// #include <Windows.h>

#include <stdlib.h>

#define DQN_IMPLEMENTATION
#include "External/tely/External/dqn/dqn.h"

struct Dqn_OSExecuteAsyncHandle
{
    void *process;
};

struct Dqn_OSExecuteResult
{
    uint32_t os_error_code;
    uint32_t exit_code;
};

struct Dqn_CPPBuildCompileFile
{
    Dqn_Slice<Dqn_String8> flags;
    Dqn_String8            path;
};

struct Dqn_CPPBuildContext
{
    Dqn_Slice<Dqn_CPPBuildCompileFile> compile_files;
    Dqn_Slice<Dqn_String8>             compile_flags;
    Dqn_Slice<Dqn_String8>             include_dirs;
    Dqn_Slice<Dqn_String8>             link_flags;
    Dqn_String8                        build_dir;
};

enum Dqn_CPPBuildStatus
{
    Dqn_CPPBuildStatus_Ok,
    Dqn_CPPBuildStatus_BuildDirectoryFailedToBeMade,
};

struct Dqn_CPPBuildAsyncResult
{
    Dqn_CPPBuildStatus       status;
    Dqn_OSExecuteAsyncHandle async_handle;
};

Dqn_OSExecuteResult Dqn_OS_ExecuteWait(Dqn_OSExecuteAsyncHandle handle)
{
    Dqn_OSExecuteResult result = {};
    if (!handle.process)
        return result;

    DWORD exec_result = WaitForSingleObject(handle.process, INFINITE);
    if (exec_result == WAIT_FAILED) {
        result.os_error_code = GetLastError();
        return result;
    }

    DWORD exit_status;
    if (!GetExitCodeProcess(handle.process, &exit_status)) {
        result.os_error_code = GetLastError();
        return result;
    }

    result.exit_code = exit_status;
    CloseHandle(handle.process);
    return result;
}

Dqn_OSExecuteAsyncHandle Dqn_OS_ExecuteAsync(Dqn_String8 cmd, Dqn_String8 working_dir)
{
    Dqn_OSExecuteAsyncHandle result = {};
    #if defined(DQN_OS_WIN32)
    Dqn_ThreadScratch scratch  = Dqn_Thread_GetScratch(nullptr);
    Dqn_String16 cmd16         = Dqn_Win_String8ToString16(scratch.arena, cmd);
    Dqn_String16 working_dir16 = Dqn_Win_String8ToString16(scratch.arena, working_dir);

    PROCESS_INFORMATION proc_info = {};
    STARTUPINFOW startup_info     = {};
    startup_info.cb               = sizeof(STARTUPINFOW);
    startup_info.hStdError        = GetStdHandle(STD_ERROR_HANDLE);
    startup_info.hStdOutput       = GetStdHandle(STD_OUTPUT_HANDLE);
    startup_info.hStdInput        = GetStdHandle(STD_INPUT_HANDLE);
    startup_info.dwFlags         |= STARTF_USESTDHANDLES;
    BOOL create_result            = CreateProcessW(nullptr, cmd16.data, nullptr, nullptr, true, 0, nullptr, working_dir16.data, &startup_info, &proc_info);
    if (!create_result)
        return result;

    CloseHandle(proc_info.hThread);
    result.process = proc_info.hProcess;
    #else
    pid_t child_pid = fork();
    if (child_pid < 0) {
        result.os_error_code = errno;
        return result;
    }

    if (child_pid == 0) {
        if (working_dir.size) {
            if (chdir(working_dir.data) == -1) {
                result.os_error_code = errno;
                return result;
            }
        }

        if (execvp(cmd.items[0], (char * const*) cmd_null.items) < 0) {
            result.os_error_code = errno;
            return result;
        }
        DQN_INVALID_CODE_PATH;
    }

    result.process = DQN_CAST(void *)child_pid;
    #endif
    return result;
}

Dqn_OSExecuteResult Dqn_OS_Execute(Dqn_String8 cmd, Dqn_String8 working_dir)
{
    Dqn_OSExecuteAsyncHandle async_handle = Dqn_OS_ExecuteAsync(cmd, working_dir);
    Dqn_OSExecuteResult result            = Dqn_OS_ExecuteWait(async_handle);
    return result;
}

