/* 
 * Copyright (c) 2007 Sean C. Rhea (srhea@srhea.net), 
 *                    Justin F. Knotzke (jknotzke@shampoo.ca)
 *
 * This program 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 2 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, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */


#include "CsvRideFile.h"
#include <QRegExp>
#include <QTextStream>
#include <algorithm> // for std::sort
#include <assert.h>
#include "math.h"

#define MILES_TO_KM 1.609344
        
static int csvFileReaderRegistered = 
    RideFileFactory::instance().registerReader("csv", new CsvFileReader());
 
RideFile *CsvFileReader::openRideFile(QFile &file, QStringList &errors) const 
{
    QRegExp metricUnits("(km|kph|km/h)", Qt::CaseInsensitive);
    QRegExp englishUnits("(miles|mph|mp/h)", Qt::CaseInsensitive);
    bool metric;

    
    // TODO: a more robust regex for ergomo files
    // i don't have an example with english headers
    // the ergomo CSV has two rows of headers. units are on the second row.
    /*
    ZEIT,STRECKE,POWER,RPM,SPEED,PULS,HÖHE,TEMP,INTERVAL,PAUSE
    L_SEC,KM,WATT,RPM,KM/H,BPM,METER,°C,NUM,SEC
    */
    QRegExp ergomoCSV("(ZEIT|STRECKE)", Qt::CaseInsensitive);
    bool ergomo = false;
    int unitsHeader = 1;
    int total_pause = 0;
    
    // TODO: with all these formats, should the logic change to a switch/case structure?
    // The iBike format CSV file has five lines of headers (data begins on line 6)
    // starting with:
    /*
    iBike,8,english
    2008,8,8,6,32,52
    
    {Various configuration data, recording interval at line[4][4]}
    Speed (mph),Wind Speed (mph),Power (W),Distance (miles),Cadence (RPM),Heartrate (BPM),Elevation (feet),Hill slope (%),Internal,Internal,Internal,DFPM Power,Latitude,Longitude
    */
	//  Modified the regExp string to allow for 2-digit version numbers - 23 Mar 2009, thm
    QRegExp iBikeCSV("iBike,\\d\\d?,[a-z]+", Qt::CaseInsensitive);
    bool iBike = false;
    int recInterval;
    
    if (!file.open(QFile::ReadOnly)) {
        errors << ("Could not open ride file: \"" 
                   + file.fileName() + "\"");
        return NULL;
    }
    int lineno = 1;
    QTextStream is(&file);
    RideFile *rideFile = new RideFile();
    while (!is.atEnd()) {
        // the readLine() method doesn't handle old Macintosh CR line endings
        // this workaround will load the the entire file if it has CR endings
        // then split and loop through each line
        // otherwise, there will be nothing to split and it will read each line as expected.
        QString linesIn = is.readLine();
        QStringList lines = linesIn.split('\r');
        // workaround for empty lines
        if(lines.isEmpty()) {
            lineno++;
            continue;
        }
        for (int li = 0; li < lines.size(); ++li) { 
            QString line = lines[li];

