import type { NextApiRequest, NextApiResponse } from 'next'
import sqlite3 from 'sqlite3'
import path from 'path'

interface DashboardStats {
  total_sources: number
  pending_sources: number
  pending_reports: number
  high_risk_sources: number
  sources_added_week: number
  reports_today: number
}

export default async function handler(
  req: NextApiRequest,
  res: NextApiResponse<DashboardStats | { error: string }>
) {
  if (req.method !== 'GET') {
    return res.status(405).json({ error: 'Method not allowed' })
  }

  const dbPath = path.join(process.cwd(), 'database', 'antihoax.db')
  const db = new sqlite3.Database(dbPath)

  try {
    const stats = await new Promise<DashboardStats>((resolve, reject) => {
      const queries = [
        "SELECT COUNT(*) as total_sources FROM sources WHERE status = 'verified'",
        "SELECT COUNT(*) as pending_sources FROM sources WHERE status = 'pending'",
        "SELECT COUNT(*) as pending_reports FROM reports WHERE status = 'pending'",
        "SELECT COUNT(*) as high_risk_sources FROM sources WHERE status = 'verified' AND risk_level >= 4",
        "SELECT COUNT(*) as sources_added_week FROM sources WHERE created_at > datetime('now', '-7 days')",
        "SELECT COUNT(*) as reports_today FROM reports WHERE created_at > datetime('now', '-1 day')"
      ]

      const results: any = {}
      let completed = 0

      queries.forEach((query, index) => {
        db.get(query, (err, row: any) => {
          if (err) {
            reject(err)
            return
          }

          const key = Object.keys(row)[0]
          results[key] = row[key]
          completed++

          if (completed === queries.length) {
            resolve({
              total_sources: results.total_sources || 0,
              pending_sources: results.pending_sources || 0,
              pending_reports: results.pending_reports || 0,
              high_risk_sources: results.high_risk_sources || 0,
              sources_added_week: results.sources_added_week || 0,
              reports_today: results.reports_today || 0
            })
          }
        })
      })
    })

    return res.status(200).json(stats)

  } catch (error) {
    console.error('Database error:', error)
    return res.status(500).json({ error: 'Internal server error' })
  } finally {
    db.close()
  }
}