Dqn_String8 Dqn_CPPBuildContext_ToCommandLine(Dqn_CPPBuildContext build_context, Dqn_Allocator allocator)
{
    // NOTE: Check if object files are newer than the source files =================================
    Dqn_ThreadScratch scratch                                = Dqn_Thread_GetScratch(allocator.user_context);
    Dqn_Slice<Dqn_CPPBuildCompileFile> dirtied_compile_files = Dqn_Slice_Alloc<Dqn_CPPBuildCompileFile>(scratch.arena, build_context.compile_files.size, Dqn_ZeroMem_Yes);
    dirtied_compile_files.size                   = 0;
    DQN_FOR_UINDEX (index, build_context.compile_files.size) {
        Dqn_CPPBuildCompileFile file = build_context.compile_files.data[index];
        Dqn_String8 file_stem        = Dqn_String8_FileNameNoExtension(file.path);

        Dqn_String8 obj_file      = {};
        if (build_context.build_dir.size)
            obj_file = Dqn_FsPath_ConvertF(scratch.arena, "%.*s/%.*s.obj", DQN_STRING_FMT(build_context.build_dir), DQN_STRING_FMT(file_stem));
        else
            obj_file = Dqn_FsPath_ConvertF(scratch.arena, "%.*s.obj", DQN_STRING_FMT(file_stem));

        Dqn_FsInfo file_info      = Dqn_Fs_GetInfo(file.path);
        Dqn_FsInfo obj_file_info  = Dqn_Fs_GetInfo(obj_file);
        if (obj_file_info.last_write_time_in_s >= file_info.last_write_time_in_s)
            continue;

        dirtied_compile_files.data[dirtied_compile_files.size++] = file;
    }

    Dqn_String8 result = {};
    if (dirtied_compile_files.size <= 0)
        return result;

    // NOTE: Build the command line invocation =====================================================
    Dqn_String8Builder builder = {};
    builder.allocator          = allocator;
    DQN_FOR_UINDEX (index, build_context.compile_flags.size) {
        Dqn_String8 flag = build_context.compile_flags.data[index];
        if (index)
            Dqn_String8Builder_AppendF(&builder, " ");
        Dqn_String8Builder_AppendRef(&builder, flag);
    }

    DQN_FOR_UINDEX (index, build_context.include_dirs.size) {
        Dqn_String8 include_dir = build_context.include_dirs.data[index];
        if (builder.count)
            Dqn_String8Builder_AppendF(&builder, " ");
        Dqn_String8Builder_AppendF(&builder, "/I %.*s", DQN_STRING_FMT(include_dir));
    }

    DQN_FOR_UINDEX (index, dirtied_compile_files.size) {
        Dqn_CPPBuildCompileFile file = dirtied_compile_files.data[index];
        Dqn_ThreadScratch scratch    = Dqn_Thread_GetScratch(allocator.user_context);
        Dqn_String8 obj_file         = {};
        if (builder.count)
            Dqn_String8Builder_AppendF(&builder, " ");
        DQN_FOR_UINDEX (flag_index, file.flags.size) {
            Dqn_String8 flag = file.flags.data[flag_index];
            Dqn_String8Builder_AppendF(&builder, "%s%.*s", flag_index ? " " : "", DQN_STRING_FMT(flag));
        }
        if (file.flags.size)
            Dqn_String8Builder_AppendF(&builder, " ");
        Dqn_String8Builder_AppendRef(&builder, file.path);
    }

