using LehrerApp.Core.Interfaces;
using LehrerApp.Core.Models;

namespace LehrerApp.Data.Repositories;

public class StudentRepository(LiteDbContext db) : IStudentRepository
{
    public Student? GetById(Guid id) => db.Students.FindById(id);
    public List<Student> GetAll(bool includeInactive = false) =>
        (includeInactive ? db.Students.FindAll() : db.Students.Find(s => s.IsActive))
        .OrderBy(s => s.LastName).ToList();
    public List<Student> GetByGroup(Guid groupId)
    {
        var ids = db.Memberships
            .Find(e => e.GroupId == groupId)
            .Select(e => e.StudentId).ToHashSet();
        return db.Students.Find(s => ids.Contains(s.Id)).OrderBy(s => s.LastName).ToList();
    }
    public void Save(Student s) { s.UpdatedAt = DateTime.UtcNow; db.Students.Upsert(s); }
    public void Delete(Guid id) => db.Students.Delete(id);
}

public class GroupRepository(LiteDbContext db) : IGroupRepository
{
    public LearningGroup? GetById(Guid id) => db.Groups.FindById(id);
    public List<LearningGroup> GetAll(bool includeInactive = false) =>
        (includeInactive ? db.Groups.FindAll() : db.Groups.Find(g => g.IsActive))
        .OrderBy(g => g.SchoolYear).ThenBy(g => g.Name).ToList();
    public List<LearningGroup> GetBySchoolYear(string schoolYear, bool includeInactive = false) =>
        (includeInactive
            ? db.Groups.Find(g => g.SchoolYear == schoolYear)
            : db.Groups.Find(g => g.SchoolYear == schoolYear && g.IsActive))
        .OrderBy(g => g.Name).ToList();
    public void Save(LearningGroup g)
    {
        if (g.SubjectId is Guid subjectId && db.Subjects.FindById(subjectId) is null)
            throw new InvalidOperationException("Das gewählte Fach existiert nicht mehr.");
        g.UpdatedAt = DateTime.UtcNow;
        db.Groups.Upsert(g);
    }
    public void Delete(Guid id)
    {
        foreach (var membership in db.Memberships.Find(e => e.GroupId == id).ToList())
            db.Memberships.Delete(membership.Id);

        foreach (var exam in db.Exams.Find(e => e.GroupId == id).ToList())
        {
            foreach (var result in db.ExamResults.Find(r => r.ExamId == exam.Id).ToList())
                db.ExamResults.Delete(result.Id);
            db.Exams.Delete(exam.Id);
        }

        foreach (var grade in db.Grades.Find(g => g.GroupId == id).ToList())
            db.Grades.Delete(grade.Id);

        foreach (var unit in db.Units.Find(u => u.GroupId == id).ToList())
        {
            foreach (var lesson in db.Lessons.Find(l => l.UnitId == unit.Id).ToList())
                db.Lessons.Delete(lesson.Id);
            db.Units.Delete(unit.Id);
        }

        foreach (var lesson in db.Lessons.Find(l => l.GroupId == id).ToList())
            db.Lessons.Delete(lesson.Id);

        foreach (var session in db.ParticipationSessions.Find(s => s.GroupId == id).ToList())
        {
            foreach (var entry in db.ParticipationEntries.Find(e => e.SessionId == session.Id).ToList())
                db.ParticipationEntries.Delete(entry.Id);
            db.ParticipationSessions.Delete(session.Id);
        }

        foreach (var aspect in db.ParticipationAspects.Find(a => a.GroupId == id).ToList())
            db.ParticipationAspects.Delete(aspect.Id);

        db.Groups.Delete(id);
    }
}

public class GroupMembershipRepository(LiteDbContext db) : IGroupMembershipRepository
{
    public List<GroupMembership> GetByStudent(Guid id) =>
        db.Memberships.Find(e => e.StudentId == id).ToList();
    public List<GroupMembership> GetByGroup(Guid id) =>
        db.Memberships.Find(e => e.GroupId == id).ToList();
    public GroupMembership? GetByStudentAndGroup(Guid studentId, Guid groupId) =>
        db.Memberships.FindOne(e => e.StudentId == studentId && e.GroupId == groupId);
    public void Save(GroupMembership membership)
    {
        var existing = GetByStudentAndGroup(membership.StudentId, membership.GroupId);
        if (existing is not null && existing.Id != membership.Id)
            throw new InvalidOperationException("Der Schüler ist dieser Lerngruppe bereits zugeordnet.");
        db.Memberships.Upsert(membership);
    }
    public void Delete(Guid id) => db.Memberships.Delete(id);
}

