/*
Copyright (c) 2023 Bad Diode

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE.
*/

// TODO: A list of features I would like to get to implement in the near future.
//
// UI tweaks.
//  + Add new UI for the parameter pages
//  + Change cursor drawing for new parameter pages
//  + Change cursor behaviour for new parameter pages
//  + Allow prob control (% based or 1:2, etc.)
//  + Display notification when editing a parameter with the highest priority
//  + Add panning support.
//  + Change ch3 to only color the waveform that is selected depending on the
//    mode.
//  + Grey out colors when foreground is also grey.
//  + Bigger indicator for currently playing pattern.
//  - Add custom user themes
//  - Animations for cursor movement/current step highlight. (A fade out maybe?)
//  - Improve "grey" cursor with dithering instead.
//  - Remove thin cursor option and make the fat one default, it's just better.
//
// Quality of life improvements.
//  + Make the channel parameters initialize to default
//  + Keep one pattern chain per bank
//  + Store pattern chains on bank if there is enough memory available.
//  - When not on play mode, adjusting a note or a parameter triggers the sound.
//    This could get annoying, so maybe it should be a configuration option to
//    enable it?
//  - Undo/Redo.
//
//  Advanced
//  + Per trig note probability.
//  + Make it so switching banks don't stop playback.
//  - Add tap tempo for BPM.
//  - Allow "marking" several trigs to be able to copy/paste them and/or adjust
//    their parameters.
//  - Add an envelope to ch3, would need to work with a timer in order to make
//    it work I think.
//  - Sync via MIDI via arduinoboy or something similar.
//  - Per trig LFO? How would we go about this? There is at least one empty slot
//    in all channels. LFO amount? LFO speed? Would need a dedicated page for
//    configuring LFOs
//  - Multiple pattern chains per bank that we can toggle between, gotta study
//    if they fit in the SRAM.
//  - Scale mode for entering notes.
//  - Make sure bank switching is queued like patterns.
//
//  Bugfixes
//  + Sound can get hung up sometimes, but I can't reproduce when this happens.
//    Not sure if this is an emulator thing or happens also in hardware. Seems
//    to only happen on mGBA. After running for a time it just stops working,
//    the sound returns after a while without issue. On `ares` or real hardware
//    it works just fine.
//

#include "gba/gba.h"

#include "renderer_m0.c"
#include "globals.c"
#include "settings.c"
#include "dsound.c"
#include "sequencer.c"

#define PROF_ENABLE 0
#include "profiling.c"

void
render_sequencer(void) {
    PROF(draw_rect(0, 0, SCREEN_WIDTH - 1, SCREEN_HEIGHT - 1, 1), clear_cycles);
    if (redraw_trigs) {
        PROF(draw_triggers(), draw_trigs_cycles);
        redraw_trigs = false;
    }
    if (redraw_channels) {
        PROF(draw_channels(), draw_btn_cycles);
        redraw_channels = false;
    }
    if (redraw_pattern_buttons) {
        PROF(draw_pattern_buttons(), draw_btn_cycles);
        redraw_pattern_buttons = false;
    }
    if (redraw_bank_buttons) {
        PROF(draw_bank_buttons(), draw_btn_cycles);
        redraw_bank_buttons = false;
    }
    if (redraw_bpm) {
        PROF(draw_bpm(), draw_btn_cycles);
        redraw_bpm = false;
    }
    if (redraw_play_pause) {
        PROF(draw_play(), draw_btn_cycles);
        PROF(draw_stop(), draw_btn_cycles);
        redraw_play_pause = false;
    }
    if (redraw_piano_note) {
        PROF(draw_piano_notes(), draw_piano_cycles);
        redraw_piano_note = false;
    }
    if (redraw_params) {
        PROF(draw_parameters(), draw_param_cycles);
        redraw_params = false;
    }

    if (input_handler == handle_pattern_selection ||
            input_handler == handle_pattern_chain) {
        draw_pattern_chain();
    }

    // TODO: redraw_notif?
    draw_notif_bar();
    PROF(draw_cursors(), draw_cursor_cycles);
}

void
render_settings(void) {
    PROF(draw_rect(0, 0, SCREEN_WIDTH - 1, SCREEN_HEIGHT - 1, 1), clear_cycles);
    txt_drawf_small("settings", 11, 5, COL_FG)
    txt_printf("\n\n\n");
    txt_printf("  SYNC:   %s\n\n", sync_setting_str[settings.sync]);
    txt_printf("  THEME:  %s\n\n", theme_setting_str[settings.theme]);
    txt_printf("  CURSOR: %s\n\n", cursor_setting_str[settings.cursor]);
    txt_printf("  HELP:   %s\n\n", help_setting_str[settings.help]);
    txt_render();
    txt_clear();
    PROF(draw_settings_cursor(), draw_cursor_cycles);
}

void
render(void) {
    if (clear_screen) {
        PROF(screen_fill(COL_BG), clear_cycles);
        clear_screen = false;
    }
    switch (scene) {
        case SCENE_SETTINGS: {
            render_settings();
        } break;
        case SCENE_SEQUENCER: {
            render_sequencer();
        } break;
    }
    // DEBUG: Ensuring the saved data don't exceed SRAM size (32k).
    // txt_drawf("SIZE: %lu", 0, 0, COL_ACC_1, sizeof(Metadata) + sizeof(patterns) * 4 + sizeof(chain) * 4);
}

void
handle_input(void) {
    switch (scene) {
        case SCENE_SETTINGS: {
            handle_settings_input();
        } break;
        case SCENE_SEQUENCER: {
            handle_sequencer_input();
        } break;
    }
}

void
update(void) {
    if (next_scene != scene) {
        scene = next_scene;
        clear_screen = true;
        redraw_trigs = true;
        redraw_channels = true;
        redraw_pattern_buttons = true;
        redraw_bank_buttons = true;
        redraw_bpm = true;
        redraw_play_pause = true;
        redraw_piano_note = true;
        redraw_params = true;
    }
    last_trig_loc = trig_selection_loc;
    last_channel_loc = channel_selection_loc;
    last_pattern_loc = pattern_selection_loc;
    last_right_col_loc = right_col_selection_loc;
    if (update_bpm) {
        set_time(patterns[current_pattern].bpm);
        update_bpm = false;
    }
    if (audio_sync_click) {
        play_click();
    }
    if (notif.time > 0) {
        notif.time--;
    }
    rng_state++;
}

int
main(void) {
    // Adjust system wait times.
    SYSTEM_WAIT = SYSTEM_WAIT_CARTRIDGE;

    // Initialize renderer.
    renderer_init();

    // Register interrupts.
    irq_init();
    irs_set(IRQ_VBLANK, sound_vsync);

    // Initialize sequencer.
    sequencer_init();
    txt_spacing(6);

    // Main loop.
    while (true) {
        poll_keys();
        bios_vblank_wait();
        PROF_SHOW();
        FRAME_START();
        PROF(flip_buffer(), flip_cycles);
        PROF(update(), update_cycles);
        PROF(handle_input(), input_cycles);
        PROF(render(), render_cycles);
        FRAME_END();
    }

    return 0;
}