import sqlite3 from 'sqlite3'
import path from 'path'

export async function optimizeDatabase(): Promise<void> {
  const dbPath = path.join(process.cwd(), 'database', 'antihoax.db')
  const db = new sqlite3.Database(dbPath)
  
  try {
    // Create performance indexes
    const indexes = [
      'CREATE INDEX IF NOT EXISTS idx_sources_domain ON sources(domain)',
      'CREATE INDEX IF NOT EXISTS idx_sources_status_risk ON sources(status, risk_level)',
      'CREATE INDEX IF NOT EXISTS idx_sources_created ON sources(created_at)',
      'CREATE INDEX IF NOT EXISTS idx_reports_status ON reports(status)',
      'CREATE INDEX IF NOT EXISTS idx_reports_created ON reports(created_at)',
      'CREATE INDEX IF NOT EXISTS idx_api_keys_hash ON api_keys(key_hash)',
      'CREATE INDEX IF NOT EXISTS idx_audit_logs_created ON audit_logs(created_at)',
      'CREATE INDEX IF NOT EXISTS idx_source_categories ON source_categories(source_id, category_id)'
    ]
    
    for (const indexQuery of indexes) {
      await new Promise<void>((resolve, reject) => {
        db.run(indexQuery, (err) => {
          if (err) reject(err)
          else resolve()
        })
      })
    }
    
    // Analyze tables for query optimization
    const analyzeTables = [
      'ANALYZE sources',
      'ANALYZE reports', 
      'ANALYZE api_keys',
      'ANALYZE audit_logs',
      'ANALYZE source_categories'
    ]
    
    for (const analyzeQuery of analyzeTables) {
      await new Promise<void>((resolve, reject) => {
        db.run(analyzeQuery, (err) => {
          if (err) reject(err)
          else resolve()
        })
      })
    }
    
    // Vacuum database to optimize storage
    await new Promise<void>((resolve, reject) => {
      db.run('VACUUM', (err) => {
        if (err) reject(err)
        else resolve()
      })
    })
    
    console.log('Database optimization completed successfully')
    
  } catch (error) {
    console.error('Database optimization failed:', error)
    throw error
  } finally {
    db.close()
  }
}

export async function getDatabaseStats(): Promise<any> {
  const dbPath = path.join(process.cwd(), 'database', 'antihoax.db')
  const db = new sqlite3.Database(dbPath)
  
  try {
    const stats = await new Promise<any>((resolve, reject) => {
      db.all(`
        SELECT 
          name as table_name,
          COUNT(*) as row_count
        FROM (
          SELECT 'sources' as name UNION
          SELECT 'reports' as name UNION  
          SELECT 'api_keys' as name UNION
          SELECT 'audit_logs' as name
        ) tables
      `, (err, rows) => {
        if (err) reject(err)
        else resolve(rows)
      })
    })
    
    return { 
      tables: stats,
      optimized_at: new Date().toISOString()
    }
    
  } catch (error) {
    console.error('Failed to get database stats:', error)
    throw error
  } finally {
    db.close()
  }
}