import {z} from 'zod'

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

export const credentialsSupportedDisplay = z.object({name: z.string().optional(), locale: z.string().optional(), logo: z.object({url: z.string().optional(), alt_text: z.string().optional()}).optional(), background_color: z.string().optional(), text_color: z.string().optional()});

export const credentialConfigurationSupported = z.object({format: z.string(), scope: z.string().optional(), cryptographic_binding_methods_supported: z.array(z.string()).optional(), credential_signing_alg_values_supported: z.array(z.string()).optional(), proof_types_supported: z.object({}).optional(), display: z.array(credentialsSupportedDisplay).optional()});

export const batchCredentialIssuance = z.object({batch_size: z.number().int()});

export const responseEncryption = z.object({alg_values_supported: z.array(z.string()), enc_values_supported: z.array(z.string()), encryption_required: z.boolean()});

export const metadataDisplay = z.object({name: z.string().optional(), locale: z.string().optional(), logo: z.object({url: z.string().optional(), alt_text: z.string().optional()}).optional(), background_color: z.string().optional(), text_color: z.string().optional()});

export const issuerMetadata = z.object({credential_issuer: z.string(), credential_configurations_supported: z.record(z.string(), credentialConfigurationSupported), credential_endpoint: z.string(), token_endpoint: z.string().optional(), authorization_challenge_endpoint: z.string().optional(), nonce_endpoint: z.string().optional(), authorization_servers: z.array(z.string()).optional(), deferred_credential_endpoint: z.string().optional(), notification_endpoint: z.string().optional(), batch_credential_issuance: batchCredentialIssuance.optional(), credential_response_encryption: responseEncryption.optional(), credential_identifiers_supported: z.boolean().optional(), display: z.array(metadataDisplay).optional()});

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
};

/**
 * Get credential issuer metadata
 * 
 * GET /.well-known/openid-credential-issuer
 */
export const getApiWellKnownOpenidCredentialIssuer = async (options?: GetApiWellKnownOpenidCredentialIssuerOptions) => {
const {baseUrl = "https://agent.findynet.demo.sphereon.com/oid4vci", fetch: fetchFn = fetch} = options ?? {}

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

const url = `${baseUrl.replace(/\/+$/, '')}/.well-known/openid-credential-issuer${query.size > 0 ? `?${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(issuerMetadata, await res.json())
};