#include <filesystem>
#include <string>
#include <unordered_map>

#include <boost/process.hpp>

#include <gtest/gtest.h>

#include <libreichwein/file.h>
#include <libreichwein/stringhelper.h>

#include "file.h"

namespace fs = std::filesystem;
namespace bp = boost::process;

namespace {
 const fs::path testpath{"testdir1"};
}

class ymakeTest: public ::testing::Test
{
private:
 fs::path original_path;

protected:
 ymakeTest() {
 }

 ~ymakeTest() override {
 }

 void SetUp() override {
  original_path = fs::current_path();

  fs::remove_all(testpath);

  fs::create_directory(testpath);

  fs::current_path(testpath);
 }

 void TearDown() override {
  fs::current_path(original_path);

  fs::remove_all(testpath);
 }

};

class yscanTest: public ymakeTest
{
};

void create_file(const fs::path& path, const std::string& contents)
{
 Reichwein::File::setFile(path, contents);
}

boost::process::environment env_from_map(const std::unordered_map<std::string, std::string>& map)
{
 boost::process::environment result{boost::this_process::environment()};

 for (const auto& pair: map) {
  result[pair.first] = pair.second;
 }
 return result;
}

int run_command(const std::string& command, const std::unordered_map<std::string, std::string>& envmap = {})
{
 return bp::system(command, bp::std_out > bp::null, bp::std_err > bp::null, env_from_map(envmap));
}

int run_command(const std::string& command, std::string& output, const std::unordered_map<std::string, std::string>& envmap = {})
{
 bp::ipstream is;
 bp::ipstream es;
 int result = bp::system(command, bp::std_out > is, bp::std_err > es, env_from_map(envmap));
 output = std::string(std::istreambuf_iterator<char>(is), {});
 output += std::string(std::istreambuf_iterator<char>(es), {});

 return result;
}

int run_command(const std::string& command, std::vector<std::string>& output, const std::unordered_map<std::string, std::string>& envmap = {})
{
 std::string output_string;
 int result = run_command(command, output_string, envmap);

 output = Reichwein::Stringhelper::split(output_string, "\r\n");
 return result;
}

TEST_F(ymakeTest, build_one_cpp)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 2); // compile, link
}

TEST_F(ymakeTest, build_one_cpp_compile_error)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 retrn 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
</ymake>
)");

 int result = run_command("../ymake");
 EXPECT_NE(result, 0);
}

TEST_F(ymakeTest, clean_one_cpp)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake clean", output);
 EXPECT_EQ(output.size(), 0);
 ASSERT_EQ(result, 0);

 result = run_command("../ymake", output);
 EXPECT_EQ(output.size(), 2); // compile, link
 ASSERT_EQ(result, 0);

 result = run_command("../ymake clean", output);
 EXPECT_EQ(output.size(), 3); // rm .o, .d, executable
 ASSERT_EQ(result, 0);
}

TEST_F(ymakeTest, YMakefile_missing)
{
 int result = run_command("../ymake");
 EXPECT_NE(result, 0);

 result = run_command("../ymake clean");
 EXPECT_NE(result, 0);
}

TEST_F(ymakeTest, build_three_cpp)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");
 create_file("second.cpp", R"(
#include "second.h"
)");
 create_file("second.h", R"(
#pragma once
)");
 create_file("third.cpp", R"(
)");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
  <source>second.cpp</source>
  <source>third.cpp</source>
 </build>
</ymake>
)");

 EXPECT_TRUE(!fs::exists("hello.o"));
 EXPECT_TRUE(!fs::exists("second.o"));
 EXPECT_TRUE(!fs::exists("third.o"));
 EXPECT_TRUE(!fs::exists("hello"));

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 4); // compile 3, link 1

 EXPECT_TRUE(fs::exists("hello.o"));
 EXPECT_TRUE(fs::exists("second.o"));
 EXPECT_TRUE(fs::exists("third.o"));
 EXPECT_TRUE(fs::exists("hello"));

 result = run_command("../ymake clean");
 EXPECT_EQ(result, 0);

 EXPECT_TRUE(!fs::exists("hello.o"));
 EXPECT_TRUE(!fs::exists("second.o"));
 EXPECT_TRUE(!fs::exists("third.o"));
 EXPECT_TRUE(!fs::exists("hello"));
}

TEST_F(ymakeTest, build_cpp_c_cc)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("second.c", R"()");
 create_file("third.cc", R"()");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
  <source>second.c</source>
  <source>third.cc</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 4); // 3 compile, 1 link
}