public class ExamRepository(LiteDbContext db) : IExamRepository
{
    public Exam? GetById(Guid id) => db.Exams.FindById(id);
    public List<Exam> GetByGroup(Guid groupId) =>
        db.Exams.Find(e => e.GroupId == groupId).OrderByDescending(e => e.Date).ToList();
    public void Save(Exam e) { e.UpdatedAt = DateTime.UtcNow; db.Exams.Upsert(e); }
    public void Delete(Guid id)
    {
        foreach (var result in db.ExamResults.Find(r => r.ExamId == id).ToList())
            db.ExamResults.Delete(result.Id);
        db.Exams.Delete(id);
    }
}

public class ExamResultRepository(LiteDbContext db) : IExamResultRepository
{
    public List<ExamResult> GetByExam(Guid id) =>
        db.ExamResults.Find(r => r.ExamId == id).ToList();
    public List<ExamResult> GetByStudent(Guid id) =>
        db.ExamResults.Find(r => r.StudentId == id).ToList();
    public ExamResult? GetByExamAndStudent(Guid examId, Guid studentId) =>
        db.ExamResults.FindOne(r => r.ExamId == examId && r.StudentId == studentId);
    public void Save(ExamResult r) { r.UpdatedAt = DateTime.UtcNow; db.ExamResults.Upsert(r); }
    public void SaveMany(List<ExamResult> results)
    {
        var now = DateTime.UtcNow;
        foreach (var r in results) r.UpdatedAt = now;
        db.ExamResults.Upsert(results);
    }
}

public class GradingKeyTemplateRepository(LiteDbContext db) : IGradingKeyTemplateRepository
{
    public List<GradingKeyTemplate> GetAll() =>
        db.GradingKeyTemplates.FindAll().OrderBy(t => t.Name).ToList();
    public List<GradingKeyTemplate> GetByGradingSystem(GradingSystem system) =>
        db.GradingKeyTemplates.Find(t => t.GradingSystem == system).OrderBy(t => t.Name).ToList();
    public GradingKeyTemplate? GetById(Guid id) => db.GradingKeyTemplates.FindById(id);
    public void Save(GradingKeyTemplate t) { t.UpdatedAt = DateTime.UtcNow; db.GradingKeyTemplates.Upsert(t); }
    public void Delete(Guid id) => db.GradingKeyTemplates.Delete(id);
}

public class GradeRepository(LiteDbContext db) : IGradeRepository
{
    public List<Grade> GetByStudentAndGroup(Guid sid, Guid gid) =>
        db.Grades.Find(g => g.StudentId == sid && g.GroupId == gid).OrderBy(g => g.Date).ToList();
    public List<Grade> GetByGroup(Guid id) =>
        db.Grades.Find(g => g.GroupId == id).OrderBy(g => g.Date).ToList();
    public void Save(Grade g) => db.Grades.Upsert(g);
    public void Delete(Guid id) => db.Grades.Delete(id);
}

public class GradingSchemeRepository(LiteDbContext db) : IGradingSchemeRepository
{
    public GradingScheme? GetByGroup(Guid groupId) => db.GradingSchemes.FindOne(s => s.GroupId == groupId);
    public GradingScheme? GetDefaultForType(GroupType type) =>
        db.GradingSchemes.FindOne(s => s.GroupId == null && s.GroupType == type);
    public void Save(GradingScheme s) { s.UpdatedAt = DateTime.UtcNow; db.GradingSchemes.Upsert(s); }
    public void Delete(Guid id) => db.GradingSchemes.Delete(id);
}

public class ReportGradeRepository(LiteDbContext db) : IReportGradeRepository
{
    public List<ReportGrade> GetByGroup(Guid groupId) => db.ReportGrades.Find(r => r.GroupId == groupId).ToList();
    public ReportGrade? GetByStudentGroupPeriod(Guid studentId, Guid groupId, string period) =>
        db.ReportGrades.FindOne(r => r.StudentId == studentId && r.GroupId == groupId && r.Period == period);
    public void Save(ReportGrade r) { r.UpdatedAt = DateTime.UtcNow; db.ReportGrades.Upsert(r); }
    public void Delete(Guid id) => db.ReportGrades.Delete(id);
}

