import { db, webhook, webhookPathClaim, workflow, workflowDeploymentVersion } from '@sim/db'
import { createLogger } from '@sim/logger'
import { toError } from '@sim/utils/errors'
import { generateId } from '@sim/utils/id'
import { truncate } from '@sim/utils/string'
import { and, eq, isNull, or } from 'drizzle-orm'
import { type NextRequest, NextResponse } from 'next/server'
import { releaseExecutionSlot } from '@/lib/billing/calculations/usage-reservation'
import type { BillingAttributionSnapshot } from '@/lib/billing/core/billing-attribution'
import { tryAdmit } from '@/lib/core/admission/gate'
import {
  ADMISSION_ERROR_DESCRIPTOR,
  classifyTransientAdmissionFailure,
  type TransientAdmissionFailure,
} from '@/lib/core/admission/transient-failure'
import { getInlineJobQueue, getJobQueue, shouldExecuteInline } from '@/lib/core/async-jobs'
import type { AsyncExecutionCorrelation } from '@/lib/core/async-jobs/types'
import { toTriggerMaxDurationSeconds } from '@/lib/core/execution-limits'
import {
  assertContentLengthWithinLimit,
  isPayloadSizeLimitError,
  readStreamToBufferWithLimit,
} from '@/lib/core/utils/stream-limits'
import { getEffectiveDecryptedEnv } from '@/lib/environment/utils'
import { preprocessExecution } from '@/lib/execution/preprocessing'
import { WEBHOOK_MAX_BODY_BYTES } from '@/lib/webhooks/constants'
import { deliverableWebhookPredicate } from '@/lib/webhooks/delivery-predicate'
import {
  getPendingWebhookVerification,
  matchesPendingWebhookVerificationProbe,
  requiresPendingWebhookVerification,
} from '@/lib/webhooks/pending-verification'
import { getProviderHandler } from '@/lib/webhooks/providers'
import type { WebhookProviderHandler } from '@/lib/webhooks/providers/types'
import { normalizeWebhookRegistrationPath } from '@/lib/webhooks/registration-identity'
import { blockExistsInDeployment } from '@/lib/workflows/persistence/utils'
import { SIM_TRIGGER_PROVIDER } from '@/lib/workspace-events/constants'
import { executeWebhookJob, type WebhookExecutionPayload } from '@/background/webhook-execution'
import { resolveEnvVarReferences } from '@/executor/utils/reference-validation'
import { isPollingWebhookProvider } from '@/triggers/constants'

const logger = createLogger('WebhookProcessor')

type WebhookRecord = typeof webhook.$inferSelect
type WorkflowRecord = typeof workflow.$inferSelect
type WebhookTarget = { webhook: WebhookRecord; workflow: WorkflowRecord }
type ResolvedWebhookRecord = Omit<WebhookRecord, 'provider' | 'providerConfig'> & {
  provider: string
  providerConfig: Record<string, unknown>
}

export interface WebhookProcessorOptions {
  requestId: string
  path?: string
  webhookId?: string
  actorUserId?: string
  billingAttribution?: BillingAttributionSnapshot
  executionId?: string
  correlation?: AsyncExecutionCorrelation
  executionTimeoutMs?: number
  /** Epoch ms when the webhook HTTP request was first received (for dispatch-latency metrics). */
  receivedAt?: number
  /** Epoch ms of the originating provider interaction (e.g. Slack x-slack-request-timestamp). */
  triggerTimestampMs?: number
}

export interface WebhookPreprocessingResult {
  error: NextResponse | null
  transientAdmissionFailure?: TransientAdmissionFailure
  actorUserId?: string
  billingAttribution?: BillingAttributionSnapshot
  executionId?: string
  correlation?: AsyncExecutionCorrelation
  executionTimeoutMs?: number
}

const WEBHOOK_BODY_LABEL = 'Webhook request body'

export async function parseWebhookBody(
  request: NextRequest,
  requestId: string
): Promise<{ body: unknown; rawBody: string } | NextResponse> {
  let rawBody: string | null = null
  try {
    assertContentLengthWithinLimit(request.headers, WEBHOOK_MAX_BODY_BYTES, WEBHOOK_BODY_LABEL)

    const buffer = await readStreamToBufferWithLimit(request.clone().body, {
      maxBytes: WEBHOOK_MAX_BODY_BYTES,
      label: WEBHOOK_BODY_LABEL,
    })
    rawBody = new TextDecoder().decode(buffer)

    if (!rawBody || rawBody.length === 0) {
      return { body: {}, rawBody: '' }
    }
  } catch (bodyError) {
    if (isPayloadSizeLimitError(bodyError)) {
      logger.warn(`[${requestId}] Rejected oversized webhook body`, {
        maxBytes: WEBHOOK_MAX_BODY_BYTES,
        observedBytes: bodyError.observedBytes,
      })
      return new NextResponse('Request body too large', { status: 413 })
    }
    logger.error(`[${requestId}] Failed to read request body`, {
      error: toError(bodyError).message,
    })
    return new NextResponse('Failed to read request body', { status: 400 })
  }

