import {
  computed,
  getCurrentInstance,
  nextTick,
  reactive,
  Ref,
  ref,
  shallowRef,
  toRaw,
  watch,
  WatchCallback,
  watchEffect,
  WatchOptions,
  WatchSource,
} from "vue";
import { v4 as uuidRaw } from "uuid";
import { DC, EntityShape, Pos, Size } from "./dec";
import { Stage } from "konva/lib/Stage";
import { Transform } from "konva/lib/Util";
import { lineLen } from "./math";
import { Viewer } from "./viewer";
import { KonvaEventObject } from "konva/lib/Node";
import { asyncTimeout } from "@/utils";

export const rendererName = "renderer";
export const rendererMap = new WeakMap<any, { unmounteds: (() => void)[] }>();
export const uuid = uuidRaw
export const useRendererInstance = () => {
  let instance = getCurrentInstance()!;
  while (instance.type.__name !== rendererName) {
    if (instance.parent) {
      instance = instance.parent;
    } else {
      throw "未发现渲染实例";
    }
  }
  return instance;
};

export const installGlobalVar = <T>(
  create: () => { var: T; onDestroy: () => void } | T,
  key = Symbol("globalVar")
) => {
  const useGlobalVar = (): T => {
    const instance = useRendererInstance() as any;
    const { unmounteds } = rendererMap.get(instance)!;
    if (!(key in instance)) {
      let val = create() as any;
      if (typeof val === "object" && "var" in val && "onDestroy" in val) {
        console.error('val.onDestory', val, key, val.onDestroy)
        val.onDestroy && unmounteds.push(val.onDestroy);
        if (import.meta.env.DEV) {
          unmounteds.push(() => {
            console.log("销毁变量", key);
          });
        }
        val = val.var;
      }
      instance[key] = val;
    }
    return instance[key];
  };

  return useGlobalVar;
};

export const useGlobalVar = installGlobalVar(() => {
  return {
    misPixel: 10,
  };
});

export const onlyId = () => uuid();

export const stackVar = <T>(init?: T) => {
  const factory = (init: T) => ({ var: init, id: onlyId() });
  const stack = reactive([]) as { var: T; id: string }[];
  if (init) {
    stack.push(factory(init));
  }
  const result = {
    get value() {
      return stack[stack.length - 1]?.var;
    },
    set value(val) {
      stack[stack.length - 1].var = val;
    },
    push(data: T) {
      stack.push(factory(data));
      const item = stack[stack.length - 1];
      const pop = (() => {
        const ndx = stack.findIndex(({ id }) => id === item.id);
        if (~ndx) {
          stack.splice(ndx, 1);
        }
      }) as (() => void) & { set: (data: T) => void };
      pop.set = (data) => {
        item.var = data;
      };
      return pop;
    },
    pop() {
      if (stack.length - 1 > 0) {
        stack.pop();
      } else {
        console.error("已到达栈顶");
      }
    },
    cycle<R>(data: T, run: () => R): R {
      result.push(data);
      const r = run();
      result.pop();
      return r;
    },
  };
  return result;
};

export const useCursor = installGlobalVar(
  () => stackVar("default"),
  Symbol("cursor")
);

/**
 * 多个函数合并成一个函数
 * @param fns
 * @returns
 */
export const mergeFuns = (...fns: (() => void)[] | (() => void)[][]) => {
  return () => {
    fns.forEach((fn) => {
      if (Array.isArray(fn)) {
        fn.forEach((f) => f());
      } else {
        fn();
      }
    });
  };
};

export const useStage = installGlobalVar(
  () => shallowRef<DC<Stage> | undefined>(),
  Symbol("stage")
);

export const listener = <
  T extends HTMLElement | Window,
  K extends keyof HTMLElementEventMap
>(
  target: T,
  eventName: K,
  callback: (this: T, ev: HTMLElementEventMap[K]) => any
) => {
  target.addEventListener(eventName, callback as any);
  return () => {
    target.removeEventListener(eventName, callback as any);
  };
};

