/**
 * Retrieve a location name (e.g. Liver Right) from the
 * PatientLocations Collection by id, if it exists. Otherwise,
 * return an empty string.
 *
 * @param id
 * @returns {*|string}
 */
function getLocationName(id) {
    var locationObject = PatientLocations.findOne(id);
    if (!locationObject || !locationObject.location) {
        return '';
    }

    return locationObject.location;
}

/**
 * Update the Timepoint object for a specific Measurement.
 * If no measurement exists yet, one will be created.
 *
 * Input is toolData from the lesion or nonTarget tool
 *
 * @param lesionData
 */
function updateLesionData(lesionData) {
    var study = Studies.findOne({
        studyInstanceUid: lesionData.studyInstanceUid
    });

    if (!study) {
        log.warn('Study is not associated with a timepoint');
        return;
    }


    var timepoint = Timepoints.findOne({
        timepointId: study.timepointId
    });

    if (!timepoint) {
        log.warn('Timepoint in an image is not present in the Timepoints Collection?');
        return;
    }

    // Find the specific lesion to be updated
    var existingMeasurement;
    if (lesionData.id && lesionData.id !== 'notready') {
        existingMeasurement = Measurements.findOne(lesionData.id);
    } else {
        existingMeasurement = Measurements.findOne({
            lesionNumber: lesionData.lesionNumber,
            isTarget: lesionData.isTarget
        });
    }

    // Create a structure for the timepointData based
    // on this Lesion's toolData
    var timepointData = {
        seriesInstanceUid: lesionData.seriesInstanceUid,
        studyInstanceUid: lesionData.studyInstanceUid,
        sopInstanceUid: lesionData.sopInstanceUid,
        handles: lesionData.handles,
        imageId: lesionData.imageId
    };

    if (lesionData.isTarget === true) {
        timepointData.shortestDiameter = lesionData.widthMeasurement;
        timepointData.longestDiameter = lesionData.measurementText;
    } else {
        timepointData.response = lesionData.response;
    }

    // If no such lesion exists, we need to add one
    if (!existingMeasurement) {
        // Create a data structure for the Measurement
        // based on the current tool data
        var measurement = {
            lesionNumber: lesionData.lesionNumber,
            isTarget: lesionData.isTarget,
            patientId: lesionData.patientId,
            id: lesionData.id
        };

        // Retrieve the location name given the locationUID
        if (lesionData.locationUID !== undefined) {
            var locationObj = PatientLocations.findOne({
                locationUID: lesionData.locationUID
            });

            measurement.location = locationObj.location;
            measurement.isNodal = locationObj.isNodal;
        }

        // Add toolData parameters to the Measurement at this Timepoint
        measurement.timepoints = {};
        measurement.timepoints[timepoint.timepointId] = timepointData;

        // Set a flag to prevent duplication of toolData
        measurement.toolDataInsertedManually = true;

        // Increment and store the absolute Lesion Number for this Measurement
        measurement.lesionNumberAbsolute = Measurements.find().count() + 1;

        // Insert this into the Measurements Collection
        // Save the ID into the toolData (not sure if this works?)
        measurement.id = Measurements.insert(measurement);

        // Update the database entry so it can be readded next time the study is loaded
        Measurements.update(measurement.id, {
            $set: {
                toolDataInsertedManually: false
            }
        });
    } else {
        lesionData.id = existingMeasurement._id;
        lesionData.isNodal = existingMeasurement.isNodal;

        // Update timepoints from lesion data
        existingMeasurement.timepoints[timepoint.timepointId] = timepointData;

        Measurements.update(existingMeasurement._id, {
            $set: {
                timepoints: existingMeasurement.timepoints
            }
        });
    }
}

/**
 * Returns new lesion number according to timepointId
 * @param timepointId
 * @param isTarget
 * @returns {*}
 */
function getNewLesionNumber(timepointId, isTarget) {
    // Get all current lesion measurements
    var numMeasurements = Measurements.find({
        isTarget: isTarget
    }).count();

    // If no measurements exist yet, start at 1
    if (!numMeasurements) {
        return 1;
    }

    // Find related measurements (i.e. target or non-target)
    var measurements = Measurements.find({
        isTarget: isTarget
    }, {
        sort: {
            lesionNumber: 1
        }
    }).fetch();

    // If measurements exist, find the last lesion number
    // from the given timepoint
    var lesionNumberCounter = 1;

    // Search through every Measurement to see which ones
    // already have data for this Timepoint, if we find one that
    // doesn't have data, we will stop there and use that as the
    // current Measurement
    measurements.every(function(measurement) {
        // If this measurement has no data for this Timepoint,
        // use this as the current Measurement
        if (!measurement.timepoints[timepointId]) {
            lesionNumberCounter = measurement.lesionNumber;
            return false;
        }

        lesionNumberCounter++;
        return true;
    });
    return lesionNumberCounter;
}

/**
 * If the current Lesion Number already exists
 * for any other timepoint, returns lesion locationUID
 * @param lesionData
 * @returns {*}
 */
function lesionNumberExists(lesionData) {
    var measurement = Measurements.findOne({
        lesionNumber: lesionData.lesionNumber,
        isTarget: lesionData.isTarget
    });

    if (!measurement) {
        return;
    }

    return measurement.locationUID;
}

LesionManager = {
    updateLesionData: updateLesionData,
    getNewLesionNumber: getNewLesionNumber,
    lesionNumberExists: lesionNumberExists,
    getLocationName: getLocationName
};