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feat: Teilnehmerlisten in Lerngruppen importieren

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admin
2026-08-18 00:44:07 +02:00
parent cdac335ad1
commit 99efa3a0fe
11 changed files with 489 additions and 79 deletions
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LehrerApp.Core/Importing/DelimitedTextParser.cs
+77
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@@ -0,0 +1,77 @@
using System.Text;
namespace LehrerApp.Core.Importing;
internal sealed record DelimitedRecord(int LineNumber, IReadOnlyList<string> Fields);
internal static class DelimitedTextParser
{
public static bool TryParse(
string text,
char delimiter,
out List<DelimitedRecord> records,
out string? error)
{
records = [];
error = null;
var fields = new List<string>();
var field = new StringBuilder();
var inQuotes = false;
var line = 1;
var recordStartLine = 1;
for (var index = 0; index < text.Length; index++)
{
var current = text[index];
if (current == '"')
{
if (inQuotes && index + 1 < text.Length && text[index + 1] == '"')
{
field.Append('"');
index++;
}
else
{
inQuotes = !inQuotes;
}
continue;
}
if (current == delimiter && !inQuotes)
{
fields.Add(field.ToString());
field.Clear();
continue;
}
if ((current == '\r' || current == '\n') && !inQuotes)
{
if (current == '\r' && index + 1 < text.Length && text[index + 1] == '\n')
index++;
fields.Add(field.ToString());
field.Clear();
records.Add(new DelimitedRecord(recordStartLine, fields.ToList()));
fields.Clear();
line++;
recordStartLine = line;
continue;
}
if (current == '\n') line++;
field.Append(current);
}
if (inQuotes)
{
error = $"Ein Textfeld ab Zeile {recordStartLine} besitzt kein schließendes Anführungszeichen.";
return false;
}
if (field.Length > 0 || fields.Count > 0)
{
fields.Add(field.ToString());
records.Add(new DelimitedRecord(recordStartLine, fields.ToList()));
}
return true;
}
}
LehrerApp.Core/Importing/LessonStudentListCsvImportHandler.cs
+121
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@@ -0,0 +1,121 @@
using System.Text;
using LehrerApp.Core.Models;
namespace LehrerApp.Core.Importing;
/// <summary>Importiert den tabulatorgetrennten Export „Teilnehmerliste“ eines Unterrichts.</summary>
public sealed class LessonStudentListCsvImportHandler : IImportHandler<ImportedStudent>
{
private static readonly string[] SignatureHeaders =
["Langname", "Vorname", "Klasse", "Geschlecht", "Eintrittsdatum", "Austrittsdatum",
"E-Mail Adresse", "Mobiltelefon", "Telefonnummer"];
private static readonly UTF8Encoding StrictUtf8 = new(false, true);
public ImportFormatId FormatId => StudentImportFormats.LessonStudentListCsv;
public string DisplayName => "Unterrichts-Teilnehmerliste";
public IReadOnlyCollection<string> SupportedExtensions { get; } = [".csv"];
public ValueTask<ImportDetection> DetectAsync(ImportFile file, CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
if (!TryDecode(file, out var text))
return ValueTask.FromResult(ImportDetection.NoMatch("Die Datei ist kein gültiges UTF-8."));
var headers = FirstLine(text).Split('\t').Select(x => x.Trim())
.ToHashSet(StringComparer.OrdinalIgnoreCase);
return ValueTask.FromResult(SignatureHeaders.All(headers.Contains)
? ImportDetection.Match(file.Extension.Equals(".csv", StringComparison.OrdinalIgnoreCase) ? 100 : 95,
"Die charakteristischen Spalten der Unterrichts-Teilnehmerliste wurden gefunden.")
