import { SwalParams } from '../../core';

import {
  throwErr,
  isPlainObject,
  ordinalSuffixOf,
} from '../utils';

import {
  ButtonList,
  getButtonListOpts,
  defaultButtonList
} from './buttons';

import {
  getContentOpts,
  ContentOptions,
} from './content';


/*
 * The final object that we transform the given params into
 */
export interface SwalOptions {
  title: string,
  text: string,
  icon: string,
  buttons: ButtonList,
  content: ContentOptions,
  className: string,
  closeOnClickOutside: boolean,
  closeOnEsc: boolean,
  dangerMode: boolean,
  timer: number,
};

const defaultOpts: SwalOptions = {
  title: null,
  text: null,
  icon: null,
  buttons: defaultButtonList,
  content: null,
  className: null,
  closeOnClickOutside: true,
  closeOnEsc: true,
  dangerMode: false,
  timer: null,
};

/*
 * Default options customizeable through "setDefaults":
 */
let userDefaults: SwalOptions = Object.assign({}, defaultOpts);

export const setDefaults = (opts: object): void => {
  userDefaults = Object.assign({}, defaultOpts, opts);
};


/*
 * Since the user can set both "button" and "buttons",
 * we need to make sure we pick one of the options
 */
const pickButtonParam = (opts: any): object => {
  const singleButton: string|object = opts && opts.button;
  const buttonList: object = opts && opts.buttons;

  if (singleButton !== undefined && buttonList !== undefined) {
    throwErr(`Cannot set both 'button' and 'buttons' options!`);
  }

  if (singleButton !== undefined) {
    return {
      confirm: singleButton,
    };
  } else {
    return buttonList;
  }
};

// Example 0 -> 1st
const indexToOrdinal = (index: number): string => ordinalSuffixOf(index + 1);

const invalidParam = (param: any, index: number): void => {
  throwErr(`${indexToOrdinal(index)} argument ('${param}') is invalid`);
};

const expectOptionsOrNothingAfter = (index: number, allParams: SwalParams): void => {
  let nextIndex = (index + 1);
  let nextParam = allParams[nextIndex];

  if (!isPlainObject(nextParam) && nextParam !== undefined) {
    throwErr(`Expected ${indexToOrdinal(nextIndex)} argument ('${nextParam}') to be a plain object`);
  }
};

const expectNothingAfter = (index: number, allParams: SwalParams): void => {
  let nextIndex = (index + 1);
  let nextParam = allParams[nextIndex];

  if (nextParam !== undefined) {
    throwErr(`Unexpected ${indexToOrdinal(nextIndex)} argument (${nextParam})`);
  }
};

/*
 * Based on the number of arguments, their position and their type,
 * we return an object that's merged into the final SwalOptions
 */
const paramToOption = (opts: any, param: any, index: number, allParams: SwalParams): object => {

  const paramType = (typeof param);
  const isString = (paramType === "string");
  const isDOMNode = (param instanceof Element);

  if (isString) {
    if (index === 0) {
      // Example: swal("Hi there!");
      return {
        text: param,
      };
    }

    else if (index === 1) {
      // Example: swal("Wait!", "Are you sure you want to do this?");
      // (The text is now the second argument)
      return {
        text: param,
        title: allParams[0],
      };
    }

    else if (index === 2) {
      // Example: swal("Wait!", "Are you sure?", "warning");
      expectOptionsOrNothingAfter(index, allParams);

      return {
        icon: param,
      };
    }

    else {
      invalidParam(param, index);
    }
  }

  else if (isDOMNode && index === 0) {
    // Example: swal(<DOMNode />);
    expectOptionsOrNothingAfter(index, allParams);

    return {
      content: param,
    };
  }

  else if (isPlainObject(param)) {
    expectNothingAfter(index, allParams);

    return param;
  }

  else {
    invalidParam(param, index);
  }

};

/*
 * No matter if the user calls swal with
 * - swal("Oops!", "An error occured!", "error") or
 * - swal({ title: "Oops!", text: "An error occured!", icon: "error" })
 * ... we always want to transform the params into the second version
 */
export const getOpts = (...params: SwalParams): SwalOptions => {
  let opts = <any>{};

  params.forEach((param, index) => {
    let changes: object = paramToOption(opts, param, index, params);
    Object.assign(opts, changes);
  });

  // Since Object.assign doesn't deep clone,
  // we need to do this:
  let buttonListOpts = pickButtonParam(opts);
  opts.buttons = getButtonListOpts(buttonListOpts);
  delete opts.button;

  opts.content = getContentOpts(opts.content);

  return Object.assign({}, defaultOpts, userDefaults, opts);
};