/* Copyright (C) 2026 Moko Consulting <hello@mokoconsulting.tech>
 *
 * This file is part of a Moko Consulting project.
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * FILE INFORMATION
 * DEFGROUP: {{PROJECT_NAME}}.Config
 * INGROUP: {{PROJECT_NAME}}
 * REPO: https://git.mokoconsulting.tech/MokoConsulting/{{PROJECT_NAME}}
 * PATH: /src/config.ts
 * VERSION: 01.00.00
 * BRIEF: Configuration loader for {{DISPLAY_NAME}} MCP connections
 */

import { readFile } from 'node:fs/promises';
import { resolve } from 'node:path';
import { homedir } from 'node:os';
import type { ApiConfig, ApiConnection } from './types.js';

// ── Customize this ──────────────────────────────────────────────────────
// Change the filename to match your project (e.g. ".dolibarr-api-mcp.json")
const CONFIG_FILENAME = '.{{PROJECT_NAME}}.json';
// Change the env var name to match your project
const CONFIG_ENV_VAR = '{{ENV_PREFIX}}_CONFIG';
// ────────────────────────────────────────────────────────────────────────

export async function loadConfig(): Promise<ApiConfig> {
	const config_path = process.env[CONFIG_ENV_VAR]
		? resolve(process.env[CONFIG_ENV_VAR]!)
		: resolve(homedir(), CONFIG_FILENAME);

	try {
		const raw = await readFile(config_path, 'utf-8');
		const parsed = JSON.parse(raw) as Partial<ApiConfig>;

		if (!parsed.connections || Object.keys(parsed.connections).length === 0) {
			throw new Error('No connections defined in config');
		}

		return {
			connections: parsed.connections,
			defaultConnection: parsed.defaultConnection ?? Object.keys(parsed.connections)[0],
		};
	} catch (err) {
		const message = err instanceof Error ? err.message : String(err);
		throw new Error(
			`Failed to load config from ${config_path}: ${message}\n` +
			`Create ${config_path} — see config.example.json for format.`,
		);
	}
}

export function getConnection(config: ApiConfig, name?: string): ApiConnection {
	const key = name ?? config.defaultConnection;
	const conn = config.connections[key];
	if (!conn) {
		throw new Error(
			`Connection "${key}" not found. Available: ${Object.keys(config.connections).join(', ')}`,
		);
	}
	return conn;
}