#include <string.h>

#include "common.h"
#include "gba-buttons.c"
#include "background-tiles.c"
#include "sprites.h"
#include "text.h"

//
// Main functions.
//

// TODO: Cleanup OBJ/OAM memory copying and access.
//

//
// BIOS calls
//

int hblank_counter = 0;

void
irs_hblank_func() {
    hblank_counter++;
    if (DISP_VCOUNT >= 160) {
        PAL_BUFFER_BG[0] = rgb15(0, 0, 0);
    } else {
        u16 clr = (DISP_VCOUNT / 8);
        PAL_BUFFER_BG[0] = rgb15(clr, 0, 31 - clr);
    }
}

int main(void) {
    // Configure the display in mode 0 to show OBJs, where tile memory is
    // sequential.
    DISP_CTRL = DISP_ENABLE_SPRITES | DISP_MODE_0 | DISP_BG_0;

    // Initialize sprite button overlay.
    init_sprite_pal(0, COLOR_WHITE);
    init_sprites(0);
    init_button_sprites();

    // Initialize text engine.
    txt_init(0, COLOR_RED, 0);

    // Register interrupts.
    irq_init();
    irs_set(IRQ_VBLANK, irs_stub);
    irs_set(IRQ_HBLANK, irs_hblank_func);

    // turn sound on
    SOUND_STATUS = SOUND_ENABLE;
    SOUND_DMG_MASTER = sound_volume(SOUND_SQUARE1 | SOUND_SQUARE2, 7);
    SOUND_DSOUND_MASTER = SOUND_DMG100;

    char *note_names[] = {
        "C"  , "C#" , "D"  , "D#" ,
        "E"  , "F"  , "F#" , "G"  ,
        "G#" , "A"  , "A#" , "B"
    };
    int frame_counter = 0;
    Note active_note = NOTE_C;
    u8 octave = 0;
    bool playing = false;
    bool new_note = false;
    u8 interval = 1;
    while(true) {
        bios_vblank_wait();
        poll_keys();

        txt_position(0, 1);
        txt_clear_line();

        if (key_pressed(KEY_B)) {
            active_note = NOTE_C;
            new_note = true;
            octave = 0;
        } else if (key_pressed(KEY_A)) {
            active_note = NOTE_D;
            new_note = true;
            octave = 0;
        } else if (key_pressed(KEY_LEFT)) {
            active_note = NOTE_E;
            new_note = true;
            octave = 0;
        } else if (key_pressed(KEY_DOWN)) {
            active_note = NOTE_F;
            new_note = true;
            octave = 0;
        } else if (key_pressed(KEY_RIGHT)) {
            active_note = NOTE_G;
            new_note = true;
            octave = 0;
        } else if (key_pressed(KEY_UP)) {
            active_note = NOTE_A;
            new_note = true;
            octave = 0;
        } else if (key_pressed(KEY_L)) {
            active_note = NOTE_B;
            new_note = true;
            octave = 0;
        } else if (key_pressed(KEY_R)) {
            active_note = NOTE_C;
            new_note = true;
            octave = 1;
        }
        if (key_pressed(KEY_START)) {
            interval++;
        }
        if (key_pressed(KEY_SELECT)) {
            interval--;
        }

        if (key_curr > 0) {
            txt_printf(" Playing: %s + %s\n",
                    note_names[active_note],
                    (note_names[(active_note + interval) % 12]));
            playing = true;
        } else {
            playing = false;
        }

        if (playing) {
            if (new_note) {
                SOUND_SQUARE1_CTRL = SOUND_SQUARE_ENV_VOL(4) | SOUND_SQUARE_ENV_TIME(0);
                SOUND_SQUARE2_CTRL = SOUND_SQUARE_ENV_VOL(4) | SOUND_SQUARE_ENV_TIME(0);
                SOUND_SQUARE1_FREQ = SOUND_SQUARE_RESET | sound_rate(active_note, octave);
                SOUND_SQUARE2_FREQ = SOUND_SQUARE_RESET | sound_rate((active_note + interval) % 12, octave);
            }
            new_note = false;
        } else {
            SOUND_SQUARE1_CTRL = SOUND_SQUARE_ENV_VOL(0) | SOUND_SQUARE_ENV_TIME(0);
            SOUND_SQUARE2_CTRL = SOUND_SQUARE_ENV_VOL(0) | SOUND_SQUARE_ENV_TIME(0);
            SOUND_SQUARE1_FREQ = 0;
            SOUND_SQUARE2_FREQ = 0;
        }

        frame_counter++;
        update_button_sprites();
    };

    return 0;
}