#ifndef MARS_DrsCalib
#define MARS_DrsCalib

#include <math.h>   // fabs
#include <errno.h>  // errno

#include "fits.h"

class DrsCalibrate
{
protected:
    uint64_t fNumEntries;

    size_t fNumSamples;
    size_t fNumChannels;

    std::vector<int64_t> fSum;
    std::vector<int64_t> fSum2;

public:
    DrsCalibrate() : fNumEntries(0), fNumSamples(0), fNumChannels(0) { }
    void Reset()
    {
        fNumEntries  = 0;
        fNumSamples  = 0;
        fNumChannels = 0;

        fSum.clear();
        fSum2.clear();
    }

    void InitSize(uint16_t channels, uint16_t samples)
    {
        fNumChannels = channels;
        fNumSamples  = samples;

        fSum.resize(samples*channels);
        fSum2.resize(samples*channels);
    }

    void AddRel(const int16_t *val, const int16_t *start)
    {
        for (size_t ch=0; ch<fNumChannels; ch++)
        {
            const int16_t spos = start[ch];
            if (spos<0)
                continue;

            const size_t pos = ch*1024;

            for (size_t i=0; i<1024; i++)
            {
                // Value is relative to trigger
                // Abs is corresponding index relative to DRS pipeline
                const size_t rel = pos +  i;
                const size_t abs = pos + (spos+i)%1024;

                const int64_t v = val[rel];

                fSum[abs]  += v;
                fSum2[abs] += v*v;
            }
        }

        fNumEntries++;
    }

    void AddRel(const int16_t *val,    const int16_t *start,
                const int32_t *offset, const uint32_t scale)
    {
        for (size_t ch=0; ch<fNumChannels; ch++)
        {
            const int16_t spos = start[ch];
            if (spos<0)
                continue;

            const size_t pos = ch*fNumSamples;

            for (size_t i=0; i<fNumSamples; i++)
            {
                // Value is relative to trigger
                // Offset is relative to DRS pipeline
                // Abs is corresponding index relative to DRS pipeline
                const size_t rel = pos +  i;
                const size_t abs = pos + (spos+i)%fNumSamples;

                const int64_t v = int64_t(val[rel])*scale-offset[abs];

                fSum[abs]  += v;
                fSum2[abs] += v*v;
            }
        }

        fNumEntries++;
    }
    /*
    void AddAbs(const int16_t *val,    const  int16_t *start,
                const int32_t *offset, const uint32_t scale)
    {
        for (size_t ch=0; ch<fNumChannels; ch++)
        {
            const int16_t spos = start[ch];
            if (spos<0)
                continue;

            const size_t pos = ch*fNumSamples;

            for (size_t i=0; i<fNumSamples; i++)
            {
                // Value is relative to trigger
                // Offset is relative to DRS pipeline
                // Abs is corresponding index relative to DRS pipeline
                const size_t rel = pos +  i;
                const size_t abs = pos + (spos+i)%fNumSamples;

                const int64_t v = int64_t(val[rel])*scale-offset[abs];

                fSum[rel]  += v;
                fSum2[rel] += v*v;
            }
        }

        fNumEntries++;
    }*/

    void AddAbs(const int16_t *val,    const  int16_t *start,
                const int32_t *offset, const uint32_t scale)
    {
        // 1440 without tm, 1600 with tm
        for (size_t ch=0; ch<fNumChannels; ch++)
        {
            const int16_t spos = start[ch];
            if (spos<0)
                continue;

            const size_t pos = ch*fNumSamples;
            const size_t drs = ch>1439 ? ((ch-1440)*9+8)*1024 : ch*1024;

            for (size_t i=0; i<fNumSamples; i++)
            {
                // Value is relative to trigger
                // Offset is relative to DRS pipeline
                // Abs is corresponding index relative to DRS pipeline
                const size_t rel = pos +  i;
                const size_t abs = drs + (spos+i)%1024;

                const int64_t v = int64_t(val[rel])*scale-offset[abs];

