import type { RoutePattern } from '../route-pattern.ts'
import type { ParseParams } from '../types/params.ts'
import type { Simplify } from '../types/utils.ts'

/** Params extracted from a route pattern match. */
export type MatchParams<source extends string> =
  ParseParams<source> extends infer params
    ? [params] extends [never]
      ? never
      : Simplify<Omit<params, '*'>>
    : never

/** Metadata describing where a matched param appeared in a normalized URL part. */
export type MatchParamMeta = {
  /** Param token kind: `:` for variables or `*` for wildcards. */
  type: ':' | '*'

  /** Param name, or `*` for an unnamed wildcard. */
  name: string

  /** Matched param value after URL normalization and decoding. */
  value: string

  /** Start offset after the URL part is normalized. */
  begin: number

  /** End offset after the URL part is normalized. */
  end: number
}

/** Result returned by route pattern matchers. */
export type Match<source extends string = string, data = unknown> = {
  /** URL object used for the match. */
  url: URL

  /** Pattern that matched the URL. */
  pattern: RoutePattern<source>

  /** Data attached to the matched pattern. */
  data: data

  /** Params captured from the matched pattern. */
  params: MatchParams<source>

  /** Metadata for hostname and pathname params captured during matching. */
  paramsMeta: {
    /** Params captured from the hostname pattern. */
    hostname: ReadonlyArray<MatchParamMeta>

    /** Params captured from the pathname pattern. */
    pathname: ReadonlyArray<MatchParamMeta>
  }
}