import { useRef, type ReactNode, type RefObject } from "react";
import { InlineTextToolbar } from "./InlineTextToolbar";
import { useDomEditActionsContextOptional } from "../../contexts/DomEditContext";
import { useInlineTextEdit } from "../../hooks/useInlineTextEdit";
import { usePlayerStore } from "../../player/store/playerStore";
import { getPreviewTargetFromPointer } from "../../utils/studioPreviewHelpers";
import {
  canEditElementTextInline,
  canEditTextInline,
  isDoublePress,
  type PressMark,
} from "./domEditInlineText";
import type { DomEditSelection } from "./domEditingTypes";

/**
 * The canvas' side of editing text where it sits.
 *
 * Holds the session, decides which presses open one, and knows the two things
 * the canvas has to do differently while one is open: stand aside so the caret
 * underneath can be reached, and stop taking focus back.
 *
 * The actions context is read here rather than threaded through the overlay's
 * props, the same way the agent surfaces in that overlay read it, and it is
 * absent in standalone player mounts, which have no project to edit.
 */
export function useInlineTextEditing(selectionRef: RefObject<DomEditSelection | null>): {
  editing: boolean;
  /** Open an edit when this press pairs with the last one. */
  startFromPress: (event: { clientX: number; clientY: number }) => boolean;
  /** Handle a key on the canvas. Returns true when it opened an edit. */
  handleKeyDown: (event: {
    key: string;
    shiftKey: boolean;
    ctrlKey: boolean;
    metaKey: boolean;
    altKey: boolean;
  }) => boolean;
  /**
   * The styling controls for the current selection, for the caller to render.
   *
   * Handed back rather than mounted somewhere central because it belongs to the
   * session this hook owns, and appears and disappears with it.
   */
  toolbar: ReactNode;
} {
  const actions = useDomEditActionsContextOptional();
  const inlineText = useInlineTextEdit({
    onCommit: (commit) => void actions?.handleDomRichTextCommit(commit),
    onPause: () => usePlayerStore.getState().setIsPlaying(false),
  });
  const lastPressRef = useRef<PressMark | null>(null);

  /**
   * The element under this press, hit-tested now rather than read from state.
   *
   * Every cached answer in the overlay is React state that has not caught up
   * with the press happening now: the hover is documented as an async cache,
   * and the selection from the first press has not re-rendered. Reading either
   * meant the first double press on any element opened nothing, which is every
   * double press that matters.
   */
  const elementUnderPress = (event: { clientX: number; clientY: number }) => {
    const iframe = actions?.previewIframeRef?.current;
    if (!iframe) return null;
    // Studio suppresses pointer events inside the composition so the canvas
    // overlay can own input, which means a plain elementFromPoint only ever
    // finds wrappers. This helper lifts that for the length of the hit test,
    // and is the same one the canvas uses to decide what was clicked.
    return getPreviewTargetFromPointer(
      iframe,
      event.clientX,
      event.clientY,
      selectionRef.current?.compositionPath ?? null,
    );
  };

  /** A point on Studio's canvas, in the scaled composition's coordinates. */
  const compositionPoint = (event: { clientX: number; clientY: number }) => {
    const iframe = actions?.previewIframeRef?.current;
    const view = iframe?.contentWindow;
    if (!iframe || !view?.innerWidth) return undefined;
    const box = iframe.getBoundingClientRect();
    const scale = box.width / view.innerWidth || 1;
    return { x: (event.clientX - box.left) / scale, y: (event.clientY - box.top) / scale };
  };

  return {
    editing: inlineText.session !== null,
    toolbar: (
      <InlineTextToolbar
        session={inlineText.session}
        iframe={actions?.previewIframeRef?.current ?? null}
      />
    ),
    // Enter opens the selected element's text, the way every design tool does,
    // and is the dependable way in: a double press has to survive the canvas'
    // gesture machinery, while this is one key on a selection that has settled.
    handleKeyDown: (event) => {
      if (event.key !== "Enter" || event.shiftKey || event.ctrlKey || event.metaKey || event.altKey)
        return false;
      const target = selectionRef.current;
      if (inlineText.session || !target || !canEditTextInline(target)) return false;
      return inlineText.start(target.element);
    },
    startFromPress: (event) => {
      if (inlineText.session) return false;
      const element = elementUnderPress(event);
      const press = { x: event.clientX, y: event.clientY, at: Date.now(), element };
      const paired = isDoublePress(lastPressRef.current, press);
      lastPressRef.current = press;

      if (!paired) return false;
      if (!element || !canEditElementTextInline(element)) return false;
      // The caret opens where the press landed, which means mapping the point
      // out of Studio's coordinates and into the composition's own.
      return inlineText.start(element, compositionPoint(event));
    },
  };
}