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import {
  MAP_MAX_SCALE,
  MAP_MIN_SCALE,
  MAP_SCALE_PER_EVENT,
  MAP_SIZE_IN_PIXELS
} from "../components/app/map/MapConstants";

export const SET_MAP_POSITION = "SET_MAP_POSITION";
export const SET_MAP_DIMENSIONS = "SET_MAP_DIMENSIONS";
export const SET_MAP_SCALE = "SET_MAP_SCALE";

export function setMapPosition(x, y) {
  return {
    type: SET_MAP_POSITION,
    x,
    y
  };
}

export function setMapDimensions(width, height) {
  return {
    type: SET_MAP_DIMENSIONS,
    width,
    height
  };
}

export function setMapScale(scale) {
  return {
    type: SET_MAP_SCALE,
    scale
  };
}

export function zoomInOnCenter(zoomIn) {
  return (dispatch, getState) => {
    const state = getState();

    dispatch(
      zoomInOnPosition(
        zoomIn,
        state.map.dimensions.width / 2,
        state.map.dimensions.height / 2
      )
    );
  };
}

export function zoomInOnPosition(zoomIn, x, y) {
  return (dispatch, getState) => {
    const state = getState();

    const centerPoint = {
      x: x / state.map.scale - state.map.position.x / state.map.scale,
      y: y / state.map.scale - state.map.position.y / state.map.scale
    };
    const newScale = zoomIn
      ? state.map.scale * MAP_SCALE_PER_EVENT
      : state.map.scale / MAP_SCALE_PER_EVENT;
    const boundedScale = Math.min(
      Math.max(MAP_MIN_SCALE, newScale),
      MAP_MAX_SCALE
    );

    const newX = -(centerPoint.x - x / boundedScale) * boundedScale;
    const newY = -(centerPoint.y - y / boundedScale) * boundedScale;

    dispatch(setMapPositionWithBoundsCheck(newX, newY));
    dispatch(setMapScale(boundedScale));
  };
}

export function setMapPositionWithBoundsCheck(x, y) {
  return (dispatch, getState) => {
    const state = getState();

    const scaledMapSize = MAP_SIZE_IN_PIXELS * state.map.scale;
    const updatedX =
      x > 0
        ? 0
        : x < -scaledMapSize + state.map.dimensions.width
          ? -scaledMapSize + state.map.dimensions.width
          : x;
    const updatedY =
      y > 0
        ? 0
        : y < -scaledMapSize + state.map.dimensions.height
          ? -scaledMapSize + state.map.dimensions.height
          : y;

    dispatch(setMapPosition(updatedX, updatedY));
  };
}