public class UnitRepository(LiteDbContext db) : IUnitRepository
{
    public Unit? GetById(Guid id) => db.Units.FindById(id);
    public List<Unit> GetByGroup(Guid id) =>
        db.Units.Find(u => u.GroupId == id).OrderBy(u => u.StartDate).ToList();
    public void Save(Unit u) { u.UpdatedAt = DateTime.UtcNow; db.Units.Upsert(u); }
    public void Delete(Guid id) => db.Units.Delete(id);
}

public class LessonRepository(LiteDbContext db) : ILessonRepository
{
    public List<Lesson> GetByUnit(Guid id) =>
        db.Lessons.Find(l => l.UnitId == id).OrderBy(l => l.Date).ToList();
    public List<Lesson> GetByGroupAndDate(Guid gid, DateOnly date) =>
        db.Lessons.Find(l => l.GroupId == gid && l.Date == date).ToList();
    public List<Lesson> GetByGroupAndRange(Guid gid, DateOnly from, DateOnly to) =>
        db.Lessons.Find(l => l.GroupId == gid && l.Date >= from && l.Date <= to)
            .OrderBy(l => l.Date).ToList();
    public void Save(Lesson l) { l.UpdatedAt = DateTime.UtcNow; db.Lessons.Upsert(l); }
    public void Delete(Guid id) => db.Lessons.Delete(id);
}

public class DocumentationRepository(LiteDbContext db) : IDocumentationRepository
{
    public List<Documentation> GetByStudent(Guid id) =>
        db.Documentation.Find(d => d.StudentId == id).OrderByDescending(d => d.Date).ToList();
    public List<Documentation> GetByStudentAndType(Guid sid, DocumentationType type) =>
        db.Documentation.Find(d => d.StudentId == sid && d.Type == type)
            .OrderByDescending(d => d.Date).ToList();
    public void Save(Documentation d) { d.UpdatedAt = DateTime.UtcNow; db.Documentation.Upsert(d); }
    public void Delete(Guid id) => db.Documentation.Delete(id);
}

public class WorkTaskRepository(LiteDbContext db) : IWorkTaskRepository
{
    public List<WorkTask> GetByStatus(WorkTaskStatus s) =>
        db.Tasks.Find(t => t.Status == s).OrderBy(t => t.DueDate).ToList();
    public List<WorkTask> GetAll() =>
        db.Tasks.FindAll().OrderBy(t => t.Status).ThenBy(t => t.DueDate).ToList();
    public void Save(WorkTask t) { t.UpdatedAt = DateTime.UtcNow; db.Tasks.Upsert(t); }
    public void Delete(Guid id) => db.Tasks.Delete(id);
}

public class TimeEntryRepository(LiteDbContext db) : ITimeEntryRepository
{
    public List<TimeEntry> GetByDate(DateOnly date) =>
        db.TimeEntries.Find(e => e.Date == date).OrderBy(e => e.StartTime).ToList();
    public List<TimeEntry> GetByDateRange(DateOnly from, DateOnly to) =>
        db.TimeEntries.Find(e => e.Date >= from && e.Date <= to).OrderBy(e => e.Date).ToList();
    public List<TimeEntry> GetByTask(Guid id) =>
        db.TimeEntries.Find(e => e.TaskId == id).ToList();
    public void Save(TimeEntry e) => db.TimeEntries.Upsert(e);
    public void Delete(Guid id) => db.TimeEntries.Delete(id);
}

public class ParticipationSessionRepository(LiteDbContext db) : IParticipationSessionRepository
{
    public List<ParticipationSession> GetByGroup(Guid groupId) =>
        db.ParticipationSessions.Find(s => s.GroupId == groupId).OrderByDescending(s => s.Date).ToList();
    public ParticipationSession? GetById(Guid id) => db.ParticipationSessions.FindById(id);
    public void Save(ParticipationSession s) { s.UpdatedAt = DateTime.UtcNow; db.ParticipationSessions.Upsert(s); }
    public void Delete(Guid id)
    {
        db.ParticipationSessions.Delete(id);
        foreach (var e in db.ParticipationEntries.Find(e => e.SessionId == id).ToList())
            db.ParticipationEntries.Delete(e.Id);
    }
}