                fSum[rel]  += v;
                fSum2[rel] += v*v;
            }
        }

        fNumEntries++;
    }


    static void ApplyCh(float *vec, const int16_t *val, int16_t start, uint32_t roi,
                        const int32_t *offset, const uint32_t scaleabs,
                        const int64_t *gain,   const uint64_t scalegain)
    {
        if (start<0)
        {
            memset(vec, 0, roi);
            return;
        }

        for (size_t i=0; i<roi; i++)
        {
            // Value is relative to trigger
            // Offset is relative to DRS pipeline
            // Abs is corresponding index relative to DRS pipeline
            const size_t abs = (start+i)%1024;

            const int64_t v =
                + int64_t(val[i])*scaleabs-offset[abs]
                ;

            const int64_t div = gain[abs];
            vec[i] = double(v)*scalegain/div;
        }
    }

    static void ApplyCh(float *vec, const int16_t *val, int16_t start, uint32_t roi,
                        const int32_t *offset, const uint32_t scaleabs,
                        const int64_t *gain,   const uint64_t scalegain,
                        const int64_t *trgoff, const uint64_t scalerel)
    {
        if (start<0)
        {
            memset(vec, 0, roi);
            return;
        }

        for (size_t i=0; i<roi; i++)
        {
            // Value is relative to trigger
            // Offset is relative to DRS pipeline
            // Abs is corresponding index relative to DRS pipeline
            const size_t abs = (start+i)%1024;

            const int64_t v =
                + (int64_t(val[i])*scaleabs-offset[abs])*scalerel
                - trgoff[i]
                ;

            const int64_t div = gain[abs]*scalerel;
            vec[i] = double(v)*scalegain/div;
        }
    }

    static void RemoveSpikes(float *vec, uint32_t roi)
    {
        if (roi<4)
            return;

        for (size_t ch=0; ch<1440; ch++)
        {
            float *p = vec + ch*roi;

            for (size_t i=1; i<roi-2; i++)
            {
                if (p[i]-p[i-1]>25 && p[i]-p[i+1]>25)
                {
                    p[i] = (p[i-1]+p[i+1])/2;
                }

                if (p[i]-p[i-1]>22 && fabs(p[i]-p[i+1])<4 && p[i+1]-p[i+2]>22)
                {
                    p[i] = (p[i-1]+p[i+2])/2;
                    p[i+1] = p[i];
                }
            }
        }
    }

    static void RemoveSpikes2(float *vec, uint32_t roi)//from Werner
    {
        if (roi<4)
            return;

        for (size_t ch=0; ch<1440; ch++)
        {
            float *p = vec + ch*roi;

            std::vector<float> Ameas(p, p+roi);

            std::vector<float> N1mean(roi);
            for (size_t i=2; i<roi-2; i++)
            {
                N1mean[i] = (p[i-1] + p[i+1])/2.;
            }

            const float fract = 0.8;
            float x, xp, xpp;

            for (size_t i=0; i<roi-3; i++)
            {
                x = Ameas[i] - N1mean[i];
                if ( x > -5.)
                    continue;

                xp  = Ameas[i+1] - N1mean[i+1];
                xpp = Ameas[i+2] - N1mean[i+2];

                if(Ameas[i+2] - (Ameas[i] + Ameas[i+3])/2. > 10.)
                {
                    p[i+1]=(Ameas[i] + Ameas[i+3])/2.;
                    p[i+2]=(Ameas[i] + Ameas[i+3])/2.;

                    i += 3;

                    continue;
                }
                if ( (xp > -2.*x*fract) && (xpp < -10.) )
                {
                    p[i+1] = N1mean[i+1];
                    N1mean[i+2] = (Ameas[i+1] - Ameas[i+3] / 2.);

                    i += 2;
                }
            }
        }
    }

    std::pair<std::vector<double>,std::vector<double> > GetSampleStats() const
    {
        if (fNumEntries==0)
            return make_pair(std::vector<double>(),std::vector<double>());

        std::vector<double> mean(fSum.size());
        std::vector<double> error(fSum.size());

