import { NextResponse } from 'next/server'
import pool from '@/lib/db'

// GET /api/drops/active - Get the earliest unfilled drop (not sold out) that has started
export async function GET() {
  try {
    const now = new Date()
    
    // Get all drops ordered by start_time (or created_at if start_time is null)
    const [rows] = await pool.execute(
      'SELECT * FROM drops ORDER BY COALESCE(start_time, created_at) ASC'
    )
    
    const drops = rows as any[]
    
    // Find the first drop that's not fully sold out and has started
    for (const drop of drops) {
      // Check if drop has started (start_time is in the past or null)
      const startTime = drop.start_time ? new Date(drop.start_time) : new Date(drop.created_at)
      if (startTime > now) {
        // Drop hasn't started yet - return it with a flag indicating it's upcoming
        // Calculate fill (will be 0 for upcoming drops)
        const [salesRows] = await pool.execute(
          'SELECT COALESCE(SUM(size), 0) as total_fill FROM sales WHERE drop_id = ?',
          [drop.id]
        )
        const salesData = salesRows as any[]
        const totalFillInGrams = salesData[0]?.total_fill || 0
        
        let fill = totalFillInGrams
        if (drop.unit === 'kg') {
          fill = totalFillInGrams / 1000
        }
        
        return NextResponse.json({
          ...drop,
          fill: fill,
          is_upcoming: true,
          start_time: drop.start_time || drop.created_at,
        })
      }
      
      // Calculate fill from sales records
      // Sales are stored in grams, so we need to convert based on drop unit
      const [salesRows] = await pool.execute(
        'SELECT COALESCE(SUM(size), 0) as total_fill FROM sales WHERE drop_id = ?',
        [drop.id]
      )
      const salesData = salesRows as any[]
      const totalFillInGrams = salesData[0]?.total_fill || 0
      
      // Convert fill to drop's unit for comparison
      let fill = totalFillInGrams
      if (drop.unit === 'kg') {
        fill = totalFillInGrams / 1000
      }
      
      // Check if drop is not fully sold out
      if (fill < drop.size) {
        // Return drop with calculated fill
        return NextResponse.json({
          ...drop,
          fill: fill,
          is_upcoming: false,
          start_time: drop.start_time || drop.created_at,
        })
      }
    }
    
    // No active drops found
    return NextResponse.json(null)
  } catch (error) {
    console.error('Error fetching active drop:', error)
    return NextResponse.json(
      { error: 'Failed to fetch active drop' },
      { status: 500 }
    )
  }
}