  let body: unknown
  try {
    const contentType = request.headers.get('content-type') || ''

    if (contentType.includes('application/x-www-form-urlencoded')) {
      const formData = new URLSearchParams(rawBody)
      const payloadString = formData.get('payload')

      if (payloadString) {
        body = JSON.parse(payloadString)
      } else {
        body = Object.fromEntries(formData.entries())
      }
    } else {
      body = JSON.parse(rawBody)
    }
  } catch (parseError) {
    logger.error(`[${requestId}] Failed to parse webhook body`, {
      error: toError(parseError).message,
      contentType: request.headers.get('content-type'),
      bodyPreview: truncate(rawBody ?? '', 100),
    })
    return new NextResponse('Invalid payload format', { status: 400 })
  }

  return { body, rawBody }
}

/** Providers that implement challenge/verification handling, checked before webhook lookup. */
const CHALLENGE_PROVIDERS = ['monday', 'slack', 'microsoft-teams', 'whatsapp', 'zoom'] as const

export async function handleProviderChallenges(
  body: unknown,
  request: NextRequest,
  requestId: string,
  path: string,
  rawBody?: string
): Promise<NextResponse | null> {
  for (const provider of CHALLENGE_PROVIDERS) {
    const handler = getProviderHandler(provider)
    if (handler.handleChallenge) {
      const response = await handler.handleChallenge(body, request, requestId, path, rawBody)
      if (response) {
        return response
      }
    }
  }
  return null
}

/**
 * Returns a verification response for provider reachability probes that happen
 * before a webhook row exists and therefore before provider lookup is possible.
 */
export async function handlePreLookupWebhookVerification(
  method: string,
  body: Record<string, unknown> | undefined,
  requestId: string,
  path: string
): Promise<NextResponse | null> {
  const pendingVerification = await getPendingWebhookVerification(path)
  if (!pendingVerification) {
    return null
  }

  if (!matchesPendingWebhookVerificationProbe(pendingVerification, { method, body })) {
    return null
  }

  logger.info(
    `[${requestId}] Returning 200 for pending ${pendingVerification.provider} webhook verification on path: ${path}`
  )

  return NextResponse.json({ status: 'ok', message: 'Webhook endpoint verified' })
}

/**
 * Handle provider-specific reachability tests that occur AFTER webhook lookup.
 * Delegates to the provider handler registry.
 */
export function handleProviderReachabilityTest(
  webhookRecord: { provider: string },
  body: unknown,
  requestId: string
): NextResponse | null {
  const handler = getProviderHandler(webhookRecord?.provider)
  return handler.handleReachabilityTest?.(body, requestId) ?? null
}

/**
 * Format error response based on provider requirements.
 * Delegates to the provider handler registry.
 */
export function formatProviderErrorResponse(
  webhookRecord: { provider: string | null },
  error: string,
  status: number
): NextResponse {
  const handler = getProviderHandler(webhookRecord.provider ?? '')
  return handler.formatErrorResponse?.(error, status) ?? NextResponse.json({ error }, { status })
}

function formatGenericTransientAdmissionResponse(
  message: string,
  failure: TransientAdmissionFailure
): NextResponse {
  return NextResponse.json(
    {
      error: message,
      code: failure.code,
      retryable: failure.retryable,
      retryAfterSeconds: failure.retryAfterSeconds,
    },
    {
      status: failure.statusCode,
      headers: { 'Retry-After': String(failure.retryAfterSeconds) },
    }
  )
}

/**
 * Check if a webhook event should be skipped based on provider-specific filtering.
 * Delegates to the provider handler registry.
 */
export function shouldSkipWebhookEvent(
  webhookRecord: { provider: string; providerConfig?: Record<string, unknown> },
  body: unknown,
  requestId: string
): boolean {
  const handler = getProviderHandler(webhookRecord.provider)
  const providerConfig = webhookRecord.providerConfig ?? {}
  return (
    handler.shouldSkipEvent?.({ webhook: webhookRecord, body, requestId, providerConfig }) ?? false
  )
}