: ImportDetection.NoMatch("Die erwarteten Spalten der Unterrichts-Teilnehmerliste fehlen."));
}
public ValueTask<ImportParseResult<ImportedStudent>> ParseAsync(ImportFile file, CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
var messages = new List<ImportMessage>();
if (!TryDecode(file, out var text))
return Result([], [Error("lesson-students.encoding", "Die Teilnehmerliste ist nicht als gültiges UTF-8 gespeichert.")]);
if (!DelimitedTextParser.TryParse(text, '\t', out var records, out var parseError))
return Result([], [Error("lesson-students.structure", parseError ?? "Die Teilnehmerliste ist syntaktisch ungültig.")]);
if (records.Count == 0)
return Result([], [Error("lesson-students.empty", "Die Teilnehmerliste ist leer.")]);
var header = records[0].Fields.Select((name, index) => (Name: name.Trim().TrimStart('\uFEFF'), Index: index)).ToList();
var duplicate = header.GroupBy(x => x.Name, StringComparer.OrdinalIgnoreCase).FirstOrDefault(x => x.Count() > 1);
if (duplicate is not null)
messages.Add(Error("lesson-students.header.duplicate", $"Die Spalte „{duplicate.Key}“ kommt mehrfach vor.", "Kopfzeile"));
var columns = header.GroupBy(x => x.Name, StringComparer.OrdinalIgnoreCase)
.ToDictionary(x => x.Key, x => x.First().Index, StringComparer.OrdinalIgnoreCase);
foreach (var required in SignatureHeaders.Where(x => !columns.ContainsKey(x)))
messages.Add(Error("lesson-students.header.missing", $"Die erforderliche Spalte „{required}“ fehlt.", "Kopfzeile"));
if (messages.Any(x => x.Severity == ImportMessageSeverity.Error)) return Result([], messages);
var students = new List<ImportedStudent>();
foreach (var record in records.Skip(1))
{
cancellationToken.ThrowIfCancellationRequested();
if (record.Fields.All(string.IsNullOrWhiteSpace)) continue;
var source = $"Zeile {record.LineNumber}";
if (record.Fields.Count != header.Count)
{
messages.Add(Error("lesson-students.columns",
$"Die Zeile enthält {record.Fields.Count} statt {header.Count} Spalten.", source));
continue;
}
students.Add(new ImportedStudent
{
LastName = Value(record, columns, "Langname"),
FirstName = Value(record, columns, "Vorname"),
GroupName = NullIfEmpty(Value(record, columns, "Klasse")),
Gender = ParseGender(Value(record, columns, "Geschlecht"), source, messages),
Contact = new ImportedStudentContact
{
Email = NullIfEmpty(Value(record, columns, "E-Mail Adresse")),
MobilePhone = NullIfEmpty(Value(record, columns, "Mobiltelefon")),
Phone = NullIfEmpty(Value(record, columns, "Telefonnummer")),
},
SourceReference = source,
});
}
return Result(students, messages);
}
private static Gender? ParseGender(string value, string source, ICollection<ImportMessage> messages)
{
if (string.IsNullOrWhiteSpace(value)) return null;
return value.Trim().ToLowerInvariant() switch
{
"m" or "männlich" or "maennlich" => Gender.M,
"w" or "weiblich" => Gender.W,
"d" or "divers" => Gender.D,
_ => UnknownGender(value, source, messages),
};
}
private static Gender? UnknownGender(string value, string source, ICollection<ImportMessage> messages)
{
messages.Add(new ImportMessage(ImportMessageSeverity.Warning, "lesson-students.gender.unknown",
$"Das Geschlecht „{value.Trim()}“ ist unbekannt und wird nicht übernommen.", source));
return null;
}
private static bool TryDecode(ImportFile file, out string text)
{
try { text = StrictUtf8.GetString(file.Content.Span); return true; }
catch (DecoderFallbackException) { text = ""; return false; }
}
private static string FirstLine(string text)
{
var end = text.IndexOfAny(['\r', '\n']);
return (end >= 0 ? text[..end] : text).TrimStart('\uFEFF');
}
private static string Value(DelimitedRecord row, IReadOnlyDictionary<string, int> columns, string name) =>
columns.TryGetValue(name, out var index) && index < row.Fields.Count ? row.Fields[index].Trim() : "";
private static string? NullIfEmpty(string value) => string.IsNullOrWhiteSpace(value) ? null : value.Trim();
private static ImportMessage Error(string code, string message, string? source = null) =>
new(ImportMessageSeverity.Error, code, message, source);
private static ValueTask<ImportParseResult<ImportedStudent>> Result(
IReadOnlyList<ImportedStudent> students, IReadOnlyList<ImportMessage> messages) =>
ValueTask.FromResult(new ImportParseResult<ImportedStudent>(students, messages));
}
LehrerApp.Core/Importing/MarksPerLessonCsvImportHandler.cs
+40
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@@ -0,0 +1,40 @@
using System.Text;
namespace LehrerApp.Core.Importing;
/// <summary>Erkennt den Notenlistenexport und erklärt dessen fehlende Teilnehmerdaten.</summary>
public sealed class MarksPerLessonCsvImportHandler : IImportHandler<ImportedStudent>
{
private static readonly string[] SignatureHeaders =
["Datum", "Name", "Klasse", "Fach", "Prüfungsart", "Note", "Bemerkung", "Benutzer", "Schlüssel (extern)", "Gesamtnote"];
private static readonly UTF8Encoding StrictUtf8 = new(false, true);
public ImportFormatId FormatId => StudentImportFormats.MarksPerLessonCsv;
public string DisplayName => "Unterrichts-Notenliste";
public IReadOnlyCollection<string> SupportedExtensions { get; } = [".csv"];
public ValueTask<ImportDetection> DetectAsync(ImportFile file, CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
string text;
try { text = StrictUtf8.GetString(file.Content.Span); }
catch (DecoderFallbackException) { return ValueTask.FromResult(ImportDetection.NoMatch()); }
var end = text.IndexOfAny(['\r', '\n']);
var firstLine = (end >= 0 ? text[..end] : text).TrimStart('\uFEFF');
var headers = firstLine.Split('\t').Select(x => x.Trim()).ToHashSet(StringComparer.OrdinalIgnoreCase);
return ValueTask.FromResult(SignatureHeaders.All(headers.Contains)
? ImportDetection.Match(file.Extension.Equals(".csv", StringComparison.OrdinalIgnoreCase) ? 100 : 95)
: ImportDetection.NoMatch());
}
public ValueTask<ImportParseResult<ImportedStudent>> ParseAsync(ImportFile file, CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
IReadOnlyList<ImportMessage> messages =
[
new(ImportMessageSeverity.Error, "marks-per-lesson.no-participants",
"Die Notenliste enthält keine verlässlichen Teilnehmerdaten. Bitte exportiere die echte Kurs-/Teilnehmerliste.")
