/**
 * Monitoring Queries Service
 * @author Descomplicar® | @link descomplicar.pt | @copyright 2026
 */
import db from '../db.js'
import type { RowDataPacket } from 'mysql2'

interface MonitoringItem {
  id: number
  name: string
  category: string
  type: string
  status: string
  details: any
  last_check: string
  created_at: string
  updated_at: string
}

interface CategorySummary {
  category: string
  total: number
  ok: number
  warning: number
  critical: number
}

/**
 * Check if a URL is accessible (HTTP HEAD request)
 */
export async function checkSiteAvailability(url: string, timeout = 10000): Promise<{
  available: boolean
  statusCode?: number
  responseTime?: number
  error?: string
}> {
  const startTime = Date.now()
  const controller = new AbortController()
  const timeoutId = setTimeout(() => controller.abort(), timeout)

  try {
    const response = await fetch(url, {
      method: 'HEAD',
      signal: controller.signal,
      headers: {
        'User-Agent': 'Descomplicar-Monitor/1.0'
      }
    })

    clearTimeout(timeoutId)
    const responseTime = Date.now() - startTime

    return {
      available: response.ok || response.status < 500,
      statusCode: response.status,
      responseTime
    }
  } catch (error) {
    clearTimeout(timeoutId)
    return {
      available: false,
      error: (error as Error).message,
      responseTime: Date.now() - startTime
    }
  }
}

/**
 * Check all sites and update their availability status
 */
export async function checkAllSitesAvailability(): Promise<{
  checked: number
  up: number
  down: number
  results: any[]
}> {
  // Get all sites from monitoring table
  const [sites] = await db.query<RowDataPacket[]>(`
    SELECT id, name, details FROM tbl_eal_monitoring
    WHERE category = 'site'
  `)

  const results: any[] = []
  let up = 0
  let down = 0

  for (const site of sites) {
    const details = typeof site.details === 'string' ? JSON.parse(site.details) : site.details
    const siteUrl = details?.site_url || `https://${site.name}`

    const check = await checkSiteAvailability(siteUrl)

    // Update status if site is down
    if (!check.available) {
      await db.query(
        'UPDATE tbl_eal_monitoring SET status = ?, last_check = NOW() WHERE id = ?',
        ['down', site.id]
      )
      down++
    } else {
      // If was down and now is up, set to 'up' (will be replaced by plugin data later)
      const currentStatus = details?.health?.status || 'ok'
      if (currentStatus === 'down') {
        await db.query(
          'UPDATE tbl_eal_monitoring SET status = ?, last_check = NOW() WHERE id = ?',
          ['up', site.id]
        )
      }
      up++
    }

    results.push({
      name: site.name,
      url: siteUrl,
      ...check
    })
  }

  return {
    checked: sites.length,
    up,
    down,
    results
  }
}

export async function getMonitoringData() {
  // Get all items
  const [items] = await db.query<RowDataPacket[]>(`
    SELECT * FROM tbl_eal_monitoring
    ORDER BY category, name
  `)

  // Get summary by category
  const [summary] = await db.query<RowDataPacket[]>(`
    SELECT
      category,
      COUNT(*) as total,
      SUM(CASE WHEN status IN ('ok','up') THEN 1 ELSE 0 END) as ok,
      SUM(CASE WHEN status = 'warning' THEN 1 ELSE 0 END) as warning,
      SUM(CASE WHEN status IN ('failed','down') THEN 1 ELSE 0 END) as critical
    FROM tbl_eal_monitoring
    GROUP BY category
  `)

  // Parse details JSON and cast to MonitoringItem
  const itemsParsed: MonitoringItem[] = items.map(item => ({
    ...item,
    details: typeof item.details === 'string' ? JSON.parse(item.details) : item.details
  } as MonitoringItem))

  // Organize by category
  const data: Record<string, MonitoringItem[]> = {}
  for (const item of itemsParsed) {
    if (!data[item.category]) {
      data[item.category] = []
    }
    data[item.category].push(item)
  }

  // Calculate overall status
  let overall: 'ok' | 'warning' | 'critical' = 'ok'
  let total_critical = 0
  let total_warning = 0

  for (const s of summary as CategorySummary[]) {
    total_critical += s.critical
    total_warning += s.warning
  }

  if (total_critical > 0) overall = 'critical'
  else if (total_warning > 0) overall = 'warning'

  return {
    items: data,
    summary,
    overall,
    stats: {
      total_critical,
      total_warning,
      total_ok: items.length - total_critical - total_warning
    }
  }
}