/*
 * Mr. 4th Dimention - Allen Webster
 *
 * 21.01.2014
 *
 * System functions for project codename "4ed"
 *
 */

// TOP

struct Plat_Handle{
    u32 d[4];
};

#define Sys_File_Time_Stamp_Sig(name) u64 name(char *filename)
typedef Sys_File_Time_Stamp_Sig(System_File_Time_Stamp);

// TODO(allen): make directory a char* to signal that it must be null terminated
#define Sys_Set_File_List_Sig(name) void name(File_List *file_list, String directory)
typedef Sys_Set_File_List_Sig(System_Set_File_List);

#define Sys_File_Paths_Equal_Sig(name) b32 name(char *path_a, char *path_b)
typedef Sys_File_Paths_Equal_Sig(System_File_Paths_Equal);

#define Sys_Post_Clipboard_Sig(name) void name(String str)
typedef Sys_Post_Clipboard_Sig(System_Post_Clipboard);

#define Sys_Time_Sig(name) u64 name()
typedef Sys_Time_Sig(System_Time);

// cli
struct CLI_Handles{
    Plat_Handle proc;
    Plat_Handle out_read;
    Plat_Handle out_write;
    u32 scratch_space[4];
    i32 exit;
};

#define Sys_CLI_Call_Sig(name) b32 name(char *path, char *script_name, CLI_Handles *cli_out)
typedef Sys_CLI_Call_Sig(System_CLI_Call);

#define Sys_CLI_Begin_Update_Sig(name) void name(CLI_Handles *cli)
typedef Sys_CLI_Begin_Update_Sig(System_CLI_Begin_Update);

#define Sys_CLI_Update_Step_Sig(name) b32 name(CLI_Handles *cli, char *dest, u32 max, u32 *amount)
typedef Sys_CLI_Update_Step_Sig(System_CLI_Update_Step);

#define Sys_CLI_End_Update_Sig(name) b32 name(CLI_Handles *cli)
typedef Sys_CLI_End_Update_Sig(System_CLI_End_Update);

// coroutine

#define Coroutine_Function_Sig(name) void name(struct Coroutine *coroutine)
typedef Coroutine_Function_Sig(Coroutine_Function);

struct Coroutine{
    Plat_Handle plat_handle;
    Coroutine_Function *func;
    void *yield_handle;
    void *in;
    void *out;
};

#define Sys_Create_Coroutine_Sig(name) Coroutine *name(Coroutine_Function *func)
typedef Sys_Create_Coroutine_Sig(System_Create_Coroutine);

#define Sys_Launch_Coroutine_Sig(name) Coroutine *name(Coroutine *coroutine, void *in, void *out)
typedef Sys_Launch_Coroutine_Sig(System_Launch_Coroutine);

#define Sys_Resume_Coroutine_Sig(name) Coroutine *name(Coroutine *coroutine, void *in, void *out)
typedef Sys_Resume_Coroutine_Sig(System_Resume_Coroutine);

#define Sys_Yield_Coroutine_Sig(name) void name(Coroutine *coroutine)
typedef Sys_Yield_Coroutine_Sig(System_Yield_Coroutine);

// thread
struct Thread_Context;

enum Lock_ID{
    FRAME_LOCK,
    INPUT_LOCK,
    FONT_LOCK,
    RENDER_LOCK,
    CANCEL_LOCK0,
    CANCEL_LOCK1,
    CANCEL_LOCK2,
    CANCEL_LOCK3,
    CANCEL_LOCK4,
    CANCEL_LOCK5,
    CANCEL_LOCK6,
    CANCEL_LOCK7,
    LOCK_COUNT
};

enum Thread_Group_ID{
    BACKGROUND_THREADS,
    THREAD_GROUP_COUNT
};

struct Thread_Memory{
    void *data;
    i32 size;
    i32 id;
};

struct Thread_Exchange;
struct System_Functions;

#define Job_Callback_Sig(name) void name(                               \
        System_Functions *system, Thread_Context *thread, Thread_Memory *memory, \
        Thread_Exchange *exchange, void *data[2])
typedef Job_Callback_Sig(Job_Callback);

struct Job_Data{
    Job_Callback *callback;
    void *data[2];
    i32 memory_request;
};

struct Full_Job_Data{
    Job_Data job;
    
    u32 job_memory_index;
    u32 running_thread;
    b32 finished;
    u32 id;
};

struct Work_Queue{
    Full_Job_Data jobs[256];
    Plat_Handle semaphore;
    volatile u32 write_position;
    volatile u32 read_position;
};

