#include "../tdkpin_multimedia.h"

#include "../tdkpin_borland_files.h"
#include "../tdkpin_borland_records.h"

#include <assert.h>
#include <stdatomic.h>
#include <stdint.h>
#include <string.h>

Win16FarPtr g_multimedia_procedures[11];
HINSTANCE16 g_multimedia_module;
uint8_t g_multimedia_initialized;
uint8_t g_multimedia_pending;
uint16_t g_multimedia_version;
uint8_t g_multimedia_auto_subclassed;
uint8_t g_multimedia_argument_2;
uint8_t g_multimedia_argument_1;
uint8_t g_multimedia_legacy_windows;
char g_multimedia_library_path[21];
uint16_t g_multimedia_system_directory_length;
uint16_t g_multimedia_windows_version;

HINSTANCE16 g_win16_previous_instance;
HINSTANCE16 g_win16_instance;
uint16_t g_win16_show_command;

_Atomic uint16_t g_borland_io_result;
uint8_t g_borland_file_mode;

static const char *g_system_directory = "SYS";
static uint16_t g_get_version_result;
static uint16_t g_open_results[4];
static unsigned g_open_result_count;
static unsigned g_open_result_index;
static unsigned g_assign_calls;
static unsigned g_close_calls;
static unsigned g_require_calls;
static uint8_t g_assigned_length;
static uint8_t g_assigned_last;

UINT16 GetSystemDirectoryFar16(Win16FarPtr buffer, UINT16 size)
{
    assert(size == 200);
    size_t length = strlen(g_system_directory);
    for (size_t index = 0; index <= length; index++) {
        win16_write_u8(
            win16_far_add_offset(buffer, (uint16_t)index),
            (uint8_t)g_system_directory[index]);
    }
    return (UINT16)length;
}

uint32_t GetVersion16(void)
{
    return 0xbeef0000u | g_get_version_result;
}

void borland_assign_file_short(Win16FarPtr name, Win16FarPtr record)
{
    (void)record;
    g_assign_calls++;
    g_assigned_length = win16_read_u8(name);
    g_assigned_last = win16_read_u8(
        win16_far_add_offset(name, g_assigned_length));
}

void borland_open_generic_file(uint16_t record_size, Win16FarPtr record)
{
    (void)record;
    assert(record_size == 1);
    assert(g_open_result_index < g_open_result_count);
    atomic_store(
        &g_borland_io_result,
        g_open_results[g_open_result_index++]);
}

uint16_t borland_take_io_result(void)
{
    return atomic_exchange(&g_borland_io_result, 0);
}

void borland_close_generic_file(Win16FarPtr record)
{
    (void)record;
    g_close_calls++;
}

void borland_require_io_success(void)
{
    assert(atomic_load(&g_borland_io_result) == 0);
    g_require_calls++;
}

static void reset_probe_results(void)
{
    g_open_result_count = 0;
    g_open_result_index = 0;
    g_assign_calls = 0;
    g_close_calls = 0;
    g_require_calls = 0;
    atomic_store(&g_borland_io_result, 0);
}

static void expect_short(
    Win16FarPtr string, const char *expected)
{
    size_t length = strlen(expected);
    assert(win16_read_u8(string) == length);
    for (size_t index = 0; index < length; index++) {
        assert(win16_read_u8(win16_far_add_offset(
                   string, (uint16_t)(index + 1))) ==
               (uint8_t)expected[index]);
    }
}

static void expect_c_string(
    Win16FarPtr string, const char *expected)
{
    size_t length = strlen(expected);
    for (size_t index = 0; index <= length; index++) {
        assert(win16_read_u8(win16_far_add_offset(
                   string, (uint16_t)index)) ==
               (uint8_t)expected[index]);
    }
}

static void reset_unit_state(uint8_t *dgroup)
{
    memset(dgroup + 0x4750, 0xcc, 0x3d);
    memcpy(dgroup + 0x0522, "CTL3D.DLL", 10);
    memcpy(dgroup + 0x052c, "CTL3DV2.DLL", 12);
    for (unsigned index = 0; index < 11; index++) {
        g_multimedia_procedures[index] =
            win16_make_far_pointer(0x8888, (uint16_t)index);
    }
    g_multimedia_module = 0x7777;
    g_multimedia_initialized = 1;
    g_multimedia_pending = 1;
    g_multimedia_auto_subclassed = 1;
    g_multimedia_argument_1 = 9;
    g_multimedia_argument_2 = 8;
}

