import type { AIMode } from "./workspace-mode";

export function createComposerFocusMemory() {
  const focused: Record<AIMode, boolean> = { chat: false, agents: false };
  let previous: AIMode | undefined;
  return {
    record(mode: AIMode, isComposer: boolean) {
      focused[mode] = isComposer;
    },
    activate(mode: AIMode, tabHasFocus: boolean) {
      const changed = previous !== mode;
      previous = mode;
      return changed && !tabHasFocus && focused[mode];
    },
  };
}

interface ScrollContainer {
  scrollTop: number;
  scrollHeight: number;
  clientHeight: number;
}

export function createChatScrollMemory() {
  let savedTop = 0;
  let following = true;
  let wasActive = false;
  return {
    record(container: ScrollContainer, active: boolean) {
      if (!active) return;
      savedTop = container.scrollTop;
      following =
        container.scrollHeight - container.clientHeight - savedTop <= 48;
    },
    update(container: ScrollContainer, active: boolean) {
      if (active) {
        if (!wasActive) container.scrollTop = savedTop;
        else if (following)
          container.scrollTop = Math.max(
            0,
            container.scrollHeight - container.clientHeight,
          );
        savedTop = container.scrollTop;
        following =
          container.scrollHeight - container.clientHeight - savedTop <= 48;
      }
      wasActive = active;
    },
  };
}