            if (lineno == 1) {
                if (ergomoCSV.indexIn(line) != -1) {
                    ergomo = true;
                    rideFile->setDeviceType("Ergomo CSV");
                    unitsHeader = 2;
                    ++lineno;
                    continue;
                }
                else {
                    if(iBikeCSV.indexIn(line) != -1) {
                        iBike = true;
                        rideFile->setDeviceType("iBike CSV");
                        unitsHeader = 5;
                        ++lineno;
                        continue;
                    }
                    rideFile->setDeviceType("PowerTap CSV");
                }
            }
            if (iBike && lineno == 4) {
                // this is the line with the iBike configuration data
                // recording interval is in the [4] location (zero-based array)
                // the trailing zeroes in the configuration area seem to be causing an error
                // the number is in the format 5.000000
                recInterval	  = (int)line.section(',',4,4).toDouble();
            }
            if (lineno == unitsHeader) {
                if (metricUnits.indexIn(line) != -1)
                    metric = true;
                else if (englishUnits.indexIn(line) != -1) 
                    metric = false;
                else {
                    errors << "Can't find units in first line: \"" + line + "\" of file \"" + file.fileName() +	"\".";
                    delete rideFile;
                    file.close();
                    return NULL;
                }
            }
            else if (lineno > unitsHeader) {
                double minutes,nm,kph,watts,km,cad,hr;
                int interval;
                int pause;
                if (!ergomo && !iBike) {
                     minutes     = line.section(',', 0, 0).toDouble();
                     nm		 = line.section(',', 1, 1).toDouble();
                     kph	 = line.section(',', 2, 2).toDouble();
                     watts	 = line.section(',', 3, 3).toDouble();
                     km		 = line.section(',', 4, 4).toDouble();
                     cad	 = line.section(',', 5, 5).toDouble();
                     hr		 = line.section(',', 6, 6).toDouble();
                     interval	= line.section(',', 7, 7).toInt();
                    if (!metric) {
                        km *= MILES_TO_KM;
                        kph *= MILES_TO_KM;
                    }
                } 
                else if (iBike) {
                    // this must be iBike
                    // can't find time as a column.
                    // will we have to extrapolate based on the recording interval?
                    // reading recording interval from config data in ibike csv file
                     minutes = (recInterval * lineno - unitsHeader)/60.0;
                     nm		 = NULL; //no torque
                     kph	 = line.section(',', 0, 0).toDouble();
                     watts	 = line.section(',', 2, 2).toDouble();
                     km		 = line.section(',', 3, 3).toDouble();
                     cad	 = line.section(',', 4, 4).toDouble();
                     hr		 = line.section(',', 5, 5).toDouble();
                     interval	= NULL; //not provided?
                    if (!metric) {
                        km *= MILES_TO_KM;
                        kph *= MILES_TO_KM;
                    }			 
                }
                else {
                     // for ergomo formatted CSV files
                     minutes     = line.section(',', 0, 0).toDouble() + total_pause;
                     km		 = line.section(',', 1, 1).toDouble();
                     watts	 = line.section(',', 2, 2).toDouble();
                     cad	 = line.section(',', 3, 3).toDouble();
                     kph	 = line.section(',', 4, 4).toDouble();
                     hr		 = line.section(',', 5, 5).toDouble();
                     interval	 = line.section(',', 8, 8).toInt();
                     pause	 = line.section(',', 9, 9).toInt();
                     total_pause += pause;
                     nm		 = NULL; // torque is not provided in the Ergomo file
                    
                     // the ergomo records the time in whole seconds
                     // RECORDING INT. 1, 2, 5, 10, 15 or 30 per sec
                     // Time is *always* perfectly sequential.  To find pauses,
                     // you need to read the PAUSE column.
                     minutes = minutes/60.0;
                    
                     if (!metric) {
                         km *= MILES_TO_KM;
                         kph *= MILES_TO_KM;
                     }
                }
                
                // PT reports no data as watts == -1.
                if (watts == -1)
                    watts = 0;
                
                rideFile->appendPoint(minutes * 60.0, cad, hr, km, 
                                      kph, nm, watts, interval);
            }
        ++lineno;
        }
    }
    file.close();

    // To estimate the recording interval, take the median of the
    // first 1000 samples and round to nearest millisecond.
    int n = rideFile->dataPoints().size();
    n = qMin(n, 1000);
    if (n >= 2) {
        double *secs = new double[n-1];
        for (int i = 0; i < n-1; ++i) {
            double now = rideFile->dataPoints()[i]->secs;
            double then = rideFile->dataPoints()[i+1]->secs;
            secs[i] = then - now;
        }
        std::sort(secs, secs + n - 1);
        int mid = n / 2 - 1;
        double recint = round(secs[mid] * 1000.0) / 1000.0;
        rideFile->setRecIntSecs(recint);
    }
    // less than 2 data points is not a valid ride file
    else {
	errors << "Insufficient valid data in file \"" + file.fileName() + "\".";
	delete rideFile;
	file.close();
	return NULL;
    }

    QRegExp rideTime("^.*/(\\d\\d\\d\\d)_(\\d\\d)_(\\d\\d)_"
                     "(\\d\\d)_(\\d\\d)_(\\d\\d)\\.csv$");
    if (rideTime.indexIn(file.fileName()) >= 0) {
        QDateTime datetime(QDate(rideTime.cap(1).toInt(),
                                 rideTime.cap(2).toInt(),
                                 rideTime.cap(3).toInt()),
                           QTime(rideTime.cap(4).toInt(),
                                 rideTime.cap(5).toInt(),
                                 rideTime.cap(6).toInt()));
        rideFile->setStartTime(datetime);
    }

    return rideFile;
}