    DQN_FOR_UINDEX (index, build_context.link_flags.size) {
        Dqn_String8 file = build_context.link_flags.data[index];
        if (builder.count)
            Dqn_String8Builder_AppendF(&builder, " ");
        Dqn_String8Builder_AppendRef(&builder, file);
    }

    result = Dqn_String8Builder_Build(&builder, allocator);
    return result;
}

Dqn_CPPBuildAsyncResult Dqn_CPPBuild_Async(Dqn_CPPBuildContext build_context)
{
    Dqn_ThreadScratch scratch      = Dqn_Thread_GetScratch(nullptr);
    Dqn_String8 cmd                = Dqn_CPPBuildContext_ToCommandLine(build_context, scratch.allocator);
    Dqn_CPPBuildAsyncResult result = {};
    if (!cmd.size)
        return result;

    if (!Dqn_Fs_MakeDir(build_context.build_dir)) {
        result.status = Dqn_CPPBuildStatus_BuildDirectoryFailedToBeMade;
        return result;
    }

    result.async_handle = Dqn_OS_ExecuteAsync(cmd, build_context.build_dir);
    return result;
}

void Dqn_CPPBuild_ExecuteOrAbort(Dqn_CPPBuildContext build_context)
{
    Dqn_CPPBuildAsyncResult build_result = Dqn_CPPBuild_Async(build_context);
    if (build_result.status == Dqn_CPPBuildStatus_BuildDirectoryFailedToBeMade) {
        Dqn_Log_ErrorF("Failed to make build dir '%.*s'", DQN_STRING_FMT(build_context.build_dir));
        exit(-1);
    }

    Dqn_OSExecuteResult exec_result = Dqn_OS_ExecuteWait(build_result.async_handle);
    if (exec_result.os_error_code) {
        Dqn_ThreadScratch scratch = Dqn_Thread_GetScratch(nullptr);
        Dqn_WinError error        = Dqn_Win_LastError(scratch.arena);
        Dqn_Log_ErrorF("Build command could not be executed, error returned was (%d): %.*s", error.code, DQN_STRING_FMT(error.msg));
        exit(-1);
    }

    if (exec_result.exit_code)
        exit(exec_result.exit_code);
}

int main()
{
    Dqn_Library_Init();
    Dqn_ThreadScratch scratch   = Dqn_Thread_GetScratch(nullptr);
    Dqn_String8 const exe_dir   = Dqn_OS_EXEDir(scratch.arena);
    Dqn_String8 const build_dir = Dqn_FsPath_ConvertF(scratch.arena, "%.*s/Build", DQN_STRING_FMT(exe_dir));
    Dqn_String8 const tely_dir  = Dqn_FsPath_ConvertF(scratch.arena, "%.*s/External/tely", DQN_STRING_FMT(exe_dir));

    Dqn_Slice<Dqn_String8> common_compile_flags = Dqn_Slice_InitCArrayCopy(scratch.arena, {
        DQN_STRING8("cl"),
        DQN_STRING8("/W4"),
        DQN_STRING8("/Z7"),
        DQN_STRING8("/MT"),
        DQN_STRING8("/EHsc"),
        DQN_STRING8("/nologo"),
    });

    Dqn_Slice<Dqn_String8> common_link_flags = Dqn_Slice_InitCArrayCopy(scratch.arena, {
        DQN_STRING8("/link"),
        DQN_STRING8("/incremental:no"),
    });

    // NOTE: Assets ================================================================================
    uint64_t robocopy_timings[2] = {};
    {
        robocopy_timings[0] = Dqn_OS_PerfCounterNow();
        DQN_DEFER { robocopy_timings[1] = Dqn_OS_PerfCounterNow(); };
        Dqn_String8 robocopy_cmd = Dqn_String8_InitF(scratch.allocator, "robocopy /MIR /NJH /NJS /NDL /NP %.*s\\Data %.*s\\Data", DQN_STRING_FMT(exe_dir), DQN_STRING_FMT(build_dir));
        Dqn_OS_Execute(robocopy_cmd, /*working_dir*/ {});
    }