/**
 * Applies an asynchronous provider event matcher before execution admission.
 * Returns the provider's ignore response, or null when execution should proceed.
 */
export async function handleWebhookEventFilter(
  webhookRecord: WebhookRecord,
  workflowRecord: WorkflowRecord,
  body: unknown,
  request: NextRequest,
  requestId: string
): Promise<NextResponse | null> {
  if (!webhookRecord.provider) {
    return null
  }

  const handler = getProviderHandler(webhookRecord.provider)
  if (!handler.matchEvent) {
    return null
  }

  const providerConfig = parseProviderConfig(webhookRecord.providerConfig)
  const result = await handler.matchEvent({
    webhook: { ...webhookRecord },
    workflow: { ...workflowRecord },
    body,
    request,
    requestId,
    providerConfig,
  })
  if (result === true) {
    return null
  }
  if (result instanceof NextResponse) {
    return result
  }
  return NextResponse.json({
    message: 'Event type does not match trigger configuration. Ignoring.',
  })
}

/** Returns 200 OK for providers that validate URLs before the workflow is deployed */
export function handlePreDeploymentVerification(
  webhookRecord: { provider: string },
  requestId: string
): NextResponse | null {
  if (requiresPendingWebhookVerification(webhookRecord.provider)) {
    logger.info(
      `[${requestId}] ${webhookRecord.provider} webhook - block not in deployment, returning 200 OK for URL validation`
    )
    return NextResponse.json({
      status: 'ok',
      message: 'Webhook endpoint verified',
    })
  }
  return null
}

async function findWebhookAndWorkflow(
  options: WebhookProcessorOptions
): Promise<WebhookTarget | null> {
  if (options.webhookId) {
    const results = await db
      .select({
        webhook: webhook,
        workflow: workflow,
      })
      .from(webhook)
      .innerJoin(workflow, eq(webhook.workflowId, workflow.id))
      .leftJoin(
        workflowDeploymentVersion,
        and(
          eq(workflowDeploymentVersion.workflowId, workflow.id),
          eq(workflowDeploymentVersion.isActive, true)
        )
      )
      .where(
        and(
          eq(webhook.id, options.webhookId),
          deliverableWebhookPredicate(webhook),
          isNull(workflow.archivedAt),
          or(
            eq(webhook.deploymentVersionId, workflowDeploymentVersion.id),
            and(isNull(workflowDeploymentVersion.id), isNull(webhook.deploymentVersionId))
          )
        )
      )
      .limit(1)

    if (results.length === 0) {
      logger.warn(`[${options.requestId}] No active webhook found for id: ${options.webhookId}`)
      return null
    }

    return { webhook: results[0].webhook, workflow: results[0].workflow }
  }

  if (options.path) {
    const results = await db
      .select({
        webhook: webhook,
        workflow: workflow,
      })
      .from(webhook)
      .innerJoin(workflow, eq(webhook.workflowId, workflow.id))
      .leftJoin(
        workflowDeploymentVersion,
        and(
          eq(workflowDeploymentVersion.workflowId, workflow.id),
          eq(workflowDeploymentVersion.isActive, true)
        )
      )
      .where(
        and(
          eq(webhook.path, options.path),
          deliverableWebhookPredicate(webhook),
          isNull(workflow.archivedAt),
          or(
            eq(webhook.deploymentVersionId, workflowDeploymentVersion.id),
            and(isNull(workflowDeploymentVersion.id), isNull(webhook.deploymentVersionId))
          )
        )
      )
      .limit(1)

    if (results.length === 0) {
      logger.warn(`[${options.requestId}] No active webhook found for path: ${options.path}`)
      return null
    }

    return { webhook: results[0].webhook, workflow: results[0].workflow }
  }

  return null
}

/**
 * Finds all webhooks matching a path, scoped to a single workflow.
 *
 * Legitimate multi-webhook matches are always within one workflow, but paths
 * are user-controlled and only unique per deployment version, so two tenants can
 * register the same path. On collision the `webhook_path_claim` owner wins;
 * without a claim we keep the workflow that registered the path first, so one
 * tenant can never receive another's webhook deliveries.
 */
export async function findAllWebhooksForPath(
  options: WebhookProcessorOptions
): Promise<WebhookTarget[]> {
  if (!options.path) {
    return []
  }

  const results = await db
    .select({
      webhook: webhook,
      workflow: workflow,
    })
    .from(webhook)
    .innerJoin(workflow, eq(webhook.workflowId, workflow.id))
    .leftJoin(
      workflowDeploymentVersion,
      and(
        eq(workflowDeploymentVersion.workflowId, workflow.id),
        eq(workflowDeploymentVersion.isActive, true)
      )
    )
    .where(
      and(
        eq(webhook.path, options.path),
        deliverableWebhookPredicate(webhook),
        isNull(workflow.archivedAt),
        or(
          eq(webhook.deploymentVersionId, workflowDeploymentVersion.id),
          and(isNull(workflowDeploymentVersion.id), isNull(webhook.deploymentVersionId))
        )
      )
    )

  if (results.length === 0) {
    logger.warn(`[${options.requestId}] No active webhooks found for path: ${options.path}`)
    return results
  }

