import { eq } from "drizzle-orm";
import { redirect } from "next/navigation";
import { auth } from "@/lib/auth";
import { db } from "@/lib/db";
import { householdMembers, households, users } from "@/modules/_core/schema";
import { ensureDefaultCalendarsForMembership } from "@/modules/calendar/server/defaults";
import { ensureDefaultListsForHousehold } from "@/modules/lists/server/defaults";

export interface CurrentSession {
  user: typeof users.$inferSelect;
  household: typeof households.$inferSelect;
  role: "owner" | "member";
}

export async function getCurrentSession(): Promise<CurrentSession> {
  const session = await auth();
  if (!session?.user?.id) redirect("/login");

  const [row] = await db
    .select({
      user: users,
      household: households,
      role: householdMembers.role,
    })
    .from(householdMembers)
    .innerJoin(users, eq(householdMembers.userId, users.id))
    .innerJoin(households, eq(householdMembers.householdId, households.id))
    .where(eq(householdMembers.userId, session.user.id))
    .limit(1);

  if (row) return row;

  // No membership yet — happens when the household was seeded after the user's
  // first sign-in (e.g. first deploy). Auto-enroll into the single household.
  const [household] = await db.select().from(households).limit(1);
  if (!household) throw new Error("No household membership");

  const [anyMember] = await db
    .select()
    .from(householdMembers)
    .where(eq(householdMembers.householdId, household.id))
    .limit(1);
  const role = anyMember ? "member" : "owner";

  await db
    .insert(householdMembers)
    .values({ householdId: household.id, userId: session.user.id, role })
    .onConflictDoNothing();

  await ensureDefaultCalendarsForMembership({ householdId: household.id, userId: session.user.id });
  await ensureDefaultListsForHousehold(household.id);

  const [fixed] = await db
    .select({ user: users, household: households, role: householdMembers.role })
    .from(householdMembers)
    .innerJoin(users, eq(householdMembers.userId, users.id))
    .innerJoin(households, eq(householdMembers.householdId, households.id))
    .where(eq(householdMembers.userId, session.user.id))
    .limit(1);

  if (!fixed) throw new Error("No household membership");
  return fixed;
}