/*
 * Mr. 4th Dimention - Allen Webster
 *
 * 28.06.2017
 *
 * Mac C++ layer for 4coder
 *
 */

// TOP

#define IS_PLAT_LAYER

#include "4ed_defines.h"
#include "4coder_API/version.h"

#include "4coder_lib/4coder_utf8.h"

#if defined(FRED_SUPER)
# include "4coder_API/keycodes.h"
# include "4coder_API/style.h"

# define FSTRING_IMPLEMENTATION
# include "4coder_lib/4coder_string.h"
# include "4coder_lib/4coder_mem.h"

# include "4coder_API/types.h"
# include "4ed_os_custom_api.h"

#else
# include "4coder_default_bindings.cpp"
#endif

#include "osx_objective_c_to_cpp_links.h"

#include "4ed_math.h"

#include "4ed_system.h"
#include "4ed_log.h"
#include "4ed_render_format.h"
#include "4ed_render_target.h"
#include "4ed.h"

#include "4ed_file_track.h"
#include "4ed_font_interface_to_os.h"
#include "4ed_system_shared.h"

#include "unix_4ed_headers.h"
#include <sys/syslimits.h>

#include <OpenGL/OpenGL.h>
#include <OpenGL/gl.h>

#undef external
#undef internal
#include <mach/mach.h>
#define external extern "C"
#define internal static
#include <mach-o/dyld.h>

#include <stdlib.h>

////////////////////////////////

#include "4ed_shared_thread_constants.h"
#include "unix_threading_wrapper.h"
#include "mac_semaphore_wrapper.h"

// TODO(allen): Make an intrinsics header that uses the cracked OS to define a single set of intrinsic names.
#define InterlockedCompareExchange(dest, ex, comp) \
__sync_val_compare_and_swap((dest), (comp), (ex))

////////////////////////////////

#define SLASH '/'
#define DLL "so"

global System_Functions sysfunc;
#include "4ed_shared_library_constants.h"
#include "unix_library_wrapper.h"
#include "4ed_standard_libraries.cpp"

#include "4ed_coroutine.cpp"

////////////////////////////////

struct OSX_Vars{
    Application_Step_Input input;
    String clipboard_contents;
    b32 keep_running;
    
    b32 has_prev_time;
    u64 prev_time_u;
};

////////////////////////////////

OSX_Objective_C_Vars osx_objc;
OSX_Vars osxvars;
global Render_Target target;
global Application_Memory memory_vars;
global Plat_Settings plat_settings;

global Libraries libraries;
global App_Functions app;
global Custom_API custom_api;

global Coroutine_System_Auto_Alloc coroutines;

////////////////////////////////

#include "mac_error_box.cpp"

////////////////////////////////

internal
Sys_Get_4ed_Path_Sig(system_get_4ed_path){
    u32 buf_size = capacity;
    i32 status = _NSGetExecutablePath(out, &buf_size);
    i32 size = 0;
    if (status == 0){
        String str = make_string_slowly(out);
        remove_last_folder(&str);
        terminate_with_null(&str);
        size = str.size;
    }
    return(size);
}

#include "unix_4ed_functions.cpp"
#include "4ed_shared_file_handling.cpp"

////////////////////////////////

internal void
system_schedule_step(void){
    osx_schedule_step();
}

////////////////////////////////

#include "4ed_work_queues.cpp"

////////////////////////////////

internal
Sys_Show_Mouse_Cursor_Sig(system_show_mouse_cursor){
    switch (show){
        case MouseCursorShow_Never:
        {
            osx_show_cursor(-1, 0);
        }break;
        
        case MouseCursorShow_Always:
        {
            osx_show_cursor(1, 0);
        }break;
    }
}

internal
Sys_Set_Fullscreen_Sig(system_set_fullscreen){
    osx_objc.do_toggle = (osx_objc.full_screen != full_screen);
    return(true);
}

internal
Sys_Is_Fullscreen_Sig(system_is_fullscreen){
    b32 result = (osx_objc.full_screen != osx_objc.do_toggle);
    return(result);
}

// HACK(allen): Why does this work differently from the win32 version!?
internal
Sys_Send_Exit_Signal_Sig(system_send_exit_signal){
    DBG_POINT();
    osxvars.keep_running = false;
}

#include "4ed_coroutine_functions.cpp"

