/*
 * main.c
 * Duality
 *
 * Copyright (C) 2025 Thomas Buck <thomas@xythobuz.de>
 *
 * Based on examples from gbdk-2020:
 * https://github.com/gbdk-2020/gbdk-2020/blob/develop/gbdk-lib/examples/gb/rand/rand.c
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * See <http://www.gnu.org/licenses/>.
 */

#include <gbdk/metasprites.h>
#include <rand.h>

#include "banks.h"
#include "maps.h"
#include "obj.h"
#include "sprites.h"
#include "sound.h"
#include "input.h"
#include "game.h"
#include "score.h"
#include "sgb_border.h"
#include "border_sgb.h"
#include "timer.h"
#include "main.h"

#ifdef DEBUG
enum debug_flag debug_flags = DBG_MENU | DBG_MARKER;
#else
enum debug_flag debug_flags = 0;
#endif

uint8_t debug_menu_index = 0;

BANKREF(main)

const struct debug_entry debug_entries[DEBUG_ENTRY_COUNT] = {
    { .name = "marker", .flag = DBG_MARKER },
    { .name = "invuln", .flag = DBG_GOD_MODE },
    { .name = "cl score", .flag = DBG_CLEAR_SCORE },
};

static void highscore(uint8_t is_black) NONBANKED {
    HIDE_WIN;

    move_win(MINWNDPOSX, MINWNDPOSY);
    hide_sprites_range(SPR_NUM_START, MAX_HARDWARE_SPRITES);
    win_score_clear(is_black ? 1 : 0);

    SHOW_WIN;

    for (uint8_t i = 0; i < SCORE_NUM; i++) {
        struct scores score;
        is_black ? score_lowest(i, &score) : score_highest(i, &score);
        win_score_draw(score, i, is_black);
    }

    while (1) {
        snd_play();
        key_read();

        if (key_pressed(J_A) || key_pressed(J_B)) {
            break;
        }

        vsync();
    }
}

static void about_screen(void) NONBANKED {
    HIDE_WIN;

    move_win(MINWNDPOSX, MINWNDPOSY);
    hide_sprites_range(SPR_NUM_START, MAX_HARDWARE_SPRITES);
    win_about();

    SHOW_WIN;

    while (1) {
        snd_play();
        key_read();

        if (key_pressed(J_A) || key_pressed(J_B) || key_pressed(J_SELECT)) {
            break;
        }

        vsync();
    }
}

static void splash_win(void) NONBANKED {
    HIDE_WIN;

    if (debug_flags & DBG_MENU) {
        win_debug();
        move_win(MINWNDPOSX, MINWNDPOSY);
    } else {
        // initially show the top 1 scores
        struct scores score;

        score_lowest(0, &score);
        int32_t low = score.score;

        score_highest(0, &score);
        int32_t high = score.score;

        win_splash_draw(-low, high);

        move_win(MINWNDPOSX, MINWNDPOSY + DEVICE_SCREEN_PX_HEIGHT - (8 * 4));
    }

    SHOW_WIN;
}

static void splash_anim(uint8_t *hiwater) NONBANKED {
    static uint8_t frame = 0;
    static uint8_t state = 0;

    if (++frame >= 60) {
        frame = 0;
        if (++state >= 10) {
            state = 0;
        }
    }

    int16_t spd_off_x = 0;
    int16_t spd_off_y = 0;
    int32_t score = 0;
    obj_do(&spd_off_x, &spd_off_y, &score, hiwater);

    switch (state) {
        case 0:
        case 2:
            spr_draw(SPR_SHIP, FLIP_NONE, -4, -42 - 1, 4, hiwater);
            break;

        case 1:
            spr_draw(SPR_SHIP, FLIP_NONE, -4, -42 - 1, 4, hiwater);
            if (frame == 0) {
                obj_add(SPR_SHOT, SHIP_OFF, -42, SHOT_SPEED, 0);
                snd_shot();
            }
            break;

