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));
    }
}