// This follows the WebIDL at: https://webassembly.github.io/spec/js-api/
// And follow on WebIDL at: https://webassembly.github.io/spec/web-api/

declare namespace WebAssembly {
  type WebAssemblyInstantiatedSource = {
    module: Module;
    instance: Instance;
  };

  /** Compiles a `WebAssembly.Module` from WebAssembly binary code.  This
   * function is useful if it is necessary to a compile a module before it can
   * be instantiated (otherwise, the `WebAssembly.instantiate()` function
   * should be used). */
  function compile(bufferSource: domTypes.BufferSource): Promise<Module>;

  /** Compiles a `WebAssembly.Module` directly from a streamed underlying
   * source. This function is useful if it is necessary to a compile a module
   * before it can be instantiated (otherwise, the
   * `WebAssembly.instantiateStreaming()` function should be used). */
  function compileStreaming(
    source: Promise<domTypes.Response>
  ): Promise<Module>;

  /** Takes the WebAssembly binary code, in the form of a typed array or
   * `ArrayBuffer`, and performs both compilation and instantiation in one step.
   * The returned `Promise` resolves to both a compiled `WebAssembly.Module` and
   * its first `WebAssembly.Instance`. */
  function instantiate(
    bufferSource: domTypes.BufferSource,
    importObject?: object
  ): Promise<WebAssemblyInstantiatedSource>;

  /** Takes an already-compiled `WebAssembly.Module` and returns a `Promise`
   * that resolves to an `Instance` of that `Module`. This overload is useful if
   * the `Module` has already been compiled. */
  function instantiate(
    module: Module,
    importObject?: object
  ): Promise<Instance>;

  /** Compiles and instantiates a WebAssembly module directly from a streamed
   * underlying source. This is the most efficient, optimized way to load wasm
   * code. */
  function instantiateStreaming(
    source: Promise<domTypes.Response>,
    importObject?: object
  ): Promise<WebAssemblyInstantiatedSource>;

  /** Validates a given typed array of WebAssembly binary code, returning
   * whether the bytes form a valid wasm module (`true`) or not (`false`). */
  function validate(bufferSource: domTypes.BufferSource): boolean;

  type ImportExportKind = "function" | "table" | "memory" | "global";

  type ModuleExportDescriptor = { name: string; kind: ImportExportKind };
  type ModuleImportDescriptor = {
    module: string;
    name: string;
    kind: ImportExportKind;
  };

  class Module {
    constructor(bufferSource: domTypes.BufferSource);

    /** Given a `Module` and string, returns a copy of the contents of all
     * custom sections in the module with the given string name. */
    static customSections(
      moduleObject: Module,
      sectionName: string
    ): ArrayBuffer;

    /** Given a `Module`, returns an array containing descriptions of all the
     * declared exports. */
    static exports(moduleObject: Module): ModuleExportDescriptor[];

    /** Given a `Module`, returns an array containing descriptions of all the
     * declared imports. */
    static imports(moduleObject: Module): ModuleImportDescriptor[];
  }

  class Instance<T extends object = { [key: string]: any }> {
    constructor(module: Module, importObject?: object);

    /** An object containing as its members all the functions exported from the
     * WebAssembly module instance, to allow them to be accessed and used by
     * JavaScript. */
    readonly exports: T;
  }

  type MemoryDescriptor = {
    initial: number;
    maximum?: number;
  };

  class Memory {
    constructor(descriptor: MemoryDescriptor);

    /** An accessor property that returns the buffer contained in the memory. */
    readonly buffer: ArrayBuffer;

    /** Increases the size of the memory instance by a specified number of
     * WebAssembly pages (each one is 64KB in size). */
    grow(delta: number): number;
  }

  type TableKind = "anyfunc";

  interface TableDescriptor {
    element: TableKind;
    initial: number;
    maximum?: number;
  }

  class Table {
    constructor(descriptor: TableDescriptor);

    /** Returns the length of the table, i.e. the number of elements. */
    readonly length: number;

    /** Accessor function — gets the element stored at a given index. */
    get(index: number): (...args: any[]) => any;

    /** Increases the size of the Table instance by a specified number of
     * elements. */
    grow(delta: number): number;

    /** Sets an element stored at a given index to a given value. */
    set(index: number, value: (...args: any[]) => any): void;
  }

  type GlobalDescriptor = { value: string; mutable?: boolean };

  /** Represents a global variable instance, accessible from both JavaScript and
   * importable/exportable across one or more `WebAssembly.Module` instances.
   * This allows dynamic linking of multiple modules. */
  class Global {
    constructor(descriptor: GlobalDescriptor, value?: any);

    /** Old-style method that returns the value contained inside the global
     * variable. */
    valueOf(): any;

    /** The value contained inside the global variable — this can be used to
     * directly set and get the global's value. */
    value: any;
  }

  /** Indicates an error during WebAssembly decoding or validation */
  class CompileError extends Error {
    constructor(message: string, fileName?: string, lineNumber?: string);
  }

  /** Indicates an error during module instantiation (besides traps from the
   * start function). */
  class LinkError extends Error {
    constructor(message: string, fileName?: string, lineNumber?: string);
  }

  /** Is thrown whenever WebAssembly specifies a trap. */
  class RuntimeError extends Error {
    constructor(message: string, fileName?: string, lineNumber?: string);
  }
}

// TODO Move ImportMeta intos its own lib.import_meta.d.ts file?
interface ImportMeta {
  url: string;
}