import { PLAN_LIMITS } from "@fetcha/core";
import { db, fetchRequests, sql } from "@fetcha/db";
import type { ApiPrincipal } from "../auth";
import { monthlyUsage } from "../limits";

export function meResponse(p: ApiPrincipal) {
  return {
    project: { id: p.projectId, name: p.projectName },
    organization: { id: p.organizationId, name: p.organizationName, plan: p.plan },
    key: { id: p.keyId, name: p.keyName, mode: p.mode, scopes: p.scopes },
  };
}

export async function usageResponse(p: ApiPrincipal) {
  const usage = await monthlyUsage(p);
  const limits = PLAN_LIMITS[p.plan];
  const start = new Date();
  start.setUTCDate(1);
  start.setUTCHours(0, 0, 0, 0);
  const [agg] = await db
    .select({
      total: sql<number>`count(*)::int`,
      ok: sql<number>`count(*) filter (where ${fetchRequests.status} = 'success')::int`,
      bytes: sql<number>`coalesce(sum(${fetchRequests.bytesIn} + ${fetchRequests.bytesOut}), 0)::float`,
      p50: sql<number>`coalesce(percentile_cont(0.5) within group (order by ${fetchRequests.latencyMs}), 0)::float`,
      p95: sql<number>`coalesce(percentile_cont(0.95) within group (order by ${fetchRequests.latencyMs}), 0)::float`,
    })
    .from(fetchRequests)
    .where(sql`${fetchRequests.projectId} = ${p.projectId} and ${fetchRequests.createdAt} >= ${start}`);
  return {
    period_start: start.toISOString(),
    plan: { id: p.plan, label: limits.label, monthly_requests: limits.monthly_requests, concurrency: limits.concurrency },
    organization: { requests: usage.requests, spend_usd: round(usage.spendUsd) },
    project: {
      requests: usage.projectRequests,
      spend_usd: round(usage.projectSpendUsd),
      successful_requests: agg?.ok ?? 0,
      success_rate: agg?.total ? round((agg.ok / agg.total) * 100, 1) : null,
      bandwidth_bytes: agg?.bytes ?? 0,
      latency_p50_ms: Math.round(agg?.p50 ?? 0),
      latency_p95_ms: Math.round(agg?.p95 ?? 0),
    },
    remaining_requests: limits.monthly_requests >= Number.MAX_SAFE_INTEGER ? null : Math.max(0, limits.monthly_requests - usage.requests),
    browser: { enabled: true, concurrency: limits.browser_concurrency },
    crawl: { max_pages: limits.crawl_max_pages, concurrent_jobs: limits.crawl_concurrent_jobs },
  };
}

function round(n: number, d = 4): number {
  const f = 10 ** d;
  return Math.round(n * f) / f;
}