import Token from "markdown-it/lib/token";
import { InputRule } from "prosemirror-inputrules";
import { Node as ProsemirrorNode, NodeSpec, NodeType } from "prosemirror-model";
import { TextSelection, NodeSelection, EditorState } from "prosemirror-state";
import * as React from "react";
import { getEventFiles } from "../../utils/files";
import { sanitizeUrl } from "../../utils/urls";
import { AttachmentValidation } from "../../validations";
import insertFiles, { Options } from "../commands/insertFiles";
import { default as ImageComponent } from "../components/Image";
import { MarkdownSerializerState } from "../lib/markdown/serializer";
import uploadPlaceholderPlugin from "../lib/uploadPlaceholder";
import uploadPlugin from "../lib/uploadPlugin";
import { ComponentProps, Dispatch } from "../types";
import Node from "./Node";

export default class SimpleImage extends Node {
  options: Options;

  get name() {
    return "image";
  }

  get schema(): NodeSpec {
    return {
      inline: true,
      attrs: {
        src: {
          default: "",
        },
        alt: {
          default: null,
        },
      },
      content: "text*",
      marks: "",
      group: "inline",
      selectable: true,
      draggable: true,
      parseDOM: [
        {
          tag: "div[class~=image]",
          getAttrs: (dom: HTMLDivElement) => {
            const img = dom.getElementsByTagName("img")[0];
            return {
              src: img?.getAttribute("src"),
              alt: img?.getAttribute("alt"),
              title: img?.getAttribute("title"),
            };
          },
        },
        {
          tag: "img",
          getAttrs: (dom: HTMLImageElement) => ({
            src: dom.getAttribute("src"),
            alt: dom.getAttribute("alt"),
            title: dom.getAttribute("title"),
          }),
        },
      ],
      toDOM: (node) => [
        "div",
        {
          class: "image",
        },
        [
          "img",
          {
            ...node.attrs,
            src: sanitizeUrl(node.attrs.src),
            contentEditable: "false",
          },
        ],
      ],
    };
  }

  handleKeyDown =
    ({ node, getPos }: { node: ProsemirrorNode; getPos: () => number }) =>
    (event: React.KeyboardEvent<HTMLSpanElement>) => {
      // Pressing Enter in the caption field should move the cursor/selection
      // below the image
      if (event.key === "Enter") {
        event.preventDefault();

        const { view } = this.editor;
        const $pos = view.state.doc.resolve(getPos() + node.nodeSize);
        view.dispatch(
          view.state.tr.setSelection(new TextSelection($pos)).split($pos.pos)
        );
        view.focus();
        return;
      }

      // Pressing Backspace in an an empty caption field should remove the entire
      // image, leaving an empty paragraph
      if (event.key === "Backspace" && event.currentTarget.innerText === "") {
        const { view } = this.editor;
        const $pos = view.state.doc.resolve(getPos());
        const tr = view.state.tr.setSelection(new NodeSelection($pos));
        view.dispatch(tr.deleteSelection());
        view.focus();
        return;
      }
    };

  handleBlur =
    ({ node, getPos }: { node: ProsemirrorNode; getPos: () => number }) =>
    (event: React.FocusEvent<HTMLSpanElement>) => {
      const caption = event.currentTarget.innerText;
      if (caption === node.attrs.alt) {
        return;
      }

      const { view } = this.editor;
      const { tr } = view.state;

      // update meta on object
      const pos = getPos();
      const transaction = tr.setNodeMarkup(pos, undefined, {
        ...node.attrs,
        alt: caption,
      });
      view.dispatch(transaction);
    };

  handleSelect =
    ({ getPos }: { getPos: () => number }) =>
    (event: React.MouseEvent) => {
      event.preventDefault();

      const { view } = this.editor;
      const $pos = view.state.doc.resolve(getPos());
      const transaction = view.state.tr.setSelection(new NodeSelection($pos));
      view.dispatch(transaction);
    };

  handleMouseDown = (ev: React.MouseEvent<HTMLParagraphElement>) => {
    if (document.activeElement !== ev.currentTarget) {
      ev.preventDefault();
      ev.stopPropagation();
      ev.currentTarget.focus();
    }
  };

  component = (props: ComponentProps) => (
    <ImageComponent {...props} onClick={this.handleSelect(props)} />
  );

  toMarkdown(state: MarkdownSerializerState, node: ProsemirrorNode) {
    state.write(
      " ![" +
        state.esc((node.attrs.alt || "").replace("\n", "") || "", false) +
        "](" +
        state.esc(node.attrs.src || "", false) +
        ")"
    );
  }

  parseMarkdown() {
    return {
      node: "image",
      getAttrs: (token: Token) => ({
        src: token.attrGet("src"),
        alt:
          (token?.children && token.children[0] && token.children[0].content) ||
          null,
      }),
    };
  }

  commands({ type }: { type: NodeType }) {
    return {
      deleteImage: () => (state: EditorState, dispatch: Dispatch) => {
        dispatch(state.tr.deleteSelection());
        return true;
      },
      replaceImage: () => (state: EditorState) => {
        if (!(state.selection instanceof NodeSelection)) {
          return false;
        }
        const { view } = this.editor;
        const { node } = state.selection;
        const { uploadFile, onFileUploadStart, onFileUploadStop, onShowToast } =
          this.editor.props;

        if (!uploadFile) {
          throw new Error("uploadFile prop is required to replace images");
        }

        if (node.type.name !== "image") {
          return false;
        }

        // create an input element and click to trigger picker
        const inputElement = document.createElement("input");
        inputElement.type = "file";
        inputElement.accept = AttachmentValidation.imageContentTypes.join(", ");
        inputElement.onchange = (event) => {
          const files = getEventFiles(event);
          insertFiles(view, event, state.selection.from, files, {
            uploadFile,
            onFileUploadStart,
            onFileUploadStop,
            onShowToast,
            dictionary: this.options.dictionary,
            replaceExisting: true,
            attrs: {
              width: node.attrs.width,
            },
          });
        };
        inputElement.click();
        return true;
      },
      createImage:
        (attrs: Record<string, any>) =>
        (state: EditorState, dispatch: Dispatch) => {
          const { selection } = state;
          const position =
            selection instanceof TextSelection
              ? selection.$cursor?.pos
              : selection.$to.pos;
          if (position === undefined) {
            return false;
          }

          const node = type.create(attrs);
          const transaction = state.tr.insert(position, node);
          dispatch(transaction);
          return true;
        },
    };
  }

  inputRules({ type }: { type: NodeType }) {
    /**
     * Matches following attributes in Markdown-typed image: [, alt, src, class]
     *
     * Example:
     * ![Lorem](image.jpg) -> [, "Lorem", "image.jpg"]
     * ![](image.jpg "class") -> [, "", "image.jpg", "small"]
     * ![Lorem](image.jpg "class") -> [, "Lorem", "image.jpg", "small"]
     */
    const IMAGE_INPUT_REGEX =
      /!\[(?<alt>[^\][]*?)]\((?<filename>[^\][]*?)(?=“|\))“?(?<layoutclass>[^\][”]+)?”?\)$/;

    return [
      new InputRule(IMAGE_INPUT_REGEX, (state, match, start, end) => {
        const [okay, alt, src] = match;
        const { tr } = state;

        if (okay) {
          tr.replaceWith(
            start - 1,
            end,
            type.create({
              src,
              alt,
            })
          );
        }

        return tr;
      }),
    ];
  }

  get plugins() {
    return [uploadPlaceholderPlugin, uploadPlugin(this.options)];
  }
}