/* Ball-end, special-respawn, player-switch, and game-over state machine. */

#include "tdkpin_turn_state.h"

#include "tdkpin_sound.h"

static Win16FarPtr caller_receiver(uint16_t caller_bp)
{
    uint16_t offset = win16_read_stack_u16((uint16_t)(caller_bp + 6));
    uint16_t selector = win16_read_stack_u16((uint16_t)(caller_bp + 8));
    return win16_make_far_pointer(selector, offset);
}

static Win16FarPtr collision_record(uint16_t id)
{
    return win16_dgroup_pointer((uint16_t)(0x095b + id * 0x53u));
}

static Win16FarPtr player_marker_count(uint8_t player)
{
    return win16_dgroup_pointer((uint16_t)(0x081f + player * 2u));
}

static void special_respawn(uint16_t caller_bp, Win16FarPtr receiver)
{
    win16_write_u8(win16_dgroup_pointer(0x0874), 0);
    tdkpin_restore_previous_ball_region(caller_bp, 0);
    g_ball_x_milli = (int32_t)win16_read_u32(win16_dgroup_pointer(0x3969));
    g_ball_y_milli = (int32_t)win16_read_u32(win16_dgroup_pointer(0x396d));
    win16_write_u32(receiver, 0x0bc2, (uint32_t)g_ball_x_milli);
    win16_write_u32(receiver, 0x0bc6, (uint32_t)g_ball_y_milli);
    win16_write_u8(
        win16_far_add_offset(receiver, (uint16_t)(
            0x047b + (uint16_t)g_current_player * 0x14u)),
        0);
    tdkpin_restore_record_b(caller_bp, 1020);
    tdkpin_update_dynamic_ball_record(caller_bp, 1);
    win16_write_u32(receiver, 0x0baa, 0);

    static const BorlandReal48 factor_point_eight =
        {{0x80, 0xcd, 0xcc, 0xcc, 0xcc, 0x4c}};
    int32_t source = (int32_t)win16_read_u32(
        win16_far_add_offset(receiver, 0x56));
    int32_t scaled = borland_real48_round_to_i32(
        borland_real48_multiply(
            borland_i32_to_real48(source), factor_point_eight));
    win16_write_u32(receiver, 0x0bae, (uint32_t)scaled);
    win16_write_u32(receiver, 0x0bca, 0);
    win16_write_u16(receiver, 0x0bce, 0);
    win16_write_u16(receiver, 0x0bd0, 0);
    win16_write_u16(receiver, 0x0bd2, 0);
    win16_write_u16(win16_dgroup_pointer(0x399a), 0, 0);
    win16_write_u8(win16_dgroup_pointer(0x0875), 1);
    win16_write_u8(win16_dgroup_pointer(0x41f9), 1);
    win16_write_u8(win16_far_add_offset(receiver, 0x61), 1);
}

static void save_current_collision_mirrors(Win16FarPtr receiver)
{
    for (uint16_t id = 1; id <= 175; id++) {
        Win16FarPtr record = collision_record(id);
        win16_write_u8(
            win16_far_add_offset(receiver, (uint16_t)(
                0x0061 + (uint16_t)g_current_player * 0x00afu + id)),
            win16_read_u8(win16_far_add_offset(record, 0x34)));
        win16_write_u16(
            receiver,
            (uint16_t)(0x036c +
                (uint16_t)g_current_player * 0x015eu + id * 2u),
            win16_read_u16(win16_far_add_offset(record, 0x43)));
    }
}

static void load_next_collision_mirrors(
    uint16_t caller_bp, Win16FarPtr receiver, uint8_t previous_player)
{
    for (uint16_t id = 1; id <= 175; id++) {
        Win16FarPtr record = collision_record(id);
        win16_write_u8(
            win16_far_add_offset(record, 0x34),
            win16_read_u8(win16_far_add_offset(receiver, (uint16_t)(
                0x0061 + (uint16_t)g_current_player * 0x00afu + id))));
        win16_write_u16(
            record,
            0x43,
            win16_read_u16(win16_far_add_offset(receiver, (uint16_t)(
                0x036c + (uint16_t)g_current_player * 0x015eu + id * 2u))));
        if (g_current_player != previous_player) {
            tdkpin_refresh_collision_record(caller_bp, id);
        }
    }
}

