import { useSession } from 'h3';

// DTO to shape the output
interface HabitCompletionDto {
  date: Date;
}

interface HabitDto {
  id: number;
  name: string;
  daysOfWeek: number[];
  completions: HabitCompletionDto[];
}

/**
 * A helper function to safely get the authenticated user's ID from the session.
 */
async function getUserIdFromSession(event: any): Promise<number> {
  const session = await useSession(event, {
    password: process.env.SESSION_PASSWORD,
  });

  const userId = session.data?.user?.id;
  if (!userId) {
    throw createError({ statusCode: 401, statusMessage: 'Unauthorized' });
  }
  return userId;
}

export default defineEventHandler(async (event): Promise<HabitDto[]> => {
  const userId = await getUserIdFromSession(event);

  const habits = await prisma.habit.findMany({
    where: {
      userId: userId,
    },
    include: {
      completions: {
        orderBy: {
          date: 'desc',
        },
        take: 30, // Limit completions to the last 30 for performance
      },
    },
  });

  // Map to DTOs
  return habits.map((habit: any) => ({
    id: habit.id,
    name: habit.name,
    daysOfWeek: habit.daysOfWeek, // Assuming daysOfWeek is already in the correct format
    completions: habit.completions.map((comp: any) => ({
      date: comp.date,
    })),
  }));
});