public class ParticipationRepository(LiteDbContext db) : IParticipationRepository
{
    public List<ParticipationEntry> GetBySession(Guid sessionId) =>
        db.ParticipationEntries.Find(e => e.SessionId == sessionId).ToList();
    public List<ParticipationEntry> GetByStudent(Guid studentId) =>
        db.ParticipationEntries.Find(e => e.StudentId == studentId).ToList();
    public ParticipationEntry? GetBySessionAndStudent(Guid sessionId, Guid studentId) =>
        db.ParticipationEntries.FindOne(e => e.SessionId == sessionId && e.StudentId == studentId);
    public void Save(ParticipationEntry e) { e.UpdatedAt = DateTime.UtcNow; db.ParticipationEntries.Upsert(e); }
    public void SaveMany(List<ParticipationEntry> entries)
    {
        var now = DateTime.UtcNow;
        foreach (var e in entries) e.UpdatedAt = now;
        db.ParticipationEntries.Upsert(entries);
    }
    public void DeleteBySession(Guid sessionId)
    {
        foreach (var e in db.ParticipationEntries.Find(e => e.SessionId == sessionId).ToList())
            db.ParticipationEntries.Delete(e.Id);
    }
}

public class ParticipationAspectRepository(LiteDbContext db) : IParticipationAspectRepository
{
    public List<ParticipationAspect> GetDefaults() =>
        db.ParticipationAspects.Find(a => a.GroupId == null && a.IsActive).OrderBy(a => a.SortOrder).ToList();
    public List<ParticipationAspect> GetByGroup(Guid groupId) =>
        db.ParticipationAspects.Find(a => a.GroupId == groupId && a.IsActive).OrderBy(a => a.SortOrder).ToList();
    public void Save(ParticipationAspect a) { a.UpdatedAt = DateTime.UtcNow; db.ParticipationAspects.Upsert(a); }
    public void Delete(Guid id) => db.ParticipationAspects.Delete(id);
}

public class ParticipationSectionRepository(LiteDbContext db) : IParticipationSectionRepository
{
    public List<ParticipationSection> GetByGroup(Guid groupId) =>
        db.ParticipationSections.Find(s => s.GroupId == groupId).OrderBy(s => s.StartDate).ToList();
    public void Save(ParticipationSection s) => db.ParticipationSections.Upsert(s);
    public void Delete(Guid id) => db.ParticipationSections.Delete(id);
}

public class SubjectRepository(LiteDbContext db) : ISubjectRepository
{
    public List<Subject> GetAll() => db.Subjects.FindAll().OrderBy(s => s.Name).ToList();
    public Subject? GetById(Guid id) => db.Subjects.FindById(id);
    public Subject? GetByName(string name) => db.Subjects.FindAll().FirstOrDefault(s =>
        string.Equals(s.Name.Trim(), name.Trim(), StringComparison.OrdinalIgnoreCase));
    public void Save(Subject s)
    {
        s.Name = s.Name.Trim();
        s.ShortName = s.ShortName.Trim();
        if (s.Name.Length == 0) throw new ArgumentException("Der Fachname darf nicht leer sein.");
        var duplicate = GetByName(s.Name);
        if (duplicate is not null && duplicate.Id != s.Id)
            throw new InvalidOperationException("Ein Fach mit diesem Namen existiert bereits.");
        s.UpdatedAt = DateTime.UtcNow;
        db.Subjects.Upsert(s);
    }
    public void Delete(Guid id)
    {
        if (db.Groups.Exists(g => g.SubjectId == id) || db.CompetencyDomains.Exists(d => d.SubjectId == id))
            throw new InvalidOperationException("Das Fach wird noch von einer Lerngruppe oder einem Kompetenzkatalog verwendet.");
        db.Subjects.Delete(id);
    }
}

public class CompetencyDomainRepository(LiteDbContext db) : ICompetencyDomainRepository
{
    public List<CompetencyDomain> GetBySubjectAndGrade(Guid subjectId, int gradeLevel) =>
        db.CompetencyDomains
          .Find(d => d.SubjectId == subjectId && d.GradeLevel == gradeLevel)
          .OrderBy(d => d.SortOrder)
          .ToList();
    public CompetencyDomain? GetById(Guid id) => db.CompetencyDomains.FindById(id);
    public void Save(CompetencyDomain d) { d.UpdatedAt = DateTime.UtcNow; db.CompetencyDomains.Upsert(d); }
    public void Delete(Guid id) => db.CompetencyDomains.Delete(id);
    public void DeleteBySubjectAndGrade(Guid subjectId, int gradeLevel)
    {
        foreach (var d in db.CompetencyDomains
                             .Find(d => d.SubjectId == subjectId && d.GradeLevel == gradeLevel)
                             .ToList())
            db.CompetencyDomains.Delete(d.Id);
    }
}