/* lisatools/io/readxml.c --- Copyright (c) 2006 Michele Vallisneri

   Permission is hereby granted, free of charge, to any person obtaining
   a copy of this software and associated documentation files (the
   "Software"), to deal in the Software without restriction, including
   without limitation the rights to use, copy, modify, merge, publish,
   distribute, sublicense, and/or sell copies of the Software, and to
   permit persons to whom the Software is furnished to do so, subject to
   the following conditions:
   
   The above copyright notice and this permission notice shall be
   included in all copies or substantial portions of the Software.
   
   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   SOFTWARE. */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include "ezxml.h"

#include "readxml.h"


char *stripcopy(const char *orig) {
    int pos = 0, len = 0, i;
    char *ret;
    
    /* Strip space-like characters at the beginning */

    while(orig[pos] == ' ' || orig[pos] == '\n' || orig[pos] == '\r')
        pos++;

    /* Walk until the end of the string */
        
    while(orig[pos+len] != 0)
        len++;

    /* Strip space-like characters at the end */

    len--;
    while(orig[pos+len] == ' ' || orig[pos+len] == '\n' || orig[pos+len] == '\r') len--;
    len++;

    /* Copy the string */
    
    ret = malloc( (len+1) * sizeof(char) );
    assert(ret != 0);
    
    for(i=0;i<len;i++) ret[i] = orig[pos+i];
    ret[len] = 0;
    
    return ret;
}


char *splitcopy(const char *orig,int i) {
    int pos = 0, len = 0, comma = 0, j;
    char *ret;
    
    while(comma < i && orig[pos]) {
        if(!orig[pos]) return 0;

        if(orig[pos] == ',') comma++;

        pos++;
    }

    /* Strip space-like characters at the beginning */

    while(orig[pos] == ' ' || orig[pos] == '\n' || orig[pos] == '\r')
        pos++;

    /* Walk until the end of the string */
    
    while(orig[pos+len] != 0 && orig[pos+len] != ',')
        len++;

    /* Strip space-like characters at the end */

    len--;
    while(orig[pos+len] == ' ' || orig[pos+len] == '\n' || orig[pos+len] == '\r') len--;
    len++;

    /* Copy the string */

    ret = malloc( (len+1) * sizeof(char) );
    assert(ret != 0);
        
    for(j=0;j<len;j++) ret[j] = orig[pos+j];
    ret[len] = 0;
    
    return ret;
}

/* Return string "bin" prepended with the path of string "xml" */

static char *basename(const char *xml, const char *bin) {
    int pos, i, lenbin;
    char *ret;

    /* Start at the end of string "xml", and go looking for a slash */
    pos = strlen(xml) - 1;
    while(pos >= 0 && xml[pos] != '/') pos--;

    /* If no slash is found, return 0 */
    if(pos < 0) return 0;
    pos++;

    /* Now prepare a char array to contain xml (without the last slash
       and whatever comes after it) */
    lenbin = strlen(bin);
    
    ret = malloc( (lenbin + pos + 1) * sizeof(char) );
    assert(ret != 0);

    /* Copy the first part of xml and bin into ret */
    for(i=0;i<pos;i++) ret[i] = xml[i];
    for(i=0;i<lenbin;i++) ret[i+pos] = bin[i];
    ret[lenbin + pos] = 0;

    return ret;
}


/* Endianness conversion: a bit rough, but should work */
/* From http://www.codeproject.com/cpp/endianness.asp */

#define BIGENDIAN      0
#define LITTLEENDIAN   1

int testbyteorder()
{
   short int word = 0x0001;
   char *byte = (char *) &word;
   return(byte[0] ? LITTLEENDIAN : BIGENDIAN);
}

/* This will work as long as doubles are 8 bytes */

static void convertendianness(double *val) {
    unsigned char cval[8];
    
    cval[0] = ((unsigned char *)val)[7];
    cval[1] = ((unsigned char *)val)[6];
    cval[2] = ((unsigned char *)val)[5];
    cval[3] = ((unsigned char *)val)[4];
    cval[4] = ((unsigned char *)val)[3];    
    cval[5] = ((unsigned char *)val)[2];
    cval[6] = ((unsigned char *)val)[1];
    cval[7] = ((unsigned char *)val)[0];
    
    *val = *((double *)cval);
}


static TimeSeries *dotimeseries(ezxml_t series,char *xmlname) {
    ezxml_t param, array, dim, stream;
    const char *name, *timeoffset, *cadence, *length, *records, *type, *encoding, *binaryfile;

