/* Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009 Dean Beeler, Jerome Fisher
 * Copyright (C) 2011-2016 Dean Beeler, Jerome Fisher, Sergey V. Mikayev
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 2.1 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MT32EMU_C_INTERFACE_H
#define MT32EMU_C_INTERFACE_H

#include <stddef.h>

#include "../globals.h"
#include "c_types.h"

#undef MT32EMU_EXPORT
#define MT32EMU_EXPORT MT32EMU_EXPORT_ATTRIBUTE

#ifdef __cplusplus
extern "C" {
#endif

/* == Context-independent functions == */

/* === Interface handling === */

/** Returns mt32emu_service_i interface. */
MT32EMU_EXPORT const mt32emu_service_i mt32emu_get_service_i();

#if MT32EMU_EXPORTS_TYPE == 2
#undef MT32EMU_EXPORT
#define MT32EMU_EXPORT
#endif

/**
 * Returns the version ID of mt32emu_report_handler_i interface the library has been compiled with.
 * This allows a client to fall-back gracefully instead of silently not receiving expected event reports.
 */
MT32EMU_EXPORT mt32emu_report_handler_version mt32emu_get_supported_report_handler_version();

/**
 * Returns the version ID of mt32emu_midi_receiver_version_i interface the library has been compiled with.
 * This allows a client to fall-back gracefully instead of silently not receiving expected MIDI messages.
 */
MT32EMU_EXPORT mt32emu_midi_receiver_version mt32emu_get_supported_midi_receiver_version();

/**
 * Returns library version as an integer in format: 0x00MMmmpp, where:
 * MM - major version number
 * mm - minor version number
 * pp - patch number
 */
MT32EMU_EXPORT mt32emu_bit32u mt32emu_get_library_version_int();

/**
 * Returns library version as a C-string in format: "MAJOR.MINOR.PATCH".
 */
MT32EMU_EXPORT const char *mt32emu_get_library_version_string();

/**
 * Returns output sample rate used in emulation of stereo analog circuitry of hardware units for particular analog_output_mode.
 * See comment for mt32emu_analog_output_mode.
 */
MT32EMU_EXPORT mt32emu_bit32u mt32emu_get_stereo_output_samplerate(const mt32emu_analog_output_mode analog_output_mode);

/* == Context-dependent functions == */

/** Initialises a new emulation context and installs custom report handler if non-NULL. */
MT32EMU_EXPORT mt32emu_context mt32emu_create_context(mt32emu_report_handler_i report_handler, void *instance_data);

/** Closes and destroys emulation context. */
MT32EMU_EXPORT void mt32emu_free_context(mt32emu_context context);

/**
 * Adds new ROM identified by its SHA1 digest to the emulation context replacing previously added ROM of the same type if any.
 * Argument sha1_digest can be NULL, in this case the digest will be computed using the actual ROM data.
 * If sha1_digest is set to non-NULL, it is assumed being correct and will not be recomputed.
 * This function doesn't immediately change the state of already opened synth. Newly added ROM will take effect upon next call of mt32emu_open_synth().
 * Returns positive value upon success.
 */
MT32EMU_EXPORT mt32emu_return_code mt32emu_add_rom_data(mt32emu_context context, const mt32emu_bit8u *data, size_t data_size, const mt32emu_sha1_digest *sha1_digest);

/**
 * Loads a ROM file, identify it by SHA1 digest, and adds it to the emulation context replacing previously added ROM of the same type if any.
 * This function doesn't immediately change the state of already opened synth. Newly added ROM will take effect upon next call of mt32emu_open_synth().
 * Returns positive value upon success.
 */
MT32EMU_EXPORT mt32emu_return_code mt32emu_add_rom_file(mt32emu_context context, const char *filename);

/**
 * Fills in mt32emu_rom_info structure with identifiers and descriptions of control and PCM ROM files identified and added to the synth context.
 * If one of the ROM files is not loaded and identified yet, NULL is returned in the corresponding fields of the mt32emu_rom_info structure.
 */
MT32EMU_EXPORT void mt32emu_get_rom_info(mt32emu_const_context context, mt32emu_rom_info *rom_info);

/**
 * Allows to override the default maximum number of partials playing simultaneously within the emulation session.
 * This function doesn't immediately change the state of already opened synth. Newly set vale will take effect upon next call of mt32emu_open_synth().
 */
MT32EMU_EXPORT void mt32emu_set_partial_count(mt32emu_context context, const mt32emu_bit32u partial_count);

