import * as path from "node:path";
import type { AgentToolResult } from "@earendil-works/pi-agent-core";
import type { Details, SubagentState } from "../../shared/types.ts";
import { deliverStopRequest } from "../background/control-channel.ts";
import { reconcileAsyncRun } from "../background/stale-run-reconciler.ts";

function getAsyncStopTarget(
	state: SubagentState,
	runId: string | undefined,
	location?: { asyncDir: string | null; resolvedId?: string },
): { asyncId: string; asyncDir: string } | undefined {
	if (location?.asyncDir) {
		return {
			asyncId: location.resolvedId ?? runId ?? path.basename(location.asyncDir),
			asyncDir: location.asyncDir,
		};
	}
	if (!runId) return undefined;
	const direct = state.asyncJobs.get(runId);
	return direct ? { asyncId: direct.asyncId, asyncDir: direct.asyncDir } : undefined;
}

export function stopAsyncRun(
	state: SubagentState,
	runId: string | undefined,
	kill?: (pid: number, signal?: NodeJS.Signals | 0) => boolean,
	location?: { asyncDir: string | null; resolvedId?: string },
): AgentToolResult<Details> | null {
	const target = getAsyncStopTarget(state, runId, location);
	if (!target) return null;
	const status = reconcileAsyncRun(target.asyncDir, { kill }).status;
	if (state.currentSessionId && status?.sessionId !== state.currentSessionId) {
		return {
			content: [{ type: "text", text: `Async run '${target.asyncId}' was not found in the active session.` }],
			isError: true,
			details: { mode: "management", results: [] },
		};
	}
	if (!status || (status.state !== "running" && status.state !== "queued")) {
		return {
			content: [{ type: "text", text: `No running or queued async run was found for '${runId ?? "current"}'.` }],
			isError: true,
			details: { mode: "management", results: [] },
		};
	}
	try {
		deliverStopRequest({ asyncDir: target.asyncDir, pid: typeof status.pid === "number" ? status.pid : undefined, kill, source: "stop-action" });
		const tracked = state.asyncJobs.get(target.asyncId);
		if (tracked) {
			tracked.activityState = undefined;
			tracked.updatedAt = Date.now();
		}
		return {
			content: [{ type: "text", text: `Stop requested for async run ${target.asyncId}.` }],
			details: { mode: "management", results: [] },
		};
	} catch (error) {
		const message = error instanceof Error ? error.message : String(error);
		return {
			content: [{ type: "text", text: `Failed to stop async run ${target.asyncId}: ${message}` }],
			isError: true,
			details: { mode: "management", results: [] },
		};
	}
}