import { isAllowedWebhookUrl } from './orchestrator.js'

export interface WebhookTestResult {
  reachable: boolean
  validResponse: boolean
  latencyMs: number
  error?: string
}

export async function testWebhook(webhookUrl: string): Promise<WebhookTestResult> {
  if (!isAllowedWebhookUrl(webhookUrl)) {
    return { reachable: false, validResponse: false, latencyMs: 0, error: 'URL blocked: private/internal addresses are not allowed.' }
  }

  const testPayload = JSON.stringify({
    fight_id: 'test_000000',
    round: 0,
    type: 'webhook_test',
    challenge: 'WEBHOOK TEST: respond with {"answer": "pong"} to verify your setup.',
    constraints: { timeout_ms: 5000, max_tokens: 500 },
    opponent: { name: 'test_bot', wins: 0, losses: 0 },
    arena: 'localhost',
    arena_modifier: null,
  })

  const start = Date.now()

  try {
    const controller = new AbortController()
    const timeout = setTimeout(() => controller.abort(), 5000)

    const res = await fetch(webhookUrl, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: testPayload,
      signal: controller.signal,
    })

    clearTimeout(timeout)
    const latencyMs = Date.now() - start

    if (!res.ok) {
      return { reachable: true, validResponse: false, latencyMs, error: `Webhook returned HTTP ${res.status}. Expected 200.` }
    }

    const text = await res.text()
    if (text.length > 10240) {
      return { reachable: true, validResponse: false, latencyMs, error: 'Response too large (>10KB).' }
    }

    let data: Record<string, unknown>
    try {
      data = JSON.parse(text)
    } catch {
      return { reachable: true, validResponse: false, latencyMs, error: 'Response is not valid JSON. Expected {"answer": "..."}.' }
    }

    if (typeof data.answer !== 'string') {
      return { reachable: true, validResponse: false, latencyMs, error: 'Response JSON missing "answer" field. Expected {"answer": "pong"}.' }
    }

    return { reachable: true, validResponse: true, latencyMs }
  } catch (err: unknown) {
    const latencyMs = Date.now() - start
    const isAbort = err instanceof Error && err.name === 'AbortError'
    if (isAbort) {
      return { reachable: false, validResponse: false, latencyMs, error: 'Webhook timed out (5s). Is your server running?' }
    }
    const msg = err instanceof Error ? err.message : String(err)
    return { reachable: false, validResponse: false, latencyMs, error: `Connection failed: ${msg}` }
  }
}