//
// Clipboard
//

internal
Sys_Post_Clipboard_Sig(system_post_clipboard){
    char *string = str.str;
    if (!terminate_with_null(&str)){
        if (osx_objc.clipboard_space_max <= str.size + 1){
            if (osx_objc.clipboard_space != 0){
                system_memory_free(osx_objc.clipboard_space, osx_objc.clipboard_space_max);
            }
            osx_objc.clipboard_space_max = l_round_up_u32(str.size*2 + 1, KB(4096));
            osx_objc.clipboard_space = (char*)system_memory_allocate(osx_objc.clipboard_space_max);
        }
        memcpy(osx_objc.clipboard_space, str.str, str.size);
        osx_objc.clipboard_space[str.size] = 0;
        string = osx_objc.clipboard_space;
    }
    osx_post_to_clipboard(string);
}

//
// CLI
//

// HACK(allen): ALMOST an exact duplicate from the Linux version.  Just epoll doesn't port.  deduplicate or switch to NSTask.
global i32 cli_count = 0;

internal
Sys_CLI_Call_Sig(system_cli_call){
    i32 pipe_fds[2];
    if (pipe(pipe_fds) == -1){
        DBG_POINT();
        return 0;
    }
    
    i32 child_pid = fork();
    if (child_pid == -1){
        DBG_POINT();
        return 0;
    }
    
    enum { PIPE_FD_READ, PIPE_FD_WRITE };
    
    // child
    if (child_pid == 0){
        close(pipe_fds[PIPE_FD_READ]);
        dup2(pipe_fds[PIPE_FD_WRITE], STDOUT_FILENO);
        dup2(pipe_fds[PIPE_FD_WRITE], STDERR_FILENO);
        
        if (chdir(path) == -1){
            DBG_POINT();
            exit(1);
        }
        
        char* argv[] = {
            "sh",
            "-c",
            script_name,
            0
        };
        
        if (execv("/bin/sh", argv) == -1){
            DBG_POINT();
        }
        exit(1);
    }
    else{
        close(pipe_fds[PIPE_FD_WRITE]);
        
        *(pid_t*)&cli_out->proc = child_pid;
        *(int*)&cli_out->out_read = pipe_fds[PIPE_FD_READ];
        *(int*)&cli_out->out_write = pipe_fds[PIPE_FD_WRITE];
        
        ++cli_count;
    }
    
    return(true);
}

internal
Sys_CLI_Begin_Update_Sig(system_cli_begin_update){
    // NOTE(inso): I don't think anything needs to be done here.
}

internal
Sys_CLI_Update_Step_Sig(system_cli_update_step){
    i32 pipe_read_fd = *(i32*)&cli->out_read;
    
    fd_set fds;
    FD_ZERO(&fds);
    FD_SET(pipe_read_fd, &fds);
    
    struct timeval tv = {};
    
    size_t space_left = max;
    char* ptr = dest;
    
    while (space_left > 0 && select(pipe_read_fd + 1, &fds, NULL, NULL, &tv) == 1){
        ssize_t num = read(pipe_read_fd, ptr, space_left);
        if (num == -1){
            DBG_POINT();
        } else if (num == 0){
            // NOTE(inso): EOF
            break;
        } else {
            ptr += num;
            space_left -= num;
        }
    }
    
    *amount = (ptr - dest);
    return((ptr - dest) > 0);
}

internal
Sys_CLI_End_Update_Sig(system_cli_end_update){
    pid_t pid = *(pid_t*)&cli->proc;
    b32 close_me = false;
    
    int status;
    if (pid && waitpid(pid, &status, WNOHANG) > 0){
        close_me = true;
        
        cli->exit = WEXITSTATUS(status);
        
        close(*(int*)&cli->out_read);
        close(*(int*)&cli->out_write);
        
        --cli_count;
    }
    
    return(close_me);
}

#include "4ed_font_data.h"
#include "4ed_system_shared.cpp"
#include "opengl/4ed_opengl_render.cpp"

////////////////////////////////

#include "4ed_link_system_functions.cpp"
#include "4ed_shared_init_logic.cpp"

external void*
osx_allocate(umem size){
    void *result = system_memory_allocate(size);
    return(result);
}

external void
osx_free(void *ptr, umem size){
    system_memory_free(ptr, size);
}

external void
osx_resize(int width, int height){
    if (width > 0 && height > 0){
        osx_objc.width = width;
        osx_objc.height = height;
        
        target.width = width;
        target.height = height;
        
        osx_schedule_step();
    }
}

internal void
osx_push_key(Key_Code code, Key_Code chr, Key_Code chr_nocaps, b8 *mods)
{
    i32 count = osxvars.input.keys.count;
    
    if (count < KEY_INPUT_BUFFER_SIZE){
        Key_Event_Data *data = osxvars.input.keys.keys;
        
        data[count].keycode = code;
        data[count].character = chr;
        data[count].character_no_caps_lock = chr_nocaps;
        
