import {
  IMAGES,
  Miscellaneous,
  SPRITE_SPECS,
  SpriteSpec,
  Sprites,
} from "../config";
import { Entity, EntityNames } from ".";
import {
  BoundingBox,
  Colliding,
  ComponentNames,
  Grid,
  Highlight,
  Interactable,
  LambdaSpawn,
  Sprite,
  Text,
} from "../components";
import { Coord2D, Direction } from "../interfaces";
import { openModal, closeModal } from "../utils";
import { EditorState, StateField, StateEffect, Range } from "@codemirror/state";
import { Decoration, EditorView, keymap } from "@codemirror/view";
import { defaultKeymap } from "@codemirror/commands";
import rainbowBrackets from "rainbowbrackets";
import { basicSetup } from "codemirror";
import { parse } from "../../interpreter";

interface CodeEditorState {
  view: EditorView;
  editorElement: HTMLElement;
}

const highlightEffect = StateEffect.define<Range<Decoration>[]>();
const highlightExtension = StateField.define({
  create() {
    return Decoration.none;
  },
  update(value, transaction) {
    value = value.map(transaction.changes);

    for (let effect of transaction.effects) {
      if (effect.is(highlightEffect))
        value = value.update({ add: effect.value, sort: true });
    }

    return value;
  },
  provide: (f) => EditorView.decorations.from(f),
});

export class LambdaFactory extends Entity {
  private static spriteSpec: SpriteSpec = SPRITE_SPECS.get(
    Sprites.LAMBDA_FACTORY,
  ) as SpriteSpec;

  private codeEditorState: CodeEditorState | null;
  private code: string;
  private spawns: number;

  constructor(gridPosition: Coord2D, code: string, spawns: number) {
    super(EntityNames.LambdaFactory);

    this.code = code;
    this.spawns = spawns;
    this.codeEditorState = null;

    this.addComponent(
      new BoundingBox(
        {
          x: 0,
          y: 0,
        },
        {
          width: LambdaFactory.spriteSpec.width,
          height: LambdaFactory.spriteSpec.height,
        },
        0,
      ),
    );

    this.addComponent(new Text(spawns.toString()));

    this.addComponent(new Colliding());

    this.addComponent(new LambdaSpawn(this.spawns, this.code));

    this.addComponent(new Grid(gridPosition));

    this.addComponent(
      new Sprite(
        IMAGES.get(LambdaFactory.spriteSpec.sheet)!,
        { x: 0, y: 0 },
        {
          width: LambdaFactory.spriteSpec.width,
          height: LambdaFactory.spriteSpec.height,
        },
        LambdaFactory.spriteSpec.msPerFrame,
        LambdaFactory.spriteSpec.frames,
      ),
    );

    this.addComponent(
      new Highlight(
        (direction) => this.onHighlight(direction),
        () => this.onUnhighlight(),
      ),
    );
  }

  private onUnhighlight() {
    closeModal();
    this.removeComponent(ComponentNames.Interactable);
  }

  private spawnNewLambda(direction: Direction) {
    const spawner = this.getComponent<LambdaSpawn>(ComponentNames.LambdaSpawn);
    spawner.spawn(direction);

    const text = this.getComponent<Text>(ComponentNames.Text);
    text.text = spawner.spawnsLeft.toString();
    this.addComponent(text);
  }

  private onHighlight(direction: Direction) {
    if (direction === Direction.LEFT || direction === Direction.RIGHT) {
      this.addComponent(new Interactable(() => this.spawnNewLambda(direction)));
      return;
    }

    let modalOpen = false;
    let editorView: EditorView | null = null;

    const syntaxErrorDecoration = Decoration.mark({
      class: "syntax-error",
    });

    const close = () => {
      if (editorView) {
        const text = editorView.state.doc.toString();

        // remove all text from the editor
        editorView.dispatch({
          changes: {
            from: 0,
            to: text.length,
            insert: "",
          },
        });
        // add the new text to the editor
        editorView.dispatch({
          changes: {
            from: 0,
            to: 0,
            insert: text,
          },
        });

        try {
          parse(text);
        } catch (e: any) {
          if (!e.location) {
            return;
          }
          const {
            location: {
              start: { offset: start },
              end: { offset: end },
            },
          } = e;

          editorView.dispatch({
            effects: highlightEffect.of([
              syntaxErrorDecoration.range(
                start === end ? start - 1 : start,
                end,
              ),
            ]),
          });

          document.getElementById("syntax-error")!.innerText = e.message;

          return;
        }

        const spawner = this.getComponent<LambdaSpawn>(
          ComponentNames.LambdaSpawn,
        );
        spawner.code = text;
        this.addComponent(spawner);
      }

      modalOpen = false;
      closeModal();

      document.getElementById(Miscellaneous.CANVAS_ID)!.focus();
      return;
    };

    const interaction = () => {
      if (modalOpen) {
        close();
        return;
      }
      modalOpen = true;

      openModal(
        "<div class='code'><div id='code'></div><br><p id='syntax-error' class='error'></p><button id='close-modal'>Save</button></div>",
      );
      const spawner = this.getComponent<LambdaSpawn>(
        ComponentNames.LambdaSpawn,
      );

      const startState = EditorState.create({
        doc: spawner.code,
        extensions: [
          basicSetup,
          keymap.of(defaultKeymap),
          rainbowBrackets(),
          highlightExtension,
        ],
      });

      const codeBox = document.getElementById("code")!;
      editorView = new EditorView({
        state: startState,
        parent: codeBox,
      });

      editorView.focus();

      document.getElementById("close-modal")!.addEventListener("click", close);
    };

    this.addComponent(new Interactable(interaction));
  }
}