export const useGlobalResize = installGlobalVar(() => {
  const stage = useStage();
  const size = ref<Size>();
  const setSize = async () => {
    if (fix.value) return;
    const container = stage.value?.getStage().container();
    if (container) {
      container.style.setProperty("display", "none");
    }

    const dom = stage.value!.getNode().container().parentElement!;
    await asyncTimeout(16)
    size.value = {
      width: dom.offsetWidth,
      height: dom.offsetHeight,
    };
    if (container) {
      container.style.removeProperty("display");
    }
  };
  const stopWatch = watchEffect(() => {
    if (stage.value) {
      setSize();
      nextTick(() => stopWatch());
    }
  });
  let unResize = listener(window, "resize", setSize);
  const fix = ref(false);
  let unWatch: (() => void) | null = null;

  const setFixSize = (fixSize: { width: number; height: number } | null) => {
    if (fixSize) {
      size.value = { ...fixSize };
      unWatch && unWatch();
      unWatch = watchEffect(() => {
        const $stage = stage.value?.getStage();
        if ($stage) {
          $stage.width(fixSize.width);
          $stage.height(fixSize.height);
          nextTick(() => unWatch && unWatch());
        }
      });
    }
    if (fix.value && !fixSize) {
      unResize = listener(window, "resize", setSize);
      fix.value = false;
      nextTick(setSize);
    } else if (!fix.value && fixSize) {
      fix.value = true;
      unResize();
    }
  };

  return {
    var: {
      setFixSize: setFixSize,
      updateSize: setSize,
      size,
      fix,
    },
    onDestroy: () => {
      console.error('size onDest')
      unResize();
      unWatch && unWatch();
    },
  };
}, Symbol("resize"));

export const globalWatch = <T>(
  source: WatchSource<T>,
  cb: WatchCallback<T, T>,
  options?: WatchOptions
): (() => void) => {
  let stop: () => void;
  nextTick(() => {
    stop = watch(source, cb as any, options as any);
  });
  return () => {
    stop && stop();
  };
};

export const getOffset = (
  ev: MouseEvent | TouchEvent,
  dom = ev.target! as HTMLElement,
  ndx = 0
) => {
  const event = ev instanceof TouchEvent ? ev.changedTouches[ndx] : ev;
  const rect = dom.getBoundingClientRect();
  const offsetX = event.clientX - rect.left;
  const offsetY = event.clientY - rect.top;
  return {
    x: offsetX,
    y: offsetY,
  };
};

type DragProps = {
  move?: (
    info: Record<"start" | "prev" | "end", Pos> & { ev: PointerEvent }
  ) => void;
  down?: (pos: Pos, ev: PointerEvent) => void;
  up?: (pos: Pos, ev: PointerEvent) => void;
  notPrevent?: boolean;
};
export const dragListener = (
  dom: HTMLElement,
  props: DragProps | DragProps["move"] = {}
) => {
  if (typeof props === "function") {
    props = { move: props };
  }
  const { move, up, down } = props;
  const mount = document.documentElement;

  if (!move && !up && !down) return () => {};

  let moveHandler: any, endHandler: any;
  let button: number = -1
  const downHandler = (ev: PointerEvent) => {
    button = ev.button
    const start = getOffset(ev, dom);
    let prev = start;
    down && down(start, ev);
    props.notPrevent || ev.preventDefault();

    moveHandler = (ev: PointerEvent) => {
      if (ev.buttons <= 0) {
        endHandler()
        return;
      }
      const end = getOffset(ev, dom);
      move!({ start, end, prev, ev });
      prev = end;

      props.notPrevent || ev.preventDefault();
    };
    endHandler = (ev: PointerEvent) => {
      up && up(getOffset(ev, dom), ev);
      mount.removeEventListener("pointermove", moveHandler);
      mount.removeEventListener("pointerup", endHandler);
      props.notPrevent || ev.preventDefault();
    };

