"use strict";

const conversions = require("webidl-conversions");
const utils = require("./utils.js");

const impl = utils.implSymbol;
const ctorRegistry = utils.ctorRegistrySymbol;

const interfaceName = "FileList";

/**
 * When an interface-module that implements this interface as a mixin is loaded, it will append its own `.is()`
 * method into this array. It allows objects that directly implements *those* interfaces to be recognized as
 * implementing this mixin interface.
 */
exports._mixedIntoPredicates = [];
exports.is = function is(obj) {
  if (obj) {
    if (utils.hasOwn(obj, impl) && obj[impl] instanceof Impl.implementation) {
      return true;
    }
    for (const isMixedInto of exports._mixedIntoPredicates) {
      if (isMixedInto(obj)) {
        return true;
      }
    }
  }
  return false;
};
exports.isImpl = function isImpl(obj) {
  if (obj) {
    if (obj instanceof Impl.implementation) {
      return true;
    }

    const wrapper = utils.wrapperForImpl(obj);
    for (const isMixedInto of exports._mixedIntoPredicates) {
      if (isMixedInto(wrapper)) {
        return true;
      }
    }
  }
  return false;
};
exports.convert = function convert(obj, { context = "The provided value" } = {}) {
  if (exports.is(obj)) {
    return utils.implForWrapper(obj);
  }
  throw new TypeError(`${context} is not of type 'FileList'.`);
};

exports.create = function create(globalObject, constructorArgs, privateData) {
  if (globalObject[ctorRegistry] === undefined) {
    throw new Error("Internal error: invalid global object");
  }

  const ctor = globalObject[ctorRegistry]["FileList"];
  if (ctor === undefined) {
    throw new Error("Internal error: constructor FileList is not installed on the passed global object");
  }

  let obj = Object.create(ctor.prototype);
  obj = exports.setup(obj, globalObject, constructorArgs, privateData);
  return obj;
};
exports.createImpl = function createImpl(globalObject, constructorArgs, privateData) {
  const obj = exports.create(globalObject, constructorArgs, privateData);
  return utils.implForWrapper(obj);
};
exports._internalSetup = function _internalSetup(obj) {};
exports.setup = function setup(obj, globalObject, constructorArgs = [], privateData = {}) {
  privateData.wrapper = obj;

  exports._internalSetup(obj);
  Object.defineProperty(obj, impl, {
    value: new Impl.implementation(globalObject, constructorArgs, privateData),
    configurable: true
  });

  obj = new Proxy(obj, proxyHandler);

  obj[impl][utils.wrapperSymbol] = obj;
  if (Impl.init) {
    Impl.init(obj[impl], privateData);
  }
  return obj;
};

exports.install = function install(globalObject) {
  class FileList {
    constructor() {
      throw new TypeError("Illegal constructor");
    }

    item(index) {
      if (!this || !exports.is(this)) {
        throw new TypeError("Illegal invocation");
      }

      if (arguments.length < 1) {
        throw new TypeError(
          "Failed to execute 'item' on 'FileList': 1 argument required, but only " + arguments.length + " present."
        );
      }
      const args = [];
      {
        let curArg = arguments[0];
        curArg = conversions["unsigned long"](curArg, {
          context: "Failed to execute 'item' on 'FileList': parameter 1"
        });
        args.push(curArg);
      }
      return utils.tryWrapperForImpl(this[impl].item(...args));
    }

    get length() {
      if (!this || !exports.is(this)) {
        throw new TypeError("Illegal invocation");
      }

      return this[impl]["length"];
    }
  }
  Object.defineProperties(FileList.prototype, {
    item: { enumerable: true },
    length: { enumerable: true },
    [Symbol.toStringTag]: { value: "FileList", configurable: true },
    [Symbol.iterator]: { value: Array.prototype[Symbol.iterator], configurable: true, writable: true }
  });
  if (globalObject[ctorRegistry] === undefined) {
    globalObject[ctorRegistry] = Object.create(null);
  }
  globalObject[ctorRegistry][interfaceName] = FileList;