  const distinctWorkflowIds = new Set(results.map((result) => result.webhook.workflowId))

  if (distinctWorkflowIds.size > 1) {
    const claimOwnerWorkflowId = await findWebhookPathClaimOwner(options.path)
    const owner =
      (claimOwnerWorkflowId &&
        results.find((result) => result.webhook.workflowId === claimOwnerWorkflowId)) ||
      results.reduce((earliest, candidate) => {
        const candidateTime = new Date(candidate.webhook.createdAt).getTime()
        const earliestTime = new Date(earliest.webhook.createdAt).getTime()
        if (candidateTime !== earliestTime) {
          return candidateTime < earliestTime ? candidate : earliest
        }
        return candidate.webhook.id < earliest.webhook.id ? candidate : earliest
      })
    const ownerWorkflowId = owner.webhook.workflowId
    const ownerResults = results.filter((result) => result.webhook.workflowId === ownerWorkflowId)

    logger.error(
      `[${options.requestId}] Cross-tenant webhook path collision for path: ${options.path}. Found ${results.length} active webhooks across ${distinctWorkflowIds.size} workflows. Dispatching only to owner workflow ${ownerWorkflowId} (${claimOwnerWorkflowId === ownerWorkflowId ? 'path-claim owner' : 'earliest registration'}) and dropping ${results.length - ownerResults.length} foreign webhook(s).`
    )

    return ownerResults
  }

  if (results.length > 1) {
    logger.info(`[${options.requestId}] Found ${results.length} webhooks for path: ${options.path}`)
  }

  return results
}

/**
 * Resolves the sticky `webhook_path_claim` owner for a delivery path, so
 * collision resolution can prefer the workflow that legitimately claimed the
 * path over an interloper that registered a row first.
 */
async function findWebhookPathClaimOwner(path: string): Promise<string | null> {
  const normalizedPath = normalizeWebhookRegistrationPath(path)
  if (!normalizedPath) return null
  const [claim] = await db
    .select({ workflowId: webhookPathClaim.workflowId })
    .from(webhookPathClaim)
    .where(eq(webhookPathClaim.path, normalizedPath))
    .limit(1)
  return claim?.workflowId ?? null
}

/**
 * Finds all active `slack_app` webhooks for a Slack `team_id` (the routing key).
 *
 * Unlike path-based lookup, multi-workflow fan-out is legitimate here: a single
 * Slack workspace can have many workflows listening on the native Sim app, so
 * every matching workflow is returned. The routing key is server-derived at
 * deploy time (Slack-attested `team_id`), not user-controlled, so the
 * cross-tenant collision guard used for guessable paths does not apply.
 */
export async function findWebhooksByRoutingKey(
  routingKey: string,
  requestId: string,
  provider = 'slack_app'
): Promise<WebhookTarget[]> {
  if (!routingKey) {
    return []
  }

  const results = await db
    .select({
      webhook: webhook,
      workflow: workflow,
    })
    .from(webhook)
    .innerJoin(workflow, eq(webhook.workflowId, workflow.id))
    .leftJoin(
      workflowDeploymentVersion,
      and(
        eq(workflowDeploymentVersion.workflowId, workflow.id),
        eq(workflowDeploymentVersion.isActive, true)
      )
    )
    .where(
      and(
        eq(webhook.routingKey, routingKey),
        eq(webhook.provider, provider),
        deliverableWebhookPredicate(webhook),
        isNull(workflow.archivedAt),
        or(
          eq(webhook.deploymentVersionId, workflowDeploymentVersion.id),
          and(isNull(workflowDeploymentVersion.id), isNull(webhook.deploymentVersionId))
        )
      )
    )

  if (results.length === 0) {
    logger.warn(`[${requestId}] No active ${provider} webhooks for routing key`)
  }

  return results
}

function resolveEnvVars(value: string, envVars: Record<string, string>): string {
  return resolveEnvVarReferences(value, envVars) as string
}

/** True when any string value in the provider config contains an env-var reference (`{{VAR}}`). */
function providerConfigReferencesEnvVars(config: Record<string, unknown>): boolean {
  for (const value of Object.values(config)) {
    if (typeof value === 'string' && value.includes('{{')) {
      return true
    }
  }
  return false
}

function resolveProviderConfigEnvVars(
  config: Record<string, unknown>,
  envVars: Record<string, string>
): Record<string, unknown> {
  const resolved: Record<string, unknown> = {}
  for (const [key, value] of Object.entries(config)) {
    if (typeof value === 'string') {
      resolved[key] = resolveEnvVars(value, envVars)
    } else {
      resolved[key] = value
    }
  }
  return resolved
}

