interface Lead {
  company: string
  contact: string
  owner: string
  stage: string
  value: number
  nextStep: string
}

export default async function handler(request, response) {
  if (!$google) {
    response.statusCode = 424
    response.setBody({ error: 'Google Sheets is not connected.' })
    return
  }

  const spreadsheetId = $kv.get('google.spreadsheetId', '')
  const sheets = $google.sheets({ version: 'v4' })

  if (request.method === 'GET') {
    const sheetData = await sheets.spreadsheets.values.get({
      spreadsheetId,
      range: 'Leads!A2:F1000'
    })

    const leads: Lead[] = (sheetData.data.values || []).map((row) => ({
      company: row[0] || '',
      contact: row[1] || '',
      owner: row[2] || '',
      stage: row[3] || 'New',
      value: row[4] ? Number(row[4]) : 0,
      nextStep: row[5] || ''
    }))

    response.setBody({
      leads,
      totals: {
        count: leads.length,
        pipeline: leads.reduce((sum, lead) => sum + lead.value, 0)
      }
    })
    return
  }

  if (request.method === 'POST') {
    const lead = request.body as Partial<Lead>
    await sheets.spreadsheets.values.append({
      spreadsheetId,
      range: 'Leads!A:F',
      valueInputOption: 'USER_ENTERED',
      requestBody: {
        values: [[
          lead.company,
          lead.contact,
          lead.owner,
          lead.stage || 'New',
          lead.value || 0,
          lead.nextStep || ''
        ]]
      }
    })

    response.statusCode = 201
    response.setBody({ success: true })
  }
}