    // NOTE: Raylib ================================================================================
    Dqn_CPPBuildContext raylib_build_context = {};
    Dqn_String8 const raylib_dir             = Dqn_FsPath_ConvertF(scratch.arena, "%.*s/External/tely/external/raylib", DQN_STRING_FMT(exe_dir));

    uint64_t raylib_timings[2] = {};
    {
        raylib_timings[0] = Dqn_OS_PerfCounterNow();
        DQN_DEFER { raylib_timings[1] = Dqn_OS_PerfCounterNow(); };

        raylib_build_context.compile_files = Dqn_Slice_InitCArrayCopy(scratch.arena, {
            Dqn_CPPBuildCompileFile{{}, Dqn_FsPath_ConvertF(scratch.arena, "%.*s/rcore.c",     DQN_STRING_FMT(raylib_dir))},
            Dqn_CPPBuildCompileFile{{}, Dqn_FsPath_ConvertF(scratch.arena, "%.*s/utils.c",     DQN_STRING_FMT(raylib_dir))},
            Dqn_CPPBuildCompileFile{{}, Dqn_FsPath_ConvertF(scratch.arena, "%.*s/raudio.c",    DQN_STRING_FMT(raylib_dir))},
            Dqn_CPPBuildCompileFile{{}, Dqn_FsPath_ConvertF(scratch.arena, "%.*s/rmodels.c",   DQN_STRING_FMT(raylib_dir))},
            Dqn_CPPBuildCompileFile{{}, Dqn_FsPath_ConvertF(scratch.arena, "%.*s/rtext.c",     DQN_STRING_FMT(raylib_dir))},
            Dqn_CPPBuildCompileFile{{}, Dqn_FsPath_ConvertF(scratch.arena, "%.*s/rtextures.c", DQN_STRING_FMT(raylib_dir))},
            Dqn_CPPBuildCompileFile{{}, Dqn_FsPath_ConvertF(scratch.arena, "%.*s/rshapes.c",   DQN_STRING_FMT(raylib_dir))},
            Dqn_CPPBuildCompileFile{{}, Dqn_FsPath_ConvertF(scratch.arena, "%.*s/rglfw.c",     DQN_STRING_FMT(raylib_dir))},
        });

        raylib_build_context.include_dirs = Dqn_Slice_InitCArrayCopy(scratch.arena, {
            Dqn_FsPath_ConvertF(scratch.arena, "%.*s", DQN_STRING_FMT(raylib_dir)),
            Dqn_FsPath_ConvertF(scratch.arena, "%.*s/external/glfw/include", DQN_STRING_FMT(raylib_dir)),
            Dqn_FsPath_ConvertF(scratch.arena, "%.*s/glfw/deps/mingw", DQN_STRING_FMT(raylib_dir)),
        });

        raylib_build_context.compile_flags = Dqn_Slice_InitCArrayCopy(scratch.arena, {
            DQN_STRING8("cl"),
            DQN_STRING8("/w"),
            DQN_STRING8("/c"),
            DQN_STRING8("/D _DEFAULT_SOURCE"),
            DQN_STRING8("/D PLATFORM_DESKTOP"),
            DQN_STRING8("/W4"),
            DQN_STRING8("/Z7"),
            DQN_STRING8("/MT"),
            DQN_STRING8("/EHsc"),
            DQN_STRING8("/nologo"),
        });

        raylib_build_context.link_flags = common_link_flags;
        raylib_build_context.build_dir  = build_dir;

        Dqn_CPPBuild_ExecuteOrAbort(raylib_build_context);
    }

    // NOTE: Feely Pona Sprite Packer ==============================================================
    uint64_t feely_pona_sprite_packer_timings[2] = {};
    {
        feely_pona_sprite_packer_timings[0] = Dqn_OS_PerfCounterNow();
        DQN_DEFER { feely_pona_sprite_packer_timings[1] = Dqn_OS_PerfCounterNow(); };