/**
 * Verify webhook provider authentication and signatures.
 * Delegates to the provider handler registry.
 */
export async function verifyProviderAuth(
  foundWebhook: WebhookRecord,
  foundWorkflow: WorkflowRecord,
  request: NextRequest,
  rawBody: string,
  requestId: string
): Promise<NextResponse | null> {
  if (!foundWebhook.provider) {
    return NextResponse.json({ error: 'Webhook provider is missing' }, { status: 500 })
  }

  const handler = getProviderHandler(foundWebhook.provider)
  const rawProviderConfig = parseProviderConfig(foundWebhook.providerConfig)

  /**
   * Only fetch + decrypt the effective env when there is auth to verify AND the
   * provider config actually references env vars (`{{VAR}}`). This avoids a DB
   * read and decryption on the synchronous pre-ack path for the common case.
   */
  let decryptedEnvVars: Record<string, string> = {}
  if (handler.verifyAuth && providerConfigReferencesEnvVars(rawProviderConfig)) {
    try {
      decryptedEnvVars = await getEffectiveDecryptedEnv(
        foundWorkflow.userId,
        foundWorkflow.workspaceId ?? undefined
      )
    } catch (error) {
      logger.error(`[${requestId}] Failed to fetch environment variables`, {
        error,
      })
    }
  }

  const providerConfig = resolveProviderConfigEnvVars(rawProviderConfig, decryptedEnvVars)

  if (handler.verifyAuth) {
    const authResult = await handler.verifyAuth({
      webhook: { ...foundWebhook },
      workflow: { ...foundWorkflow },
      request,
      rawBody,
      requestId,
      providerConfig,
    })
    if (authResult) return authResult
  }

  return null
}

/**
 * Run preprocessing checks for webhook execution
 */
export async function checkWebhookPreprocessing(
  foundWorkflow: WorkflowRecord,
  foundWebhook: WebhookRecord,
  requestId: string
): Promise<WebhookPreprocessingResult> {
  try {
    const executionId = generateId()
    const correlation = {
      executionId,
      requestId,
      source: 'webhook' as const,
      workflowId: foundWorkflow.id,
      webhookId: foundWebhook.id,
      path: foundWebhook.path ?? undefined,
      provider: foundWebhook.provider ?? undefined,
      triggerType: 'webhook',
    }

    const preprocessResult = await preprocessExecution({
      workflowId: foundWorkflow.id,
      userId: foundWorkflow.userId,
      triggerType: 'webhook',
      executionId,
      requestId,
      triggerData: { correlation },
      checkRateLimit: true,
      checkDeployment: true,
      workspaceId: foundWorkflow.workspaceId ?? undefined,
      workflowRecord: foundWorkflow,
      executionType: 'async',
    })

    if (!preprocessResult.success) {
      const error = preprocessResult.error
      const transientAdmissionFailure = classifyTransientAdmissionFailure(error)
      logger.warn(`[${requestId}] Webhook preprocessing failed`, {
        provider: foundWebhook.provider,
        error: error.message,
        statusCode: error.statusCode,
      })

      return {
        error:
          transientAdmissionFailure && foundWebhook.provider === 'generic'
            ? formatGenericTransientAdmissionResponse(error.message, transientAdmissionFailure)
            : formatProviderErrorResponse(foundWebhook, error.message, error.statusCode),
        ...(transientAdmissionFailure ? { transientAdmissionFailure } : {}),
      }
    }

    return {
      error: null,
      actorUserId: preprocessResult.actorUserId,
      billingAttribution: preprocessResult.billingAttribution,
      executionId,
      correlation,
      executionTimeoutMs: preprocessResult.executionTimeout.async,
    }
  } catch (preprocessError) {
    logger.error(`[${requestId}] Error during webhook preprocessing:`, preprocessError)

    return {
      error: formatProviderErrorResponse(foundWebhook, 'Internal error during preprocessing', 500),
    }
  }
}

export type WebhookDispatchOutcome = 'queued' | 'ignored' | 'failed'

export interface WebhookDispatchResult {
  outcome: WebhookDispatchOutcome
  response: NextResponse
  reason:
    | 'queued'
    | 'event-mismatch'
    | 'filtered'
    | 'preprocessing'
    | 'block-missing'
    | 'queue-failed'
}

function parseProviderConfig(value: unknown): Record<string, unknown> {
  return value !== null && typeof value === 'object' && !Array.isArray(value)
    ? (value as Record<string, unknown>)
    : {}
}

function getCredentialId(providerConfig: Record<string, unknown>): string | undefined {
  return typeof providerConfig.credentialId === 'string' ? providerConfig.credentialId : undefined
}

function shouldUseDurableQueue(provider: string, handler: WebhookProviderHandler): boolean {
  return (
    isPollingWebhookProvider(provider) ||
    provider === SIM_TRIGGER_PROVIDER ||
    handler.executionMode === 'queue'
  )
}

