#ifndef MIDI_H
#define MIDI_H

#include <stdint.h>
#include <stdbool.h>
#include <stddef.h>

// Configuration.
#define DEBUG 0           // If defined, enable input safety checking (e.g. too large data bytes, bad ID numbers, etc).
                          // These checks have some performance downside.
/* #define RUNNING_STATUS 0  // If defined, the MIDI instrument stores a transmit status and uses running statuses whenever possible .*/

#define KEY_ON_VELOCITY 0 // If defined, the MIDI instrument sends velocities with Note On messages.
#undef RELEASE_VELOCITY   // If defined, the MIDI instrument sends Note Off messages with velocities.
                          // Otherwise, sends Note On velocity 0 or Note Off velocity 0 according to ACTUAL_OFF_MESSAGE.
#undef ACTUAL_OFF_MESSAGE // If defined, the MIDI instrument sends true Note Off messages.
                          // Otherwise sends Note On velocity 0 (so as to exploit running status).
#undef EXPORT_CONTROLLERS // If defined, export constants useful for controller messages.

// Device info. Modify to suit your use-case.
#define DEVICE_MANUFACTURER 0x7d
#define DEVICE_FAMILY 0x00'00
#define DEVICE_MODEL_NUMBER 0x00'00
#define SOFTWARE_REVISION 0x00'00'00'00

// Consumers must specify
typedef struct {
  void (*uart_write)(uint8_t); // Blocking, single-byte UART transmit function.
  // Channel voice handlers.
  void (*note_on_handler)(uint8_t, uint8_t, uint8_t);
  void (*note_off_handler)(uint8_t, uint8_t, uint8_t);
  void (*poly_key_handler)(uint8_t, uint8_t, uint8_t);
  void (*control_change_handler)(uint8_t, uint8_t, uint8_t);
  void (*program_change_handler)(uint8_t, uint8_t);
  void (*aftertouch_handler)(uint8_t, uint8_t);
  void (*pitch_bend_change_handler)(uint8_t, uint8_t);
  // Channel mode handlers.
  void (*all_sound_off_handler)(uint8_t);
  void (*reset_all_controllers_handler)(uint8_t);
  void (*local_control_handler)(uint8_t, uint8_t);
  void (*all_notes_off_handler)(uint8_t);
  void (*omni_on_handler)(uint8_t);
  void (*omni_off_handler)(uint8_t);
  void (*mono_on_handler)(uint8_t, uint8_t);
  void (*poly_on_handler)(uint8_t);
  // System common handlers.
  void (*mtc_quarter_frame_handler)(uint8_t, uint8_t);
  void (*song_position_pointer_handler)(uint8_t, uint8_t);
  void (*song_select_handler)(uint8_t);
  void (*tune_request_handler)();
  // System real time handlers.
  void (*timing_clock_handler)();
  void (*start_handler)();
  void (*continue_handler)();
  void (*stop_handler)();
  void (*active_sensing_handler)();
  void (*system_reset_handler)();
  // System Exclusive handlers.
  bool (*sysex_collector)(uint8_t); // Feeds most recent byte system exclusive byte (status and eox excluded, ID included)
                                    // to client, returning false whenever the client determines sysex can be safely discarded.
                                    // Client is expected to maintain parsing state externally,
                                    // including resetting correctly after aborted parses.
                                    // Client also should not abort the parse before the first post-manufacturer-ID byte.
  void (*end_of_sysex_handler)(); // Sent only when client
  // Universal System Exclusive handlers.
  void (*bulk_tuning_dump_request_handler)(uint8_t, uint8_t);
  void (*bulk_tuning_dump_handler)(uint8_t, uint8_t, char*, uint8_t*);
  void (*single_note_tuning_change_handler)(uint8_t, uint8_t, uint8_t, uint8_t*);
  // TODO: more.
  bool (*unimplemented_universal_sysex_collector)(uint8_t); // Same as above. Parsing ends with end_of_sysex_handler.
} ConsumerBehavior;

typedef struct {
  uint8_t status;
  bool first_byte;
  uint8_t byte0;
  bool send_eox;
  uint8_t *stack;
  size_t top;
  size_t size;
} ParserMemory;

void midi_init(ConsumerBehavior new_pfns);

// System exclusive sends.
void sysex(uint16_t manufacturer_id, uint8_t* contents, size_t contents_len);
void universal_nonrealtime(uint8_t device_id, uint16_t sub_id, uint8_t* contents, size_t contents_len);
void universal_realtime(uint8_t device_id, uint16_t sub_id, uint8_t* contents, size_t contents_len);

