/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the Source EULA. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import * as vscode from 'vscode';
import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';
import * as constants from '../common/constants';
import * as utils from '../common/utils';

/**
 * Returns the default location to save a new database project
 */
export function defaultProjectSaveLocation(): vscode.Uri | undefined {
	const workspaceApi = utils.getDataWorkspaceExtensionApi();
	return workspaceApi.defaultProjectSaveLocation;
}

/**
 * Returns default project name for a fresh new project, such as 'DatabaseProject1'. Auto-increments
 * the suggestion if a project of that name already exists in the default save location
 */
export function defaultProjectNameNewProj(): string {
	return defaultProjectName(constants.defaultProjectNameStarter, 1);
}

/**
 * Returns default project name for a new project based on given dbName. Auto-increments
 * the suggestion if a project of that name already exists in the default save location
 *
 * @param dbName the database name to base the default project name off of
 */
export function defaultProjectNameFromDb(dbName: string | undefined): string {
	if (!dbName) {
		return '';
	}

	const projectNameStarter = constants.defaultProjectNameStarter + dbName;
	const defaultLocation = defaultProjectSaveLocation() ?? vscode.Uri.file(os.homedir());
	const projectPath: string = path.join(defaultLocation.fsPath, projectNameStarter);
	if (!fs.existsSync(projectPath)) {
		return projectNameStarter;
	}

	return defaultProjectName(projectNameStarter, 2);
}

/**
 * Returns a project name that begins with the given nameStarter, and ends in a number, such as
 * 'DatabaseProject1'. Number begins at the given counter, but auto-increments if a project of
 * that name already exists in the default save location.
 *
 * @param nameStarter the beginning of the default project name, such as 'DatabaseProject'
 * @param counter the starting value of of the number appended to the nameStarter
 */
function defaultProjectName(nameStarter: string, counter: number): string {
	while (counter < Number.MAX_SAFE_INTEGER) {
		const name: string = nameStarter + counter;
		const defaultLocation = defaultProjectSaveLocation() ?? vscode.Uri.file(os.homedir());
		const projectPath: string = path.join(defaultLocation.fsPath, name);
		if (!fs.existsSync(projectPath)) {
			return name;
		}
		counter++;
	}
	return constants.defaultProjectNameStarter + counter;
}