        memcpy(data[count].modifiers, mods, sizeof(*mods)*MDFR_INDEX_COUNT);
        
        osxvars.input.keys.count = count + 1;
    }
}

external void
osx_character_input(u32 code, OSX_Keyboard_Modifiers modifier_flags){
    Key_Code c = 0;
    switch (code){
        // TODO(allen): Find the canonical list of these things.
        case 0x007F: c = key_back; break;
        case 0xF700: c = key_up; break;
        case 0xF701: c = key_down; break;
        case 0xF702: c = key_left; break;
        case 0xF703: c = key_right; break;
        case 0xF728: c = key_del; break;
        case 0xF729: c = key_home; break;
        case 0xF72B: c = key_end; break;
        case 0xF72C: c = key_page_up; break;
        case 0xF72D: c = key_page_down; break;
        case 0x001B: c = key_esc; break;
        
        case 0xF704: c = key_f1; break;
        case 0xF705: c = key_f2; break;
        case 0xF706: c = key_f3; break;
        case 0xF707: c = key_f4; break;
        
        case 0xF708: c = key_f5; break;
        case 0xF709: c = key_f6; break;
        case 0xF70A: c = key_f7; break;
        case 0xF70B: c = key_f8; break;
        
        case 0xF70C: c = key_f9; break;
        case 0xF70D: c = key_f10; break;
        case 0xF70E: c = key_f11; break;
        case 0xF70F: c = key_f12; break;
        
        case 0xF710: c = key_f13; break;
        case 0xF711: c = key_f14; break;
        case 0xF712: c = key_f15; break;
        case 0xF713: c = key_f16; break;
    }
    
    b8 mods[MDFR_INDEX_COUNT] = {0};
    
    if (modifier_flags.shift)   mods[MDFR_SHIFT_INDEX] = true;
    if (modifier_flags.control) mods[MDFR_CONTROL_INDEX] = true;
    if (modifier_flags.option)  mods[MDFR_ALT_INDEX] = true;
    if (modifier_flags.command) mods[MDFR_COMMAND_INDEX] = true;
    if (modifier_flags.caps)    mods[MDFR_CAPS_INDEX] = true;
    
    if (c != 0){
        osx_push_key(c, 0, 0, mods);
    }
    else if (code != 0){
        if (code < 0xE000 || code > 0xF8FF){
            if (code == '\r'){
                code = '\n';
            }
            Key_Code chr = code;
            Key_Code nocaps = code;
            if (modifier_flags.caps){
                if ('a' <= chr && chr <= 'z'){
                    chr += 'A' - 'a';
                }
                else if ('A' <= chr && chr <= 'Z'){
                    chr += 'a' - 'A';
                }
            }
            osx_push_key(code, chr, nocaps, mods);
        }
        else{
            fprintf(stdout, "unhandled private code %x\n", code);
        }
    }
    else{
        osx_push_key(0, 0, 0, mods);
    }
    
    osx_schedule_step();
}

external void
osx_mouse(i32 mx, i32 my, u32 type){
    i32 new_x = mx;
    i32 new_y = osx_objc.height - my;
    if (new_x != osxvars.input.mouse.x || new_y != osxvars.input.mouse.y){
        osxvars.input.mouse.x = new_x;
        osxvars.input.mouse.y = new_y;
        osx_schedule_step();
    }
    
    if (type == MouseType_Press){
        osxvars.input.mouse.press_l = true;
        osxvars.input.mouse.l = true;
        osx_schedule_step();
    }
    if (type == MouseType_Release){
        osxvars.input.mouse.release_l = true;
        osxvars.input.mouse.l = false;
        osx_schedule_step();
    }
}

external void
osx_mouse_wheel(float dx, float dy){
    osxvars.input.mouse.wheel = - (int32_t)(dy);
    osx_schedule_step();
}

external void
osx_try_to_close(void){
    system_send_exit_signal();
    osx_schedule_step();
}

external void
osx_step(void){
    DBG_POINT();
    
    Application_Step_Result result = {};
    result.mouse_cursor_type = APP_MOUSE_CURSOR_DEFAULT;
    result.trying_to_kill = !osxvars.keep_running;
    
    // NOTE(allen): Prepare the Frame Input
    osxvars.input.dt = 1.f/60.f;
    if (osxvars.has_prev_time){
        u64 time_u = system_now_time();
        u64 time_elapsed_u = time_u - osxvars.prev_time_u;
        osxvars.input.dt = time_elapsed_u/1000000.f;
        osxvars.prev_time_u = time_u;
    }
    else{
        osxvars.has_prev_time = true;
        osxvars.prev_time_u = system_now_time();
    }
    
