import * as os from "os";
import * as path from "path";
import * as vscode from "vscode";
import { getWorkspaceConfiguration, getWorkspaceFolder } from "./workspace";
import { IQuickItemEx } from '../types/index';

export async function selectWorkspaceFolder(): Promise<string> {
    let workspaceFolderSetting: string = getWorkspaceFolder();
    vscode.workspace.updateWorkspaceFolders(0, 3);
    if (workspaceFolderSetting.trim() === "") {
        workspaceFolderSetting = await determineFEInterviewFolder();
        if (workspaceFolderSetting === "") {
            // User cancelled
            return workspaceFolderSetting;
        }
    }
    const workspaceFolders = vscode.workspace.workspaceFolders || [];
    let needAsk: boolean = true;
    for (const folder of workspaceFolders) {
        if (isSubFolder(folder.uri.fsPath, workspaceFolderSetting)) {
            needAsk = false;
        }
    }

    if (needAsk) {
        const choice: string | undefined = await vscode.window.showQuickPick(
            [
                OpenOption.justOpenFile,
                OpenOption.openInCurrentWindow,
                OpenOption.openInNewWindow,
                OpenOption.addToWorkspace,
            ],
            {
                placeHolder:
                    "当前窗口没有打开练习题的工作目录，请选择你的打开方式？（如果在对应目录里将不会提醒）",
            }
        );

        switch (choice) {
            case OpenOption.justOpenFile:
                return workspaceFolderSetting;
            case OpenOption.openInCurrentWindow:
                await vscode.commands.executeCommand(
                    "vscode.openFolder",
                    vscode.Uri.file(workspaceFolderSetting),
                    false
                );
                return "";
            case OpenOption.openInNewWindow:
                await vscode.commands.executeCommand(
                    "vscode.openFolder",
                    vscode.Uri.file(workspaceFolderSetting),
                    true
                );
                return "";
            case OpenOption.addToWorkspace:
                vscode.workspace.updateWorkspaceFolders(workspaceFolders.length, 0, {
                    uri: vscode.Uri.file(workspaceFolderSetting),
                });
                break;
            default:
                return "";
        }
    }

    return workspaceFolderSetting;
}

function isSubFolder(from: string, to: string): boolean {
    const relative: string = path.relative(from, to);
    if (relative === "") {
        return true;
    }
    return !relative.startsWith("..") && !path.isAbsolute(relative);
}


async function determineFEInterviewFolder(): Promise<string> {
    let result: string;
    const picks: Array<IQuickItemEx<string>> = [];
    picks.push(
        {
            label: `Default location`,
            detail: `${path.join(os.homedir(), ".panfeng/study")}`,
            value: `${path.join(os.homedir(), ".panfeng/study")}`,
        },
        {
            label: "$(file-directory) Browse...",
            value: ":browse",
        }
    );
    const choice: IQuickItemEx<string> | undefined =
        await vscode.window.showQuickPick(picks, {
            placeHolder: "选择存放习题的工作目录",
        });
    if (!choice) {
        result = "";
    } else if (choice.value === ":browse") {
        const directory: vscode.Uri[] | undefined =
            await showDirectorySelectDialog();
        if (!directory || directory.length < 1) {
            result = "";
        } else {
            result = directory[0].fsPath;
        }
    } else {
        result = choice.value;
    }

    getWorkspaceConfiguration().update(
        "workspaceFolder",
        result,
        vscode.ConfigurationTarget.Global
    );

    return result;
}

export async function showDirectorySelectDialog(
    fsPath?: string
): Promise<vscode.Uri[] | undefined> {
    const defaultUri: vscode.Uri | undefined =
        getBelongingWorkspaceFolderUri(fsPath);
    const options: vscode.OpenDialogOptions = {
        defaultUri,
        canSelectFiles: false,
        canSelectFolders: true,
        canSelectMany: false,
        openLabel: "Select",
    };
    return await vscode.window.showOpenDialog(options);
}


function getBelongingWorkspaceFolderUri(
    fsPath: string | undefined
): vscode.Uri | undefined {
    let defaultUri: vscode.Uri | undefined;
    if (fsPath) {
        const workspaceFolder: vscode.WorkspaceFolder | undefined =
            vscode.workspace.getWorkspaceFolder(vscode.Uri.file(fsPath));
        if (workspaceFolder) {
            defaultUri = workspaceFolder.uri;
        }
    }
    return defaultUri;
}

enum OpenOption {
    justOpenFile = "只打开习题文件不替换工作目录",
    openInCurrentWindow = "在当前窗口打开工作目录",
    openInNewWindow = "在新窗口打开工作目录",
    addToWorkspace = "添加新的习题目录",
}