    TimeSeries *timeseries;
    double *buffer;
    
    char *pathbinfile;
    FILE *binfile;

    int i,j,k;
        
    name = ezxml_attr(series,"Name");
    
    for(param = ezxml_child(series,"Param"); param; param = param->next) {
        // TODO: again we're reading a FrequencySeries by pretending it's a TimeSeries
        if(!strcmp(ezxml_attr(param,"Name"),"TimeOffset") || !strcmp(ezxml_attr(param,"Name"),"FrequencyOffset")) {
            timeoffset = ezxml_txt(param);
            assert(timeoffset);
            }

        if(!strcmp(ezxml_attr(param,"Name"),"Cadence")) {
            cadence = ezxml_txt(param);
            assert(cadence);
            }
    }
    
    array = ezxml_child(series,"Array");
    assert(array);
    /* Expected Array here */
    
    for(dim = ezxml_child(array,"Dim"); dim; dim = dim->next) {
        if(!strcmp(ezxml_attr(dim,"Name"),"Length")) {
            length = ezxml_txt(dim);
            assert(length);
        }
            
        if(!strcmp(ezxml_attr(dim,"Name"),"Records")) {
            records = ezxml_txt(dim);
            assert(records);
        }
    }
    
    stream = ezxml_child(array,"Stream");
    assert(stream);
    
    type = ezxml_attr(stream,"Type");
    encoding = ezxml_attr(stream,"Encoding");

    binaryfile = ezxml_txt(stream);
    assert(binaryfile);
    
    /* Now create the TimeSeries structure */
    
    timeseries = malloc(sizeof(TimeSeries));
    assert(timeseries != 0);
    
    timeseries->Name = stripcopy(name);
    timeseries->FileName = stripcopy(binaryfile);
  
    if(timeoffset) {
        timeseries->TimeOffset = strtod(timeoffset,NULL);
    } else {
        timeseries->TimeOffset = 0.0;
    }
    
    timeseries->Cadence = strtod(cadence,NULL);

    timeseries->Length = strtol(length,NULL,10);
    timeseries->Records = strtol(records,NULL,10);
        
    fprintf(stderr,"Allocating %d bytes for read buffer...\n",timeseries->Length * timeseries->Records * sizeof(double));
    buffer = malloc(timeseries->Length * timeseries->Records * sizeof(double));
    assert(buffer != 0);

    /* Note: pathbinfile may return zero if xmlname has no path; in this case
       fopen should safely return zero also, no harm done. */
    pathbinfile = basename(xmlname,timeseries->FileName);

    binfile = fopen(pathbinfile,"r");

    if(binfile == 0) {             
        fprintf(stderr,"...can't find %s, trying in the working directory...\n",pathbinfile);                                                                    
        
        binfile = fopen(timeseries->FileName,"r");
        assert(binfile != 0);
    }
    
    free(pathbinfile);
    
    fread(buffer,sizeof(double),timeseries->Length * timeseries->Records,binfile);

    /* Do the encoding switch if necessary */

    if( (strstr(encoding,"LittleEndian") && testbyteorder() == BIGENDIAN) ||
        (strstr(encoding,"BigEndian")    && testbyteorder() == LITTLEENDIAN) ) {
        fprintf(stderr,"Converting endianness of binary data!\n");
        
        for(i=0;i<timeseries->Length * timeseries->Records;i++)
            convertendianness(&buffer[i]);
    }
        
    fclose(binfile);

    timeseries->Data = malloc(timeseries->Records * sizeof(DataColumn *));
    assert(timeseries->Data != 0);
    
    for(i=0;i<timeseries->Records;i++) {
        timeseries->Data[i] = malloc(sizeof(DataColumn));
        assert(timeseries->Data[i] != 0);
        
        timeseries->Data[i]->Name = splitcopy(timeseries->Name,i);
        
        timeseries->Data[i]->TimeOffset = timeseries->TimeOffset;
        timeseries->Data[i]->Cadence = timeseries->Cadence;

        timeseries->Data[i]->Length = timeseries->Length;
        
        timeseries->Data[i]->data = malloc(timeseries->Length * sizeof(double));
        assert(timeseries->Data[i]->data != 0);

        for(j=0;j<timeseries->Length;j++) {
            timeseries->Data[i]->data[j] = buffer[(j*timeseries->Records) + i];
        }
    }
    
    free(buffer);
    
    return timeseries;
}


void freeTimeSeries(TimeSeries *timeseries) {
    int i;

    for(i=0;i<timeseries->Records;i++) {
        free(timeseries->Data[i]->data);
        free(timeseries->Data[i]->Name);
        
        free(timeseries->Data[i]);
    }
    
    free(timeseries->Data);
    
    free(timeseries->FileName);
    free(timeseries->Name);
    
    free(timeseries);
}


void freeLISASources(LISASource *lisasource) {
    LISASource *next, *current;

    next = lisasource;

    while(next) {
        current = next;
        next = current->NextSource;
        
        free(current->Name);
        free(current->TimeSeries);
    }
}


LISASource *getLISASources(char *filename) {
    ezxml_t tree, section, source, param, series;
    const char *type, *name, *elat, *elon, *pol;

