/**
 * Communication Admin API Route - Stats Proxy
 *
 * Proxies requests to Matrix/Jitsi admin endpoints via backend
 * Aggregates statistics from both services
 */

import { NextRequest, NextResponse } from 'next/server'

// Service URLs
const BACKEND_URL = process.env.NEXT_PUBLIC_BACKEND_URL || 'http://localhost:8000'
const CONSENT_SERVICE_URL = process.env.CONSENT_SERVICE_URL || 'http://localhost:8081'
const MATRIX_ADMIN_URL = process.env.MATRIX_ADMIN_URL || 'http://localhost:8448'
const JITSI_URL = process.env.JITSI_URL || 'http://localhost:8443'

// Matrix Admin Token (for Synapse Admin API)
const MATRIX_ADMIN_TOKEN = process.env.MATRIX_ADMIN_TOKEN || ''

interface MatrixStats {
  total_users: number
  active_users: number
  total_rooms: number
  active_rooms: number
  messages_today: number
  messages_this_week: number
  status: 'online' | 'offline' | 'degraded'
}

interface JitsiStats {
  active_meetings: number
  total_participants: number
  meetings_today: number
  average_duration_minutes: number
  peak_concurrent_users: number
  total_minutes_today: number
  status: 'online' | 'offline' | 'degraded'
}

async function fetchFromBackend(): Promise<{
  matrix: MatrixStats
  jitsi: JitsiStats
  active_meetings: unknown[]
  recent_rooms: unknown[]
} | null> {
  try {
    const response = await fetch(`${BACKEND_URL}/api/v1/communication/admin/stats`, {
      headers: { 'Content-Type': 'application/json' },
      signal: AbortSignal.timeout(5000),
    })
    if (response.ok) {
      return await response.json()
    }
  } catch (error) {
    console.log('Backend not reachable, trying consent service:', error)
  }
  return null
}

async function fetchFromConsentService(): Promise<{
  matrix: MatrixStats
  jitsi: JitsiStats
  active_meetings: unknown[]
  recent_rooms: unknown[]
} | null> {
  try {
    const response = await fetch(`${CONSENT_SERVICE_URL}/api/v1/communication/admin/stats`, {
      headers: { 'Content-Type': 'application/json' },
      signal: AbortSignal.timeout(5000),
    })
    if (response.ok) {
      return await response.json()
    }
  } catch (error) {
    console.log('Consent service not reachable:', error)
  }
  return null
}

async function fetchMatrixStats(): Promise<MatrixStats> {
  try {
    // Check if Matrix is reachable
    const healthCheck = await fetch(`${MATRIX_ADMIN_URL}/_matrix/client/versions`, {
      signal: AbortSignal.timeout(5000)
    })

    if (healthCheck.ok) {
      // Try to get user count from admin API
      if (MATRIX_ADMIN_TOKEN) {
        try {
          const usersResponse = await fetch(`${MATRIX_ADMIN_URL}/_synapse/admin/v2/users?limit=1`, {
            headers: { 'Authorization': `Bearer ${MATRIX_ADMIN_TOKEN}` },
            signal: AbortSignal.timeout(5000),
          })
          if (usersResponse.ok) {
            const data = await usersResponse.json()
            return {
              total_users: data.total || 0,
              active_users: 0,
              total_rooms: 0,
              active_rooms: 0,
              messages_today: 0,
              messages_this_week: 0,
              status: 'online'
            }
          }
        } catch {
          // Admin API not available
        }
      }

      return {
        total_users: 0,
        active_users: 0,
        total_rooms: 0,
        active_rooms: 0,
        messages_today: 0,
        messages_this_week: 0,
        status: 'degraded' // Server reachable but no admin access
      }
    }
  } catch (error) {
    console.error('Matrix stats fetch error:', error)
  }

  return {
    total_users: 0,
    active_users: 0,
    total_rooms: 0,
    active_rooms: 0,
    messages_today: 0,
    messages_this_week: 0,
    status: 'offline'
  }
}

async function fetchJitsiStats(): Promise<JitsiStats> {
  try {
    // Check if Jitsi is reachable
    const healthCheck = await fetch(`${JITSI_URL}/http-bind`, {
      method: 'HEAD',
      signal: AbortSignal.timeout(5000)
    })

    return {
      active_meetings: 0,
      total_participants: 0,
      meetings_today: 0,
      average_duration_minutes: 0,
      peak_concurrent_users: 0,
      total_minutes_today: 0,
      status: healthCheck.ok ? 'online' : 'offline'
    }
  } catch (error) {
    console.error('Jitsi stats fetch error:', error)
    return {
      active_meetings: 0,
      total_participants: 0,
      meetings_today: 0,
      average_duration_minutes: 0,
      peak_concurrent_users: 0,
      total_minutes_today: 0,
      status: 'offline'
    }
  }
}

export async function GET(request: NextRequest) {
  try {
    // Try backend first
    let data = await fetchFromBackend()

    // Fallback to consent service
    if (!data) {
      data = await fetchFromConsentService()
    }

    // If both fail, try direct service checks
    if (!data) {
      const [matrixStats, jitsiStats] = await Promise.all([
        fetchMatrixStats(),
        fetchJitsiStats()
      ])

      data = {
        matrix: matrixStats,
        jitsi: jitsiStats,
        active_meetings: [],
        recent_rooms: []
      }
    }

    return NextResponse.json({
      ...data,
      last_updated: new Date().toISOString()
    })
  } catch (error) {
    console.error('Communication stats error:', error)
    return NextResponse.json(
      {
        error: 'Fehler beim Abrufen der Statistiken',
        matrix: { status: 'offline', total_users: 0, active_users: 0, total_rooms: 0, active_rooms: 0, messages_today: 0, messages_this_week: 0 },
        jitsi: { status: 'offline', active_meetings: 0, total_participants: 0, meetings_today: 0, average_duration_minutes: 0, peak_concurrent_users: 0, total_minutes_today: 0 },
        active_meetings: [],
        recent_rooms: [],
        last_updated: new Date().toISOString()
      },
      { status: 503 }
    )
  }
}