import { z } from "zod"

import { createLogger } from "@scandic-hotels/common/logger/createLogger"

import { env } from "@/env/server"

const logger = createLogger("contentstack-references")

/**
 * Schema for validating Contentstack Management API references response
 */
const entryReferenceSchema = z.object({
  uid: z.string().optional(),
  entry_uid: z.string(),
  content_type_uid: z.string(),
  locale: z.string(),
  title: z.string(),
  _version: z.number().optional(),
  content_type_title: z.string().optional(),
})

const referencesResponseSchema = z.object({
  references: z.array(entryReferenceSchema).optional().default([]),
})

export type EntryReference = z.infer<typeof entryReferenceSchema>

/**
 * Fetches all entries that reference the given entry from Contentstack Management API.
 *
 * This is used during cache invalidation to find parent pages that embed/reference
 * the changed entry, so we can invalidate their caches as well.
 *
 * @see https://www.contentstack.com/docs/developers/apis/content-management-api#entry-references
 */
export async function fetchEntryReferences(
  contentTypeUid: string,
  entryUid: string
): Promise<EntryReference[]> {
  const managementToken = env.CMS_MANAGEMENT_TOKEN

  if (!managementToken) {
    throw new Error("CMS_MANAGEMENT_TOKEN not configured")
  }

  // Contentstack EU region base URL
  const baseUrl = "https://eu-api.contentstack.com"
  const url = `${baseUrl}/v3/content_types/${contentTypeUid}/entries/${entryUid}/references`

  const response = await fetch(url, {
    method: "GET",
    headers: {
      api_key: env.CMS_API_KEY,
      authorization: managementToken,
      branch: env.CMS_BRANCH,
      "Content-Type": "application/json",
    },
    // Don't cache this request - we need fresh data
    cache: "no-store",
  })

  if (!response.ok) {
    const errorText = await response.text()
    throw new Error(
      `Failed to fetch entry references: ${response.status} ${errorText}`,
      {
        cause: response,
      }
    )
  }

  const data = await response.json()
  const parsed = referencesResponseSchema.safeParse(data)

  if (!parsed.success) {
    throw new Error("Invalid response from Contentstack references API", {
      cause: parsed.error,
    })
  }

  logger.debug(
    `Found ${parsed.data.references.length} references for ${contentTypeUid}/${entryUid}`
  )

  return parsed.data.references
}