        std::vector<int64_t>::const_iterator it = fSum.begin();
        std::vector<int64_t>::const_iterator i2 = fSum2.begin();
        std::vector<double>::iterator        im = mean.begin();
        std::vector<double>::iterator        ie = error.begin();

        while (it!=fSum.end())
        {
            *im = /*cnt<fResult.size() ? fResult[cnt] :*/ double(*it)/fNumEntries;
            *ie = sqrt(double(*i2*int64_t(fNumEntries) - *it * *it))/fNumEntries;

            im++;
            ie++;
            it++;
            i2++;
        }


        /*
         valarray<double> ...

         mean /= fNumEntries;
         error = sqrt(error/fNumEntries - mean*mean);
         */

        return make_pair(mean, error);
    }

    void GetSampleStats(float *ptr, float scale) const
    {
        const size_t sz = fNumSamples*fNumChannels;

        if (fNumEntries==0)
        {
            memset(ptr, 0, sizeof(float)*sz*2);
            return;
        }

        std::vector<int64_t>::const_iterator it = fSum.begin();
        std::vector<int64_t>::const_iterator i2 = fSum2.begin();

        while (it!=fSum.end())
        {
            *ptr      = scale*double(*it)/fNumEntries;
            *(ptr+sz) = scale*sqrt(double(*i2*int64_t(fNumEntries) - *it * *it))/fNumEntries;

            ptr++;
            it++;
            i2++;
        }
    }

    static void GetPixelStats(float *ptr, const float *data, uint16_t roi)
    {
        if (roi==0)
            return;

        for (int i=0; i<1440; i++)
        {
            const float *vec = data+i*roi;

            int    pos  = 0;
            double sum  = vec[0];
            double sum2 = vec[0]*vec[0];
            for (int j=1; j<roi; j++)
            {
                sum  += vec[j];
                sum2 += vec[j]*vec[j];

                if (vec[j]>vec[pos])
                    pos = j;
            }
            sum  /= roi;
            sum2 /= roi;

            *(ptr+0*1440+i) = sum;
            *(ptr+1*1440+i) = sqrt(sum2 - sum * sum);
            *(ptr+2*1440+i) = vec[pos];
            *(ptr+3*1440+i) = pos;
        }
    }

    static void GetPixelMax(float *max, const float *data, uint16_t roi, int32_t first, int32_t last)
    {
        if (roi==0 || first<0 || last<0 || first>=roi || last>=roi || last<first)
            return;

        for (int i=0; i<1440; i++)
        {
            const float *beg = data+i*roi+first;
            const float *end = data+i*roi+last;

            const float *pmax = beg;

            for (const float *ptr=beg+1; ptr<=end; ptr++)
                if (*ptr>*pmax)
                    pmax = ptr;

            max[i] = *pmax;
        }
    }

    const std::vector<int64_t> &GetSum() const { return fSum; }

    uint64_t GetNumEntries() const { return fNumEntries; }
};

class DrsCalibrateTime
{
public:
    uint64_t fNumEntries;

    size_t fNumSamples;
    size_t fNumChannels;

    std::vector<std::pair<double, double>> fStat;

public:
    DrsCalibrateTime() : fNumEntries(0), fNumSamples(0), fNumChannels(0)
    {
        InitSize(160, 1024);
    }

    DrsCalibrateTime(const DrsCalibrateTime &p) : fNumEntries(p.fNumEntries), fNumSamples(p.fNumSamples), fNumChannels(p.fNumChannels), fStat(p.fStat)
    {
    }

    double Sum(uint32_t i) const { return fStat[i].first; }
    double W(uint32_t i) const { return fStat[i].second; }

    void InitSize(uint16_t channels, uint16_t samples)
    {
        fNumChannels = channels;
        fNumSamples  = samples;

        fNumEntries  = 0;

        fStat.clear();

        fStat.resize(samples*channels);
    }

    void AddT(const float *val, const int16_t *start, signed char edge=0)
    {
        if (fNumSamples!=1024 || fNumChannels!=160)
            return;