    LISASource *first = 0, *current = 0;
    TimeSeries *timeseries = 0;

    tree = ezxml_parse_file(filename);
    assert(tree);

    for(section = ezxml_child(tree, "XSIL"); section; section = section->next) {
        type = ezxml_attr(section, "Type");
        
        if(!strcmp(type,"SourceData")) {
            for(source = ezxml_child(section,"XSIL"); source; source = source->next) { 
                assert(!strcmp(ezxml_attr(source,"Type"),"SampledPlaneWave"));
                /* Expected SampledPlaneWave here... */

                name = ezxml_attr(source,"Name");

                for(param = ezxml_child(source,"Param"); param; param = param->next) {
                    if(!strcmp(ezxml_attr(param,"Name"),"EclipticLatitude")) {
                        elat = ezxml_txt(param);
                        assert(elat);
                    }
            
                    if(!strcmp(ezxml_attr(param,"Name"),"EclipticLongitude")) {
                        elon = ezxml_txt(param);
                        assert(elon);
                    }
                        
                    if(!strcmp(ezxml_attr(param,"Name"),"Polarization")) {
                        pol = ezxml_txt(param);
                        assert(pol);
                    }
                }

                if(!first) {
                    first = malloc(sizeof(LISASource));
                    assert(first != 0);

                    current = first;
                } else {
                    current->NextSource = malloc(sizeof(LISASource));
                    assert(current->NextSource != 0);

                    current = current->NextSource;
                }

                current->Name = stripcopy(name);

                current->EclipticLatitude  = strtod(elat,NULL); 
                current->EclipticLongitude = strtod(elon,NULL);                 
                current->Polarization      = strtod(pol,NULL);
                        
                series = ezxml_child(source,"XSIL");
                assert(!strcmp(ezxml_attr(series,"Type"),"TimeSeries"));
                /* Expected TimeSeries here... */

                current->TimeSeries = dotimeseries(series,filename);

                current->NextSource = 0;
            }
        }
    }

    ezxml_free(tree);
    
    return first;
}


/* For the moment, support only the first TDIObservable/TimeSeries section per file */

TimeSeries *getTDIdata(char *filename) {
    ezxml_t tree, section, obs, series;
    const char *type;
    TimeSeries *timeseries = 0;

    tree = ezxml_parse_file(filename);
    assert(tree);
    
    for(section = ezxml_child(tree, "XSIL"); section; section = section->next) {
        type = ezxml_attr(section, "Type");
        
        if(!strcmp(type,"TDIData")) {
            for(obs = ezxml_child(section,"XSIL"); obs; obs = obs->next) {
                assert(!strcmp(ezxml_attr(obs,"Type"),"TDIObservable"));
            
                series = ezxml_child(obs,"XSIL");
                if(!strcmp(ezxml_attr(series,"Type"),"TimeSeries")) {
                    timeseries = dotimeseries(series,filename);
                    return timeseries;
                }
            }
        }
    }

    ezxml_free(tree);

    return 0;
}

TimeSeries *getmultipleTDIdata(char *filename,int obsnum) {
    ezxml_t tree, section, obs, series;
    const char *type;
    TimeSeries *timeseries = 0;

    tree = ezxml_parse_file(filename);
    assert(tree);
    
    for(section = ezxml_child(tree, "XSIL"); section; section = section->next) {
        type = ezxml_attr(section, "Type");
        
        if(!strcmp(type,"TDIData")) {
            int obscnt = 0;
            
            for(obs = ezxml_child(section,"XSIL"); obs; obs = obs->next) {
                assert(!strcmp(ezxml_attr(obs,"Type"),"TDIObservable"));
                
                if(obscnt == obsnum) {
                    series = ezxml_child(obs,"XSIL");
                    // TODO: here we're reading a FrequencySeries by pretending it's a TimeSeries
                    if(!strcmp(ezxml_attr(series,"Type"),"TimeSeries") || !strcmp(ezxml_attr(series,"Type"),"FrequencySeries")) {
                        timeseries = dotimeseries(series,filename);
                        return timeseries;
                    }
                }
                
                obscnt++;
            }
        }
    }

    ezxml_free(tree);

    return 0;    
}