        case 3:
            if (frame == 30) {
                obj_add(SPR_LIGHT, 42, -42, 0, 0);
            }
            spr_draw(SPR_SHIP, FLIP_NONE, -1, -42 + 4, 0, hiwater);
            break;

        case 8:
            if (frame == 30) {
                obj_add(SPR_DARK, -42, -42, 0, 0);
            }
            spr_draw(SPR_SHIP, FLIP_NONE, -1, -42 + 4, 0, hiwater);
            break;

        case 4:
        case 9:
            spr_draw(SPR_SHIP, FLIP_NONE, -1, -42 + 4, 0, hiwater);
            break;

        case 5:
        case 7:
            spr_draw(SPR_SHIP, FLIP_X, 4, -42, 4, hiwater);
            break;

        case 6:
            spr_draw(SPR_SHIP, FLIP_X, 4, -42, 4, hiwater);
            if (frame == 0) {
                obj_add(SPR_SHOT, -SHIP_OFF, -42, -SHOT_SPEED, 0);
                snd_shot();
            }
            break;
    }
}

static void splash(void) NONBANKED {
    disable_interrupts();
    DISPLAY_OFF;
    map_title();
    move_bkg(0, 0);
    SHOW_BKG;
    spr_init_pal();
    SHOW_SPRITES;
    SPRITES_8x8;

    obj_init();
    obj_add(SPR_LIGHT, 42, -42, 0, 0);
    obj_add(SPR_DARK, -42, -42, 0, 0);

    win_init(1);
    splash_win();

    DISPLAY_ON;
    enable_interrupts();

    snd_music_off();
    snd_menu_music();

    while (1) {
        snd_play();
        key_read();

        if (key_pressed(J_LEFT)) {
            highscore(1);
            splash_win();
        } else if (key_pressed(J_RIGHT)) {
            highscore(0);
            splash_win();
        } else if (key_pressed(J_SELECT)) {
            about_screen();
            splash_win();
        } else if (key_pressed(J_START)) {
            if ((key_debug() == 0) && (!(debug_flags & DBG_MENU))) {
                debug_flags |= DBG_MENU;
                splash_win();
            } else {
                break;
            }
        } else {
            if (debug_flags & DBG_MENU) {
                // do it here so you quickly see the flag going to 1 and back to 0
                if (debug_flags & DBG_CLEAR_SCORE) {
                    score_reset();
                    debug_flags &= ~DBG_CLEAR_SCORE;
                    splash_win();
                }

                if (key_pressed(J_UP)) {
                    if (debug_menu_index > 0) {
                        debug_menu_index--;
                    } else {
                        debug_menu_index = DEBUG_ENTRY_COUNT - 1;
                    }
                    splash_win();
                } else if (key_pressed(J_DOWN)) {
                    if (debug_menu_index < (DEBUG_ENTRY_COUNT - 1)) {
                        debug_menu_index++;
                    } else {
                        debug_menu_index = 0;
                    }
                    splash_win();
                } else if (key_pressed(J_A)) {
                    START_ROM_BANK(BANK(main));
                        debug_flags ^= debug_entries[debug_menu_index].flag;
                    END_ROM_BANK();
                    splash_win();
                } else if (key_pressed(J_B)) {
                    debug_flags &= ~DBG_MENU;
                    splash_win();
                }
            }
        }

        uint8_t hiwater = SPR_NUM_START;

        if (!(debug_flags & DBG_MENU)) {
            if (debug_flags & DBG_MARKER) {
                spr_draw(SPR_DEBUG, FLIP_NONE, 0, -10, 0, &hiwater);
                spr_draw(SPR_SHOT_LIGHT, FLIP_NONE, 0, -10, 0, &hiwater);

                spr_draw(SPR_DEBUG, FLIP_NONE, 0, 0, 0, &hiwater);
                spr_draw(SPR_SHOT, FLIP_NONE, 0, 0, 0, &hiwater);

                spr_draw(SPR_DEBUG, FLIP_NONE, 0, 10, 0, &hiwater);
                spr_draw(SPR_SHOT_DARK, FLIP_NONE, 0, 10, 0, &hiwater);