#define THREAD_NOT_ASSIGNED 0xFFFFFFFF

#define JOB_ID_WRAP (ArrayCount(queue->jobs) * 4)
#define QUEUE_WRAP (ArrayCount(queue->jobs))

struct Thread_Exchange{
    Work_Queue queues[THREAD_GROUP_COUNT];
    volatile u32 force_redraw;
};

#define Sys_Post_Job_Sig(name) u32 name(Thread_Group_ID group_id, Job_Data job)
typedef Sys_Post_Job_Sig(System_Post_Job);

#define Sys_Cancel_Job_Sig(name) void name(Thread_Group_ID group_id, u32 job_id)
typedef Sys_Cancel_Job_Sig(System_Cancel_Job);

#define Sys_Grow_Thread_Memory_Sig(name) void name(Thread_Memory *memory)
typedef Sys_Grow_Thread_Memory_Sig(System_Grow_Thread_Memory);

#define Sys_Acquire_Lock_Sig(name) void name(i32 id)
typedef Sys_Acquire_Lock_Sig(System_Acquire_Lock);

#define Sys_Release_Lock_Sig(name) void name(i32 id)
typedef Sys_Release_Lock_Sig(System_Release_Lock);

// debug
#define INTERNAL_Sys_Sentinel_Sig(name) Bubble* name()
typedef INTERNAL_Sys_Sentinel_Sig(INTERNAL_System_Sentinel);

#define INTERNAL_Sys_Get_Thread_States_Sig(name) void name(Thread_Group_ID id, b8 *running, i32 *pending)
typedef INTERNAL_Sys_Get_Thread_States_Sig(INTERNAL_System_Get_Thread_States);

#define INTERNAL_Sys_Debug_Message_Sig(name) void name(char *message)
typedef INTERNAL_Sys_Debug_Message_Sig(INTERNAL_System_Debug_Message);

struct System_Functions{
    // files: 2
    System_File_Time_Stamp *file_time_stamp;
    System_Set_File_List *set_file_list;

    // file system navigation (4coder_custom.h): 2
    File_Exists_Function *file_exists;
    Directory_CD_Function *directory_cd;

    // clipboard: 1
    System_Post_Clipboard *post_clipboard;

    // time: 1
    System_Time *time;
    
    // coroutine: 4
    System_Create_Coroutine *create_coroutine;
    System_Launch_Coroutine *launch_coroutine;
    System_Resume_Coroutine *resume_coroutine;
    System_Yield_Coroutine *yield_coroutine;
    
    // cli: 4
    System_CLI_Call *cli_call;
    System_CLI_Begin_Update *cli_begin_update;
    System_CLI_Update_Step *cli_update_step;
    System_CLI_End_Update *cli_end_update;

    // threads: 5
    System_Post_Job *post_job;
    System_Cancel_Job *cancel_job;
    System_Grow_Thread_Memory *grow_thread_memory;
    System_Acquire_Lock *acquire_lock;
    System_Release_Lock *release_lock;

    // debug: 3
    INTERNAL_System_Sentinel *internal_sentinel;
    INTERNAL_System_Get_Thread_States *internal_get_thread_states;
    INTERNAL_System_Debug_Message *internal_debug_message;
    
    // non-function details
    char slash;
};

#define FileNameMax (1 << 9)

struct File_Slot{
    File_Slot *next, *prev;
    byte *data;
    i32 size, max;
    char *filename;
    i32 filename_len;
    u32 flags;
};

enum File_Exchange_Flag{
    FEx_Request = 0x1,
    FEx_Ready = 0x2,
    FEx_Not_Exist = 0x4,
    FEx_Save = 0x8,
    FEx_Save_Complete = 0x10,
    FEx_Save_Failed = 0x20
};

struct File_Exchange{
    File_Slot available, active, free_list;
    File_Slot *files;
    i32 num_active, max;
};

struct Exchange{
    Thread_Exchange thread;
    File_Exchange file;
};

// BOTTOM