static void refresh_changed_player_ui(
    Win16FarPtr receiver, uint8_t previous_player)
{
    if (g_current_player == previous_player) {
        return;
    }
    uint16_t active_items = 0;
    for (uint16_t item = 1; item <= 9; item++) {
        if (win16_read_u8(win16_far_add_offset(receiver, (uint16_t)(
                0x046c + (uint16_t)g_current_player * 0x14u + item))) != 0) {
            active_items++;
        }
    }
    HWND16 window = win16_read_u16(win16_far_add_offset(receiver, 4));
    HDC16 dc = GetDC16(window);
    tdkpin_draw_item_status((int16_t)active_items, dc);
    tdkpin_update_status_display(g_current_player, dc);
    (void)ReleaseDC16(window, dc);
}

static void normal_ball_end(uint16_t caller_bp, Win16FarPtr receiver)
{
    win16_write_u8(win16_dgroup_pointer(0x0875), 0);
    tdkpin_play_sound_if_not_tilted(8);
    tdkpin_restore_previous_ball_region(caller_bp, 0);
    if (win16_read_u8(win16_dgroup_pointer(0x0874)) == 0) {
        win16_write_u8(win16_far_add_offset(receiver, 0x0bdd), 0);
    }
    win16_write_u8(win16_far_add_offset(receiver, 0x0bdc), 0);
    if ((int16_t)win16_read_u16(player_marker_count(g_current_player)) == 0) {
        win16_write_u8(win16_far_add_offset(receiver, 0x0bda), 0);
        win16_write_u8(win16_far_add_offset(receiver, 0x0bdb), 0);
        tdkpin_load_highscores(caller_bp);
        tdkpin_insert_current_score(caller_bp);
    }
    win16_write_u16(receiver, 0x0bce, 0);
    win16_write_u16(receiver, 0x0bd0, 0);
    win16_write_u16(receiver, 0x0bd2, 0);
    save_current_collision_mirrors(receiver);

    uint8_t previous_player = g_current_player;
    if (g_player_count == 0) {
        win16_integer_divide_fault();
    }
    do {
        g_current_player = (uint8_t)(
            (uint16_t)g_current_player % g_player_count + 1u);
        if ((int16_t)win16_read_u16(
                player_marker_count(g_current_player)) > 0) {
            break;
        }
    } while (g_current_player != previous_player);

    if ((int16_t)win16_read_u16(
            player_marker_count(g_current_player)) < 1) {
        g_current_player = 0;
        tdkpin_set_gameplay_transition_flags(caller_bp);
        if (win16_read_u8(win16_dgroup_pointer(0x07d2)) == 0) {
            win16_write_u8(win16_far_add_offset(receiver, 0x0bda), 0);
            win16_write_u8(win16_far_add_offset(receiver, 0x0bdb), 0);
            tdkpin_show_highscore_windows(caller_bp);
        }
        return;
    }

    load_next_collision_mirrors(caller_bp, receiver, previous_player);
    for (uint16_t item = 1; item <= 20; item++) {
        if (g_current_player != previous_player) {
            tdkpin_refresh_player_item(caller_bp, item);
        }
    }
    uint8_t ready = win16_read_u8(win16_dgroup_pointer((uint16_t)(
        0x0816 + (uint16_t)g_current_player)));
    for (uint16_t item = 2; item <= 6; item++) {
        if (item <= ready) {
            tdkpin_restore_record_or_item_a(
                caller_bp, (uint16_t)(item + 999u));
        }
    }
    refresh_changed_player_ui(receiver, previous_player);
    tdkpin_redraw_all_players(caller_bp);
    Win16FarPtr markers = player_marker_count(g_current_player);
    win16_write_u16(
        markers, 0, (uint16_t)(win16_read_u16(markers) - 1u));
    tdkpin_reset_ball_state(caller_bp);

    HWND16 window = win16_read_u16(win16_far_add_offset(receiver, 4));
    HDC16 dc = GetDC16(window);
    tdkpin_restore_background_region_b(20, 148, 243, 84, dc);
    tdkpin_present_background_region(20, 148, 243, 84, dc);
    (void)ReleaseDC16(window, dc);
    tdkpin_refresh_player_progress_markers(caller_bp);
}

/* 1000:ae6e -- complete ball-end and player-advance state machine. */
void tdkpin_finish_ball_or_advance_player(uint16_t caller_bp)
{
    Win16FarPtr receiver = caller_receiver(caller_bp);
    if (win16_read_u8(win16_dgroup_pointer(0x0874)) == 0 &&
        win16_read_u16(win16_dgroup_pointer(0x399a)) != 0) {
        special_respawn(caller_bp, receiver);
    } else {
        normal_ball_end(caller_bp, receiver);
    }
}