/*
 * Copyright (c) 2025 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { KPointer, int32 } from './InteropTypes';
import { Wrapper } from './mainWrapper';
import { CustomTextDecoder, CustomTextEncoder } from './strings';
import { throwError } from './utils';

const encoder = new CustomTextEncoder();
const decoder = new CustomTextDecoder();

export function decodeToString(array: Uint8Array): string {
  return decoder.decode(array);
}

export function encodeToData(string: string): Uint8Array {
  return encoder.encode(string, false);
}

export function withString<R>(data: string, exec: Exec<string, R>): R {
  return exec(data);
}

export function withStringArray(strings: Array<string> | undefined): Uint8Array {
  if (strings === undefined || strings.length === 0) {
    throwError('Error in strings array');
  }

  let array = encoder.encodeArray(strings);
  return array;
}

function withArray<C extends TypedArray, R>(data: C | undefined, exec: ExecWithLength<C | null, R>): R {
  return exec(data ?? null, data?.length ?? 0);
}

export function withPtrArray<R>(
  data: BigUint64Array,
  access: Access,
  exec: ExecWithLength<BigUint64Array | null, R>
): R {
  return exec(data ?? null, data?.length ?? 0); // TODO rethink
}

export function toPtrArray<T extends Wrapper>(data: Array<T | undefined> | undefined): BigUint64Array {
  if (data === undefined || data.length === 0) {
    return new BigUint64Array(0);
  }
  const array = new BigUint64Array(data.length);
  for (let i = 0; i < data.length; i++) {
    let item = data[i];
    array[i] = item !== undefined ? (item.ptr as bigint) : nullptr;
  }
  return array;
}

export function fromPtrArray<T extends Wrapper>(array: PtrArray, factory: (ptr: KPointer) => T): Array<T | undefined> {
  if (array.length === 0) {
    return new Array<T>(0);
  }
  const result = new Array<T | undefined>(array.length);
  for (let i = 0; i < array.length; i++) {
    let ptr = array[i];
    if (ptr === nullptr) {
      result[i] = undefined;
    } else {
      result[i] = factory(ptr);
    }
  }
  return result;
}

export function withUint8Array<T>(
  data: Uint8Array | undefined,
  access: Access,
  exec: ExecWithLength<Uint8Array | null, T>
): T {
  return withArray(data, exec);
}
export function withInt8Array<T>(
  data: Int8Array | undefined,
  access: Access,
  exec: ExecWithLength<Int8Array | null, T>
): T {
  return withArray(data, exec);
}
export function withUint16Array<T>(
  data: Uint16Array | undefined,
  access: Access,
  exec: ExecWithLength<Uint16Array | null, T>
): T {
  return withArray(data, exec);
}
export function withInt16Array<T>(
  data: Int16Array | undefined,
  access: Access,
  exec: ExecWithLength<Int16Array | null, T>
): T {
  return withArray(data, exec);
}
export function withUint32Array<T>(
  data: Uint32Array | undefined,
  access: Access,
  exec: ExecWithLength<Uint32Array | null, T>
): T {
  return withArray(data, exec);
}
export function withInt32Array<T>(
  data: Int32Array | undefined,
  access: Access,
  exec: ExecWithLength<Int32Array | null, T>
): T {
  return withArray(data, exec);
}
export function withFloat32Array<T>(
  data: Float32Array | undefined,
  access: Access,
  exec: ExecWithLength<Float32Array | null, T>
): T {
  return withArray(data, exec);
}
export function withFloat64Array<T>(
  data: Float64Array | undefined,
  access: Access,
  exec: ExecWithLength<Float64Array | null, T>
): T {
  return withArray(data, exec);
}
export function wasmHeap(): ArrayBuffer {
  throw new Error('Unused');
}

export enum Access {
  READ = 1, // 1 << 0,
  WRITE = 2, // 1 << 1,
  READWRITE = 3 // READ | WRITE
}
export function isRead(access: Access): boolean {
  return !!(access & Access.READ);
}
export function isWrite(access: Access): boolean {
  return !!(access & Access.WRITE);
}

export type Exec<P, R> = (pointer: P) => R;
export type ExecWithLength<P, R> = (pointer: P, length: int32) => R;

export type TypedArray =
  | Uint8Array
  | Int8Array
  | Uint16Array
  | Int16Array
  | Uint32Array
  | Int32Array
  | Float32Array
  | Float64Array;

export const nullptr: bigint = BigInt(0);
export type PtrArray = Uint32Array | BigUint64Array;