import { NAME_MSG_BOX, NAME_MODAL } from '../../../constants/components';
import { HOOK_EVENT_NAME_DESTROYED, EVENT_NAME_HIDDEN, HOOK_EVENT_NAME_BEFORE_DESTROY, EVENT_NAME_HIDE } from '../../../constants/events';
import { useParentMixin } from '../../../mixins/use-parent';
import { concat } from '../../../utils/array';
import { getComponentConfig } from '../../../utils/config';
import { requestAF } from '../../../utils/dom';
import { getRootActionEventName } from '../../../utils/events';
import { isFunction, isUndefined } from '../../../utils/inspect';
import { keys, omit, hasOwnProperty, defineProperty, assign, defineProperties, readonlyDescriptor } from '../../../utils/object';
import { pluginFactory } from '../../../utils/plugins';
import { warn, warnNoPromiseSupport, warnNotClient } from '../../../utils/warn';
import { createNewChildComponent } from '../../../utils/create-new-child-component';
import { getEventRoot } from '../../../utils/get-event-root';
import { props, BModal } from '../modal';

// Plugin for adding `$bvModal` property to all Vue instances

// --- Constants ---

const PROP_NAME = '$bvModal';
const PROP_NAME_PRIV = '_bv__modal';

// Base modal props that are allowed
// Some may be ignored or overridden on some message boxes
// Prop ID is allowed, but really only should be used for testing
// We need to add it in explicitly as it comes from the `idMixin`
const BASE_PROPS = ['id', ...keys(omit(props, ['busy', 'lazy', 'noStacking', 'static', 'visible']))];

// Fallback event resolver (returns undefined)
const defaultResolver = () => {};

// Map prop names to modal slot names
const propsToSlots = {
  msgBoxContent: 'default',
  title: 'modal-title',
  okTitle: 'modal-ok',
  cancelTitle: 'modal-cancel'
};

// --- Helper methods ---

// Method to filter only recognized props that are not undefined
const filterOptions = options => {
  return BASE_PROPS.reduce((memo, key) => {
    if (!isUndefined(options[key])) {
      memo[key] = options[key];
    }
    return memo;
  }, {});
};

// Method to install `$bvModal` VM injection
const plugin = Vue => {
  // Create a private sub-component that extends BModal
  // which self-destructs after hidden
  // @vue/component
  const BMsgBox = Vue.extend({
    name: NAME_MSG_BOX,
    extends: BModal,
    mixins: [useParentMixin],
    destroyed() {
      // Make sure we not in document any more
      if (this.$el && this.$el.parentNode) {
        this.$el.parentNode.removeChild(this.$el);
      }
    },
    mounted() {
      // Self destruct handler
      const handleDestroy = () => {
        this.$nextTick(() => {
          // In a `requestAF()` to release control back to application
          requestAF(() => {
            this.$destroy();
          });
        });
      };
      // Self destruct if parent destroyed
      this.bvParent.$once(HOOK_EVENT_NAME_DESTROYED, handleDestroy);
      // Self destruct after hidden
      this.$once(EVENT_NAME_HIDDEN, handleDestroy);
      // Self destruct on route change
      /* istanbul ignore if */
      if (this.$router && this.$route) {
        // Destroy ourselves if route changes
        /* istanbul ignore next */
        this.$once(HOOK_EVENT_NAME_BEFORE_DESTROY, this.$watch('$router', handleDestroy));
      }
      // Show the `BMsgBox`
      this.show();
    }
  });

  // Method to generate the on-demand modal message box
  // Returns a promise that resolves to a value returned by the resolve
  const asyncMsgBox = function (parent, props) {
    let resolver = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : defaultResolver;
    if (warnNotClient(PROP_NAME) || warnNoPromiseSupport(PROP_NAME)) {
      /* istanbul ignore next */
      return;
    }
    // Create an instance of `BMsgBox` component
    // We set parent as the local VM so these modals can emit events on
    // the app `$root`, as needed by things like tooltips and popovers
    // And it helps to ensure `BMsgBox` is destroyed when parent is destroyed
    const msgBox = createNewChildComponent(parent, BMsgBox, {
      // Preset the prop values
      propsData: {
        ...filterOptions(getComponentConfig(NAME_MODAL)),
        // Defaults that user can override
        hideHeaderClose: true,
        hideHeader: !(props.title || props.titleHtml),
        // Add in (filtered) user supplied props
        ...omit(props, keys(propsToSlots)),
        // Props that can't be overridden
        lazy: false,
        busy: false,
        visible: false,
        noStacking: false,
        noEnforceFocus: false
      }
    });
    // Convert certain props to scoped slots
    keys(propsToSlots).forEach(prop => {
      if (!isUndefined(props[prop])) {
        // Can be a string, or array of VNodes.
        // Alternatively, user can use HTML version of prop to pass an HTML string.
        msgBox.$slots[propsToSlots[prop]] = concat(props[prop]);
      }
    });
    // Return a promise that resolves when hidden, or rejects on destroyed
    return new Promise((resolve, reject) => {
      let resolved = false;
      msgBox.$once(HOOK_EVENT_NAME_DESTROYED, () => {
        if (!resolved) {
          /* istanbul ignore next */
          reject(new Error('BootstrapVue MsgBox destroyed before resolve'));
        }
      });
      msgBox.$on(EVENT_NAME_HIDE, bvModalEvent => {
        if (!bvModalEvent.defaultPrevented) {
          const result = resolver(bvModalEvent);
          // If resolver didn't cancel hide, we resolve
          if (!bvModalEvent.defaultPrevented) {
            resolved = true;
            resolve(result);
          }
        }
      });
      // Create a mount point (a DIV) and mount the msgBo which will trigger it to show
      const div = document.createElement('div');
      document.body.appendChild(div);
      msgBox.$mount(div);
    });
  };

