import { streamFrameApplies } from "../../streamScope";
import { parseTool, parseToolCall } from "../../wsParse";
import type { FrameEvent, FramePayload, StoreState } from "./shared";

/** 工具帧处理组：tool_call.start / tool_call.end / tool_call.delta /
 *  tool_execution.update + 遗留 tool_used。命中（含组内主动丢弃）返回 true，
 *  未命中返回 false 交给下一组。 */
export function handleToolEvent(ev: FrameEvent, r: FramePayload, s: StoreState): boolean {
  switch (ev.type) {
    case "tool_call.start":
    case "tool_call.end": {
      if (!streamFrameApplies(ev, r, s.activeSessionId)) return true;
      const tool = parseToolCall(ev.data);
      if (tool) s.addTool(tool);
      return true;
    }
    case "tool_call.delta": {
      // Argument fragments stream between start/end; the card is added at the
      // boundary so mid-stream reconnects do not drop it.
      return true;
    }
    case "tool_execution.update": {
      // Same card as tool_call.* — same guard.
      if (!streamFrameApplies(ev, r, s.activeSessionId)) return true;
      const tool = parseToolCall(ev.data);
      if (tool) s.addTool(tool);
      return true;
    }
    case "tool_used": {
      // Legacy tool echo — same card as tool_call.*.
      if (!streamFrameApplies(ev, r, s.activeSessionId)) return true;
      const tool = parseTool(ev.data);
      if (tool) s.addTool(tool);
      return true;
    }
    default:
      return false;
  }
}