import type { ProxyUserRecord } from '../../src/shared/contracts';
import { deriveDashboardSnapshot, render3proxyConfig, type ObservedRuntimeState, type RuntimePaths, type RuntimeSnapshot } from './config';
import type { StateStore } from './store';
import { readObservedTraffic } from './traffic';

export async function getDashboardSnapshot(
  store: StateStore,
  runtime: { getSnapshot(): RuntimeSnapshot },
  runtimePaths: RuntimePaths,
) {
  const state = await store.read();
  const previewConfig = render3proxyConfig(state, runtimePaths);
  const traffic = await readObservedTraffic(runtimePaths, state.userRecords);
  const observedUsers = deriveObservedUsers(
    state.userRecords,
    traffic.userBytesByName,
    traffic.lastSeenByName,
    traffic.recentUsers,
  );
  const observed: ObservedRuntimeState = {
    totalBytes: traffic.totalBytes,
    liveConnections: traffic.liveConnections,
    activeUsers: traffic.activeUsers,
    daily: traffic.daily,
    userRecords: observedUsers,
  };

  return deriveDashboardSnapshot(state, runtime.getSnapshot(), observed, previewConfig);
}

function deriveObservedUsers(
  users: ProxyUserRecord[],
  userBytesByName: Map<string, number>,
  lastSeenByName: Map<string, string | null>,
  recentUsers: Set<string>,
): ProxyUserRecord[] {
  return users.map((user) => {
    const usedBytes = userBytesByName.get(user.username) ?? 0;
    const lastSeenAt = lastSeenByName.get(user.username) ?? null;

    if (user.paused) {
      return {
        ...user,
        lastSeenAt,
        usedBytes,
        status: 'idle',
      };
    }

    if (user.quotaBytes !== null && usedBytes >= user.quotaBytes) {
      return {
        ...user,
        lastSeenAt,
        usedBytes,
        status: 'fail',
      };
    }

    if (user.quotaBytes !== null && user.quotaBytes > 0 && usedBytes / user.quotaBytes >= 0.8) {
      return {
        ...user,
        lastSeenAt,
        usedBytes,
        status: recentUsers.has(user.username) ? 'live' : 'warn',
      };
    }

    return {
      ...user,
      lastSeenAt,
      usedBytes,
      status: recentUsers.has(user.username) ? 'live' : 'idle',
    };
  });
}