        // Rising or falling edge detection has the advantage that
        // we are much less sensitive to baseline shifts

        for (size_t ch=0; ch<160; ch++)
        {
            const size_t tm = ch*9+8;

            const int16_t spos = start[tm];
            if (spos<0)
                continue;

            const size_t pos = ch*1024;

            double  p_prev =  0;
            int32_t i_prev = -1;

            for (size_t i=0; i<1024-1; i++)
            {
                const size_t rel = tm*1024 + i;

                const float &v0 = val[rel];  //-avg;
                const float &v1 = val[rel+1];//-avg;

                // Is rising edge?
                if (edge>0 && v0>0)
                    continue;

                // Is falling edge?
                if (edge<0 && v0<0)
                    continue;

                // Has sign changed?
                if ((v0<0 && v1<0) || (v0>0 && v1>0))
                    continue;

                const double p = v0==v1 ? 0.5 : v0/(v0-v1);

                const double l = i+p - (i_prev+p_prev);

                if (i_prev>=0)
                {
                    const double w0 = 1-p_prev;
                    const double w1 = p;

                    fStat[pos+(spos+i_prev)%1024].first  += w0*l;
                    fStat[pos+(spos+i_prev)%1024].second += w0;

                    for (size_t k=i_prev+1; k<i; k++)
                    {
                        fStat[pos+(spos+k)%1024].first  += l;
                        fStat[pos+(spos+k)%1024].second += 1;
                    }

                    fStat[pos+(spos+i)%1024].first  += w1*l;
                    fStat[pos+(spos+i)%1024].second += w1;
                }

                p_prev = p;
                i_prev = i;
            }
        }
        fNumEntries++;
    }

    void FillEmptyBins()
    {
        for (int ch=0; ch<160; ch++)
        {
            const auto beg = fStat.begin() + ch*1024;
            const auto end = beg + 1024;

            double   avg = 0;
            uint32_t num = 0;
            for (auto it=beg; it!=end; it++)
            {
                if (it->second<fNumEntries-0.5)
                    continue;

                avg += it->first / it->second;
                num++;
            }
            avg /= num;

            for (auto it=beg; it!=end; it++)
            {
                if (it->second>=fNumEntries-0.5)
                    continue;

                // {
                //     result[i+1].first  = *is2;
                //     result[i+1].second = *iw2;
                // }
                // else
                // {
                it->first  = avg*fNumEntries;
                it->second = fNumEntries;
                // }
            }
        }
    }

    DrsCalibrateTime GetComplete() const
    {
        DrsCalibrateTime rc(*this);
        rc.FillEmptyBins();
        return rc;
    }

    void CalcResult()
    {
        for (int ch=0; ch<160; ch++)
        {
            const auto beg = fStat.begin() + ch*1024;
            const auto end = beg + 1024;

            // Calculate mean
            double s = 0;
            double w = 0;

            for (auto it=beg; it!=end; it++)
            {
                s += it->first;
                w += it->second;
            }

            s /= w;

            double sumw = 0;
            double sumv = 0;
            int n = 0;

            // Sums about many values are numerically less stable than
            // just sums over less. So we do the exercise from both sides.
            for (auto it=beg; it!=end-512; it++, n++)
            {
                const double valv = it->first;
                const double valw = it->second;

                it->first = sumv>0 ? n*(1-s*sumw/sumv) :0;

                sumv += valv;
                sumw += valw;
            }

            sumw = 0;
            sumv = 0;
            n = 1;

            for (auto it=end-1; it!=beg-1+512; it--, n++)
            {
                const double valv = it->first;
                const double valw = it->second;

                sumv += valv;
                sumw += valw;

                it->first = sumv>0 ? n*(s*sumw/sumv-1) : 0;
            }
        }
    }

    DrsCalibrateTime GetResult() const
    {
        DrsCalibrateTime rc(*this);
        rc.CalcResult();
        return rc;
    }

    double Offset(uint32_t ch, double pos) const
    {
        const auto p = fStat.begin() + ch*1024;