async function queueWebhookExecutionWithResult(
  foundWebhook: ResolvedWebhookRecord,
  foundWorkflow: typeof workflow.$inferSelect,
  body: unknown,
  request: NextRequest,
  options: WebhookProcessorOptions
): Promise<WebhookDispatchResult> {
  const providerConfig = foundWebhook.providerConfig ?? {}
  const handler = getProviderHandler(foundWebhook.provider)
  const reservedExecutionId = options.executionId
  let reservationTransferred = false

  try {
    const { 'x-sim-idempotency-key': _, ...headers } = Object.fromEntries(request.headers.entries())

    if (handler.enrichHeaders) {
      handler.enrichHeaders(
        { webhook: foundWebhook, body, requestId: options.requestId, providerConfig },
        headers
      )
    }

    const credentialId = getCredentialId(providerConfig)

    const actorUserId = options.actorUserId
    const billingAttribution = options.billingAttribution
    const workspaceId = foundWorkflow.workspaceId
    if (!actorUserId || !billingAttribution || !workspaceId) {
      logger.error(`[${options.requestId}] Missing billing context for webhook ${foundWebhook.id}`)
      return {
        outcome: 'failed',
        response: NextResponse.json(
          { error: 'Unable to resolve billing account' },
          { status: 500 }
        ),
        reason: 'queue-failed',
      }
    }

    const executionId = options.executionId ?? generateId()
    const correlation =
      options.correlation ??
      ({
        executionId,
        requestId: options.requestId,
        source: 'webhook' as const,
        workflowId: foundWorkflow.id,
        webhookId: foundWebhook.id,
        // Routing-key webhooks (e.g. Slack) have no path.
        path: options.path || foundWebhook.path || undefined,
        provider: foundWebhook.provider,
        triggerType: 'webhook',
      } satisfies AsyncExecutionCorrelation)
    const payload = {
      webhookId: foundWebhook.id,
      workflowId: foundWorkflow.id,
      userId: actorUserId,
      billingAttribution,
      executionId,
      requestId: options.requestId,
      correlation,
      provider: foundWebhook.provider,
      body,
      headers,
      path: options.path || foundWebhook.path || '',
      blockId: foundWebhook.blockId ?? undefined,
      ...(foundWebhook.deploymentVersionId
        ? { deploymentVersionId: foundWebhook.deploymentVersionId }
        : {}),
      workspaceId,
      ...(credentialId ? { credentialId } : {}),
      ...(options.receivedAt !== undefined ? { webhookReceivedAt: options.receivedAt } : {}),
      ...(options.triggerTimestampMs !== undefined
        ? { triggerTimestampMs: options.triggerTimestampMs }
        : {}),
      ...(options.executionTimeoutMs !== undefined
        ? { executionTimeoutMs: options.executionTimeoutMs }
        : {}),
    } satisfies WebhookExecutionPayload

    const shouldUseQueue = shouldUseDurableQueue(payload.provider, handler)
    const maxDurationSeconds = toTriggerMaxDurationSeconds(options.executionTimeoutMs)

    if (shouldUseQueue && !shouldExecuteInline()) {
      const jobId = await (await getJobQueue()).enqueue('webhook-execution', payload, {
        metadata: {
          workflowId: foundWorkflow.id,
          workspaceId,
          userId: actorUserId,
          correlation,
        },
        maxDurationSeconds,
      })
      reservationTransferred = true
      logger.info(
        `[${options.requestId}] Queued webhook execution task ${jobId} for ${foundWebhook.provider} webhook via job queue`
      )
    } else {
      const jobQueue = await getInlineJobQueue()
      const jobId = await jobQueue.enqueue('webhook-execution', payload, {
        metadata: {
          workflowId: foundWorkflow.id,
          workspaceId,
          userId: actorUserId,
          correlation,
        },
        maxDurationSeconds,
        runner: (_queuedPayload: unknown, signal: AbortSignal) =>
          executeWebhookJob(payload, signal),
      })
      reservationTransferred = true
      logger.info(
        `[${options.requestId}] Queued ${foundWebhook.provider} webhook execution ${jobId} via inline backend`
      )
    }

    const successResponse = handler.formatSuccessResponse?.(providerConfig) ?? null
    if (successResponse) {
      return { outcome: 'queued', response: successResponse, reason: 'queued' }
    }

    return {
      outcome: 'queued',
      response: NextResponse.json({ message: 'Webhook processed' }),
      reason: 'queued',
    }
  } catch (error: unknown) {
    logger.error(`[${options.requestId}] Failed to queue webhook execution:`, error)

    const errorResponse = handler.formatQueueErrorResponse?.() ?? null
    if (errorResponse) {
      return { outcome: 'failed', response: errorResponse, reason: 'queue-failed' }
    }

    return {
      outcome: 'failed',
      response: NextResponse.json({ error: 'Internal server error' }, { status: 500 }),
      reason: 'queue-failed',
    }
  } finally {
    if (!reservationTransferred && reservedExecutionId) {
      await releaseExecutionSlot(reservedExecutionId)
    }
  }
}

