import type { MediaType, SchemaType } from '@kubb/ast/types'
import type { HttpMethods as OASHttpMethods } from 'oas/types'

/**
 * JSON Schema keywords that indicate structural composition.
 * Used when deciding whether an inline `allOf` fragment can be safely flattened
 * into its parent (fragments containing any of these keys must not be inlined).
 */
export const STRUCTURAL_KEYS = new Set<string>(['properties', 'items', 'additionalProperties', 'oneOf', 'anyOf', 'allOf', 'not'])

/**
 * Maps OAS/JSON Schema `format` strings to their Kubb `SchemaType` equivalents.
 *
 * Only formats that require a type different from the raw OAS `type` are listed here.
 * `int64`, `date-time`, `date`, and `time` are handled separately because their
 * output depends on runtime parser options and cannot live in a static map.
 *
 * Note: `ipv4`, `ipv6`, and `hostname` map to `'url'` — not semantically accurate,
 * but `'url'` is the closest supported scalar type in the Kubb AST.
 */
export const FORMAT_MAP = {
  uuid: 'uuid',
  email: 'email',
  'idn-email': 'email',
  uri: 'url',
  'uri-reference': 'url',
  url: 'url',
  ipv4: 'url',
  ipv6: 'url',
  hostname: 'url',
  'idn-hostname': 'url',
  binary: 'blob',
  byte: 'blob',
  // Numeric formats — format is more specific than type, so these override type.
  // see https://json-schema.org/draft/2020-12/draft-bhutton-json-schema-validation-00#rfc.section.7
  int32: 'integer',
  float: 'number',
  double: 'number',
} as const satisfies Record<string, SchemaType>

/**
 * Exhaustive list of media types that Kubb recognizes.
 * Kept as a module-level constant to avoid re-allocating the array on every call.
 */
export const KNOWN_MEDIA_TYPES = [
  'application/json',
  'application/xml',
  'application/x-www-form-urlencoded',
  'application/octet-stream',
  'application/pdf',
  'application/zip',
  'application/graphql',
  'multipart/form-data',
  'text/plain',
  'text/html',
  'text/csv',
  'text/xml',
  'image/png',
  'image/jpeg',
  'image/gif',
  'image/webp',
  'image/svg+xml',
  'audio/mpeg',
  'video/mp4',
] as const satisfies ReadonlyArray<MediaType>

/**
 * Vendor extension keys used by various spec generators to attach human-readable
 * labels to enum values. Checked in priority order: the first key found wins.
 */
export const ENUM_EXTENSION_KEYS = ['x-enumNames', 'x-enum-varnames'] as const

/**
 * Canonical HTTP method names used throughout the Kubb OAS layer.
 * Keys are uppercase (as used in generated code); values are the lowercase
 * strings that the `oas` library uses internally.
 * @deprecated use httpMethods from @kubb/ast
 */
export const httpMethods = {
  GET: 'get',
  POST: 'post',
  PUT: 'put',
  PATCH: 'patch',
  DELETE: 'delete',
  HEAD: 'head',
  OPTIONS: 'options',
  TRACE: 'trace',
} as const satisfies Record<Uppercase<OASHttpMethods>, OASHttpMethods>