#include "sequence.h"

void delete_sequence_step(FlizzerTrackerApp *tracker)
{
    uint8_t sequence_position = tracker->tracker_engine.sequence_position;
    uint8_t *pattern = &tracker->tracker_engine.song->sequence.sequence_step[sequence_position].pattern_indices[tracker->current_channel];
    *pattern = 0;
}

void edit_sequence_step(FlizzerTrackerApp *tracker, int8_t delta)
{
    uint8_t digit = tracker->current_digit;

    uint8_t sequence_position = tracker->tracker_engine.sequence_position;
    uint8_t pattern_index = tracker->tracker_engine.song->sequence.sequence_step[sequence_position].pattern_indices[tracker->current_channel];

    uint8_t *pattern = &tracker->tracker_engine.song->sequence.sequence_step[sequence_position].pattern_indices[tracker->current_channel];
    uint8_t temp_pattern = *pattern;

    switch (digit)
    {
        case 0: // upper nibble
        {
            int8_t nibble = ((pattern_index & 0xf0) >> 4);

            if (nibble + delta < 0)
            {
                nibble = 0xf;
            }

            else if (nibble + delta > 0xf)
            {
                nibble = 0;
            }

            else
            {
                nibble += delta;
            }

            temp_pattern &= 0xf0;
            temp_pattern |= (nibble << 4);

            break;
        }

        case 1: // lower nibble
        {
            int8_t nibble = (pattern_index & 0x0f);

            if (nibble + delta < 0)
            {
                nibble = 0xf;
            }

            else if (nibble + delta > 0xf)
            {
                nibble = 0;
            }

            else
            {
                nibble += delta;
            }

            temp_pattern &= 0xf0;
            temp_pattern |= nibble;

            break;
        }
    }

    if (check_and_allocate_pattern(&tracker->song, temp_pattern))
    {
        *pattern = temp_pattern;
    }
}

void sequence_edit_event(FlizzerTrackerApp *tracker, FlizzerTrackerEvent *event)
{
    if (event->input.key == InputKeyOk && event->input.type == InputTypeShort && !tracker->tracker_engine.playing)
    {
        tracker->editing = !tracker->editing;
    }

    if (event->input.key == InputKeyRight && event->input.type == InputTypeShort && tracker->editing)
    {
        tracker->current_digit++;

        if (tracker->current_digit > 1)
        {
            tracker->current_channel++;

            tracker->current_digit = 0;

            if (tracker->current_channel > SONG_MAX_CHANNELS - 1)
            {
                tracker->current_channel = 0;
            }
        }
    }

    if (event->input.key == InputKeyLeft && event->input.type == InputTypeShort && tracker->editing)
    {
        tracker->current_digit--;

        if (tracker->current_digit > 1) // unsigned int overflow
        {
            tracker->current_channel--;

            tracker->current_digit = 1;

            if (tracker->current_channel > SONG_MAX_CHANNELS - 1) // unsigned int overflow
            {
                tracker->current_channel = SONG_MAX_CHANNELS - 1;
            }
        }
    }

    if (event->input.key == InputKeyDown && event->input.type == InputTypeShort)
    {
        if (!(tracker->editing))
        {
            tracker->tracker_engine.sequence_position++;

            if (tracker->tracker_engine.sequence_position >= tracker->tracker_engine.song->num_sequence_steps)
            {
                tracker->tracker_engine.sequence_position = 0;
            }
        }

        if (tracker->editing)
        {
            edit_sequence_step(tracker, -1);
        }
    }

    if (event->input.key == InputKeyUp && event->input.type == InputTypeShort)
    {
        if (!(tracker->editing))
        {
            int16_t temp_sequence_position = tracker->tracker_engine.sequence_position - 1;

            if (temp_sequence_position < 0)
            {
                tracker->tracker_engine.sequence_position = tracker->tracker_engine.song->num_sequence_steps - 1;
            }

            else
            {
                tracker->tracker_engine.sequence_position--;
            }
        }

        if (tracker->editing)
        {
            edit_sequence_step(tracker, 1);
        }
    }

    if (event->input.key == InputKeyBack && event->input.type == InputTypeShort && tracker->editing)
    {
        delete_sequence_step(tracker);
    }
}