import { NextResponse } from 'next/server'
import { prisma } from '@/lib/prisma'
import { redis } from '@/lib/redis'

export const dynamic = 'force-dynamic'

export async function GET() {
  const start = Date.now()
  const checks: Record<string, { status: string; latency?: string; error?: string; [k: string]: unknown }> = {}

  // Database check
  try {
    const dbStart = Date.now()
    const [noteCount, notebookCount, userCount] = await Promise.all([
      prisma.note.count(),
      prisma.notebook.count(),
      prisma.user.count(),
    ])
    checks.database = {
      status: 'healthy',
      latency: `${Date.now() - dbStart}ms`,
      notes: noteCount,
      notebooks: notebookCount,
      users: userCount,
    }
  } catch (e) {
    checks.database = { status: 'unhealthy', error: e instanceof Error ? e.message : 'Unknown error' }
  }

  // Redis check
  try {
    const redisStart = Date.now()
    await redis.ping()
    const info = await redis.info('memory')
    const dbSize = await redis.dbsize()
    const memMatch = info.match(/used_memory_human:(\S+)/)
    checks.redis = {
      status: 'healthy',
      latency: `${Date.now() - redisStart}ms`,
      keys: dbSize,
      memory: memMatch ? memMatch[1] : 'unknown',
    }
  } catch (e) {
    checks.redis = { status: 'unhealthy', error: e instanceof Error ? e.message : 'Unknown error' }
  }

  // AI providers check
  try {
    const { getSystemConfig } = await import('@/lib/config')
    const config = await getSystemConfig()
    const { resolveAiRoute } = await import('@/lib/ai/router')
    const tagsRoute = resolveAiRoute('tags', config)
    const chatRoute = resolveAiRoute('chat', config)
    checks.ai = {
      status: 'configured',
      embedding: { provider: tagsRoute.providerType, model: tagsRoute.modelName },
      chat: { provider: chatRoute.providerType, model: chatRoute.modelName },
    }
  } catch (e) {
    checks.ai = { status: 'unhealthy', error: e instanceof Error ? e.message : 'Unknown error' }
  }

  // Disk check
  try {
    const { execSync } = await import('child_process')
    const diskInfo = execSync("df -h /opt/memento | awk 'NR==2{print $2,$3,$4,$5}'").toString().trim()
    const [total, used, available, percent] = diskInfo.split(/\s+/)
    checks.storage = {
      status: parseInt(percent) > 90 ? 'warning' : 'healthy',
      total,
      used,
      available,
      usagePercent: percent,
    }
  } catch {
    checks.storage = { status: 'unknown' }
  }

  const allHealthy = Object.values(checks).every(c => c.status === 'healthy' || c.status === 'configured')
  const hasDegraded = Object.values(checks).some(c => c.status === 'warning')

  return NextResponse.json({
    status: allHealthy ? (hasDegraded ? 'degraded' : 'healthy') : 'unhealthy',
    uptime: process.uptime(),
    version: process.env.npm_package_version || '0.2.0',
    timestamp: new Date().toISOString(),
    responseTime: `${Date.now() - start}ms`,
    components: checks,
  }, {
    status: allHealthy ? 200 : 503,
  })
}