import {z} from 'zod'

export type GetApiBuyHeadersArgs = {url: string};

export type GetApiBuyHeadersOptions = {baseUrl?: string | undefined, fetch?: typeof fetch | undefined};

export const getApiBuyHeadersResponse = z.object({ok: z.boolean(), url: z.string(), status: z.number().int().optional(), text: z.string().optional(), fetchedAt: z.string().optional(), data: z.object({grade: z.enum(["A", "B", "C", "D", "E", "F"]).optional(), score: z.number().int().optional(), maxScore: z.number().int().optional(), percentage: z.number().int().optional(), passed: z.number().int().optional(), failed: z.number().int().optional(), checks: z.array(z.object({header: z.string().optional(), label: z.string().optional(), present: z.boolean().optional(), pass: z.boolean().optional(), weight: z.number().int().optional(), value: z.string().nullable().optional(), note: z.string().optional()})).optional(), findings: z.array(z.object({header: z.string().optional(), severity: z.enum(["high", "medium", "low"]).optional(), remediate: z.string().optional()})).optional(), serverBanner: z.string().nullable().optional(), rubric: z.string().optional()}).optional(), error: z.string().optional()}).and(z.record(z.string(), z.unknown()));

export const validateResponse = async <Output>(
  schema: {
    readonly '~standard': {
      readonly validate: (value: unknown) => ({ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }) | Promise<{ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }>
    }
  },
  value: unknown
): Promise<Output> => {
  const result = await schema['~standard'].validate(value)

  if (result.issues !== undefined) {
    const detail = result.issues
      .map(({ message, path }) =>
        path?.length
          ? `${path.map((segment) => String(typeof segment === 'object' ? segment.key : segment)).join('.')}: ${message}`
          : message
      )
      .join('; ')

    throw new Error(`Response does not match the schema: ${detail}`, { cause: { issues: result.issues } })
  }

  return result.value
};

/**
 * MERCURY Cited Security-Headers Audit
 * 
 * GET /buy/headers
 */
export const getApiBuyHeaders = async (args: GetApiBuyHeadersArgs, options?: GetApiBuyHeadersOptions) => {
const {baseUrl = "https://network.mercury-hq.com", fetch: fetchFn = fetch} = options ?? {}

const query = new URLSearchParams()
const headers = new Headers()
headers.set('accept', "application/json")

if (args.url != null) query.append("url", String(args.url))

const url = `${baseUrl.replace(/\/+$/, '')}/buy/headers${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "GET", headers})

if (!res.ok) throw new Error(`Request failed with status ${res.status}`, {cause: {status: res.status, body: await res.text()}})

return validateResponse(getApiBuyHeadersResponse, await res.json())
};