HTime.ts

/*
 * Copyright (c) 2020, J2 Innovations. All Rights Reserved
 */

import { Kind } from './Kind'
import {
	HVal,
	CANNOT_CHANGE_READONLY_VALUE,
	valueInspect,
	valueIsKind,
	valueMatches,
} from './HVal'
import { HaysonTime } from './hayson'
import { Node } from '../filter/Node'
import { HGrid } from './HGrid'
import { HList } from './HList'
import { HDict } from './HDict'
import { EvalContext } from '../filter/EvalContext'
import { JsonV3Time } from './jsonv3'

/**
 * A date object.
 */
export interface TimeObj {
	hours: number
	minutes: number
	seconds?: number
	milliseconds?: number
}

/**
 * Haystack time.
 */
export class HTime implements HVal {
	/**
	 * The string time value.
	 */
	readonly #value: string

	/**
	 * Internal implementation.
	 */
	readonly #date: Date

	/**
	 * Constructs a new haystack time.
	 *
	 * @param value The value.
	 */
	private constructor(value: string | Date | TimeObj | HaysonTime) {
		if (typeof value === 'string') {
			this.#value = value as string
			this.#date = HTime.toJsDate(this.#value)
		} else if (value instanceof Date) {
			this.#date = value as Date
			this.#value = HTime.getTimeFromDateObj(this.#date)
		} else if ((value as HaysonTime).val) {
			this.#value = (value as HaysonTime).val
			this.#date = HTime.toJsDate(this.#value)
		} else if (typeof (value as TimeObj).hours === 'number') {
			const obj = value as TimeObj
			this.#value = HTime.getTime(
				obj.hours,
				obj.minutes,
				obj.seconds || 0,
				obj.milliseconds || 0
			)
			this.#date = HTime.toJsDate(this.#value)
		} else {
			// Mark this so an error is thrown below.
			this.#value = ''
			this.#date = new Date()
		}

		if (!this.#value) {
			throw new Error('Invalid time')
		}
	}

	private static toJsDate(value: string): Date {
		const time = Date.parse('1970-01-01T' + value + 'Z')
		if (isNaN(time)) {
			throw new Error(`Invalid Time format ${value}`)
		}
		return new Date(time)
	}

	/**
	 * Makes a haystack time.
	 *
	 * @param value The value.
	 * @returns A haystack time.
	 */
	public static make(
		value: string | Date | TimeObj | HaysonTime | HTime
	): HTime {
		if (valueIsKind<HTime>(value, Kind.Time)) {
			return value
		} else {
			return new HTime(value as string | Date | TimeObj | HaysonTime)
		}
	}

	/**
	 * @returns The time value.
	 */
	public get value(): string {
		return this.#value
	}

	public set value(value: string) {
		throw new Error(CANNOT_CHANGE_READONLY_VALUE)
	}

	/**
	 * @returns The hours in a 24 hour format.
	 */
	public get hours(): number {
		return this.date.getUTCHours()
	}

	public set hours(hours: number) {
		throw new Error(CANNOT_CHANGE_READONLY_VALUE)
	}

	/**
	 * @returns The minutes.
	 */
	public get minutes(): number {
		return this.date.getMinutes()
	}

	public set minutes(minutes: number) {
		throw new Error(CANNOT_CHANGE_READONLY_VALUE)
	}

	/**
	 * @returns The seconds.
	 */
	public get seconds(): number {
		return this.date.getSeconds()
	}

	public set seconds(seconds: number) {
		throw new Error(CANNOT_CHANGE_READONLY_VALUE)
	}

	/**
	 * @returns The milliseconds.
	 */
	public get milliseconds(): number {
		return this.date.getMilliseconds()
	}

	public set milliseconds(milliseconds: number) {
		throw new Error(CANNOT_CHANGE_READONLY_VALUE)
	}

	/**
	 * @returns The value's kind.
	 */
	public getKind(): Kind {
		return Kind.Time
	}

	/**
	 * Compares the value's kind.
	 *
	 * @param kind The kind to compare against.
	 * @returns True if the kind matches.
	 */
	public isKind(kind: Kind): boolean {
		return valueIsKind<HTime>(this, kind)
	}