        const uint32_t f = floor(pos);

        const double v0 = p[f].first;
        const double v1 = p[(f+1)%1024].first;

        return v0 + fmod(pos, 1)*(v1-v0);
    }

    double Calib(uint32_t ch, double pos) const
    {
        return pos-Offset(ch, pos);
    }
};

struct DrsCalibration
{
    std::vector<int32_t> fOffset;
    std::vector<int64_t> fGain;
    std::vector<int64_t> fTrgOff;

    uint64_t fNumOffset;
    uint64_t fNumGain;
    uint64_t fNumTrgOff;

    uint32_t fStep;
    uint16_t fRoi;   // Region of interest for trgoff
    uint16_t fNumTm; // Number of time marker channels in trgoff

//    uint16_t fDAC[8];

    DrsCalibration() :
        fOffset  (1440*1024, 0),
        fGain    (1440*1024, 4096),
        fTrgOff  (1600*1024, 0),
        fNumOffset(1),
        fNumGain(2000),
        fNumTrgOff(1),
        fStep(0)
    {
    }

    void Clear()
    {
        // Default gain:
        // 0.575*[45590]*2.5V / 2^16 = 0.99999 V
        fOffset.assign(1440*1024, 0);
        fGain.assign  (1440*1024, 4096);
        fTrgOff.assign(1600*1024, 0);

        fNumOffset = 1;
        fNumGain   = 2000;
        fNumTrgOff = 1;

        fStep = 0;
    }

    std::string ReadFitsImp(const std::string &str, std::vector<float> &vec)
    {
        std::fits file(str);
        if (!file)
        {
            std::ostringstream msg;
            msg << "Could not open file '" << str << "': " << strerror(errno);
            return msg.str();
        }

        if (file.GetStr("TELESCOP")!="FACT")
        {
            std::ostringstream msg;
            msg << "Reading '" << str << "' failed: Not a valid FACT file (TELESCOP not FACT in header)";
            return msg.str();
        }

        if (!file.HasKey("STEP"))
        {
            std::ostringstream msg;
            msg << "Reading '" << str << "' failed: Is not a DRS calib file (STEP not found in header)";
            return msg.str();
        }

        if (file.GetNumRows()!=1)
        {
            std::ostringstream msg;
            msg << "Reading '" << str << "' failed: Number of rows in table is not 1.";
            return msg.str();
        }

        fStep      = file.GetUInt("STEP");
        fNumOffset = file.GetUInt("NBOFFSET");
        fNumGain   = file.GetUInt("NBGAIN");
        fNumTrgOff = file.GetUInt("NBTRGOFF");
        fRoi       = file.GetUInt("NROI");
        fNumTm     = file.HasKey("NTM") ? file.GetUInt("NTM") : 0;
/*
        fDAC[0]    = file.GetUInt("DAC_A");
        fDAC[1]    = file.GetUInt("DAC_B");
        fDAC[4]    = file.GetUInt("DAC_C");
*/
        vec.resize(1440*1024*4 + (1440+fNumTm)*fRoi*2 + 4);

        float *base = vec.data();

        reinterpret_cast<uint32_t*>(base)[0] = fRoi;

        file.SetPtrAddress("RunNumberBaseline",      base+1, 1);
        file.SetPtrAddress("RunNumberGain",          base+2, 1);
        file.SetPtrAddress("RunNumberTriggerOffset", base+3, 1);
        file.SetPtrAddress("BaselineMean",           base+4+0*1024*1440,           1024*1440);
        file.SetPtrAddress("BaselineRms",            base+4+1*1024*1440,           1024*1440);
        file.SetPtrAddress("GainMean",               base+4+2*1024*1440,           1024*1440);
        file.SetPtrAddress("GainRms",                base+4+3*1024*1440,           1024*1440);
        file.SetPtrAddress("TriggerOffsetMean",      base+4+4*1024*1440,           fRoi*1440);
        file.SetPtrAddress("TriggerOffsetRms",       base+4+4*1024*1440+fRoi*1440, fRoi*1440);
        if (fNumTm>0)
        {
            file.SetPtrAddress("TriggerOffsetTMMean", base+4+4*1024*1440+ 2*fRoi*1440,              fRoi*fNumTm);
            file.SetPtrAddress("TriggerOffsetTMRms",  base+4+4*1024*1440+ 2*fRoi*1440+ fRoi*fNumTm, fRoi*fNumTm);
        }

