export function ReadonlyMap<Key extends Constraint, Value extends Constraint>(
  key: Key,
  value: Value
): $ReadonlyMap<Key, Value> {
  const schema = declareConstructor<
    globalThis.ReadonlyMap<Key["Type"], Value["Type"]>,
    globalThis.ReadonlyMap<Key["Encoded"], Value["Encoded"]>,
    ReadonlyMapIso<Key, Value>
  >()(
    [key, value],
    ([key, value]) => {
      const array = ArraySchema(Tuple([key, value]))
      return (input, ast, options) => {
        if (input instanceof globalThis.Map) {
          return Effect.mapBothEager(
            SchemaParser.decodeUnknownEffect(array)([...input], options),
            {
              onSuccess: (array: ReadonlyArray<readonly [Key["Type"], Value["Type"]]>) => new globalThis.Map(array),
              onFailure: (issue) =>
                new SchemaIssue.Composite(ast, Option_.some(input), [new SchemaIssue.Pointer(["entries"], issue)])
            }
          )
        }
        return Effect.fail(new SchemaIssue.InvalidType(ast, Option_.some(input)))
      }
    },
    {
      typeConstructor: {
        _tag: "ReadonlyMap"
      },
      generation: {
        runtime: `Schema.ReadonlyMap(?, ?)`,
        Type: `globalThis.ReadonlyMap<?, ?>`
      },
      expected: "ReadonlyMap",
      toCodec: ([key, value]) =>
        link<globalThis.Map<Key["Encoded"], Value["Encoded"]>>()(
          ArraySchema(Tuple([key, value])),
          SchemaTransformation.transform({
            decode: (e) => new globalThis.Map(e),
            encode: (map) => [...map.entries()]
          })
        ),
      toArbitrary: ([key, value]) => (fc, ctx) => entriesArbitrary(fc, ctx, key, value, (as) => new globalThis.Map(as)),
      toEquivalence: ([key, value]) => Equal.makeCompareMap(key, value),
      toFormatter: ([key, value]) => (t) => {
        const size = t.size
        if (size === 0) {
          return "ReadonlyMap(0) {}"
        }
        const entries = globalThis.Array.from(t.entries()).sort().map(([k, v]) => `${key(k)} => ${value(v)}`)
        return `ReadonlyMap(${size}) { ${entries.join(", ")} }`
      }
    }
  )
  return make(schema.ast, { key, value })
}