	/**
	 * Returns true if the haystack filter matches the value.
	 *
	 * @param filter The filter to test.
	 * @param cx Optional haystack filter evaluation context.
	 * @returns True if the filter matches ok.
	 */
	public matches(filter: string | Node, cx?: Partial<EvalContext>): boolean {
		return valueMatches(this, filter, cx)
	}

	/**
	 * Dump the value to the local console output.
	 *
	 * @param message An optional message to display before the value.
	 * @returns The value instance.
	 */
	public inspect(message?: string): this {
		return valueInspect(this, message)
	}

	/**
	 * Encodes to an encoded zinc value that can be used
	 * in a haystack filter string.
	 *
	 * The encoding for a haystack filter is mostly zinc but contains
	 * some exceptions.
	 *
	 * @returns The encoded value that can be used in a haystack filter.
	 */
	public toFilter(): string {
		return this.toZinc()
	}

	/**
	 * Value equality check.
	 *
	 * @param value The value to test.
	 * @returns True if the value is the same.
	 */
	public equals(value: unknown): boolean {
		return (
			valueIsKind<HTime>(value, Kind.Time) && this.#value === value.#value
		)
	}

	/**
	 * Compares two values.
	 *
	 * @param value The value to compare against.
	 * @returns The sort order as negative, 0, or positive
	 */
	public compareTo(value: unknown): number {
		if (!valueIsKind<HTime>(value, Kind.Time)) {
			return -1
		}

		if (this.#value < value.#value) {
			return -1
		}
		if (this.#value === value.#value) {
			return 0
		}
		return 1
	}

	/**
	 * @returns A string representation of the value.
	 */
	public toString(): string {
		return this.#value
	}

	/**
	 * @returns The encoded time value.
	 */
	public valueOf(): string {
		return this.#value
	}

	/**
	 * Encodes to an encoding zinc value.
	 *
	 * @returns The encoded zinc string.
	 */
	public toZinc(): string {
		return this.#value
	}

	/**
	 * @returns The current time.
	 */
	public static now(): HTime {
		return HTime.make(new Date())
	}

	/**
	 * @returns The Date for this time.
	 */
	public get date(): Date {
		return this.#date
	}

	/**
	 * Return the time from the JS date object.
	 *
	 * @param date The JS date object.
	 * @returns The time string.
	 * @throws An error if the time can't be found.
	 */
	private static getTimeFromDateObj(date: Date): string {
		const hours = date.getUTCHours()
		const minutes = date.getUTCMinutes()
		const seconds = date.getUTCSeconds()
		const ms = date.getUTCMilliseconds()

		return HTime.getTime(hours, minutes, seconds, ms)
	}

	/**
	 * Return the time from the JS date object.
	 *
	 * @param date The JS date object.
	 * @returns The time string.
	 * @throws An error if the time can't be found.
	 */
	private static getTime(
		hours: number,
		minutes: number,
		seconds: number,
		milliseconds: number
	): string {
		let time = (hours < 10 ? '0' : '') + String(hours)
		time += ':' + (minutes < 10 ? '0' : '') + String(minutes)
		time += ':' + (seconds < 10 ? '0' : '') + String(seconds)

		if (milliseconds) {
			let nsStr = String(milliseconds)

			while (nsStr.length < 3) {
				nsStr = '0' + nsStr
			}

			time += '.' + nsStr
		}

		return time
	}

	/**
	 * @returns A JSON reprentation of the object.
	 */
	public toJSON(): HaysonTime {
		return {
			_kind: this.getKind(),
			val: this.#value,
		}
	}

	/**
	 * @returns A JSON v3 representation of the object.
	 */
	public toJSONv3(): JsonV3Time {
		return `h:${this.#value}`
	}

	/**
	 * @returns An Axon encoded string of the value.
	 */
	public toAxon(): string {
		return this.toZinc()
	}

	/**
	 * @returns Returns the value instance.
	 */
	public newCopy(): HTime {
		return this
	}

	/**
	 * @returns The value as a grid.
	 */
	public toGrid(): HGrid {
		return HGrid.make(this)
	}

	/**
	 * @returns The value as a list.
	 */
	public toList(): HList<HTime> {
		return HList.make(this)
	}

	/**
	 * @returns The value as a dict.
	 */
	public toDict(): HDict {
		return HDict.make(this)
	}
}