import * as vscode from 'vscode';
import * as lc from 'vscode-languageclient';
import { Server } from '../server';

interface RunnablesParams {
    textDocument: lc.TextDocumentIdentifier;
    position?: lc.Position;
}

interface Runnable {
    range: lc.Range;
    label: string;
    bin: string;
    args: string[];
    env: { [index: string]: string };
}

class RunnableQuickPick implements vscode.QuickPickItem {
    public label: string;
    public description?: string | undefined;
    public detail?: string | undefined;
    public picked?: boolean | undefined;

    constructor(public runnable: Runnable) {
        this.label = runnable.label;
    }
}

interface CargoTaskDefinition extends vscode.TaskDefinition {
    type: 'cargo';
    label: string;
    command: string;
    args: string[];
    env?: { [key: string]: string };
}

function createTask(spec: Runnable): vscode.Task {
    const TASK_SOURCE = 'Rust';
    const definition: CargoTaskDefinition = {
        type: 'cargo',
        label: 'cargo',
        command: spec.bin,
        args: spec.args,
        env: spec.env,
    };

    const execCmd = `${definition.command} ${definition.args.join(' ')}`;
    const execOption: vscode.ShellExecutionOptions = {
        cwd: '.',
        env: definition.env,
    };
    const exec = new vscode.ShellExecution(`clear; ${execCmd}`, execOption);

    const f = vscode.workspace.workspaceFolders![0];
    const t = new vscode.Task(definition, f, definition.label, TASK_SOURCE, exec, ['$rustc']);
    return t;
}

let prevRunnable: RunnableQuickPick | undefined;
export async function handle() {
    const editor = vscode.window.activeTextEditor;
    if (editor == null || editor.document.languageId !== 'rust') { return; }
    const textDocument: lc.TextDocumentIdentifier = {
        uri: editor.document.uri.toString(),
    };
    const params: RunnablesParams = {
        textDocument,
        position: Server.client.code2ProtocolConverter.asPosition(editor.selection.active),
    };
    const runnables = await Server.client.sendRequest<Runnable[]>('m/runnables', params);
    const items: RunnableQuickPick[] = [];
    if (prevRunnable) {
        items.push(prevRunnable);
    }
    for (const r of runnables) {
        if (prevRunnable && JSON.stringify(prevRunnable.runnable) === JSON.stringify(r)) {
            continue;
        }
        items.push(new RunnableQuickPick(r));
    }
    const item = await vscode.window.showQuickPick(items);
    if (item) {
        item.detail = 'rerun';
        prevRunnable = item;
        const task = createTask(item.runnable);
        return await vscode.tasks.executeTask(task);
    }
}