        Dqn_String8 code_dir              = exe_dir;
        Dqn_CPPBuildContext build_context = {};
        build_context.compile_files = Dqn_Slice_InitCArrayCopy(scratch.arena, {
            Dqn_CPPBuildCompileFile{{}, Dqn_FsPath_ConvertF(scratch.arena, "%.*s/feely_pona_sprite_packer.h", DQN_STRING_FMT(code_dir)) },
        });

        build_context.compile_flags = common_compile_flags;
        build_context.link_flags    = common_link_flags;
        build_context.build_dir     = build_dir;

        Dqn_CPPBuild_ExecuteOrAbort(build_context);
    }

    // NOTE: Feely Pona No DLL =====================================================================
    uint64_t feely_pona_no_dll_timings[2]               = {};
    Dqn_CPPBuildContext feely_pona_no_dll_build_context = {};
    {
        feely_pona_no_dll_timings[0] = Dqn_OS_PerfCounterNow();
        DQN_DEFER { feely_pona_no_dll_timings[1] = Dqn_OS_PerfCounterNow(); };

        Dqn_String8 code_dir              = exe_dir;
        feely_pona_no_dll_build_context.compile_files = Dqn_Slice_InitCArrayCopy(scratch.arena, {
            Dqn_CPPBuildCompileFile{
                {Dqn_Slice_InitCArrayCopy(scratch.arena, {DQN_STRING8("/Tp")})},
                Dqn_FsPath_ConvertF(scratch.arena, "%.*s/feely_pona_nodll.h", DQN_STRING_FMT(code_dir))
            },
        });

        feely_pona_no_dll_build_context.include_dirs = Dqn_Slice_InitCArrayCopy(scratch.arena, {
            Dqn_FsPath_ConvertF(scratch.arena, "%.*s", DQN_STRING_FMT(raylib_dir)),
        });

        feely_pona_no_dll_build_context.compile_flags = common_compile_flags;

        // NOTE: Link to raylib object files and windows libs ======================================
        Dqn_List<Dqn_String8> link_flags = Dqn_List_InitSliceCopy(scratch.arena, 128, common_link_flags);
        {
            for (Dqn_CPPBuildCompileFile file : raylib_build_context.compile_files) {
                Dqn_String8 file_stem = Dqn_String8_FileNameNoExtension(file.path);
                Dqn_String8 obj_file  = Dqn_FsPath_ConvertF(scratch.arena, "%.*s/%.*s.obj", DQN_STRING_FMT(raylib_build_context.build_dir), DQN_STRING_FMT(file_stem));
                Dqn_List_Add(&link_flags, obj_file);
            }
            Dqn_List_Add(&link_flags, DQN_STRING8("gdi32.lib"));
            Dqn_List_Add(&link_flags, DQN_STRING8("opengl32.lib"));
            Dqn_List_Add(&link_flags, DQN_STRING8("winmm.lib"));
            Dqn_List_Add(&link_flags, DQN_STRING8("user32.lib"));
            Dqn_List_Add(&link_flags, DQN_STRING8("shell32.lib"));
        }

        feely_pona_no_dll_build_context.link_flags = Dqn_List_ToSliceCopy(&link_flags, scratch.arena);
        feely_pona_no_dll_build_context.build_dir  = build_dir;

        Dqn_CPPBuild_ExecuteOrAbort(feely_pona_no_dll_build_context);
    }

    // NOTE: Feely Pona DLL ========================================================================
    uint64_t feely_pona_dll_timings[2] = {};
    {
        feely_pona_dll_timings[0] = Dqn_OS_PerfCounterNow();
        DQN_DEFER { feely_pona_dll_timings[1] = Dqn_OS_PerfCounterNow(); };

        Dqn_String8 code_dir              = exe_dir;
        Dqn_CPPBuildContext build_context = {};
        build_context.compile_files = Dqn_Slice_InitCArrayCopy(scratch.arena, {
            Dqn_CPPBuildCompileFile{
                {Dqn_Slice_InitCArrayCopy(scratch.arena, {DQN_STRING8("/Tp")})},
                Dqn_FsPath_ConvertF(scratch.arena, "%.*s/feely_pona_unity.h", DQN_STRING_FMT(code_dir))
            },
        });

