// -*- c++ -*-
// Distributed under the BSD 2-Clause License.
// See accompanying file LICENSE for details.
#include "../../src/util.cc"
#include "../../src/pointerlist.cc"
#include "../../src/execute.cc"

#include <iostream>
#include <string>
#include <filesystem>
#include <thread>
#include <chrono>
#include <sstream>

using namespace std::chrono_literals;

std::vector<std::string> tokenize(const std::string& str)
{
	std::vector<std::string> tokens;
	std::stringstream ss(str);
	std::string token;
	 while(getline(ss, token, ' '))
	 {
		 tokens.push_back(token);
	 }
	 return tokens;
}

int fail(int value = 1,
         const std::source_location location = std::source_location::current())
{
	std::cout << "*** Failure at line " << location.line() << '\n';
	return value;
}

const std::string ctor_exe{"./ctor"};
const std::string obj_ext{".o"};

void copy_config(std::string cfg)
{
	std::cout << "** ctor_files/ctor.cc." + cfg + "\n";
	std::filesystem::copy("ctor_files/ctor.cc." + cfg, "ctor.cc",
	                      std::filesystem::copy_options::overwrite_existing);
	if(std::filesystem::exists(ctor_exe))
	{
		auto ctor_exe_time = std::filesystem::last_write_time(ctor_exe);
		std::filesystem::last_write_time("ctor.cc",  ctor_exe_time + 1s);
	}
}

int main()
{
	ctor::settings settings{};
	settings.verbose = 2;
	auto paths = get_paths();

	std::string CXX = "g++";
	get_env("CXX", CXX);
	std::string CTORDIR = "../../build";
	get_env("CTORDIR", CTORDIR);
	std::string BUILDDIR = "build";
	get_env("BUILDDIR", BUILDDIR);
	std::string CXXFLAGS;
	get_env("CXXFLAGS", CXXFLAGS);
	std::string LDFLAGS;
	get_env("LDFLAGS", LDFLAGS);

	auto cxx_prog = locate(CXX, paths);

	// Wipe the board
	std::filesystem::remove_all(BUILDDIR);
	std::filesystem::remove("configuration.cc");
	std::filesystem::remove("config.h");
	std::filesystem::remove("ctor");

	//////////////////////////////////////////////////////////////////////////////
	copy_config("base");

	// Compile bootstrap binary
	std::vector<std::string> args =
		{"-pthread", "-std=c++20", "-L", CTORDIR, "-lctor", "-I", "../../src",
		 "ctor.cc", "-o", ctor_exe};

	// TODO: add support for quoted strings with spaces
	if(!CXXFLAGS.empty())
	{
		auto tokens = tokenize(CXXFLAGS);
		for(const auto& token : tokens)
		{
			args.push_back(token);
		}
	}
	if(!LDFLAGS.empty())
	{
		auto tokens = tokenize(LDFLAGS);
		for(const auto& token : tokens)
		{
			args.push_back(token);
		}
	}

	auto ret = execute(settings, cxx_prog, args);
	if(ret != 0)
	{
		return fail(ret);
	}

	//////////////////////////////////////////////////////////////////////////////
	{
	// No build files should have been created yet
	if(std::filesystem::exists(BUILDDIR))
	{
		return fail();
	}

	// capture ctor binary before configure is called
	auto ctor_bin = readFile(ctor_exe);
	args = {"configure", "--ctor-includedir", "../../src",
	        "--ctor-libdir=" + CTORDIR, "--build-dir=" + BUILDDIR};
	ret = execute(settings, ctor_exe, args);
	if(ret != 0)
	{
		return fail(ret);
	}

	// ctor should be rebuilt at this point, so binary should have changed
	auto ctor_bin2 = readFile(ctor_exe);
	if(ctor_bin == ctor_bin2)
	{
		return fail();
	}

	// configuration.cc should have been generated now
	if(!std::filesystem::exists("configuration.cc"))
	{
		return fail();
	}
	if(!std::filesystem::exists("config.h"))
	{
		return fail();
	}

	// Shouldn't compile anything yet - only configure
	if(std::filesystem::exists(BUILDDIR + "/hello-hello_cc" + obj_ext))
	{
		return fail();
	}

	ctor_bin = readFile(ctor_exe);

	// Run normally to build project
	args = {"-v"};
	ret = execute(settings, ctor_exe, args);
	if(ret != 0)
	{
		return fail(ret);
	}

	// Compiled object should now exist
	if(!std::filesystem::exists(BUILDDIR + "/hello-hello_cc" + obj_ext))
	{
		return fail();
	}

	// ctor should not have been rebuilt, so binary should be the same
	ctor_bin2 = readFile(ctor_exe);
	if(ctor_bin != ctor_bin2)
	{
		return fail();
	}

	std::this_thread::sleep_for(1100ms);

	auto time =
		std::filesystem::last_write_time(BUILDDIR + "/hello-hello_cc" + obj_ext);
	std::filesystem::last_write_time("hello.cc", time + 1s);
	std::this_thread::sleep_for(1100ms);

	// Run normally to rebuild hello.cc
	args = {"-v"};
	ret = execute(settings, ctor_exe, args);
	if(ret != 0)
	{
		return fail(ret);
	}