    move &&
      mount.addEventListener("pointermove", moveHandler, { passive: false });
    mount.addEventListener("pointerup", endHandler, { passive: false });
  };

  dom.addEventListener("pointerdown", downHandler, { passive: false });
  return () => {
    dom.removeEventListener("pointerdown", downHandler);
    moveHandler && mount.removeEventListener("pointermove", moveHandler);
    endHandler && mount.removeEventListener("pointerup", endHandler);
  };
};

export const getTouchScaleProps = (
  ev: TouchEvent,
  dom = ev.target! as HTMLElement
) => {
  const start = getOffset(ev, dom, 0);
  const end = getOffset(ev, dom, 1);
  const center = {
    x: (end.x + start.x) / 2,
    y: (end.y + start.y) / 2,
  };
  const initDist = lineLen(start, end);
  return {
    center,
    dist: initDist,
  };
};

export const touchScaleListener = (
  dom: HTMLElement,
  cb: (props: { center: Pos; scale: number }) => void
) => {
  const mount = document.documentElement;
  let moveHandler: (ev: TouchEvent) => void;
  let endHandler: (ev: TouchEvent) => void;
  const startHandler = (ev: TouchEvent) => {
    if (ev.changedTouches.length <= 1) return;
    let prevScale = getTouchScaleProps(ev, dom);
    ev.preventDefault();

    moveHandler = (ev: TouchEvent) => {
      if (ev.changedTouches.length <= 1) return;
      const curScale = getTouchScaleProps(ev, dom);
      cb({ center: prevScale.center, scale: curScale.dist / prevScale.dist });
      prevScale = curScale;
      ev.preventDefault();
    };
    endHandler = (ev: TouchEvent) => {
      mount.removeEventListener("touchmove", moveHandler);
      mount.removeEventListener("touchend", endHandler);
      ev.preventDefault();
    };

    mount.addEventListener("touchmove", moveHandler, {
      passive: false,
    });
    mount.addEventListener("touchend", endHandler, {
      passive: false,
    });
  };

  dom.addEventListener("touchstart", startHandler, { passive: false });

  return () => {
    dom.removeEventListener("touchstart", startHandler);
    mount.removeEventListener("touchmove", moveHandler);
    mount.removeEventListener("touchend", endHandler);
  };
};

export const wheelListener = (
  dom: HTMLElement,
  cb: (props: { center: Pos; scale: number }) => void
) => {
  const wheelHandler = (ev: WheelEvent) => {
    const scale = 1 - ev.deltaY / 1000;
    const center = { x: ev.offsetX, y: ev.offsetY };
    cb({ center, scale });
    ev.preventDefault();
  };

  dom.addEventListener("wheel", wheelHandler);
  return () => {
    dom.removeEventListener("wheel", wheelHandler);
  };
};

export const scaleListener = (
  dom: HTMLElement,
  cb: (props: { center: Pos; scale: number }) => void
) => mergeFuns(touchScaleListener(dom, cb), wheelListener(dom, cb));

export const useViewer = installGlobalVar(() => {
  const stage = useStage();
  const viewer = new Viewer();
  const transform = ref(new Transform());
  const cursor = useCursor();

  const init = (dom: HTMLDivElement) => {
    const dragDestroy = dragListener(dom, {
      move: ({ end, prev, ev }) => {
        if (cursor.value !== "move") {
          viewer.movePixel({ x: end.x - prev.x, y: 0 });
        }
      },
      notPrevent: true,
    });
    const scaleDestroy = scaleListener(dom, (info) => {
      const currentScalex = viewer.viewMat.decompose().scaleX;
      const finalScale = currentScalex * info.scale;
      const scale = Math.min(Math.max(finalScale, 0.5), 8);
      if (cursor.value !== "move") {
        viewer.scalePixel(info.center, { x: scale / currentScalex, y: 1 });
      }
    });
    viewer.bus.on("transformChange", (newTransform) => {
      // console.log(newTransform.m)
      transform.value = newTransform;
    });
    transform.value = viewer.transform;
    return mergeFuns(dragDestroy, scaleDestroy);
  };