        if (!file.GetNextRow())
        {
            std::ostringstream msg;
            msg << "Reading data from " << str << " failed.";
            return msg.str();
        }
/*
        fDAC[2] = fDAC[1];
        fDAC[4] = fDAC[1];

        fDAC[5] = fDAC[4];
        fDAC[6] = fDAC[4];
        fDAC[7] = fDAC[4];
*/
        fOffset.resize(1024*1440);
        fGain.resize(1024*1440);

        fTrgOff.resize(fRoi*(1440+fNumTm));

        // Convert back to ADC counts: 256/125 = 4096/2000
        // Convert back to sum (mean * num_entries)
        for (int i=0; i<1024*1440; i++)
        {
            fOffset[i] = fNumOffset         *256*base[i+1024*1440*0+4]/125;
            fGain[i]   = fNumOffset*fNumGain*256*base[i+1024*1440*2+4]/125;
        }

        for (int i=0; i<fRoi*1440; i++)
            fTrgOff[i] = fNumOffset*fNumTrgOff*256*base[i+1024*1440*4+4]/125;

        for (int i=0; i<fRoi*fNumTm; i++)
            fTrgOff[i+1440*fRoi] = fNumOffset*fNumTrgOff*256*base[i+1024*1440*4+2*fRoi*1440+4]/125;


        // DAC:  0..2.5V == 0..65535
        // V-mV: 1000
        //fNumGain *= 2500*50000;
        //for (int i=0; i<1024*1440; i++)
        //    fGain[i] *= 65536;
        if (fStep==0)
        {
            for (int i=0; i<1024*1440; i++)
                fGain[i] = fNumOffset*4096;
        }
        else
        {
            fNumGain *= 1953125;
            for (int i=0; i<1024*1440; i++)
                fGain[i] *= 1024;
        }

        // Now mark the stored DRS data as "officially valid"
        // However, this is not thread safe. It only ensures that
        // this data is not used before it is completely and correctly
        // read.
        fStep++;

        return std::string();
    }

    std::string ReadFitsImp(const std::string &str)
    {
        std::vector<float> vec;
        return ReadFitsImp(str, vec);
    }

    bool IsValid() { return fStep>2; }

    bool Apply(float *vec, const int16_t *val, const int16_t *start, uint32_t roi)
    {
        if (roi!=fRoi)
        {
            for (size_t ch=0; ch<1440; ch++)
            {
                const size_t pos = ch*roi;
                const size_t drs = ch*1024;

                DrsCalibrate::ApplyCh(vec+pos, val+pos, start[ch], roi,
                                      fOffset.data()+drs, fNumOffset,
                                      fGain.data()  +drs, fNumGain);
            }

            return false;
        }

        for (size_t ch=0; ch<1440; ch++)
        {
            const size_t pos = ch*fRoi;
            const size_t drs = ch*1024;

            DrsCalibrate::ApplyCh(vec+pos, val+pos, start[ch], roi,
                                  fOffset.data()+drs, fNumOffset,
                                  fGain.data()  +drs, fNumGain,
                                  fTrgOff.data()+pos, fNumTrgOff);
        }

        for (size_t ch=0; ch<fNumTm; ch++)
        {
            const size_t pos = (ch+1440)*fRoi;
            const size_t drs = (ch*9+8)*1024;

            DrsCalibrate::ApplyCh(vec+pos, val+pos, start[ch], roi,
                                  fOffset.data()+drs, fNumOffset,
                                  fGain.data()  +drs, fNumGain,
                                  fTrgOff.data()+pos, fNumTrgOff);
        }

        return true;
    }
};

#endif