/**
 * Runs the common post-authentication lifecycle for a resolved webhook target and returns a typed
 * outcome so app-level fanout workers do not infer queue state from HTTP response bodies.
 */
export async function dispatchResolvedWebhookTarget(
  foundWebhook: typeof webhook.$inferSelect,
  foundWorkflow: typeof workflow.$inferSelect,
  body: unknown,
  request: NextRequest,
  options: WebhookProcessorOptions
): Promise<WebhookDispatchResult> {
  if (!foundWebhook.provider) {
    return {
      outcome: 'failed',
      response: NextResponse.json({ error: 'Webhook provider is missing' }, { status: 500 }),
      reason: 'queue-failed',
    }
  }

  const webhookRecord = {
    ...foundWebhook,
    provider: foundWebhook.provider,
    providerConfig: parseProviderConfig(foundWebhook.providerConfig),
  }

  if (shouldSkipWebhookEvent(webhookRecord, body, options.requestId)) {
    return {
      outcome: 'ignored',
      response: NextResponse.json({ message: 'Webhook event ignored' }),
      reason: 'filtered',
    }
  }

  const eventFilterResponse = await handleWebhookEventFilter(
    webhookRecord,
    foundWorkflow,
    body,
    request,
    options.requestId
  )
  if (eventFilterResponse) {
    return {
      outcome: eventFilterResponse.ok ? 'ignored' : 'failed',
      response: eventFilterResponse,
      reason: 'event-mismatch',
    }
  }

  if (webhookRecord.blockId) {
    const blockExists = await blockExistsInDeployment(foundWorkflow.id, webhookRecord.blockId)
    if (!blockExists) {
      const verificationResponse = handlePreDeploymentVerification(webhookRecord, options.requestId)
      return {
        outcome: 'ignored',
        response:
          verificationResponse ??
          new NextResponse('Trigger block not found in deployment', { status: 404 }),
        reason: 'block-missing',
      }
    }
  }

  const preprocessResult = await checkWebhookPreprocessing(
    foundWorkflow,
    webhookRecord,
    options.requestId
  )
  if (preprocessResult.error) {
    return {
      outcome: 'failed',
      response: preprocessResult.error,
      reason: 'preprocessing',
    }
  }

  return queueWebhookExecutionWithResult(webhookRecord, foundWorkflow, body, request, {
    ...options,
    actorUserId: preprocessResult.actorUserId,
    billingAttribution: preprocessResult.billingAttribution,
    executionId: preprocessResult.executionId,
    correlation: preprocessResult.correlation,
    executionTimeoutMs: preprocessResult.executionTimeoutMs,
  })
}

export interface PolledWebhookEventResult {
  success: boolean
  error?: string
  statusCode?: number
  code?: string
  retryable?: boolean
  retryAfterSeconds?: number
  executionId?: string
}

type PolledWebhookRecord = typeof webhook.$inferSelect
type PolledWorkflowRecord = typeof workflow.$inferSelect

/**
 * Processes a polled webhook event directly, bypassing the HTTP trigger route.
 * Used by polling services (Gmail, Outlook, IMAP, RSS) to avoid the self-POST
 * anti-pattern where they would otherwise POST back to /api/webhooks/trigger/{path}.
 *
 * Performs only the steps actually needed for polling providers:
 * admission control, block existence check, preprocessing, and queue execution.
 */
export async function processPolledWebhookEvent(
  foundWebhook: PolledWebhookRecord,
  foundWorkflow: PolledWorkflowRecord,
  body: Record<string, unknown> | object,
  requestId: string
): Promise<PolledWebhookEventResult> {
  if (!foundWebhook.provider) {
    return { success: false, error: 'Webhook has no provider', statusCode: 400 }
  }
  const provider = foundWebhook.provider

  const ticket = tryAdmit()
  if (!ticket) {
    const gateFailure = ADMISSION_ERROR_DESCRIPTOR.GATE_CAPACITY
    logger.warn(`[${requestId}] Admission gate rejected polled webhook event`)
    return {
      success: false,
      error: 'Server at capacity',
      statusCode: gateFailure.statusCode,
      code: gateFailure.code,
      retryable: gateFailure.retryable,
      retryAfterSeconds: gateFailure.retryAfterSeconds,
    }
  }

  let reservedExecutionId: string | undefined
  let reservationTransferred = false
  try {
    if (foundWebhook.blockId) {
      const blockExists = await blockExistsInDeployment(foundWorkflow.id, foundWebhook.blockId)
      if (!blockExists) {
        logger.info(
          `[${requestId}] Trigger block ${foundWebhook.blockId} not found in deployment for workflow ${foundWorkflow.id}`
        )
        return { success: false, error: 'Trigger block not found in deployment', statusCode: 404 }
      }
    }