        Dqn_List<Dqn_String8> compile_flags = Dqn_List_InitSliceCopy(scratch.arena, 128, common_compile_flags);
        Dqn_List_Add(&compile_flags, DQN_STRING8("/LD"));
        Dqn_List_Add(&compile_flags, DQN_STRING8("/Fotely_dll_msvc"));
        Dqn_List_Add(&compile_flags, DQN_STRING8("/Fetely_dll_msvc"));

        build_context.compile_flags = Dqn_List_ToSliceCopy(&compile_flags, scratch.arena);
        build_context.link_flags    = feely_pona_no_dll_build_context.link_flags;
        build_context.build_dir     = build_dir;

        Dqn_CPPBuild_ExecuteOrAbort(build_context);
    }

    // NOTE: Feely Pona platform ===================================================================
    uint64_t feely_pona_platform_timings[2] = {};
    {
        feely_pona_platform_timings[0] = Dqn_OS_PerfCounterNow();
        DQN_DEFER { feely_pona_platform_timings[1] = Dqn_OS_PerfCounterNow(); };

        Dqn_String8 code_dir              = exe_dir;
        Dqn_CPPBuildContext build_context = {};
        build_context.compile_files = Dqn_Slice_InitCArrayCopy(scratch.arena, {
            Dqn_CPPBuildCompileFile{
                {Dqn_Slice_InitCArrayCopy(scratch.arena, {DQN_STRING8("/Tp")})},
                Dqn_FsPath_ConvertF(scratch.arena, "%.*s/tely_platform_raylib_unity.h", DQN_STRING_FMT(tely_dir))
            },
        });

        build_context.include_dirs  = Dqn_Slice_InitCArrayCopy(scratch.arena, {
            raylib_dir,
        });

        Dqn_List<Dqn_String8> compile_flags = Dqn_List_InitSliceCopy(scratch.arena, 128, common_compile_flags);
        Dqn_List_Add(&compile_flags, DQN_STRING8("/Fofeely_pona_msvc"));
        Dqn_List_Add(&compile_flags, DQN_STRING8("/Fefeely_pona_msvc"));
        build_context.compile_flags = Dqn_List_ToSliceCopy(&compile_flags, scratch.arena);
        build_context.link_flags    = feely_pona_no_dll_build_context.link_flags;
        build_context.build_dir     = build_dir;

        Dqn_CPPBuild_ExecuteOrAbort(build_context);
    }

    Dqn_Print_StdLnF(Dqn_PrintStd_Out, "");
    Dqn_Print_StdLnF(Dqn_PrintStd_Out, "robocopy:                 %.2fms", Dqn_OS_PerfCounterMs(robocopy_timings[0],                 robocopy_timings[1]));
    Dqn_Print_StdLnF(Dqn_PrintStd_Out, "raylib:                   %.2fms", Dqn_OS_PerfCounterMs(raylib_timings[0],                   raylib_timings[1]));
    Dqn_Print_StdLnF(Dqn_PrintStd_Out, "feely pona sprite packer: %.2fms", Dqn_OS_PerfCounterMs(feely_pona_sprite_packer_timings[0], feely_pona_sprite_packer_timings[1]));
    Dqn_Print_StdLnF(Dqn_PrintStd_Out, "feely pona (no dll):      %.2fms", Dqn_OS_PerfCounterMs(feely_pona_no_dll_timings[0],        feely_pona_no_dll_timings[1]));
    Dqn_Print_StdLnF(Dqn_PrintStd_Out, "feely pona (dll):         %.2fms", Dqn_OS_PerfCounterMs(feely_pona_dll_timings[0],           feely_pona_dll_timings[1]));
    Dqn_Print_StdLnF(Dqn_PrintStd_Out, "feely pona (platform):    %.2fms", Dqn_OS_PerfCounterMs(feely_pona_platform_timings[0],      feely_pona_platform_timings[1]));
    return 0;
}