  // Private utility method to open a user defined message box and returns a promise.
  // Not to be used directly by consumers, as this method may change calling syntax
  const makeMsgBox = function (parent, content) {
    let options = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {};
    let resolver = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : null;
    if (!content || warnNoPromiseSupport(PROP_NAME) || warnNotClient(PROP_NAME) || !isFunction(resolver)) {
      /* istanbul ignore next */
      return;
    }
    return asyncMsgBox(parent, {
      ...filterOptions(options),
      msgBoxContent: content
    }, resolver);
  };

  // BvModal instance class
  class BvModal {
    constructor(vm) {
      // Assign the new properties to this instance
      assign(this, {
        _vm: vm,
        _root: getEventRoot(vm)
      });
      // Set these properties as read-only and non-enumerable
      defineProperties(this, {
        _vm: readonlyDescriptor(),
        _root: readonlyDescriptor()
      });
    }

    // --- Instance methods ---

    // Show modal with the specified ID args are for future use
    show(id) {
      if (id && this._root) {
        for (var _len = arguments.length, args = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
          args[_key - 1] = arguments[_key];
        }
        this._root.$emit(getRootActionEventName(NAME_MODAL, 'show'), id, ...args);
      }
    }

    // Hide modal with the specified ID args are for future use
    hide(id) {
      if (id && this._root) {
        for (var _len2 = arguments.length, args = new Array(_len2 > 1 ? _len2 - 1 : 0), _key2 = 1; _key2 < _len2; _key2++) {
          args[_key2 - 1] = arguments[_key2];
        }
        this._root.$emit(getRootActionEventName(NAME_MODAL, 'hide'), id, ...args);
      }
    }

    // The following methods require Promise support!
    // IE 11 and others do not support Promise natively, so users
    // should have a Polyfill loaded (which they need anyways for IE 11 support)

    // Open a message box with OK button only and returns a promise
    msgBoxOk(message) {
      let options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
      // Pick the modal props we support from options
      const props = {
        ...options,
        // Add in overrides and our content prop
        okOnly: true,
        okDisabled: false,
        hideFooter: false,
        msgBoxContent: message
      };
      return makeMsgBox(this._vm, message, props, () => {
        // Always resolve to true for OK
        return true;
      });
    }

    // Open a message box modal with OK and CANCEL buttons
    // and returns a promise
    msgBoxConfirm(message) {
      let options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
      // Set the modal props we support from options
      const props = {
        ...options,
        // Add in overrides and our content prop
        okOnly: false,
        okDisabled: false,
        cancelDisabled: false,
        hideFooter: false
      };
      return makeMsgBox(this._vm, message, props, bvModalEvent => {
        const trigger = bvModalEvent.trigger;
        return trigger === 'ok' ? true : trigger === 'cancel' ? false : null;
      });
    }
  }

  // Add our instance mixin
  Vue.mixin({
    beforeCreate() {
      // Because we need access to `$root` for `$emits`, and VM for parenting,
      // we have to create a fresh instance of `BvModal` for each VM
      this[PROP_NAME_PRIV] = new BvModal(this);
    }
  });

  // Define our read-only `$bvModal` instance property
  // Placed in an if just in case in HMR mode
  if (!hasOwnProperty(Vue.prototype, PROP_NAME)) {
    defineProperty(Vue.prototype, PROP_NAME, {
      get() {
        /* istanbul ignore next */
        if (!this || !this[PROP_NAME_PRIV]) {
          warn(`"${PROP_NAME}" must be accessed from a Vue instance "this" context.`, NAME_MODAL);
        }
        return this[PROP_NAME_PRIV];
      }
    });
  }
};
const BVModalPlugin = /*#__PURE__*/pluginFactory({
  plugins: {
    plugin
  }
});

export { BVModalPlugin };