// Channel voice sends.
#ifdef KEY_ON_VELOCITY
void note_on(uint8_t channel, uint8_t note, uint8_t velocity);
#else
void note_on(uint8_t channel, uint8_t note);
#endif
#ifdef RELEASE_VELOCITY
void note_off(uint8_t channel, uint8_t note, uint8_t velocity);
#else
void note_off(uint8_t channel, uint8_t note);
#endif
void control_change(uint8_t channel, uint8_t controller_number, uint8_t control_value);
void program_change(uint8_t channel, uint8_t program_number);
void aftertouch(uint8_t channel, uint8_t pressure_value);
void pitch_bend_change(uint8_t channel, uint16_t pressure_value);

// Channel mode sends.
void all_sound_off(uint8_t channel);
void reset_all_controllers(uint8_t channel);
void local_control_on(uint8_t channel);
void local_control_off(uint8_t channel);
void all_notes_off(uint8_t channel);
void omni_on(uint8_t channel);
void omni_off(uint8_t channel);
void mono_on(uint8_t channel, uint8_t channel_count);
void poly_on(uint8_t channel);


// System Common sends.
// MTC Quarter Frame unimplemented.
void song_position_pointer(uint16_t position);
void song_select(uint8_t song);
void tune_request();

// System Real Time sends.
void timing_clock();
void srt_start();
void srt_continue();
void srt_stop();
void active_sensing();
void MIDI_reset();

// Universal SysEx.
// Only implement MTS; consumers can do their own parsing via unimplemented_universal_sysex_collector.

// MIDI Tuning Standard sends.
void bulk_tuning_dump_request(uint8_t device_id, uint8_t program);
void bulk_tuning_dump(uint8_t device_id, uint8_t program, char* name, uint8_t* tuning_data);
void single_note_tuning_change(uint8_t device_id, uint8_t program, uint8_t *note_tuning_data, uint8_t keys_changed);


// Feed bytes to this in the UART interrupt handler.
void parse_midi_stream(uint8_t byte);


// Public constants; magic numbers useful for consumers.
#define ALL_CALL_DEVICE_ID 0x7f
#define DEVICE_KEY_COUNT 128
#define TUNING_LENGTH (3 * DEVICE_KEY_COUNT)
#define TUNING_NAME_LENGTH 16
#define NOTE_TUNING_BYTES_PER_KEY 4


#ifdef EXPORT_CONTROLLERS
// Controller constants.
typedef enum Controller {
  BANK_SELECT = 0,
  MODULATION_WHEEL = 1,
  BREATH_CONTROLLER = 2,
  // Undefined
  FOOT_CONTROLLER = 4,
  PORTAMENTO_TIME = 5,
  DATA_ENTRY_MSB = 6,
  CHANNEL_VOLUME = 7,
  BALANCE = 8,
  // Undefined
  PAN = 10,
  EXPRESSION = 11,
  EFFECT1 = 12,
  EFFECT2 = 13,
  // Undefined
  GP1 = 16,
  GP2 = 17,
  GP3 = 18,
  GP4 = 19,
  DAMPER_PEDAL = 64,
  PORTAMENTO_TOGGLE = 65,
  SOSTENUTO = 66,
  SOFT_PEDAL = 67,
  LEGATO_FOOTSWITCH = 68,
  HOLD2 = 69,
  SC1_SOUND_VARIATION = 70,
  SC2_TIMBRE = 71,
  SC3_RELEASE_TIME = 72,
  SC4_ATTACK_TIME = 73,
  SC5_BRIGHTNESS = 74,
  SC6 = 75,
  SC7 = 76,
  SC8 = 77,
  SC9 = 78,
  SC10 = 79,
  GP5 = 80,
  GP6 = 81,
  GP7 = 82,
  GP8 = 83,
  PORTAMENTO_CONTROL = 84,
  // Undefined
  EFFECTS_DEPTH1 = 91,
  EFFECTS_DEPTH2 = 92,
  EFFECTS_DEPTH3 = 93,
  EFFECTS_DEPTH4 = 94,
  EFFECTS_DEPTH5 = 95,
  DATA_INCREMENT = 96,
  DATA_DECREMENT = 97,
  NONREGISTERED_LSB = 98,
  NONREGISTERED_MSB = 99,
  REGISTERED_LSB = 100,
  REGISTERED_MSB = 101,
  // undefined 102-119
  // reserved for channel mode 120-127
};

typedef enum RegisteredParams {
  PITCH_BEND_SENSITIVITY = 0,
  FINE_TUNING = 1,
  COARSE_TUNING = 2,
  TUNING_PROGRAM_SELECT = 3,
  TUNING_BANK_SELECT = 4
};

#endif


#endif