import { eq } from "drizzle-orm";
import { db } from "@/lib/db";
import { subscriptions, users } from "@/lib/schema";

const TRIAL_DAYS = 14;

export interface SubscriptionStatus {
  isActive: boolean;
  status: "trialing" | "active" | "expired" | "canceled" | "canceling";
  daysRemainingInTrial: number | null;
  trialEndsAt: Date | null;
  subscriptionEndsAt: Date | null;
}

/**
 * Check if a user has an active subscription or valid trial
 */
export async function checkSubscriptionStatus(userId: string): Promise<SubscriptionStatus> {
  // Get user creation date
  const [user] = await db
    .select({ createdAt: users.createdAt })
    .from(users)
    .where(eq(users.id, userId))
    .limit(1);

  if (!user) {
    return {
      isActive: false,
      status: "expired",
      daysRemainingInTrial: null,
      trialEndsAt: null,
      subscriptionEndsAt: null,
    };
  }

  // Get subscription record
  const [subscription] = await db
    .select()
    .from(subscriptions)
    .where(eq(subscriptions.userId, userId))
    .limit(1);

  const now = new Date();
  const trialEndsAt = new Date(user.createdAt);
  trialEndsAt.setDate(trialEndsAt.getDate() + TRIAL_DAYS);

  // If user has active or canceling subscription, they can use the service
  if (subscription?.status === "active" || subscription?.status === "canceling") {
    // If subscription is marked as canceling, return canceling status
    if (subscription.status === "canceling") {
      return {
        isActive: true,
        status: "canceling",
        daysRemainingInTrial: null,
        trialEndsAt: null,
        subscriptionEndsAt: subscription.currentPeriodEnd || null,
      };
    }

    return {
      isActive: true,
      status: "active",
      daysRemainingInTrial: null,
      trialEndsAt: null,
      subscriptionEndsAt: subscription.currentPeriodEnd || null,
    };
  }

  // If still in trial period
  if (now < trialEndsAt) {
    const daysRemaining = Math.ceil(
      (trialEndsAt.getTime() - now.getTime()) / (1000 * 60 * 60 * 24)
    );
    return {
      isActive: true,
      status: "trialing",
      daysRemainingInTrial: daysRemaining,
      trialEndsAt,
      subscriptionEndsAt: null,
    };
  }

  // Trial expired and no paid subscription
  if (subscription?.status === "canceled") {
    return {
      isActive: false,
      status: "canceled",
      daysRemainingInTrial: null,
      trialEndsAt,
      subscriptionEndsAt: null,
    };
  }

  return {
    isActive: false,
    status: "expired",
    daysRemainingInTrial: null,
    trialEndsAt,
    subscriptionEndsAt: null,
  };
}