/************************** BEGIN Soundfile.h **************************/
/************************************************************************
 FAUST Architecture File
 Copyright (C) 2017 GRAME, Centre National de Creation Musicale
 ---------------------------------------------------------------------
 This Architecture section is free software; you can redistribute it
 and/or modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 3 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 General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; If not, see <http://www.gnu.org/licenses/>.

 EXCEPTION : As a special exception, you may create a larger work
 that contains this FAUST architecture section and distribute
 that work under terms of your choice, so long as this FAUST
 architecture section is not modified.
 ************************************************************************/

#ifndef __Soundfile__
#define __Soundfile__

#include <string.h>
#include <string>
#include <vector>

#ifndef FAUSTFLOAT
#define FAUSTFLOAT float
#endif

#define BUFFER_SIZE 1024
#define SAMPLE_RATE 44100
#define MAX_CHAN 64
#define MAX_SOUNDFILE_PARTS 256

#ifdef _MSC_VER
#define PRE_PACKED_STRUCTURE __pragma(pack(push, 1))
#define POST_PACKED_STRUCTURE \
    ;                         \
    __pragma(pack(pop))
#else
#define PRE_PACKED_STRUCTURE
#define POST_PACKED_STRUCTURE __attribute__((__packed__))
#endif

/*
 The soundfile structure to be used by the DSP code. Soundfile has a MAX_SOUNDFILE_PARTS parts 
 (even a single soundfile or an empty soundfile). 
 fLength, fOffset and fSR fields are filled accordingly by repeating
 the actual parts if needed.
 
 It has to be 'packed' to that the LLVM backend can correctly access it.

 Index computation:
    - p is the current part number [0..MAX_SOUNDFILE_PARTS-1] (must be proved by the type system)
    - i is the current position in the part. It will be constrained between [0..length]
    - idx(p,i) = fOffset[p] + max(0, min(i, fLength[p]));
*/

PRE_PACKED_STRUCTURE
struct Soundfile {
    void* fBuffers; // will be set with double** or float** chosen at runtime
    int* fLength;   // length of each part (so fLength[P] contains the length in frames of part P)
    int* fSR;       // sample rate of each part (so fSR[P] contains the SR of part P)
    int* fOffset;   // offset of each part in the global buffer (so fOffset[P] contains the offset in frames of part P)
    int fChannels;  // max number of channels of all concatenated files
    bool fIsDouble; // keep the sample format (float or double)

    Soundfile(int cur_chan, int length, int max_chan, bool is_double)
    {
        fLength   = new int[MAX_SOUNDFILE_PARTS];
        fSR       = new int[MAX_SOUNDFILE_PARTS];
        fOffset   = new int[MAX_SOUNDFILE_PARTS];
        fIsDouble = is_double;
        fChannels = cur_chan;
        if (fIsDouble) {
            fBuffers = allocBufferReal<double>(cur_chan, length, max_chan);
        } else {
            fBuffers = allocBufferReal<float>(cur_chan, length, max_chan);
        }
    }
    
    template <typename REAL>
    void* allocBufferReal(int cur_chan, int length, int max_chan)
    {
        REAL** buffers = new REAL*[max_chan];
        for (int chan = 0; chan < cur_chan; chan++) {
            buffers[chan] = new REAL[length];
            memset(buffers[chan], 0, sizeof(REAL) * length);
        }
        return buffers;
    }
    
    void copyToOut(int size, int channels, int max_channels, int offset, void* buffer)
    {
        if (fIsDouble) {
            copyToOutReal<double>(size, channels, max_channels, offset, buffer);
       } else {
            copyToOutReal<float>(size, channels, max_channels, offset, buffer);
        }
    }
    
    void shareBuffers(int cur_chan, int max_chan)
    {
        // Share the same buffers for all other channels so that we have max_chan channels available
        if (fIsDouble) {
            for (int chan = cur_chan; chan < max_chan; chan++) {
                static_cast<double**>(fBuffers)[chan] = static_cast<double**>(fBuffers)[chan % cur_chan];
            }
        } else {
            for (int chan = cur_chan; chan < max_chan; chan++) {
                static_cast<float**>(fBuffers)[chan] = static_cast<float**>(fBuffers)[chan % cur_chan];
            }
        }
    }
    
    template <typename REAL>
    void copyToOutReal(int size, int channels, int max_channels, int offset, void* buffer)
    {
        for (int sample = 0; sample < size; sample++) {
            for (int chan = 0; chan < channels; chan++) {
                static_cast<REAL**>(fBuffers)[chan][offset + sample] = static_cast<REAL*>(buffer)[sample * max_channels + chan];
            }
        }
    }
    
    template <typename REAL>
    void getBuffersOffsetReal(void* buffers, int offset)
    {
        for (int chan = 0; chan < fChannels; chan++) {
            static_cast<REAL**>(buffers)[chan] = &(static_cast<REAL**>(fBuffers))[chan][offset];
        }
    }
    
    void emptyFile(int part, int& offset)
    {
        fLength[part] = BUFFER_SIZE;
        fSR[part] = SAMPLE_RATE;
        fOffset[part] = offset;
        // Update offset
        offset += fLength[part];
    }
 
    ~Soundfile()
    {
        // Free the real channels only
        if (fIsDouble) {
            for (int chan = 0; chan < fChannels; chan++) {
                delete[] static_cast<double**>(fBuffers)[chan];
            }
            delete[] static_cast<double**>(fBuffers);
        } else {
            for (int chan = 0; chan < fChannels; chan++) {
                delete[] static_cast<float**>(fBuffers)[chan];
            }
            delete[] static_cast<float**>(fBuffers);
        }
        delete[] fLength;
        delete[] fSR;
        delete[] fOffset;
    }