  Object.defineProperty(globalObject, interfaceName, {
    configurable: true,
    writable: true,
    value: FileList
  });
};

const proxyHandler = {
  get(target, P, receiver) {
    if (typeof P === "symbol") {
      return Reflect.get(target, P, receiver);
    }
    const desc = this.getOwnPropertyDescriptor(target, P);
    if (desc === undefined) {
      const parent = Object.getPrototypeOf(target);
      if (parent === null) {
        return undefined;
      }
      return Reflect.get(target, P, receiver);
    }
    if (!desc.get && !desc.set) {
      return desc.value;
    }
    const getter = desc.get;
    if (getter === undefined) {
      return undefined;
    }
    return Reflect.apply(getter, receiver, []);
  },

  has(target, P) {
    if (typeof P === "symbol") {
      return Reflect.has(target, P);
    }
    const desc = this.getOwnPropertyDescriptor(target, P);
    if (desc !== undefined) {
      return true;
    }
    const parent = Object.getPrototypeOf(target);
    if (parent !== null) {
      return Reflect.has(parent, P);
    }
    return false;
  },

  ownKeys(target) {
    const keys = new Set();

    for (const key of target[impl][utils.supportedPropertyIndices]) {
      keys.add(`${key}`);
    }

    for (const key of Reflect.ownKeys(target)) {
      keys.add(key);
    }
    return [...keys];
  },

  getOwnPropertyDescriptor(target, P) {
    if (typeof P === "symbol") {
      return Reflect.getOwnPropertyDescriptor(target, P);
    }
    let ignoreNamedProps = false;

    if (utils.isArrayIndexPropName(P)) {
      const index = P >>> 0;
      const indexedValue = target[impl].item(index);
      if (indexedValue !== null) {
        return {
          writable: false,
          enumerable: true,
          configurable: true,
          value: utils.tryWrapperForImpl(indexedValue)
        };
      }
      ignoreNamedProps = true;
    }

    return Reflect.getOwnPropertyDescriptor(target, P);
  },

  set(target, P, V, receiver) {
    if (typeof P === "symbol") {
      return Reflect.set(target, P, V, receiver);
    }
    if (target === receiver) {
      utils.isArrayIndexPropName(P);
    }
    let ownDesc;

    if (utils.isArrayIndexPropName(P)) {
      const index = P >>> 0;
      const indexedValue = target[impl].item(index);
      if (indexedValue !== null) {
        ownDesc = {
          writable: false,
          enumerable: true,
          configurable: true,
          value: utils.tryWrapperForImpl(indexedValue)
        };
      }
    }

    if (ownDesc === undefined) {
      ownDesc = Reflect.getOwnPropertyDescriptor(target, P);
    }
    if (ownDesc === undefined) {
      const parent = Reflect.getPrototypeOf(target);
      if (parent !== null) {
        return Reflect.set(parent, P, V, receiver);
      }
      ownDesc = { writable: true, enumerable: true, configurable: true, value: undefined };
    }
    if (!ownDesc.writable) {
      return false;
    }
    if (!utils.isObject(receiver)) {
      return false;
    }
    const existingDesc = Reflect.getOwnPropertyDescriptor(receiver, P);
    let valueDesc;
    if (existingDesc !== undefined) {
      if (existingDesc.get || existingDesc.set) {
        return false;
      }
      if (!existingDesc.writable) {
        return false;
      }
      valueDesc = { value: V };
    } else {
      valueDesc = { writable: true, enumerable: true, configurable: true, value: V };
    }
    return Reflect.defineProperty(receiver, P, valueDesc);
  },

  defineProperty(target, P, desc) {
    if (typeof P === "symbol") {
      return Reflect.defineProperty(target, P, desc);
    }

    if (utils.isArrayIndexPropName(P)) {
      return false;
    }

    return Reflect.defineProperty(target, P, desc);
  },

  deleteProperty(target, P) {
    if (typeof P === "symbol") {
      return Reflect.deleteProperty(target, P);
    }

    if (utils.isArrayIndexPropName(P)) {
      const index = P >>> 0;
      return !(target[impl].item(index) !== null);
    }

    return Reflect.deleteProperty(target, P);
  },

  preventExtensions() {
    return false;
  }
};

const Impl = require("../file-api/FileList-impl.js");