TEST_F(ymakeTest, multiple_builds)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("second.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");
 create_file("third.cpp", R"()");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
 <build>
  <name>second</name>
  <source>second.cpp</source>
  <source>third.cpp</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 5); // 3 compile, 2 link
}

TEST_F(ymakeTest, build_and_test)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("second.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");
 create_file("third.cpp", R"()");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
 <test>
  <name>second</name>
  <source>second.cpp</source>
  <source>third.cpp</source>
 </test>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 2); // 1 compile, 1 link

 result = run_command("../ymake test", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 4); // 2 compile, 1 link, 1 test

 result = run_command("../ymake clean", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 8); // hello second hello.o second.o thord.o hello.d second.d third.d

 result = run_command("../ymake clean", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 0);
}

TEST_F(ymakeTest, build_and_no_test_defined)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 2); // 1 compile, 1 link

 result = run_command("../ymake test", output);
 EXPECT_EQ(result, 0);

 ASSERT_EQ(output.size(), 1);
 EXPECT_EQ(output[0], "Everything up to date.");
}

TEST_F(ymakeTest, test_fail)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("test-hello.cpp", R"(int main(int argc, char* argv[])
{
 return 1;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
 <test>
  <name>test-hello</name>
  <source>test-hello.cpp</source>
 </test>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output.size(), 2); // 1 compile, 1 link

 result = run_command("../ymake test", output);
 EXPECT_EQ(result, 1);

 ASSERT_EQ(output.size(), 4); // 1 compile, 1 link, test: run, exit code
}

TEST_F(ymakeTest, test_only)
{
 create_file("test-hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <test>
  <name>test-hello</name>
  <source>test-hello.cpp</source>
 </test>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 ASSERT_EQ(output.size(), 1);
 EXPECT_EQ(output[0], "Everything up to date.");

 result = run_command("../ymake test", output);
 EXPECT_EQ(result, 0);

 ASSERT_EQ(output.size(), 3); // 1 compile, 1 link, test: run
}

TEST_F(ymakeTest, build_with_gcc)
{
 if (!is_executable("g++")) {
  GTEST_SKIP() << "g++ not available";
 }

 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output, {{"CXX", "g++"}});
 EXPECT_EQ(result, 0);

 ASSERT_EQ(output.size(), 2); // compile, link
 for (const auto&i: output) {
  EXPECT_EQ(i.substr(0, 4), "g++ ");
 }
}

TEST_F(ymakeTest, build_with_clang)
{
 if (!is_executable("clang++")) {
  GTEST_SKIP() << "clang++ not available";
 }

 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output, {{"CXX", "clang++"}});
 EXPECT_EQ(result, 0);

 ASSERT_EQ(output.size(), 2); // compile, link
 for (const auto&i: output) {
  EXPECT_EQ(i.substr(0, 8), "clang++ ");
 }
}

TEST_F(ymakeTest, multiple_dirs)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello</name>
  <source>hello.cpp</source>
 </build>
</ymake>
)");

 fs::create_directory("subdir1");

 create_file("subdir1/second.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("subdir1/YMakefile", R"(
<ymake>
 <build>
  <name>second</name>
  <source>second.cpp</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);
 EXPECT_EQ(output.size(), 4); // compile, link, compile, link

 EXPECT_TRUE(fs::exists("hello"));
 EXPECT_TRUE(fs::exists("hello.o"));
 EXPECT_TRUE(fs::exists("hello.d"));

 EXPECT_TRUE(fs::exists("subdir1/second"));
 EXPECT_TRUE(fs::exists("subdir1/second.o"));
 EXPECT_TRUE(fs::exists("subdir1/second.d"));

 result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);
 EXPECT_EQ(output.size(), 1); // everything up to date

 result = run_command("../ymake clean", output);
 EXPECT_EQ(result, 0);
 EXPECT_EQ(output.size(), 6); // hello hello.o hello.d second second.o second.d

 result = run_command("../ymake clean", output);
 EXPECT_EQ(result, 0);
 EXPECT_EQ(output.size(), 0);
}

TEST_F(ymakeTest, build_one_static_lib)
{
 create_file("hello.cpp", R"(int maine(int argc, char* argv[])
{
 return 0;
})");
 create_file("second.cpp", R"(int maini(int argc, char* argv[])
{
 return 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello.a</name>
  <source>hello.cpp</source>
  <source>second.cpp</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 ASSERT_EQ(output.size(), 3); // 2x compile, link
 EXPECT_EQ(output[2].substr(0, 7), "ar rcs ");

 EXPECT_TRUE(fs::exists("hello.d"));
 EXPECT_TRUE(fs::exists("hello.o"));
 EXPECT_TRUE(fs::exists("hello.a"));