/**
 * Allows to override the default mode for emulation of analogue circuitry of the hardware units within the emulation session.
 * This function doesn't immediately change the state of already opened synth. Newly set vale will take effect upon next call of mt32emu_open_synth().
 */
MT32EMU_EXPORT void mt32emu_set_analog_output_mode(mt32emu_context context, const mt32emu_analog_output_mode analog_output_mode);

/**
 * Prepares the emulation context to receive MIDI messages and produce output audio data using aforehand added set of ROMs,
 * and optionally set the maximum partial count and the analog output mode.
 * Returns MT32EMU_RC_OK upon success.
 */
MT32EMU_EXPORT mt32emu_return_code mt32emu_open_synth(mt32emu_const_context context);

/** Closes the emulation context freeing allocated resources. Added ROMs remain unaffected and ready for reuse. */
MT32EMU_EXPORT void mt32emu_close_synth(mt32emu_const_context context);

/** Returns true if the synth is in completely initialized state, otherwise returns false. */
MT32EMU_EXPORT mt32emu_boolean mt32emu_is_open(mt32emu_const_context context);

/**
 * Returns actual output sample rate used in emulation of stereo analog circuitry of hardware units.
 * See comment for mt32emu_analog_output_mode.
 */
MT32EMU_EXPORT mt32emu_bit32u mt32emu_get_actual_stereo_output_samplerate(mt32emu_const_context context);

/** All the enqueued events are processed by the synth immediately. */
MT32EMU_EXPORT void mt32emu_flush_midi_queue(mt32emu_const_context context);

/**
 * Sets size of the internal MIDI event queue. The queue size is set to the minimum power of 2 that is greater or equal to the size specified.
 * The queue is flushed before reallocation.
 * Returns the actual queue size being used.
 */
MT32EMU_EXPORT mt32emu_bit32u mt32emu_set_midi_event_queue_size(mt32emu_const_context context, const mt32emu_bit32u queue_size);

/**
 * Installs custom MIDI receiver object intended for receiving MIDI messages generated by MIDI stream parser.
 * MIDI stream parser is involved when functions mt32emu_parse_stream() and mt32emu_play_short_message() or the likes are called.
 * By default, parsed short MIDI messages and System Exclusive messages are sent to the synth input MIDI queue.
 * This function allows to override default behaviour. If midi_receiver argument is set to NULL, the default behaviour is restored.
 */
MT32EMU_EXPORT void mt32emu_set_midi_receiver(mt32emu_context context, mt32emu_midi_receiver_i midi_receiver, void *instance_data);

/* Enqueues a MIDI event for subsequent playback.
 * The MIDI event will be processed not before the specified timestamp.
 * The timestamp is measured as the global rendered sample count since the synth was created (at the native sample rate 32000 Hz).
 * The minimum delay involves emulation of the delay introduced while the event is transferred via MIDI interface
 * and emulation of the MCU busy-loop while it frees partials for use by a new Poly.
 * Calls from multiple threads must be synchronised, although, no synchronisation is required with the rendering thread.
 * onMIDIQueueOverflow callback is invoked when the MIDI event queue is full and the message cannot be enqueued.
 */

/**
 * Parses a block of raw MIDI bytes and enqueues parsed MIDI messages for further processing ASAP.
 * SysEx messages are allowed to be fragmented across several calls to this method. Running status is also handled for short messages.
 * When a System Realtime MIDI message is parsed, onMIDISystemRealtime callback is invoked.
 * NOTE: the total length of a SysEx message being fragmented shall not exceed MT32EMU_MAX_STREAM_BUFFER_SIZE (32768 bytes).
 */
MT32EMU_EXPORT void mt32emu_parse_stream(mt32emu_const_context context, const mt32emu_bit8u *stream, mt32emu_bit32u length);

/**
 * Parses a block of raw MIDI bytes and enqueues parsed MIDI messages to play at specified time.
 * SysEx messages are allowed to be fragmented across several calls to this method. Running status is also handled for short messages.
 * When a System Realtime MIDI message is parsed, onMIDISystemRealtime callback is invoked.
 * NOTE: the total length of a SysEx message being fragmented shall not exceed MT32EMU_MAX_STREAM_BUFFER_SIZE (32768 bytes).
 */
MT32EMU_EXPORT void mt32emu_parse_stream_at(mt32emu_const_context context, const mt32emu_bit8u *stream, mt32emu_bit32u length, mt32emu_bit32u timestamp);