  return {
    var: {
      transform: transform,
      viewer,
    },
    onDestroy: globalWatch(
      () => stage.value?.getNode().container(),
      (dom, _, onCleanup) => {
        dom && onCleanup(init(dom));
      },
      { immediate: true }
    ),
  };
}, Symbol("viewer"));

export const useViewerTransform = installGlobalVar(() => {
  const viewer = useViewer();
  return viewer.transform;
}, Symbol("viewTransform"));

export const useViewerTransformConfig = () => {
  const transform = useViewerTransform();
  return computed(() => transform.value.decompose());
};

export const useViewerInvertTransform = () => {
  const transform = useViewerTransform();
  return computed(() => transform.value.copy().invert());
};

export const useViewerInvertTransformConfig = () => {
  const transform = useViewerInvertTransform();
  return computed(() => transform.value.decompose());
};

export const flatPositions = (positions: Pos[]) =>
  positions.flatMap((p) => [p.x, p.y]);

export type PausePack<T extends object> = T & {
  pause: () => void;
  resume: () => void;
  isPause: boolean;
};
export const usePause = <T extends object>(api?: T): PausePack<T> => {
  const isPause = ref(false);
  const result = (api || {}) as PausePack<T>;

  Object.defineProperty(result, "isPause", {
    get() {
      return isPause.value;
    },
    set(v) {
      return true;
    },
  });

  result.pause = () => (isPause.value = true);
  result.resume = () => (isPause.value = false);

  return result;
};

const hoverPointer = (shape: EntityShape, cursor: ReturnType<typeof useCursor>) => {
  shape.on("pointerenter.hover", () => {
    const pop = cursor.push("pointer");
    shape.on("pointerleave.hover", () => {
      pop();
      shape.off("pointerleave.hover");
    });
  });
  return () => {
    shape.off("pointerenter.hover pointerleave.hover");
  }
}

export const useHoverPointer = (shape: Ref<DC<EntityShape> |  undefined>) => {
  const cursor = useCursor()
  watchEffect((onCleanup) => {
    if (shape.value) {
      console.error('shape.value', shape.value)
      onCleanup(hoverPointer(shape.value.getNode(), cursor))
    }
  })
  return cursor
}

export const useDrag = (
  shape: Ref<DC<EntityShape> | DC<EntityShape>[] | undefined>,
) => {
  const cursor = useCursor();
  const stage = useStage();
  const drag = ref<Pos & { ndx: number }>();
  const invMat = useViewerInvertTransform();

  const init = (shape: EntityShape, dom: HTMLDivElement, ndx: number) => {
    shape.on("pointerenter.drag", () => {
      const pop = cursor.push("pointer");
      shape.on("pointerleave.drag", () => {
        pop();
        shape.off("pointerleave.drag");
      });
    });

    let pop: (() => void) | null = null;
    let start = { x: 0, y: 0 }
    shape.on("pointerdown.drag", (ev) => {
      pop = cursor.push("move")
      start = invMat.value.point(getOffset(ev.evt, stage.value!.getNode().container()));
    });

    shape.draggable(true);
    shape.dragBoundFunc(function (this: any, _: any, ev: MouseEvent) {
      console.log(ev.buttons)
      if (ev.buttons <= 0) return upHandler()
      const current = invMat.value.point(getOffset(ev, stage.value!.getNode().container()));
      drag.value = {
        x: current.x - start.x,
        y: current.y - start.y,
        ndx,
      };
      start = current
      return this.absolutePosition();
    });
    const upHandler = () => {
      pop && pop();
      pop = null;
      drag.value = undefined;
      console.error('up')
    }

