AlexAegis/advent-of-code

import { Interval, INTERVAL_CLOSED, split } from '@alexaegis/advent-of-code-lib';

export type Ticket = number[];

export interface TicketObservation {
    fieldRanges: Map<string, Interval[]>;
    myTicket: number[];
    nearbyTickets: number[][];
}

export const parse = (input: string): TicketObservation => {
    const lines = split(input);
    const fieldRanges = new Map<string, Interval[]>();
    let myTicket: Ticket = [];
    const nearbyTickets: Ticket[] = [];
    let currentSection: undefined | string;
    for (const line of lines) {
        if (line.endsWith(':')) {
            currentSection = line;
            continue;
        }
        switch (currentSection) {
            case undefined: {
                const [category, value] = line.splitIntoStringPair(': ');
                const ranges = value.splitIntoStringPair(' or ').map((rawRange) => {
                    const [low, high] = rawRange.splitIntoStringPair('-');
                    return Number.parseInt(low, 10).interval(
                        Number.parseInt(high, 10),
                        INTERVAL_CLOSED,
                    );
                });
                fieldRanges.set(category, ranges);

                break;
            }
            case 'your ticket:': {
                myTicket = line.split(',').map((v) => Number.parseInt(v, 10));

                break;
            }
            case 'nearby tickets:': {
                nearbyTickets.push(line.split(',').map((v) => Number.parseInt(v, 10)));

                break;
            }
            // No default
        }
    }
    return { fieldRanges, myTicket, nearbyTickets };
};