function summary = generateTests(options)
%GENERATETESTS Generate placeholder tests for class files without tests.

    arguments
        options.force (1, 1) logical = false
        options.verbose (1, 1) logical = true
    end

    testsRoot = fileparts(mfilename('fullpath'));
    repoRoot = fileparts(testsRoot);
    classesRoot = fullfile(repoRoot, 'Classes');

    classFiles = collectMFiles(classesRoot);
    classInfos = struct('className', {}, 'relativeDir', {}, 'classFile', {});
    baseNameCounts = containers.Map('KeyType', 'char', 'ValueType', 'double');

    for idx = 1:numel(classFiles)
        classFile = fullfile(classFiles(idx).folder, classFiles(idx).name);
        if ~isClassFile(classFile)
            continue
        end

        [relativeDir, className] = relativeClassInfo(classFile, classesRoot);

        classInfos(end + 1) = struct( ... %#ok<AGROW>
            'className', className, ...
            'relativeDir', relativeDir, ...
            'classFile', classFile);

        key = lower(className);
        if isKey(baseNameCounts, key)
            baseNameCounts(key) = baseNameCounts(key) + 1;
        else
            baseNameCounts(key) = 1;
        end
    end

    generated = 0;
    skippedExisting = 0;

    for idx = 1:numel(classInfos)
        info = classInfos(idx);
        key = lower(info.className);

        testClassName = buildTestClassName( ...
            info.className, info.relativeDir, baseNameCounts(key) > 1);
        testDir = fullfile(testsRoot, info.relativeDir);
        testFile = fullfile(testDir, [testClassName, '.m']);

        if ~options.force
            if isfile(testFile)
                skippedExisting = skippedExisting + 1;
                continue
            end
        end

        if ~isfolder(testDir)
            mkdir(testDir);
        end

        createTestFile(testClassName, info.className, info.classFile, testFile);
        generated = generated + 1;
    end

    summary = struct( ...
        'generated', generated, ...
        'skippedExisting', skippedExisting, ...
        'classCount', numel(classInfos));

    if options.verbose
        fprintf(['Generated %d placeholder tests, skipped %d existing tests, ', ...
            'tracked %d class files.\n'], ...
            summary.generated, summary.skippedExisting, summary.classCount);
    end
end

function tf = isClassFile(filePath)
    source = fileread(filePath);
    tf = contains(source, 'classdef');
end

function [relativeDir, className] = relativeClassInfo(classFile, classesRoot)
    relativePath = strrep(classFile, [classesRoot, filesep], '');
    [relativeDir, className] = fileparts(relativePath);
end

function testClassName = buildTestClassName(className, relativeDir, hasDuplicateBaseName)
    if ~hasDuplicateBaseName
        testClassName = [className, '_test'];
    else
        if isempty(relativeDir)
            prefix = 'root';
        else
            prefix = regexprep(relativeDir, '[^A-Za-z0-9]+', '_');
            prefix = regexprep(prefix, '^_+|_+$', '');
        end

        testClassName = [prefix, '_', className, '_test'];
    end

    if ~isletter(testClassName(1))
        testClassName = ['T_', testClassName];
    end
end

function files = collectMFiles(rootFolder)
    pathString = genpath(rootFolder);
    folders = regexp(pathString, pathsep, 'split');
    folders = folders(~cellfun('isempty', folders));

    files = dir(fullfile(rootFolder, '*.m'));
    files = files([]); % empty struct with dir() fields

    for idx = 1:numel(folders)
        currentFiles = dir(fullfile(folders{idx}, '*.m'));
        if isempty(currentFiles)
            continue
        end

        currentFiles = currentFiles(~[currentFiles.isdir]);
        files = [files; currentFiles]; %#ok<AGROW>
    end
end