function tbl = issFlowImportData(fullFileName)
%FLOWIMPORTDATA Import the MFC flow-log channels from a new-format LabView file.
%
%   tbl = flowImportData(fullFileName) reads the mid-2026 LabView chamber log
%   (tab-delimited, 2 header lines, ISO-8859-1) and returns a table of the
%   7 MFC flow channels:
%     datetime  - absolute time (date + time columns)
%     MFC4 .. MFC10  - one column per mass-flow controller, named by its
%                       physical MFC number (as on the gas panel).
%       MFC4  [l/min] - cryo cooling flow (the old "flow cryo" channel)
%       MFC5..MFC10 [sccm] - dosing/carrier gas flows (the old flow1..flow6)
%
%   MFC <-> COLUMN MAPPING
%   The file's header line 1 names 7 controllers in order (MFC4..MFC10,
%   with a gas type each), and the data columns log 7 flow channels in the
%   same order (flow-cryo, then flow1..flow6). This function maps them
%   1:1 by that shared order:
%       MFC4  <- "flow cryo (l/min)"   (col 9)
%       MFC5  <- "flow1 (sccm)"        (col 11)
%       MFC6  <- "flow2 (sccm)"        (col 12)
%       MFC7  <- "flow3 (sccm)"        (col 13)
%       MFC8  <- "flow4 (sccm)"        (col 14)
%       MFC9  <- "flow5 (sccm)"        (col 15)
%       MFC10 <- "flow6 (sccm)"        (col 16)
%   This is an ORDER-MATCH inference (the file does not literally print
%   "flow3 = MFC7"), so double-check it once against the gas panel /
%   LabView front panel if in doubt. The parsed gas type per MFC (from the
%   header) is stored in tbl.Properties.UserData.mfcMap for that check.
%
%   OUTPUT
%     tbl.Properties.UserData.mfcMap  - table with MFC, SourceColumn, Gas,
%                                       Unit, MfcVarName for all 7 channels
%                                       (for verification and lookup)
%
%   EXAMPLE
%     tbl = flowImportData('01-07-2026_11-28datafile.txt');
%     tbl.Properties.UserData.mfcMap        % inspect / verify the mapping
%     ax  = plotFlowData(tbl, [4 7 10]);    % plot by MFC number
%     ax  = plotFlowData(tbl, 'flow3');     % or by the raw logged tag
%
%   See also PLOTFLOWDATA, LABVIEW_IMPORTDATA

    lines = readlines(fullFileName, 'Encoding', 'ISO-8859-1');
    lines = lines(strlength(lines) > 0);   % drop trailing blank from final CRLF

    if numel(lines) < 3
        error('flowImportData:tooShort', 'File does not look like a valid log.');
    end

    hdr1 = lines(1);   % gas name line
    hdr2 = lines(2);   % column names
    data = lines(3:end);

    if ~contains(hdr2, 'pressure_cell') && ~contains(hdr1, 'gas name')
        error('flowImportData:wrongFormat', ...
            'This does not look like the new-format LabView file (no "gas name"/"pressure_cell" header found).');
    end

    %--- Parse gas names/types from header line 1: "gas name MFCn:Gas" ---
    tok = regexp(hdr1, 'gas name (MFC\d+):(\S+)', 'tokens');
    mfcNum  = cellfun(@(t) str2double(erase(t{1},'MFC')), tok);
    gasType = cellfun(@(t) string(t{2}), tok);
    [mfcNum, order] = sort(mfcNum);
    gasType = gasType(order);

    if numel(mfcNum) ~= 7
        warning('flowImportData:unexpectedMfcCount', ...
            'Expected 7 named MFCs in the header, found %d. Mapping may be wrong.', numel(mfcNum));
    end

    %--- Parse the data rows ---
    parts = split(data, sprintf('\t'));
    if size(parts, 2) < 16
        error('flowImportData:tooFewColumns', 'Fewer columns than expected in data rows.');
    end

    dateStr = parts(:,1);
    timeStr = parts(:,2);
    dt      = datetime(strcat(dateStr, timeStr), 'InputFormat', 'dd.MM.yyyyHH:mm:ss');

    flowCryo = str2double(parts(:,9));                    % "flow cryo (l/min)"
    flowN    = str2double(parts(:,11:16));                % flow1..flow6 (sccm)

    %--- Order-matched MFC <-> column mapping ---
    columnData  = [{flowCryo}, num2cell(flowN,1)];         % 1x7 cell of column vectors
    columnNames = {'flowCryo','flow1','flow2','flow3','flow4','flow5','flow6'};
    columnUnits = [{'l/min'}, repmat({'sccm'}, 1, 6)];

    tbl = table(dt, 'VariableNames', {'datetime'});
    nCh = min(7, numel(mfcNum));
    mfcVarNames = strings(1, nCh);
    for k = 1:nCh
        varName = sprintf('MFC%d', mfcNum(k));
        tbl.(varName) = columnData{k};
        mfcVarNames(k) = varName;
    end

    mfcMap = table(mfcNum(1:nCh)', columnNames(1:nCh)', gasType(1:nCh)', columnUnits(1:nCh)', ...
        'VariableNames', {'MFC','SourceColumn','Gas','Unit'});
    mfcMap.MfcVarName = cellstr(mfcVarNames(:));

    tbl.Properties.VariableUnits = [{''}, columnUnits(1:nCh)];
    tbl.Properties.UserData = struct('mfcMap', mfcMap);
end