 EXPECT_TRUE(fs::exists("second.d"));
 EXPECT_TRUE(fs::exists("second.o"));

 result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);
 ASSERT_EQ(output.size(), 1); // everything up to date

 result = run_command("../ymake clean", output);
 EXPECT_EQ(result, 0);
 ASSERT_EQ(output.size(), 5); // deleted 5 files

 EXPECT_TRUE(!fs::exists("hello.d"));
 EXPECT_TRUE(!fs::exists("hello.o"));
 EXPECT_TRUE(!fs::exists("hello.a"));

 EXPECT_TRUE(!fs::exists("second.d"));
 EXPECT_TRUE(!fs::exists("second.o"));

 result = run_command("../ymake clean", output);
 EXPECT_EQ(result, 0);
 ASSERT_EQ(output.size(), 0);
}

TEST_F(ymakeTest, build_one_dynamic_lib)
{
 create_file("hello.cpp", R"(int maine(int argc, char* argv[])
{
 return 0;
})");
 create_file("second.cpp", R"(int maini(int argc, char* argv[])
{
 return 0;
})");

 create_file("YMakefile", R"(
<ymake>
 <build>
  <name>hello.so.1.2.3</name>
  <source>hello.cpp</source>
  <source>second.cpp</source>
 </build>
</ymake>
)");

 std::vector<std::string> output;
 int result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);

 ASSERT_EQ(output.size(), 3); // 2x compile, link
 EXPECT_EQ(output[2].substr(0, 4), "g++ ");

 EXPECT_TRUE(fs::exists("hello.d"));
 EXPECT_TRUE(fs::exists("hello.o"));
 EXPECT_TRUE(fs::exists("hello.so.1.2.3"));

 EXPECT_TRUE(fs::exists("second.d"));
 EXPECT_TRUE(fs::exists("second.o"));

 result = run_command("../ymake", output);
 EXPECT_EQ(result, 0);
 ASSERT_EQ(output.size(), 1); // everything up to date

 result = run_command("../ymake clean", output);
 EXPECT_EQ(result, 0);
 ASSERT_EQ(output.size(), 5); // deleted 5 files

 EXPECT_TRUE(!fs::exists("hello.d"));
 EXPECT_TRUE(!fs::exists("hello.o"));
 EXPECT_TRUE(!fs::exists("hello.so.1.2.3"));

 EXPECT_TRUE(!fs::exists("second.d"));
 EXPECT_TRUE(!fs::exists("second.o"));

 result = run_command("../ymake clean", output);
 EXPECT_EQ(result, 0);
 ASSERT_EQ(output.size(), 0);
}

// TODO:
// use static lib
// use dynamic lib

TEST_F(yscanTest, no_cpp_file)
{
 std::string output;
 int result = run_command("../yscan", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output, R"(<ymake>
 <build>
  <name>testdir1</name>
 </build>
</ymake>
)");
}

TEST_F(yscanTest, one_cpp_file)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 std::string output;
 int result = run_command("../yscan", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output, R"(<ymake>
 <build>
  <name>testdir1</name>
  <source>hello.cpp</source>
 </build>
</ymake>
)");
}

TEST_F(yscanTest, four_files)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");
 create_file("second.cpp", R"()");
 create_file("third.cpp", R"()");
 create_file("fourth.cpp", R"()");

 std::string output;
 int result = run_command("../yscan", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output, R"(<ymake>
 <build>
  <name>testdir1</name>
  <source>fourth.cpp</source>
  <source>hello.cpp</source>
  <source>second.cpp</source>
  <source>third.cpp</source>
 </build>
</ymake>
)");
}

TEST_F(yscanTest, tests)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");
 create_file("test-second.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");
 create_file("test-third.cpp", R"()");

 std::string output;
 int result = run_command("../yscan", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output, R"(<ymake>
 <build>
  <name>testdir1</name>
  <source>hello.cpp</source>
 </build>
 <test>
  <name>test-testdir1</name>
  <source>test-second.cpp</source>
  <source>test-third.cpp</source>
 </test>
</ymake>
)");
}

TEST_F(yscanTest, unrelated_files)
{
 create_file("hello.cpp", R"(int main(int argc, char* argv[])
{
 return 0;
})");

 create_file("Makefile", "");
 create_file("other.h", "");
 create_file("second.rb", "");
 create_file("third.d", "");

 std::string output;
 int result = run_command("../yscan", output);
 EXPECT_EQ(result, 0);

 EXPECT_EQ(output, R"(<ymake>
 <build>
  <name>testdir1</name>
  <source>hello.cpp</source>
 </build>
</ymake>
)");
}

// TODO: test multiple directories