7.18'), sys.version\n"
							 "assert _struct.calcsize('<Ii') == 8\n"
							 "assert math.floor(2.7) == 2.0\n"
							 "assert len(''.join(chr(c) for c in range(32))) == 32\n") == 0);

	if (!stdlib.empty())
	{
		// The codec registry and zipimport both go through the stdlib the host puts on sys.path.
		CHECK(PyRun_SimpleString("assert u'ab'.encode('utf-8') == 'ab'\n"
								 "assert '\\xc3\\xa9'.decode('utf-8') == u'\\xe9'\n"
								 "import os, pickle, StringIO, struct, random\n"
								 "assert pickle.loads(pickle.dumps({'a': 1})) == {'a': 1}\n") == 0);
		// 40250 text is CP949/CP1252; cp949 needs a C codec module we do not build yet (see docs).
		CHECK(PyRun_SimpleString("assert u'\\xe9'.encode('cp1252') == '\\xe9'\n") == 0);
	}

	Py_Finalize();
	CHECK(!Py_IsInitialized());

	std::printf("py_embed: %zu builtin modules, %zu imported, %s\n", names.size(), imported, Py_GetVersion());
	if (g_failures)
		std::fprintf(stderr, "%d failure(s)\n", g_failures);
	return g_failures ? 1 : 0;
}