#!/usr/bin/env node

import * as courses from '../src/tam/courses.js';
import {displayTime} from '../src/util.js';
import process from 'process';
import path from 'path';
import { readFile } from 'fs/promises';

const network = JSON.parse(await readFile(
    new URL('../src/tam/network.json', import.meta.url)
));

/**
 * Convert stop ID to human-readable stop name.
 *
 * If the stop ID is not known, the ID will be kept as-is.
 */
const getStopName = stopId =>
{
    if (stopId in network.stops)
    {
        return network.stops[stopId].properties.name;
    }

    return stopId;
};

/** Create a string representing a course for printing. */
const courseToString = course =>
{
    let result = `Course #${course.id}
Line ${course.line} - Direction ${course.direction} - Bound for ${getStopName(course.finalStopId)}

Next stops:
`;

    for (let [stopId, time] of course.passings)
    {
        result += `${displayTime(new Date(time))} - ${getStopName(stopId)}\n`;
    }

    return result;
};

/** Show user help. */
const doHelp = () =>
{
    const name = "./" + path.relative(process.cwd(), process.argv[1]);
    process.stdout.write(`Usage: ${name} TYPE [COURSE]
Show TaM courses data.

Set TYPE to 'realtime' to fetch real-time data (limited time scope) or to
'theoretical' to fetch planned courses for the day.

Set COURSE to a valid course ID to limit the output to a given course.
`);
};

/** Print realtime information for a course or all courses. */
const doPrint = async (kind, courseId) =>
{
    const results = await courses.fetch(kind);

    if (courseId)
    {
        if (courseId in results)
        {
            console.log(courseToString(results[courseId]));
        }
        else
        {
            console.log('Unknown course');
        }
    }
    else
    {
        for (let course of Object.values(results))
        {
            console.log(courseToString(course));
            console.log("======\n");
        }
    }
};

const argv = process.argv.slice(2);

if (argv.length === 0)
{
    doHelp();
    process.exit(1);
}

doPrint(argv[0], argv[1]);