import { HttpError } from "@batch-cooking/error-tools";
import { ErrorCode, type SafeUserProfile } from "@batch-cooking/shared";
import { prisma } from "../../db/prisma.js";
import { toSafeProfile } from "../../lib/safe-profile.js";

/**
 * Sets (or clears, if `dietId` is `null`) a profile's dietary regime — the
 * regime step of the profile journey is skippable, so `null` is a normal,
 * valid value, not an omission to reject.
 *
 * @throws {HttpError} `404 DIET_NOT_FOUND` if `dietId` doesn't match a reference `Diet` row.
 */
export async function updateDiet(
  userProfileId: number,
  dietId: number | null,
): Promise<SafeUserProfile> {
  if (dietId !== null) {
    const diet = await prisma.diet.findUnique({ where: { id: dietId } });
    if (!diet) {
      throw new HttpError(404, ErrorCode.DIET_NOT_FOUND, `No diet with id ${dietId}`);
    }
  }

  const profile = await prisma.userProfile.update({
    where: { id: userProfileId },
    data: { dietId },
  });
  return toSafeProfile(profile);
}

/** Current allergen ids for a profile — an empty array is normal (no allergies declared, or the step was skipped). */
export async function getAllergyIds(userProfileId: number): Promise<number[]> {
  const rows = await prisma.userProfileAllergy.findMany({
    where: { userProfileId },
    select: { allergyId: true },
  });
  return rows.map((row) => row.allergyId);
}

/**
 * Replaces a profile's full allergen set (not a merge — the caller sends
 * the complete list every time, same shape the multi-select UI already
 * holds). Validates every id up front so a partially-invalid request never
 * leaves the set half-updated.
 *
 * @throws {HttpError} `404 ALLERGY_NOT_FOUND` if any `allergyId` doesn't match a reference `Allergy` row.
 */
export async function updateAllergies(
  userProfileId: number,
  allergyIds: number[],
): Promise<number[]> {
  if (allergyIds.length > 0) {
    const found = await prisma.allergy.findMany({
      where: { id: { in: allergyIds } },
      select: { id: true },
    });
    const foundIds = new Set(found.map((allergy) => allergy.id));
    const missing = allergyIds.filter((id) => !foundIds.has(id));
    if (missing.length > 0) {
      throw new HttpError(
        404,
        ErrorCode.ALLERGY_NOT_FOUND,
        `Unknown allergy id(s): ${missing.join(", ")}`,
      );
    }
  }

  await prisma.$transaction([
    prisma.userProfileAllergy.deleteMany({ where: { userProfileId } }),
    prisma.userProfileAllergy.createMany({
      data: allergyIds.map((allergyId) => ({ userProfileId, allergyId })),
    }),
  ]);

  return allergyIds;
}