/**
 * Produces a QIDO URL given server details and a set of specified search filter
 * items
 *
 * @param server
 * @param filter
 * @returns {string} The URL with encoded filter query data
 */
function filterToQIDOURL(server, filter) {
    var commaSeparatedFields = [
        '00081030' // Study Description
        // Add more fields here if you want them in the Study List
    ].join(',');

    var parameters = {
        PatientName: filter.patientName,
        PatientID: filter.patientId,
        AccessionNumber: filter.accessionNumber,
        StudyDescription: filter.studyDescription,
        limit: filter.limit || 20,
        includefield: server.qidoSupportsIncludeField ? 'all' : commaSeparatedFields
    };
    return server.qidoRoot + '/studies?' + encodeQueryData(parameters);
}

/**
 * Parses resulting data from a QIDO call into a set of Study MetaData
 *
 * @param resultData
 * @returns {Array} An array of Study MetaData objects
 */
function resultDataToStudies(resultData) {
    var studies = [];

    resultData.forEach(function(study) {
        studies.push({
            studyInstanceUid: DICOMWeb.getString(study['0020000D']),
            // 00080005 = SpecificCharacterSet
            studyDate: DICOMWeb.getString(study['00080020']),
            studyTime: DICOMWeb.getString(study['00080030']),
            accessionNumber: DICOMWeb.getNumber(study['00080050']),
            referringPhysicianName: DICOMWeb.getString(study['00080090']),
            // 00081190 = URL
            patientName: DICOMWeb.getName(study['00100010']),
            patientId: DICOMWeb.getString(study['00100020']),
            patientBirthdate: DICOMWeb.getString(study['00100030']),
            patientSex: DICOMWeb.getString(study['00100040']),
            studyId: DICOMWeb.getString(study['00200010']),
            numberOfStudyRelatedSeries: DICOMWeb.getString(study['00201206']),
            numberOfStudyRelatedInstances: DICOMWeb.getString(study['00201208']),
            studyDescription: DICOMWeb.getString(study['00081030']),
            modalities: DICOMWeb.getString(study['00080061'])
        });
    });
    return studies;
}

Services.QIDO.Studies = function(server, filter) {
    var url = filterToQIDOURL(server, filter);
    var result = DICOMWeb.getJSON(url, server.requestOptions);
    return resultDataToStudies(result.data);
};