/**
 * Enqueues a single mt32emu_bit32u-encoded short MIDI message with full processing ASAP.
 * The short MIDI message may contain no status byte, the running status is used in this case.
 * When the argument is a System Realtime MIDI message, onMIDISystemRealtime callback is invoked.
 */
MT32EMU_EXPORT void mt32emu_play_short_message(mt32emu_const_context context, mt32emu_bit32u message);

/**
 * Enqueues a single mt32emu_bit32u-encoded short MIDI message to play at specified time with full processing.
 * The short MIDI message may contain no status byte, the running status is used in this case.
 * When the argument is a System Realtime MIDI message, onMIDISystemRealtime callback is invoked.
 */
MT32EMU_EXPORT void mt32emu_play_short_message_at(mt32emu_const_context context, mt32emu_bit32u message, mt32emu_bit32u timestamp);

/** Enqueues a single short MIDI message to be processed ASAP. The message must contain a status byte. */
MT32EMU_EXPORT mt32emu_return_code mt32emu_play_msg(mt32emu_const_context context, mt32emu_bit32u msg);
/** Enqueues a single well formed System Exclusive MIDI message to be processed ASAP. */
MT32EMU_EXPORT mt32emu_return_code mt32emu_play_sysex(mt32emu_const_context context, const mt32emu_bit8u *sysex, mt32emu_bit32u len);

/** Enqueues a single short MIDI message to play at specified time. The message must contain a status byte. */
MT32EMU_EXPORT mt32emu_return_code mt32emu_play_msg_at(mt32emu_const_context context, mt32emu_bit32u msg, mt32emu_bit32u timestamp);
/** Enqueues a single well formed System Exclusive MIDI message to play at specified time. */
MT32EMU_EXPORT mt32emu_return_code mt32emu_play_sysex_at(mt32emu_const_context context, const mt32emu_bit8u *sysex, mt32emu_bit32u len, mt32emu_bit32u timestamp);

/* WARNING:
 * The methods below don't ensure minimum 1-sample delay between sequential MIDI events,
 * and a sequence of NoteOn and immediately succeeding NoteOff messages is always silent.
 * A thread that invokes these methods must be explicitly synchronised with the thread performing sample rendering.
 */

/**
 * Sends a short MIDI message to the synth for immediate playback. The message must contain a status byte.
 * See the WARNING above.
 */
MT32EMU_EXPORT void mt32emu_play_msg_now(mt32emu_const_context context, mt32emu_bit32u msg);
/**
 * Sends unpacked short MIDI message to the synth for immediate playback. The message must contain a status byte.
 * See the WARNING above.
 */
MT32EMU_EXPORT void mt32emu_play_msg_on_part(mt32emu_const_context context, mt32emu_bit8u part, mt32emu_bit8u code, mt32emu_bit8u note, mt32emu_bit8u velocity);

/**
 * Sends a single well formed System Exclusive MIDI message for immediate processing. The length is in bytes.
 * See the WARNING above.
 */
MT32EMU_EXPORT void mt32emu_play_sysex_now(mt32emu_const_context context, const mt32emu_bit8u *sysex, mt32emu_bit32u len);
/**
 * Sends inner body of a System Exclusive MIDI message for direct processing. The length is in bytes.
 * See the WARNING above.
 */
MT32EMU_EXPORT void mt32emu_write_sysex(mt32emu_const_context context, mt32emu_bit8u channel, const mt32emu_bit8u *sysex, mt32emu_bit32u len);