];
return ValueTask.FromResult(new ImportParseResult<ImportedStudent>([], messages));
}
}
LehrerApp.Core/Importing/StudentImportModels.cs
+5
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@@ -32,6 +32,8 @@ public sealed record ImportedStudent
public static class StudentImportFormats
{
public static readonly ImportFormatId MasterDataCsv = new("student-master-data.csv");
public static readonly ImportFormatId LessonStudentListCsv = new("lesson-student-list.csv");
public static readonly ImportFormatId MarksPerLessonCsv = new("marks-per-lesson.csv");
}
public enum StudentImportResolutionKind { CreateNew, UseExisting, Skip }
@@ -60,6 +62,7 @@ public sealed class StudentImportPreview
public IReadOnlyList<ImportMessage> Messages { get; }
public IReadOnlyList<ImportConflict> Conflicts { get; }
public IReadOnlyList<StudentImportGroupAssignment> GroupAssignments { get; }
public Guid? TargetGroupId { get; }
internal string ExistingStudentsFingerprint { get; }
internal string GroupStateFingerprint { get; }
@@ -73,6 +76,7 @@ public sealed class StudentImportPreview
IEnumerable<ImportMessage> messages,
IEnumerable<ImportConflict> conflicts,
IEnumerable<StudentImportGroupAssignment> groupAssignments,
Guid? targetGroupId,
string existingStudentsFingerprint,
string groupStateFingerprint)
{
@@ -82,6 +86,7 @@ public sealed class StudentImportPreview
Messages = ReadOnly(messages);
Conflicts = ReadOnly(conflicts);
GroupAssignments = ReadOnly(groupAssignments);
TargetGroupId = targetGroupId;
ExistingStudentsFingerprint = existingStudentsFingerprint;
GroupStateFingerprint = groupStateFingerprint;
}
LehrerApp.Core/Importing/StudentMasterDataCsvImportHandler.cs
-73
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@@ -222,77 +222,4 @@ public sealed class StudentMasterDataCsvImportHandler : IImportHandler<ImportedS
private static string? NullIfWhiteSpace(string? value) =>
string.IsNullOrWhiteSpace(value) ? null : value.Trim();
private sealed record DelimitedRecord(int LineNumber, IReadOnlyList<string> Fields);
private static class DelimitedTextParser
{
public static bool TryParse(
string text,
char delimiter,
out List<DelimitedRecord> records,
out string? error)
{
records = [];
error = null;
var fields = new List<string>();
var field = new StringBuilder();
var inQuotes = false;
var line = 1;
var recordStartLine = 1;
for (var index = 0; index < text.Length; index++)
{
var current = text[index];
if (current == '"')
{
if (inQuotes && index + 1 < text.Length && text[index + 1] == '"')
{
field.Append('"');
index++;
}
else
{
inQuotes = !inQuotes;
}
continue;
}
if (current == delimiter && !inQuotes)
{
fields.Add(field.ToString());
field.Clear();
continue;
}
if ((current == '\r' || current == '\n') && !inQuotes)
{
if (current == '\r' && index + 1 < text.Length && text[index + 1] == '\n')
index++;
fields.Add(field.ToString());
field.Clear();
records.Add(new DelimitedRecord(recordStartLine, fields.ToList()));
fields.Clear();
line++;
recordStartLine = line;
continue;
}
if (current == '\n') line++;
field.Append(current);
}
if (inQuotes)
{
error = $"Ein Textfeld ab Zeile {recordStartLine} besitzt kein schließendes Anführungszeichen.";
return false;
}
if (field.Length > 0 || fields.Count > 0)
{
fields.Add(field.ToString());
records.Add(new DelimitedRecord(recordStartLine, fields.ToList()));
}
return true;
}
}
}