import * as fs from "node:fs";
import * as path from "node:path";
import { CONFIG_DIR_NAME, getAgentDir } from "@earendil-works/pi-coding-agent";
import { createDefaultClusterConfig, parseClusterConfig } from "./config-core.ts";
import type { ClusterConfig } from "./types.ts";

export { createDefaultClusterConfig, workerLevelConfigSignature } from "./config-core.ts";

export interface LoadedClusterConfig {
	config: ClusterConfig;
	path: string;
}

export function getGlobalConfigPath(): string {
	return path.join(getAgentDir(), "subagent-cluster.json");
}

export function getConfigCandidates(cwd: string): string[] {
	const candidates: string[] = [];
	let current = path.resolve(cwd);
	while (true) {
		candidates.push(path.join(current, CONFIG_DIR_NAME, "subagent-cluster.json"));
		const parent = path.dirname(current);
		if (parent === current) break;
		current = parent;
	}
	candidates.push(path.join(getAgentDir(), "subagent-cluster.json"));
	return candidates;
}

export function readClusterConfig(configPath: string): LoadedClusterConfig {
	let content: string;
	try {
		content = fs.readFileSync(configPath, "utf8");
	} catch (error) {
		throw new Error(`无法读取集群配置 ${configPath}: ${error instanceof Error ? error.message : String(error)}`);
	}
	try {
		return { config: parseClusterConfig(JSON.parse(content)), path: configPath };
	} catch (error) {
		throw new Error(`集群配置无效 ${configPath}: ${error instanceof Error ? error.message : String(error)}`);
	}
}

export async function readOrCreateClusterConfig(configPath: string, model: string): Promise<LoadedClusterConfig> {
	if (fs.existsSync(configPath)) return readClusterConfig(configPath);
	const config = createDefaultClusterConfig(model);
	await writeClusterConfig(configPath, config);
	return { config, path: configPath };
}

export function loadClusterConfig(cwd: string): LoadedClusterConfig {
	const candidates = getConfigCandidates(cwd);
	for (const configPath of candidates) {
		if (fs.existsSync(configPath)) return readClusterConfig(configPath);
	}
	throw new Error(
		[`未找到集群配置。`, `请创建 ${candidates[0]}，或使用全局配置 ${candidates[1]}。`, `配置示例见 pi-subagent-cluster 包 README.md`].join("\n"),
	);
}

export async function writeClusterConfig(configPath: string, config: ClusterConfig): Promise<void> {
	await fs.promises.mkdir(path.dirname(configPath), { recursive: true });
	await fs.promises.writeFile(configPath, `${JSON.stringify(config, null, 2)}\n`, "utf8");
}