/** Allows to disable wet reverb output altogether. */
MT32EMU_EXPORT void mt32emu_set_reverb_enabled(mt32emu_const_context context, const mt32emu_boolean reverb_enabled);
/** Returns whether wet reverb output is enabled. */
MT32EMU_EXPORT mt32emu_boolean mt32emu_is_reverb_enabled(mt32emu_const_context context);
/**
 * Sets override reverb mode. In this mode, emulation ignores sysexes (or the related part of them) which control the reverb parameters.
 * This mode is in effect until it is turned off. When the synth is re-opened, the override mode is unchanged but the state
 * of the reverb model is reset to default.
 */
MT32EMU_EXPORT void mt32emu_set_reverb_overridden(mt32emu_const_context context, const mt32emu_boolean reverb_overridden);
/** Returns whether reverb settings are overridden. */
MT32EMU_EXPORT mt32emu_boolean mt32emu_is_reverb_overridden(mt32emu_const_context context);
/**
 * Forces reverb model compatibility mode. By default, the compatibility mode corresponds to the used control ROM version.
 * Invoking this method with the argument set to true forces emulation of old MT-32 reverb circuit.
 * When the argument is false, emulation of the reverb circuit used in new generation of MT-32 compatible modules is enforced
 * (these include CM-32L and LAPC-I).
 */
MT32EMU_EXPORT void mt32emu_set_reverb_compatibility_mode(mt32emu_const_context context, const mt32emu_boolean mt32_compatible_mode);
/** Returns whether reverb is in old MT-32 compatibility mode. */
MT32EMU_EXPORT mt32emu_boolean mt32emu_is_mt32_reverb_compatibility_mode(mt32emu_const_context context);
/** Returns whether default reverb compatibility mode is the old MT-32 compatibility mode. */
MT32EMU_EXPORT mt32emu_boolean mt32emu_is_default_reverb_mt32_compatible(mt32emu_const_context context);

/** Sets new DAC input mode. See mt32emu_dac_input_mode for details. */
MT32EMU_EXPORT void mt32emu_set_dac_input_mode(mt32emu_const_context context, const mt32emu_dac_input_mode mode);
/** Returns current DAC input mode. See mt32emu_dac_input_mode for details. */
MT32EMU_EXPORT mt32emu_dac_input_mode mt32emu_get_dac_input_mode(mt32emu_const_context context);

/** Sets new MIDI delay mode. See mt32emu_midi_delay_mode for details. */
MT32EMU_EXPORT void mt32emu_set_midi_delay_mode(mt32emu_const_context context, const mt32emu_midi_delay_mode mode);
/** Returns current MIDI delay mode. See mt32emu_midi_delay_mode for details. */
MT32EMU_EXPORT mt32emu_midi_delay_mode mt32emu_get_midi_delay_mode(mt32emu_const_context context);

/**
 * Sets output gain factor for synth output channels. Applied to all output samples and unrelated with the synth's Master volume,
 * it rather corresponds to the gain of the output analog circuitry of the hardware units. However, together with mt32emu_set_reverb_output_gain()
 * it offers to the user a capability to control the gain of reverb and non-reverb output channels independently.
 * Ignored in MT32EMU_DAC_PURE mode.
 */
MT32EMU_EXPORT void mt32emu_set_output_gain(mt32emu_const_context context, float gain);
/** Returns current output gain factor for synth output channels. */
MT32EMU_EXPORT float mt32emu_get_output_gain(mt32emu_const_context context);

/**
 * Sets output gain factor for the reverb wet output channels. It rather corresponds to the gain of the output
 * analog circuitry of the hardware units. However, together with mt32emu_set_output_gain() it offers to the user a capability
 * to control the gain of reverb and non-reverb output channels independently.
 *
 * Note: We're currently emulate CM-32L/CM-64 reverb quite accurately and the reverb output level closely
 * corresponds to the level of digital capture. Although, according to the CM-64 PCB schematic,
 * there is a difference in the reverb analogue circuit, and the resulting output gain is 0.68
 * of that for LA32 analogue output. This factor is applied to the reverb output gain.
 * Ignored in MT32EMU_DAC_PURE mode.
 */
MT32EMU_EXPORT void mt32emu_set_reverb_output_gain(mt32emu_const_context context, float gain);
/** Returns current output gain factor for reverb wet output channels. */
MT32EMU_EXPORT float mt32emu_get_reverb_output_gain(mt32emu_const_context context);

/** Swaps left and right output channels. */
MT32EMU_EXPORT void mt32emu_set_reversed_stereo_enabled(mt32emu_const_context context, const mt32emu_boolean enabled);
/** Returns whether left and right output channels are swapped. */
MT32EMU_EXPORT mt32emu_boolean mt32emu_is_reversed_stereo_enabled(mt32emu_const_context context);