int main(void)
{
    static uint8_t dgroup[0x6000];
    static uint8_t code[0x600];
    uint8_t stack_anchor = 0;
    uintptr_t stack_base = (uintptr_t)&stack_anchor - 0x8000;
    win16_reset_segment_bindings();
    win16_bind_segment(0x7000, dgroup, sizeof(dgroup), true);
    win16_set_dgroup_selector(0x7000);
    win16_bind_ne_segment(3, 0x6000, code, sizeof(code), false);
    win16_bind_segment(0x7200, (void *)stack_base, 0x10000, true);
    code[0x0470] = 1;
    code[0x0471] = '\\';

    Win16FarPtr short_name = win16_make_far_pointer(0x7000, 0x600);
    win16_write_u8(short_name, 3);
    win16_write_u8(win16_far_add_offset(short_name, 1), 'A');
    win16_write_u8(win16_far_add_offset(short_name, 2), 'B');
    win16_write_u8(win16_far_add_offset(short_name, 3), 'C');

    reset_probe_results();
    g_open_result_count = 1;
    g_open_results[0] = 2;
    assert(!multimedia_short_file_exists(short_name));
    assert(g_assign_calls == 1 && g_assigned_length == 3 &&
           g_assigned_last == 'C');
    assert(g_close_calls == 0 && g_require_calls == 0);

    reset_probe_results();
    g_open_result_count = 1;
    g_open_results[0] = 0;
    assert(multimedia_short_file_exists(short_name));
    assert(g_close_calls == 1 && g_require_calls == 1);

    reset_probe_results();
    reset_unit_state(dgroup);
    g_system_directory = "SYS";
    g_open_result_count = 1;
    g_open_results[0] = 0; /* CTL3DV2 exists. */
    g_get_version_result = 0x0003;
    multimedia_initialize_runtime_unit();
    assert(g_open_result_index == 1);
    expect_short(
        win16_make_far_pointer(0x7000, 0x486d),
        "SYS\\CTL3D.DLL");
    expect_short(
        win16_make_far_pointer(0x7000, 0x496d),
        "SYS\\CTL3DV2.DLL");
    expect_c_string(
        win16_make_far_pointer(0x7000, 0x478d),
        "CTL3DV2.DLL");
    assert(g_multimedia_system_directory_length == 3);
    assert(g_multimedia_windows_version == 0x0003);
    assert(g_multimedia_legacy_windows == 1);
    for (unsigned index = 0; index < 11; index++) {
        assert(g_multimedia_procedures[index] == 0);
    }
    assert(g_multimedia_auto_subclassed == 0);
    assert(g_multimedia_argument_2 == 0 && g_multimedia_argument_1 == 1);
    assert(g_multimedia_module == 0 && g_multimedia_pending == 0 &&
           g_multimedia_initialized == 0);

    reset_probe_results();
    reset_unit_state(dgroup);
    g_open_result_count = 2;
    g_open_results[0] = 2; /* V2 absent. */
    g_open_results[1] = 0; /* Classic present. */
    g_get_version_result = 0x0a03;
    multimedia_initialize_runtime_unit();
    assert(g_open_result_index == 2);
    expect_c_string(
        win16_make_far_pointer(0x7000, 0x478d),
        "CTL3D.DLL");
    assert(g_multimedia_legacy_windows == 0);

    reset_probe_results();
    reset_unit_state(dgroup);
    g_open_result_count = 2;
    g_open_results[0] = 2;
    g_open_results[1] = 3;
    g_get_version_result = 0x0004;
    multimedia_initialize_runtime_unit();
    expect_c_string(
        win16_make_far_pointer(0x7000, 0x478d),
        "CTL3DV2.DLL");
    assert(g_multimedia_legacy_windows == 0);

    reset_probe_results();
    reset_unit_state(dgroup);
    memcpy(dgroup + 0x478d, "KEEP", 5);
    g_system_directory = "";
    g_get_version_result = 0x0004;
    multimedia_initialize_runtime_unit();
    assert(g_open_result_index == 0);
    expect_c_string(
        win16_make_far_pointer(0x7000, 0x478d), "KEEP");
    return 0;
}