import { createClient } from '@/lib/supabase/server'
import { NextResponse } from 'next/server'
import { extractBearerToken, validateApiKey, createServiceClientNoCookies } from '@/lib/auth/api-keys'
import { validateQuery } from '@/lib/api/validate'
import { EventsQuerySchema } from '@/lib/api/schemas'
import { requireCompanyId } from '@/lib/company/context'
import type { SupabaseClient } from '@supabase/supabase-js'

/**
 * GET /api/events
 *
 * Cursor-based polling endpoint for external automation platforms (n8n, Make, Zapier).
 * Returns events from the event_log table in sequence order.
 *
 * Query params:
 *   - after (bigint, optional): return events with sequence > this value
 *   - types (string, optional): comma-separated event type filter
 *   - limit (int, optional): max results, default 50, cap 100
 *
 * Supports both session auth (browser) and API key auth (automation platforms).
 */
export async function GET(request: Request) {
  // Dual auth: API key or session
  let userId: string
  let supabase: SupabaseClient

  const token = extractBearerToken(request)
  if (token?.startsWith('gnubok_sk_')) {
    const authResult = await validateApiKey(token)
    if ('error' in authResult) {
      return NextResponse.json({ error: authResult.error }, { status: authResult.status })
    }
    userId = authResult.userId
    supabase = createServiceClientNoCookies()
  } else {
    supabase = await createClient()
    const { data: { user } } = await supabase.auth.getUser()
    if (!user) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
    }
    userId = user.id
  }

  const companyId = await requireCompanyId(supabase, userId)

  // Validate query params
  const result = validateQuery(request, EventsQuerySchema)
  if (!result.success) return result.response
  const { after, types, limit } = result.data

  // Build query
  let query = supabase
    .from('event_log')
    .select('sequence, event_type, entity_id, data, created_at')
    .eq('company_id', companyId)
    .order('sequence', { ascending: true })
    .limit(limit)

  if (after !== undefined) {
    query = query.gt('sequence', after)
  }

  if (types && types.length > 0) {
    query = query.in('event_type', types)
  }

  const { data, error } = await query

  if (error) {
    return NextResponse.json({ error: error.message }, { status: 500 })
  }

  const events = data ?? []

  return NextResponse.json({
    data: events,
    cursor: events.length > 0 ? events[events.length - 1].sequence : (after ?? 0),
    has_more: events.length === limit,
  })
}