                spr_draw(SPR_DEBUG, FLIP_NONE, 42, -42, 0, &hiwater);
                spr_draw(SPR_DEBUG, FLIP_NONE, 0, -42, 0, &hiwater);
                spr_draw(SPR_DEBUG, FLIP_NONE, -42, -42, 0, &hiwater);
            }

            splash_anim(&hiwater);
        }

        hide_sprites_range(hiwater, MAX_HARDWARE_SPRITES);

        vsync();
    }
}

static uint16_t ask_name(int32_t score) NONBANKED {
    disable_interrupts();
    DISPLAY_OFF;
    map_title();
    move_bkg(0, 0);
    SHOW_BKG;
    spr_init_pal();
    SHOW_SPRITES;
    SPRITES_8x8;

    hide_sprites_range(SPR_NUM_START, MAX_HARDWARE_SPRITES);

    win_init(1);
    win_name(score);

    move_win(MINWNDPOSX, MINWNDPOSY);
    SHOW_WIN;

    DISPLAY_ON;
    enable_interrupts();

    snd_music_off();
    snd_gameover_music();

    char name[3] = { 'a', 'a', 'a' };
    uint8_t pos = 0;
    win_name_draw(convert_name(name[0], name[1], name[2]), score < 0, pos);

    while (1) {
        snd_play();
        key_read();

        if (key_pressed(J_LEFT)) {
            if (pos > 0) {
                pos--;
                win_name_draw(convert_name(name[0], name[1], name[2]), score < 0, pos);
            }
        } else if (key_pressed(J_RIGHT)) {
            if (pos < 3) {
                pos++;
                win_name_draw(convert_name(name[0], name[1], name[2]), score < 0, pos);
            }
        } else if (key_pressed(J_UP)) {
            if (pos < 3) {
                name[pos]++;
                if (name[pos] > 'z') {
                    name[pos] -= 'z' - 'a' + 1;
                }
                win_name_draw(convert_name(name[0], name[1], name[2]), score < 0, pos);
            }
        } else if (key_pressed(J_DOWN)) {
            if (pos < 3) {
                name[pos]--;
                if (name[pos] < 'a') {
                    name[pos] += 'z' - 'a' + 1;
                }
                win_name_draw(convert_name(name[0], name[1], name[2]), score < 0, pos);
            }
        } else if (key_pressed(J_A)) {
            if (pos < 3) {
                pos++;
                win_name_draw(convert_name(name[0], name[1], name[2]), score < 0, pos);
            } else {
                break;
            }
        } else if (key_pressed(J_START)) {
            break;
        }

        vsync();
    }

    return convert_name(name[0], name[1], name[2]);
}

static void sgb_init(void) NONBANKED {
    // Wait 4 frames
    // For SGB on PAL SNES this delay is required on startup, otherwise borders don't show up
    for (uint8_t i = 0; i < 4; i++) {
        vsync();
    }

    DISPLAY_ON;

    START_ROM_BANK(BANK(border_sgb));
        set_sgb_border((const uint8_t *)border_sgb_tiles, sizeof(border_sgb_tiles),
                       (const uint8_t *)border_sgb_map, sizeof(border_sgb_map),
                       (const uint8_t *)border_sgb_palettes, sizeof(border_sgb_palettes));
    END_ROM_BANK();

    DISPLAY_OFF;
}

void main(void) NONBANKED {
    // load sgb border
    sgb_init();

    // "cheat" and enable double-speed CPU mode on GBC
    if (_cpu == CGB_TYPE) {
        cpu_fast();
    }

    timer_init();
    spr_init();
    snd_init();

    splash();

    uint16_t seed = DIV_REG;
    waitpadup();
    seed |= ((uint16_t)DIV_REG) << 8;
    initarand(seed);

    while (1) {
        int32_t score = game();

        if ((!(debug_flags & DBG_GOD_MODE)) && (score != 0) && score_ranking(score)) {
            uint16_t name = ask_name(score);
            struct scores s = { .name = name, .score = score };
            score_add(s);
        }

        splash();
    }
}