import type { ToolCallEvent } from "@earendil-works/pi-coding-agent";
import { checkAskBashCommand, isAskBashTool } from "./ask-bash-policy.js";
import { isPlanFilePath, isProjectPiPath } from "./paths.js";
import { ENTER_PLAN_TOOL, EXIT_PLAN_TOOL } from "./plan-file.js";
import {
	checkReadOnlySubagentCall,
	SUBAGENT_FOLLOWUP_TOOL,
	SUBAGENT_OBSERVE_TOOLS,
	SUBAGENT_SPAWN_TOOL,
} from "./subagent-policy.js";

const PATH_GATED_TOOLS = new Set(["write", "edit"]);
const SAFE_TOOLS = new Set([
	"ask_user_choice",
	"read",
	"grep",
	"find",
	"ls",
	"repo_search",
	"tapd_review",
	"resolve-library-id",
	"query-docs",
	"agent_todo_write",
	ENTER_PLAN_TOOL,
	EXIT_PLAN_TOOL,
	...SUBAGENT_OBSERVE_TOOLS,
]);
/** Allowed per call once the target child is confirmed read-only. */
const ROLE_GATED_TOOLS = new Set([SUBAGENT_SPAWN_TOOL, SUBAGENT_FOLLOWUP_TOOL]);

export function restrictedModeToolNames(
	activeTools: string[],
	mode: "ask" | "plan",
): string[] {
	const names = activeTools.filter(
		(name) =>
			SAFE_TOOLS.has(name) ||
			PATH_GATED_TOOLS.has(name) ||
			ROLE_GATED_TOOLS.has(name) ||
			isAskBashTool(name, mode),
	);
	for (const name of [ENTER_PLAN_TOOL, EXIT_PLAN_TOOL]) {
		if (!names.includes(name)) names.push(name);
	}
	return names;
}

export async function checkAskToolCall(
	event: ToolCallEvent,
	cwd: string,
	projectTrusted = false,
): Promise<string | undefined> {
	if (SAFE_TOOLS.has(event.toolName)) return undefined;
	if (ROLE_GATED_TOOLS.has(event.toolName))
		return checkReadOnlySubagentCall(event, cwd, projectTrusted, "Ask");
	if (event.toolName === "bash") {
		return checkAskBashCommand((event.input as { command?: unknown }).command);
	}
	if (!PATH_GATED_TOOLS.has(event.toolName)) {
		return `Ask mode blocked "${event.toolName}" because it is not an approved read-only tool. Press Shift+Tab to switch mode.`;
	}

	const input = event.input as { path?: unknown };
	if (typeof input.path !== "string") {
		return `Ask mode blocked "${event.toolName}" because no target path was provided.`;
	}
	if (await isProjectPiPath(cwd, input.path)) return undefined;
	return `Ask mode only allows ${event.toolName} inside the project-local .pi directory. Press Shift+Tab to switch mode.`;
}

export async function checkPlanToolCall(
	event: ToolCallEvent,
	cwd: string,
	activePlanRelativePath: string | undefined,
	projectTrusted = false,
): Promise<string | undefined> {
	if (SAFE_TOOLS.has(event.toolName)) return undefined;
	if (ROLE_GATED_TOOLS.has(event.toolName))
		return checkReadOnlySubagentCall(event, cwd, projectTrusted, "Plan");
	if (!PATH_GATED_TOOLS.has(event.toolName)) {
		return `Rejected: "${event.toolName}" is not allowed in plan mode.`;
	}

	const input = event.input as { path?: unknown };
	if (typeof input.path !== "string") {
		return `Rejected: "${event.toolName}" requires a target path.`;
	}
	if (await isPlanFilePath(cwd, input.path, activePlanRelativePath)) {
		return undefined;
	}
	const target = activePlanRelativePath ?? "unavailable";
	return `Rejected: file edits are not allowed in plan mode - the only editable file is the active plan (${target}).`;
}