    const preprocessResult = await checkWebhookPreprocessing(foundWorkflow, foundWebhook, requestId)
    if (preprocessResult.error) {
      const errorResponse = preprocessResult.error
      const statusCode = errorResponse.status
      const errorBody: unknown = await errorResponse.json().catch(() => null)
      const errorMessage =
        errorBody !== null &&
        typeof errorBody === 'object' &&
        'error' in errorBody &&
        typeof errorBody.error === 'string'
          ? errorBody.error
          : 'Preprocessing failed'
      logger.warn(`[${requestId}] Polled webhook preprocessing failed`, {
        statusCode,
        error: errorMessage,
      })
      return {
        success: false,
        error: errorMessage,
        statusCode,
        ...(preprocessResult.transientAdmissionFailure
          ? {
              code: preprocessResult.transientAdmissionFailure.code,
              retryable: preprocessResult.transientAdmissionFailure.retryable,
              retryAfterSeconds: preprocessResult.transientAdmissionFailure.retryAfterSeconds,
            }
          : {}),
      }
    }
    reservedExecutionId = preprocessResult.executionId

    const providerConfig = parseProviderConfig(foundWebhook.providerConfig)
    const credentialId = getCredentialId(providerConfig)

    const actorUserId = preprocessResult.actorUserId
    const billingAttribution = preprocessResult.billingAttribution
    const workspaceId = foundWorkflow.workspaceId ?? undefined
    if (!actorUserId || !billingAttribution || !workspaceId) {
      logger.error(`[${requestId}] Missing billing context for webhook ${foundWebhook.id}`)
      return { success: false, error: 'Unable to resolve billing account', statusCode: 500 }
    }

    const executionId = preprocessResult.executionId ?? generateId()
    const correlation =
      preprocessResult.correlation ??
      ({
        executionId,
        requestId,
        source: 'webhook' as const,
        workflowId: foundWorkflow.id,
        webhookId: foundWebhook.id,
        path: foundWebhook.path ?? undefined,
        provider,
        triggerType: 'webhook',
      } satisfies AsyncExecutionCorrelation)

    const payload = {
      webhookId: foundWebhook.id,
      workflowId: foundWorkflow.id,
      userId: actorUserId,
      billingAttribution,
      executionId,
      requestId,
      correlation,
      provider,
      body,
      headers: { 'content-type': 'application/json' } as Record<string, string>,
      path: foundWebhook.path ?? '',
      blockId: foundWebhook.blockId ?? undefined,
      ...(foundWebhook.deploymentVersionId
        ? { deploymentVersionId: foundWebhook.deploymentVersionId }
        : {}),
      workspaceId,
      ...(credentialId ? { credentialId } : {}),
      ...(preprocessResult.executionTimeoutMs !== undefined
        ? { executionTimeoutMs: preprocessResult.executionTimeoutMs }
        : {}),
    } satisfies WebhookExecutionPayload

    const isQueueRoutedProvider = shouldUseDurableQueue(provider, getProviderHandler(provider))
    const maxDurationSeconds = toTriggerMaxDurationSeconds(preprocessResult.executionTimeoutMs)
    if (isQueueRoutedProvider && !shouldExecuteInline()) {
      const jobId = await (await getJobQueue()).enqueue('webhook-execution', payload, {
        metadata: {
          workflowId: foundWorkflow.id,
          workspaceId,
          userId: actorUserId,
          correlation,
        },
        maxDurationSeconds,
      })
      reservationTransferred = true
      logger.info(
        `[${requestId}] Queued polling webhook execution task ${jobId} for ${provider} webhook via job queue`
      )
    } else {
      const jobQueue = await getInlineJobQueue()
      const jobId = await jobQueue.enqueue('webhook-execution', payload, {
        metadata: {
          workflowId: foundWorkflow.id,
          workspaceId,
          userId: actorUserId,
          correlation,
        },
        maxDurationSeconds,
        runner: (_queuedPayload: unknown, signal: AbortSignal) =>
          executeWebhookJob(payload, signal),
      })
      reservationTransferred = true
      logger.info(`[${requestId}] Queued ${provider} webhook execution ${jobId} via inline backend`)
    }

    return { success: true, executionId }
  } catch (error: unknown) {
    logger.error(`[${requestId}] Failed to process polled webhook event:`, error)
    return { success: false, error: 'Internal server error', statusCode: 500 }
  } finally {
    if (!reservationTransferred && reservedExecutionId) {
      await releaseExecutionSlot(reservedExecutionId)
    }
    ticket.release()
  }
}