/**
 * Renders samples to the specified output stream as if they were sampled at the analog stereo output.
 * When mt32emu_analog_output_mode is set to ACCURATE (OVERSAMPLED), the output signal is upsampled to 48 (96) kHz in order
 * to retain emulation accuracy in whole audible frequency spectra. Otherwise, native digital signal sample rate is retained.
 * mt32emu_get_actual_stereo_output_samplerate() can be used to query actual sample rate of the output signal.
 * The length is in frames, not bytes (in 16-bit stereo, one frame is 4 bytes). Uses NATIVE byte ordering.
 */
MT32EMU_EXPORT void mt32emu_render_bit16s(mt32emu_const_context context, mt32emu_bit16s *stream, mt32emu_bit32u len);
/** Same as above but outputs to a float stereo stream. */
MT32EMU_EXPORT void mt32emu_render_float(mt32emu_const_context context, float *stream, mt32emu_bit32u len);

/**
 * Renders samples to the specified output streams as if they appeared at the DAC entrance.
 * No further processing performed in analog circuitry emulation is applied to the signal.
 * NULL may be specified in place of any or all of the stream buffers to skip it.
 * The length is in samples, not bytes. Uses NATIVE byte ordering.
 */
MT32EMU_EXPORT void mt32emu_render_bit16s_streams(mt32emu_const_context context, const mt32emu_dac_output_bit16s_streams *streams, mt32emu_bit32u len);
/** Same as above but outputs to float streams. */
MT32EMU_EXPORT void mt32emu_render_float_streams(mt32emu_const_context context, const mt32emu_dac_output_float_streams *streams, mt32emu_bit32u len);

/** Returns true when there is at least one active partial, otherwise false. */
MT32EMU_EXPORT mt32emu_boolean mt32emu_has_active_partials(mt32emu_const_context context);

/** Returns true if mt32emu_has_active_partials() returns true, or reverb is (somewhat unreliably) detected as being active. */
MT32EMU_EXPORT mt32emu_boolean mt32emu_is_active(mt32emu_const_context context);

/** Returns the maximum number of partials playing simultaneously. */
MT32EMU_EXPORT mt32emu_bit32u mt32emu_get_partial_count(mt32emu_const_context context);

/**
 * Returns current states of all the parts as a bit set. The least significant bit corresponds to the state of part 1,
 * total of 9 bits hold the states of all the parts. If the returned bit for a part is set, there is at least one active
 * non-releasing partial playing on this part. This info is useful in emulating behaviour of LCD display of the hardware units.
 */
MT32EMU_EXPORT mt32emu_bit32u mt32emu_get_part_states(mt32emu_const_context context);

/**
 * Fills in current states of all the partials into the array provided. Each byte in the array holds states of 4 partials
 * starting from the least significant bits. The state of each partial is packed in a pair of bits.
 * The array must be large enough to accommodate states of all the partials.
 * @see getPartialCount()
 */
MT32EMU_EXPORT void mt32emu_get_partial_states(mt32emu_const_context context, mt32emu_bit8u *partial_states);

/**
 * Fills in information about currently playing notes on the specified part into the arrays provided. The arrays must be large enough
 * to accommodate data for all the playing notes. The maximum number of simultaneously playing notes cannot exceed the number of partials.
 * Argument partNumber should be 0..7 for Part 1..8, or 8 for Rhythm.
 * Returns the number of currently playing notes on the specified part.
 */
MT32EMU_EXPORT mt32emu_bit32u mt32emu_get_playing_notes(mt32emu_const_context context, mt32emu_bit8u part_number, mt32emu_bit8u *keys, mt32emu_bit8u *velocities);

/**
 * Returns name of the patch set on the specified part.
 * Argument partNumber should be 0..7 for Part 1..8, or 8 for Rhythm.
 */
MT32EMU_EXPORT const char *mt32emu_get_patch_name(mt32emu_const_context context, mt32emu_bit8u part_number);

/** Stores internal state of emulated synth into an array provided (as it would be acquired from hardware). */
MT32EMU_EXPORT void mt32emu_read_memory(mt32emu_const_context context, mt32emu_bit32u addr, mt32emu_bit32u len, mt32emu_bit8u *data);

#ifdef __cplusplus
} // extern "C"
#endif

#endif /* #ifndef MT32EMU_C_INTERFACE_H */