Files
train-quiz/gtfs.ts
T
2024-10-07 23:06:00 -04:00

136 lines
3.1 KiB
TypeScript

import { TextWriter } from "jsr:@zip-js/zip-js";
import { ZipReader } from "jsr:@zip-js/zip-js";
import { parse } from "npm:csv-parse/sync";
function indexRecords(records, key) {
const result = {};
for (const record of records) {
result[record[key]] = record;
}
return result;
}
const reader = new ZipReader((await Deno.open(Deno.args[0])).readable);
const files = await reader.getEntries();
const wantedFiles = [
"routes",
"trips",
"stops",
"stop_times",
"calendar",
] as const;
const entries: Partial<Record<(typeof wantedFiles)[number], any[]>> = {};
console.log("reading files");
await Promise.all(
files
.filter((f) => {
//@ts-ignore
return wantedFiles.includes(f.filename.replace(".txt", ""));
})
.map(async (f) => {
const writer = new TextWriter();
entries[f.filename.replace(".txt", "") as (typeof wantedFiles)[number]] =
parse(await f.getData!(writer), { columns: true });
})
);
reader.close();
console.log(`Indexing ${entries.stops?.length} stops...`);
function actualStop(stop_id: string): string {
return indexedStops[stop_id]?.parent_station || stop_id;
}
const indexedStops = indexRecords(entries.stops, "stop_id");
const metroRoutes = entries.routes!.filter(
(r) => r.route_type == 1 || r.route_type == 0
);
const metroRouteIds = metroRoutes.map((r) => r.route_id);
console.log(`Indexing trips...`);
const trips = entries.trips!.filter(
(t) => t.service_id == "canonical" && metroRouteIds.includes(t.route_id)
);
const indexedTrips = indexRecords(trips, "trip_id");
console.log("sorting stop times");
const stop_times = entries
.stop_times!.filter((s) => s.trip_id in indexedTrips)
.sort((a, b) => {
if (a.trip_id < b.trip_id) {
return -1;
} else if (a.trip_id > b.trip_id) {
return 1;
} else {
return a.stop_sequence - b.stop_sequence;
}
});
const edges: Record<string, any> = {};
console.log("calculating edges...");
for (let i = 0; i < stop_times.length - 1; i++) {
const a = stop_times[i];
const b = stop_times[i + 1];
if (a.trip_id == b.trip_id) {
const trip = indexedTrips[a.trip_id];
const route_id = trip.route_id;
const aStop = actualStop(a.stop_id);
const bStop = actualStop(b.stop_id);
const key = `${aStop}-${bStop}`;
if (key in edges) {
edges[key].route.add(route_id);
} else {
edges[key] = {
a: aStop,
b: bStop,
route: new Set([route_id]),
headsign: trip.trip_headsign,
};
}
}
}
const stations = [
...new Set(
Object.values(edges)
.flatMap((e) => [e.a, e.b])
.map((e) => actualStop(e))
),
];
const output = {
stations: indexRecords(
stations.map((s) => indexedStops[s]),
"stop_id"
),
edges: Object.values(edges).map((e) => ({ ...e, route: [...e.route] })),
routes: indexRecords(metroRoutes, "route_id"),
agency: {
city: "Boston",
slug: "boston",
},
};
console.log(
entries.calendar?.sort(
(a, b) => parseInt(b.end_date) - parseInt(a.end_date)
)[0]
);
await Deno.writeTextFile("cities/boston.json", JSON.stringify(output));