} POST_PACKED_STRUCTURE;

/*
 The generic soundfile reader.
 */

class SoundfileReader {
    
   protected:
    
    int fDriverSR;
   
    // Check if a soundfile exists and return its real path_name
    std::string checkFile(const std::vector<std::string>& sound_directories, const std::string& file_name)
    {
        if (checkFile(file_name)) {
            return file_name;
        } else {
            for (size_t i = 0; i < sound_directories.size(); i++) {
                std::string path_name = sound_directories[i] + "/" + file_name;
                if (checkFile(path_name)) { return path_name; }
            }
            return "";
        }
    }
    
    bool isResampling(int sample_rate) { return (fDriverSR > 0 && fDriverSR != sample_rate); }
 
    // To be implemented by subclasses

    /**
     * Check the availability of a sound resource.
     *
     * @param path_name - the name of the file, or sound resource identified this way
     *
     * @return true if the sound resource is available, false otherwise.
     */
    virtual bool checkFile(const std::string& path_name) = 0;
    
    /**
     * Check the availability of a sound resource.
     *
     * @param buffer - the sound buffer
     * @param size - the sound buffer length
     *
     * @return true if the sound resource is available, false otherwise.
     */

    virtual bool checkFile(unsigned char* buffer, size_t size) { return true; }

    /**
     * Get the channels and length values of the given sound resource.
     *
     * @param path_name - the name of the file, or sound resource identified this way
     * @param channels - the channels value to be filled with the sound resource number of channels
     * @param length - the length value to be filled with the sound resource length in frames
     *
     */
    virtual void getParamsFile(const std::string& path_name, int& channels, int& length) = 0;
    
    /**
     * Get the channels and length values of the given sound resource.
     *
     * @param buffer - the sound buffer
     * @param size - the sound buffer length
     * @param channels - the channels value to be filled with the sound resource number of channels
     * @param length - the length value to be filled with the sound resource length in frames
     *
     */
    virtual void getParamsFile(unsigned char* buffer, size_t size, int& channels, int& length) {}

    /**
     * Read one sound resource and fill the 'soundfile' structure accordingly
     *
     * @param soundfile - the soundfile to be filled
     * @param path_name - the name of the file, or sound resource identified this way
     * @param part - the part number to be filled in the soundfile
     * @param offset - the offset value to be incremented with the actual sound resource length in frames
     * @param max_chan - the maximum number of mono channels to fill
     *
     */
    virtual void readFile(Soundfile* soundfile, const std::string& path_name, int part, int& offset, int max_chan) = 0;
    
    /**
     * Read one sound resource and fill the 'soundfile' structure accordingly
     *
     * @param soundfile - the soundfile to be filled
     * @param buffer - the sound buffer
     * @param size - the sound buffer length
     * @param part - the part number to be filled in the soundfile
     * @param offset - the offset value to be incremented with the actual sound resource length in frames
     * @param max_chan - the maximum number of mono channels to fill
     *
     */
    virtual void readFile(Soundfile* soundfile, unsigned char* buffer, size_t size, int part, int& offset, int max_chan) {}

  public:
    
    virtual ~SoundfileReader() {}
    
    void setSampleRate(int sample_rate) { fDriverSR = sample_rate; }
   
    Soundfile* createSoundfile(const std::vector<std::string>& path_name_list, int max_chan, bool is_double)
    {
        try {
            int cur_chan = 1; // At least one channel
            int total_length = 0;
            
            // Compute total length and channels max of all files
            for (int i = 0; i < int(path_name_list.size()); i++) {
                int chan, length;
                if (path_name_list[i] == "__empty_sound__") {
                    length = BUFFER_SIZE;
                    chan = 1;
                } else {
                    getParamsFile(path_name_list[i], chan, length);
                }
                cur_chan = std::max<int>(cur_chan, chan);
                total_length += length;
            }
           
            // Complete with empty parts
            total_length += (MAX_SOUNDFILE_PARTS - path_name_list.size()) * BUFFER_SIZE;
            
            // Create the soundfile
            Soundfile* soundfile = new Soundfile(cur_chan, total_length, max_chan, is_double);
            
            // Init offset
            int offset = 0;
            
            // Read all files
            for (int i = 0; i < int(path_name_list.size()); i++) {
                if (path_name_list[i] == "__empty_sound__") {
                    soundfile->emptyFile(i, offset);
                } else {
                    readFile(soundfile, path_name_list[i], i, offset, max_chan);
                }
            }
            
            // Complete with empty parts
            for (int i = int(path_name_list.size()); i < MAX_SOUNDFILE_PARTS; i++) {
                soundfile->emptyFile(i, offset);
            }
            
            // Share the same buffers for all other channels so that we have max_chan channels available
            soundfile->shareBuffers(cur_chan, max_chan);
            return soundfile;
            
        } catch (...) {
            return nullptr;
        }
    }

    // Check if all soundfiles exist and return their real path_name
    std::vector<std::string> checkFiles(const std::vector<std::string>& sound_directories,
                                        const std::vector<std::string>& file_name_list)
    {
        std::vector<std::string> path_name_list;
        for (size_t i = 0; i < file_name_list.size(); i++) {
            std::string path_name = checkFile(sound_directories, file_name_list[i]);
            // If 'path_name' is not found, it is replaced by an empty sound (= silence)
            path_name_list.push_back((path_name == "") ? "__empty_sound__" : path_name);
        }
        return path_name_list;
    }

};

#endif
/**************************  END  Soundfile.h **************************/