womenOnlyTrainCar.ts

import { match } from "ts-pattern";
import z from "zod";

const Station = z.object({
    name: z.string()
})
const Time = z.object({
    hour: z.number().int().min(0).max(12),
    minute: z.number().int().min(0).max(59),
})
type Time = z.infer<typeof Time>

const Gender = z.union([z.literal("MALE"), z.literal("FEMALE")])
type Gender = z.infer<typeof Gender>
const Age = z.number().int().min(0)
type Age = z.infer<typeof Age>

const Train = z.object({
    departureFrom: Station,
    depatureAt: Time,
})
type Train = z.infer<typeof Train>

const Person = z.object({
    gender: Gender,
    age: Age,
    hasHandicap: z.boolean(),
    isHelper: z.boolean(),
}).brand("Person")
type Person = z.infer<typeof Person>

const Section = z.object({
    from: Station,
    to: Station,
})
type Section = z.infer<typeof Section>

type CanBoard = (p: Person, s :Section, t: Train) => boolean
type CanPersonBoardWomenOnly = (p: Person) => boolean
type IsWomenOnlyTrain = (t: Train) => boolean
type IsWomenOnlySection = (s: Section) => boolean
type HasHandicapOrHelper = (p: Person) => boolean
type IsJuvenile = (p: Person) => boolean
type TimeContains = (target: Time, from: Time, to: Time) => boolean
type SectionContains = (target: Section, preselected: Section) => boolean

// Implementations 
const timeContains: TimeContains = (target, from, to) =>
    (from.hour < target.hour && target.hour < to.hour) 
    || (target.hour === from.hour && target.minute >= from.minute)
    || (target.hour === to.hour && target.minute <= to.minute)

const sectionContains: SectionContains = (target, preselected)=>
    true // Dummy; 実際は総武線の駅区間と照らし合わせて判定

const hasHandicapOrHelper: HasHandicapOrHelper = person => 
    person.hasHandicap || person.isHelper

const isJuvenile:IsJuvenile = person => person.age <= 12

const canPersonBoardWomenOnly: CanPersonBoardWomenOnly = person =>
    match(person)
        .with({ gender: "MALE"}, p => hasHandicapOrHelper(p) || isJuvenile(p))
        .with({ gender: "FEMALE"}, _ => true)
        .exhaustive()

const isWomenOnlyTrain: IsWomenOnlyTrain = train =>
    train.departureFrom.name === "西船橋"
    && timeContains(train.depatureAt, {hour: 6, minute: 57}, {hour: 8, minute: 56})

const isWomenOnlySection: IsWomenOnlySection = section =>
    sectionContains(section, {from: {name: "千葉"}, to: {name: "御茶ノ水"}})   

const canBoard: CanBoard = (person, section, train) =>
    !isWomenOnlySection(section)
    || !isWomenOnlyTrain(train)
    || canPersonBoardWomenOnly(person)