    return mergeFuns(
      listener(document.documentElement, "pointerup", upHandler),
      () => {
        shape.off("pointerenter.drag pointerleave.drag pointerdown.drag");
        if (pop) {
          pop();
          shape.draggable(false);
        }
      }
    );
  };

  const result = usePause({
    drag,
    stop: () => {
      stopWatch();
    },
  });

  const stopWatch = watch(
    () => {
      const shapes = shape.value
        ? Array.isArray(shape.value)
          ? [...shape.value]
          : [shape.value]
        : [];
      if (shapes.some((item) => !item)) {
        return [];
      }
      return shapes;
    },
    (shapes, _, onCleanup) => {
      onCleanup(
        mergeFuns(
          shapes.map((shape, ndx) =>
            watchEffect((onCleanup) => {
              if (!result.isPause && shape?.getNode() && stage.value?.getNode) {
                onCleanup(
                  init(
                    shape?.getNode(),
                    stage.value?.getNode().container(),
                    ndx
                  )
                );
              }
            })
          )
        )
      );
    },
    { immediate: true }
  );
  return result;
};

const stageHoverMap = new WeakMap<
  Stage,
  { result: Ref<EntityShape | undefined>; count: number; des: () => void }
>();
export const getHoverShape = (stage: Stage) => {
  let isStop = false;
  const stop = () => {
    if (isStop || !stageHoverMap.has(stage)) return;
    isStop = true;
    const data = stageHoverMap.get(stage)!;
    if (--data.count <= 0) {
      data.des();
    }
  };

  if (stageHoverMap.has(stage)) {
    const data = stageHoverMap.get(stage)!;
    ++data.count;
    return [data.result, stop] as const;
  }

  const hover = ref<EntityShape>();
  const enterHandler = (ev: KonvaEventObject<any, Stage>) => {
    const target = ev.target;
    hover.value = target;
    target.off(`pointerleave`, leaveHandler);
    target.on(`pointerleave`, leaveHandler as any);
  };

  const leaveHandler = () => {
    if (hover.value) {
      hover.value.off(`pointerleave`, leaveHandler);
      hover.value = undefined;
    }
  };

  stage.on(`pointerenter`, enterHandler);
  stageHoverMap.set(stage, {
    result: hover,
    count: 1,
    des: () => {
      stage.off(`pointerenter`, enterHandler);
      leaveHandler();
      stageHoverMap.delete(stage);
    },
  });
  return [hover, stop] as const;
};

export const useShapeIsHover = (shape: Ref<DC<EntityShape> | undefined>) => {
  const stage = useStage();
  const isHover = ref(false);
  const stop = watch(
    () => ({ stage: stage.value?.getNode(), shape: shape.value?.getNode() }),
    ({ stage, shape }, _, onCleanup) => {
      if (!stage || !shape || result.isPause) {
        isHover.value = false;
        return;
      }

      const [hoverShape, stopHoverListener] = getHoverShape(stage);

      watchEffect(() => {
        isHover.value = !!(
          hoverShape.value && shapeTreeContain([shape], toRaw(hoverShape.value))
        );
      });
      onCleanup(stopHoverListener);
    },
    { immediate: true }
  );
  const result = usePause([isHover, stop] as const);
  return result;
};

export const shapeTreeContain = (
  parent: EntityShape | EntityShape[],
  target: EntityShape,
  checked: EntityShape[] = []
) => {
  const eq = Array.isArray(parent)
    ? (shape: EntityShape) => parent.includes(shape)
    : (shape: EntityShape) => parent === shape;
  return shapeParentsEq(target, eq, checked);
};

export const shapeParentsEq = (
  target: EntityShape,
  eq: (shape: EntityShape) => boolean,
  checked: EntityShape[] = []
) => {
  while (target) {
    if (checked.includes(target)) return null;
    if (eq(target)) {
      return target;
    }
    target = target.parent as any;
  }
  return null;
};