[chore:] implemented initial crafting functio

crafter.cs

@@ -1,9 +1,213 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
 namespace spplus;
 
 public class CourseCrafter
 {
+    private class CourseInstance
+    {
+        public Sport Sport = null!;
+        public int Remaining;
+        public List<Student> Students = new();
+    }
     public static void Craft()
     {
+        var settings = Settings.Instance;
+        var students = settings.Students;
+        var sports = settings.Sports;
 
+        if (students.Count == 0 || sports.Count == 0)
+            return;
+
+        int semesterCount = sports.Max(s => s.Semester.Length);
+
+        // Result initialisieren
+        foreach (var st in students)
+            st.Result = Enumerable.Repeat("Fehler", semesterCount).ToList();
+
+        // Mapping Name + Alternativen → Sport
+        var nameMap = new Dictionary<string, Sport>(StringComparer.OrdinalIgnoreCase);
+        foreach (var sp in sports)
+        {
+            nameMap[sp.Name] = sp;
+            foreach (var alt in sp.AlternativeNames)
+                nameMap[alt] = sp;
+        }
+
+        // ===== Semesterweise Planung =====
+        for (int sem = 0; sem < semesterCount; sem++)
+        {
+            int remainingCourseSlots = settings.NumCoursesPerSemester;
+
+            // Interessenten dieses Semesters
+            var interested = new Dictionary<Sport, List<Student>>();
+            foreach (var sp in sports)
+                interested[sp] = new List<Student>();
+
+            foreach (var st in students)
+            {
+                if (st.SelectedCourseNames.Count <= sem)
+                    continue;
+
+                var sel = st.SelectedCourseNames[sem];
+                if (nameMap.TryGetValue(sel, out var sp))
+                    interested[sp].Add(st);
+            }
+
+            var instances = new List<CourseInstance>();
+
+            // ===== Kurse erzeugen =====
+            foreach (var sp in sports)
+            {
+                if (sem >= sp.Semester.Length)
+                    continue;
+
+                int demand = interested[sp].Count;
+                if (demand < sp.MinStudents)
+                    continue;
+
+                int needed = (int)Math.Ceiling(demand / (double)sp.MaxStudents);
+                int allowed = Math.Min(needed, sp.Semester[sem]);
+                allowed = Math.Min(allowed, remainingCourseSlots);
+
+                if (allowed <= 0)
+                    continue;
+
+                remainingCourseSlots -= allowed;
+
+                for (int i = 0; i < allowed; i++)
+                {
+                    instances.Add(new CourseInstance
+                    {
+                        Sport = sp,
+                        Remaining = sp.MaxStudents
+                    });
+                }
+            }
+
+            // ===== Schüler verteilen =====
+            foreach (var sp in sports)
+            {
+                var pool = interested[sp];
+                if (pool.Count == 0)
+                    continue;
+
+                var targets = instances.Where(i => i.Sport == sp).ToList();
+                if (targets.Count == 0)
+                    continue;
+
+                int idx = 0;
+                foreach (var st in pool)
+                {
+                    if (st.SelectedCourseNames.Count <= sem)
+                        continue;
+
+                    if (st.Result![sem] != "Fehler")
+                        continue;
+
+                    bool assigned = false;
+
+                    for (int t = 0; t < targets.Count; t++)
+                    {
+                        var inst = targets[(idx + t) % targets.Count];
+                        if (inst.Remaining > 0)
+                        {
+                            inst.Remaining--;
+                            inst.Students.Add(st);
+                            st.Result[sem] = sp.Name;
+                            idx++;
+                            assigned = true;
+                            break;
+                        }
+                    }
+
+                    if (!assigned)
+                        continue;
+                }
+            }
+
+            // ===== Alternativen =====
+            foreach (var st in students)
+            {
+                if (st.SelectedCourseNames.Count <= sem)
+                    continue;
+
+                if (st.Result![sem] != "Fehler")
+                    continue;
+
+                var sel = st.SelectedCourseNames[sem];
+                if (!nameMap.TryGetValue(sel, out var wanted))
+                    continue;
+
+                foreach (var altId in wanted.AlternativeCourses)
+                {
+                    var altSport = sports.FirstOrDefault(s => s.ID == altId);
+                    if (altSport == null)
+                        continue;
+
+                    var inst = instances.FirstOrDefault(i => i.Sport == altSport && i.Remaining > 0);
+                    if (inst == null)
+                        continue;
+
+                    inst.Remaining--;
+                    inst.Students.Add(st);
+                    st.Result[sem] = altSport.Name;
+                    break;
+                }
+            }
+        }
+    }
+    
+    public static string GenerateStatistics()
+    {
+        var settings = Settings.Instance;
+        var students = settings.Students;
+        var sports = settings.Sports;
+
+        if (students.Count == 0 || sports.Count == 0)
+            return "Keine Daten vorhanden.";
+
+        int semesterCount = sports.Max(s => s.Semester.Length);
+
+        // Kurszählung: (Semester, SportName) → Liste Schüler
+        var dict = new Dictionary<(int, string), List<Student>>();
+
+        foreach (var st in students)
+        {
+            if (st.Result == null)
+                continue;
+
+            for (int sem = 0; sem < st.Result.Count; sem++)
+            {
+                var course = st.Result[sem];
+                if (string.IsNullOrWhiteSpace(course) || course == "Fehler")
+                    continue;
+
+                var key = (sem, course);
+
+                if (!dict.ContainsKey(key))
+                    dict[key] = new List<Student>();
+
+                dict[key].Add(st);
+            }
+        }
+
+        var sb = new System.Text.StringBuilder();
+
+        sb.AppendLine($"Anzahl generierter Kurse: {dict.Count}");
+        sb.AppendLine("Übersicht:");
+
+        foreach (var entry in dict.OrderBy(e => e.Key.Item1).ThenBy(e => e.Key.Item2))
+        {
+            int semester = entry.Key.Item1 + 1;
+            string name = entry.Key.Item2;
+            int count = entry.Value.Count;
+
+            sb.AppendLine($"Semester {semester}: {name} — {count} Schüler*innen");
+        }
+
+        return sb.ToString();
     }
 }