import { NextResponse } from "next/server";
import { getSupabaseAdmin } from "@/lib/admin";
import { TIER_LIMITS } from "@/services/tierLimits";
import { requireOrgMembership } from "@/lib/apiAuth";

/**
 * GET /api/billing/usage
 * 
 * Returns current usage vs tier limits for an organization.
 * Requires authenticated user who is a member of the organization.
 * Query params: ?organizationId=xxx
 */
export async function GET(request: Request) {
  try {
    const url = new URL(request.url);
    const organizationId = url.searchParams.get("organizationId");

    if (!organizationId) {
      return NextResponse.json({ error: "organizationId required" }, { status: 400 });
    }

    // Verify caller belongs to this organization
    const auth = await requireOrgMembership(organizationId, request);
    if (auth instanceof NextResponse) return auth;

    const supabase = getSupabaseAdmin();

    // Get organization with tier info
    const { data: org, error: orgError } = await supabase
      .from("organizations")
      .select("id, name, subscription_tier, subscription_status, created_at")
      .eq("id", organizationId)
      .single();

    if (orgError || !org) {
      return NextResponse.json({ error: "Organization not found" }, { status: 404 });
    }

    const tier = String(org.subscription_tier || "free");
    const limits = TIER_LIMITS[tier] || TIER_LIMITS.free;

    // Get current usage (parallel queries)
    const startOfMonth = new Date();
    startOfMonth.setDate(1);
    startOfMonth.setHours(0, 0, 0, 0);

    const [
      { count: websiteCount },
      { count: memberCount },
      { count: scanCountThisMonth },
      { count: scanCountTotal },
      { count: alertCount },
    ] = await Promise.all([
      supabase.from("websites").select("*", { count: "exact", head: true }).eq("organization_id", organizationId),
      supabase.from("organization_members").select("*", { count: "exact", head: true }).eq("organization_id", organizationId),
      supabase
        .from("scans")
        .select("*", { count: "exact", head: true })
        .gte("created_at", startOfMonth.toISOString()),
      supabase.from("scans").select("*", { count: "exact", head: true }),
      supabase.from("alerts").select("*", { count: "exact", head: true }).eq("status", "active"),
    ]);

    const usage = {
      websites: { used: websiteCount || 0, limit: limits.websites, percentage: limits.websites === -1 ? 0 : Math.round(((websiteCount || 0) / limits.websites) * 100) },
      scansThisMonth: { used: scanCountThisMonth || 0, limit: limits.scansPerMonth, percentage: limits.scansPerMonth === -1 ? 0 : Math.round(((scanCountThisMonth || 0) / limits.scansPerMonth) * 100) },
      teamMembers: { used: memberCount || 0, limit: limits.teamMembers, percentage: limits.teamMembers === -1 ? 0 : Math.round(((memberCount || 0) / limits.teamMembers) * 100) },
      totalScans: scanCountTotal || 0,
      activeAlerts: alertCount || 0,
    };

    return NextResponse.json({
      organization: {
        id: org.id,
        name: org.name,
        tier,
        status: org.subscription_status || "active",
        createdAt: org.created_at,
      },
      plan: limits,
      usage,
      features: {
        scheduledScans: limits.scheduledScans,
        alertNotifications: limits.alertNotifications,
        competitorAnalysis: limits.competitorAnalysis,
        apiAccess: limits.apiAccess,
        prioritySupport: limits.prioritySupport,
      },
    });
  } catch (error) {
    return NextResponse.json(
      { error: error instanceof Error ? error.message : "Unknown error" },
      { status: 500 }
    );
  }
}