// @flow
import * as React from "react";
import ReactDOM from "react-dom";
import { observable, computed } from "mobx";
import { observer, inject } from "mobx-react";
import { Search } from "js-search";
import { last } from "lodash";
import ArrowKeyNavigation from "boundless-arrow-key-navigation";
import styled from "styled-components";

import Modal from "components/Modal";
import Input from "components/Input";
import Labeled from "components/Labeled";
import PathToDocument from "components/PathToDocument";
import Flex from "components/Flex";

import Document from "models/Document";
import DocumentsStore from "stores/DocumentsStore";
import UiStore from "stores/UiStore";
import CollectionsStore, { type DocumentPath } from "stores/CollectionsStore";

const MAX_RESULTS = 8;

type Props = {|
  document: Document,
  documents: DocumentsStore,
  collections: CollectionsStore,
  ui: UiStore,
  onRequestClose: () => void,
|};

@observer
class DocumentMove extends React.Component<Props> {
  firstDocument: ?PathToDocument;
  @observable searchTerm: ?string;
  @observable isSaving: boolean;

  @computed
  get searchIndex() {
    const { collections } = this.props;
    const paths = collections.pathsToDocuments;
    const index = new Search("id");
    index.addIndex("title");

    // Build index
    const indexeableDocuments = [];
    paths.forEach((path) => indexeableDocuments.push(path));
    index.addDocuments(indexeableDocuments);

    return index;
  }

  @computed
  get results(): DocumentPath[] {
    const { document, collections } = this.props;

    let results = [];
    if (collections.isLoaded) {
      if (this.searchTerm) {
        results = this.searchIndex.search(this.searchTerm);
      } else {
        results = this.searchIndex._documents;
      }
    }

    // Exclude root from search results if document is already at the root
    if (!document.parentDocumentId) {
      results = results.filter((result) => result.id !== document.collectionId);
    }

    // Exclude document if on the path to result, or the same result
    results = results.filter(
      (result) =>
        !result.path.map((doc) => doc.id).includes(document.id) &&
        last(result.path.map((doc) => doc.id)) !== document.parentDocumentId
    );

    return results;
  }

  handleKeyDown = (ev) => {
    // Down
    if (ev.which === 40) {
      ev.preventDefault();
      if (this.firstDocument) {
        const element = ReactDOM.findDOMNode(this.firstDocument);
        if (element instanceof HTMLElement) element.focus();
      }
    }
  };

  handleSuccess = () => {
    this.props.ui.showToast("Document moved");
    this.props.onRequestClose();
  };

  handleFilter = (ev: SyntheticInputEvent<*>) => {
    this.searchTerm = ev.target.value;
  };

  setFirstDocumentRef = (ref) => {
    this.firstDocument = ref;
  };

  renderPathToCurrentDocument() {
    const { collections, document } = this.props;
    const result = collections.getPathForDocument(document.id);

    if (result) {
      return (
        <PathToDocument
          result={result}
          collection={collections.get(result.collectionId)}
        />
      );
    }
  }

  render() {
    const { document, collections, onRequestClose } = this.props;

    return (
      <Modal isOpen onRequestClose={onRequestClose} title="Move document">
        {document && collections.isLoaded && (
          <Flex column>
            <Section>
              <Labeled label="Current location">
                {this.renderPathToCurrentDocument()}
              </Labeled>
            </Section>

            <Section column>
              <Labeled label="Choose a new location">
                <Input
                  type="search"
                  placeholder="Search collections & documents…"
                  onKeyDown={this.handleKeyDown}
                  onChange={this.handleFilter}
                  required
                  autoFocus
                />
              </Labeled>
              <Flex column>
                <StyledArrowKeyNavigation
                  mode={ArrowKeyNavigation.mode.VERTICAL}
                  defaultActiveChildIndex={0}
                >
                  {this.results.slice(0, MAX_RESULTS).map((result, index) => (
                    <PathToDocument
                      key={result.id}
                      result={result}
                      document={document}
                      collection={collections.get(result.collectionId)}
                      ref={(ref) =>
                        index === 0 && this.setFirstDocumentRef(ref)
                      }
                      onSuccess={this.handleSuccess}
                    />
                  ))}
                </StyledArrowKeyNavigation>
              </Flex>
            </Section>
          </Flex>
        )}
      </Modal>
    );
  }
}

const Section = styled(Flex)`
  margin-bottom: 24px;
`;

const StyledArrowKeyNavigation = styled(ArrowKeyNavigation)`
  display: flex;
  flex-direction: column;
  flex: 1;
`;

export default inject("documents", "collections", "ui")(DocumentMove);