    // TODO(allen): CROSS REFERENCE WITH WINDOWS SPECIAL CODE "TIC898989"
    Application_Step_Input frame_input = osxvars.input;
    osxvars.input.first_step = false;
    osxvars.input.keys = null_key_input_data;
    osxvars.input.mouse.press_l = false;
    osxvars.input.mouse.release_l = false;
    osxvars.input.mouse.press_r = false;
    osxvars.input.mouse.release_r = false;
    osxvars.input.mouse.wheel = 0;
    
    // NOTE(allen): Frame Clipboard Input
    if (osx_objc.has_clipboard_item){
        osxvars.input.clipboard = make_string(osx_objc.clipboard_data, (i32)osx_objc.clipboard_size);
    }
    else{
        osxvars.input.clipboard = null_string;
    }
    
    // HACK(allen): Got this all messed up with respect to how everyone else (other OS layers) work
    osx_objc.do_toggle = false;
    osx_objc.full_screen = osx_is_fullscreen();
    
    // HACK(allen): THIS SHIT IS FUCKED (happens on linux too)
    b32 keep_running = osxvars.keep_running;
    
    // NOTE(allen): Application Core Update
    if (app.step == 0){
        LOG("app.step == 0 -- skipping\n");
        app.step(&sysfunc, &target, &memory_vars, &frame_input, &result);
    }
    
    // NOTE(allen): Finish the Loop
    if (result.perform_kill){
        osx_close_app();
    }
    else if (!keep_running && !osxvars.keep_running){
        osxvars.keep_running = true;
    }
    
    // NOTE(allen): Switch to New Cursor
    osx_show_cursor(0, result.mouse_cursor_type);
    
    // NOTE(allen): Render
    osx_begin_render();
    interpret_render_buffer(&sysfunc, &target);
    osx_end_render();
    
    // NOTE(allen): Toggle Full Screen
    if (osx_objc.do_toggle){
        osx_toggle_fullscreen();
    }
    
    // NOTE(allen): Schedule Another Step if Needed
    if (result.animating || cli_count > 0){
        osx_schedule_step();
    }
}

external void
osx_init(){
    //
    // System Linkage
    //
    
    DBG_POINT();
    link_system_code();
    
    //
    // Memory init
    //
    
    DBG_POINT();
    memset(&target, 0, sizeof(target));
    memset(&memory_vars, 0, sizeof(memory_vars));
    memset(&plat_settings, 0, sizeof(plat_settings));
    
    memset(&libraries, 0, sizeof(libraries));
    memset(&app, 0, sizeof(app));
    memset(&custom_api, 0, sizeof(custom_api));
    
    memory_init();
    
    osxvars.keep_running = true;
    osxvars.input.first_step = true;
    
    //
    // HACK(allen): 
    // Previously zipped stuff is here, it should be zipped in the new pattern now.
    //
    
    DBG_POINT();
    init_shared_vars();
    
    //
    // Dynamic Linkage
    //
    
    DBG_POINT();
    load_app_code();
#if defined(FRED_SUPER)
    load_custom_code();
#else
    custom_api.get_bindings = get_bindings;
#endif
    
    //
    // Read command line
    //
    
    DBG_POINT();
    read_command_line(osx_objc.argc, osx_objc.argv);
    
    //
    // Threads
    //
    
    DBG_POINT();
    work_system_init();
    
    //
    // Coroutines
    //
    
    DBG_POINT();
    coroutines_init();
    
    //
    // Font System Init
    //
    
    DBG_POINT();
    system_font_init(&sysfunc.font, 0, 0, plat_settings.font_size, plat_settings.use_hinting);
    
    //
    // App Init
    //
    
    DBG_POINT();
    char cwd[4096];
    u32 size = sysfunc.get_current_path(cwd, sizeof(cwd));
    if (size == 0 || size >= sizeof(cwd)){
        system_error_box("Could not get current directory at launch.");
    }
    String curdir = make_string(cwd, size);
    terminate_with_null(&curdir);
    replace_char(&curdir, '\\', '/');
    
    DBG_POINT();
    
    String clipboard_string = {0};
    if (osx_objc.has_clipboard_item){
        clipboard_string = make_string(osx_objc.clipboard_data, osx_objc.clipboard_size);
    }
    
    DBG_POINT();
    
    LOG("Initializing application variables\n");
    app.init(&sysfunc, &target, &memory_vars, clipboard_string, curdir, custom_api);
    
    DBG_POINT();
}

#include "4ed_shared_fonts.cpp"
#include "mac_4ed_file_track.cpp"
#include "4ed_font_static_functions.cpp"

// BOTTOM