import prisma from '../utils/prisma';

export class CurriculumService {
  async getSubjects() {
    return prisma.subject.findMany({ where: { isDeleted: false }, select: { id: true, name: true, code: true, icon: true }, orderBy: { name: 'asc' } });
  }

  async getTextbookTree(id: string) {
    let textbook = await prisma.textbook.findUnique({
      where: { id, isDeleted: false },
      include: {
        units: {
          where: { isDeleted: false },
          include: {
            lessons: {
              where: { isDeleted: false },
              include: { knowledgePoints: { where: { isDeleted: false }, orderBy: { difficulty: 'asc' } } },
              orderBy: { sortOrder: 'asc' }
            }
          },
          orderBy: { sortOrder: 'asc' }
        }
      }
    });
    if (!textbook) {
      textbook = await prisma.textbook.findFirst({
        where: { subjectId: id, isDeleted: false },
        include: {
          units: {
            where: { isDeleted: false },
            include: {
              lessons: {
                where: { isDeleted: false },
                include: { knowledgePoints: { where: { isDeleted: false }, orderBy: { difficulty: 'asc' } } },
                orderBy: { sortOrder: 'asc' }
              }
            },
            orderBy: { sortOrder: 'asc' }
          }
        }
      });
    }
    if (!textbook) throw new Error('Textbook not found');
    const units = textbook.units.map(unit => ({
      id: unit.id,
      textbookId: unit.textbookId,
      name: unit.name,
      sortOrder: unit.sortOrder,
      lessons: unit.lessons.map(lesson => ({
        id: lesson.id,
        unitId: lesson.unitId,
        name: lesson.name,
        sortOrder: lesson.sortOrder,
        knowledgePoints: lesson.knowledgePoints.map(kp => ({ id: kp.id, lessonId: kp.lessonId, name: kp.name, difficulty: kp.difficulty, description: kp.description }))
      }))
    }));
    return { textbook: { id: textbook.id, name: textbook.name, publisher: textbook.publisher, versionYear: textbook.versionYear, coverUrl: textbook.coverUrl }, units };
  }

  async getTextbooksBySubject(subjectId: string) {
    return prisma.textbook.findMany({ where: { subjectId, isDeleted: false }, select: { id: true, name: true, publisher: true, versionYear: true, coverUrl: true }, orderBy: { name: 'asc' } });
  }

  async createTextbook(userId: string, data: { subjectId: string; name: string; publisher: string; versionYear: string; coverUrl?: string }) {
    const { subjectId, name, publisher, versionYear, coverUrl } = data;
    return prisma.textbook.create({ data: { subjectId, name, publisher, versionYear, coverUrl: coverUrl || '', createdBy: userId, updatedBy: userId } });
  }

  async updateTextbook(id: string, data: { name?: string; publisher?: string; versionYear?: string; coverUrl?: string }) {
    return prisma.textbook.update({ where: { id }, data });
  }

  async deleteTextbook(id: string) {
    await prisma.textbook.update({ where: { id }, data: { isDeleted: true } });
    return { success: true };
  }

  async createUnit(userId: string, data: { textbookId: string; name: string; sortOrder?: number }) {
    const { textbookId, name, sortOrder } = data;
    return prisma.textbookUnit.create({ data: { textbookId, name, sortOrder: sortOrder || 0, createdBy: userId, updatedBy: userId } });
  }

  async updateUnit(id: string, data: { name?: string; sortOrder?: number }) {
    return prisma.textbookUnit.update({ where: { id }, data });
  }

  async deleteUnit(id: string) {
    await prisma.textbookUnit.update({ where: { id }, data: { isDeleted: true } });
    return { success: true };
  }

  async createLesson(userId: string, data: { unitId: string; name: string; sortOrder?: number }) {
    const { unitId, name, sortOrder } = data;
    return prisma.textbookLesson.create({ data: { unitId, name, sortOrder: sortOrder || 0, createdBy: userId, updatedBy: userId } });
  }

  async updateLesson(id: string, data: { name?: string; sortOrder?: number }) {
    return prisma.textbookLesson.update({ where: { id }, data });
  }

  async deleteLesson(id: string) {
    await prisma.textbookLesson.update({ where: { id }, data: { isDeleted: true } });
    return { success: true };
  }

  async createKnowledgePoint(userId: string, data: { lessonId: string; name: string; difficulty?: number; description?: string }) {
    const { lessonId, name, difficulty, description } = data;
    return prisma.knowledgePoint.create({ data: { lessonId, name, difficulty: difficulty || 1, description: description || '', createdBy: userId, updatedBy: userId } });
  }

  async updateKnowledgePoint(id: string, data: { name?: string; difficulty?: number; description?: string }) {
    return prisma.knowledgePoint.update({ where: { id }, data });
  }

  async deleteKnowledgePoint(id: string) {
    await prisma.knowledgePoint.update({ where: { id }, data: { isDeleted: true } });
    return { success: true };
  }
}

export const curriculumService = new CurriculumService();