	// Object file should have been recompiled
	auto time2 =
		std::filesystem::last_write_time(BUILDDIR + "/hello-hello_cc" + obj_ext);
	if(time == time2)
	{
		return fail();
	}
	}

	//////////////////////////////////////////////////////////////////////////////
	{
	// Replace -DFOO with -DBAR in foo external.cxxflags
	copy_config("bar");
	auto configuration_cc_bin = readFile("configuration.cc");
	auto ctor_bin = readFile(ctor_exe);
	auto time =
		std::filesystem::last_write_time(BUILDDIR + "/hello-hello_cc" + obj_ext);
	std::this_thread::sleep_for(1100ms);

	// Run normally to reconfigure, rebuild ctor and rebuild hello.cc
	args = {"-v"};
	ret = execute(settings, ctor_exe, args);
	if(ret != 0)
	{
		return fail(ret);
	}

	auto time2 =
		std::filesystem::last_write_time(BUILDDIR + "/hello-hello_cc" + obj_ext);
	if(time == time2)
	{
		return fail();
	}

	auto configuration_cc_bin2 = readFile("configuration.cc");
	if(configuration_cc_bin == configuration_cc_bin2)
	{
		return fail();
	}

	auto ctor_bin2 = readFile(ctor_exe);
	if(ctor_bin == ctor_bin2)
	{
		return fail();
	}
	}

	//////////////////////////////////////////////////////////////////////////////
	{
	copy_config("multi");
	auto configuration_cc_bin = readFile("configuration.cc");
	auto ctor_bin = readFile(ctor_exe);
	auto time =
		std::filesystem::last_write_time(BUILDDIR + "/hello-hello_cc" + obj_ext);
	std::this_thread::sleep_for(1100ms);

	// Run normally to reconfigure, rebuild ctor and rebuild hello.cc
	args = {"-v"};
	ret = execute(settings, ctor_exe, args);
	if(ret != 0)
	{
		return fail(ret);
	}

	auto time2 =
		std::filesystem::last_write_time(BUILDDIR + "/hello-hello_cc" + obj_ext);
	if(time == time2)
	{
		return fail();
	}

	auto configuration_cc_bin2 = readFile("configuration.cc");
	if(configuration_cc_bin == configuration_cc_bin2)
	{
		return fail();
	}

	auto ctor_bin2 = readFile(ctor_exe);
	if(ctor_bin == ctor_bin2)
	{
		return fail();
	}

	// now touching foobar.h, should retrigger re-configuration
	time = std::filesystem::last_write_time(ctor_exe);
	std::filesystem::last_write_time("foobar.h", time + 1s);
	std::this_thread::sleep_for(1100ms);

	// Run normally to reconfigure, rebuild ctor and rebuild hello.cc
	args = {"-v"};
	ret = execute(settings, ctor_exe, args);
	if(ret != 0)
	{
		return fail(ret);
	}

	time2 = std::filesystem::last_write_time(ctor_exe);
	if(time == time2)
	{
		return fail();
	}
	}

	//////////////////////////////////////////////////////////////////////////////
	{
	copy_config("generated");
	std::filesystem::remove(BUILDDIR + "/world.cc");
	std::filesystem::remove(BUILDDIR + "/foo.cc");

	auto configuration_cc_bin = readFile("configuration.cc");
	auto ctor_bin = readFile(ctor_exe);
	std::this_thread::sleep_for(1100ms);

	// Run normally to reconfigure, rebuild ctor and build world.cc
	args = {"-v", "world"};
	ret = execute(settings, ctor_exe, args);
	if(ret != 0)
	{
		return fail(ret);
	}

	auto configuration_cc_bin2 = readFile("configuration.cc");
	if(configuration_cc_bin == configuration_cc_bin2)
	{
		return fail();
	}

	auto ctor_bin2 = readFile(ctor_exe);
	if(ctor_bin == ctor_bin2)
	{
		return fail();
	}

	// foo.cc should not be generated at this point
	if(std::filesystem::exists(BUILDDIR+"/foo.cc"))
	{
		return fail();
	}

	auto time_w = std::filesystem::last_write_time(BUILDDIR + "/world.cc");
	auto time_wo =
		std::filesystem::last_write_time(BUILDDIR + "/" + BUILDDIR+
		                                 "/world-world_cc" + obj_ext);
	std::this_thread::sleep_for(1100ms);

	// now touching hello.cc, should trigger regeneration of world.cc and rebuild
	std::filesystem::last_write_time("hello.cc", time_w + 1s);
	args = {"-v", "world"};
	ret = execute(settings, ctor_exe, args);
	if(ret != 0)
	{
		return fail(ret);
	}

	auto time_w2 = std::filesystem::last_write_time(BUILDDIR + "/world.cc");
	auto time_wo2 =
		std::filesystem::last_write_time(BUILDDIR + "/" + BUILDDIR +
		                                 "/world-world_cc" + obj_ext);
	if(time_w == time_w2)
	{
		return fail();
	}
	if(time_wo == time_wo2)
	{
		return fail();
	}
	}

	return 0;
}