schema/Schema.ts

import SchemaArray from "./items/array"
import SchemaBoolean from "./items/boolean"
import SchemaEnum, { EnumLike } from "./items/enum"
import SchemaLiteral from "./items/literal"
import SchemaNullable from "./items/nullable"
import SchemaNumber from "./items/number"
import SchemaObject from "./items/object"
import SchemaString from "./items/string"
import { SchemaUnion } from "./items/union"
import SchemaItem from "./SchemaItem"
import { SchemaJSON } from "./types"

export function parceable() {

	return (target: Object, propertyKey: string | symbol, descriptor: TypedPropertyDescriptor<any>) => {
		if (!(target instanceof SchemaItem)) {
			throw new Error('the decorator is only usable on Schema')
		}


		const original = target[propertyKey]

		const t = function () { }

		descriptor.value = function (this: SchemaItem, ...args: Array<any>) {
			this.savedCalls.push({ name: propertyKey as string, args: args })
			const res = original.call(this, ...args)
			return res
		}

		return descriptor
	}
}

interface SchemaItemStatic {
	new(...args: Array<any>): SchemaItem
}

type ExtractGeneric<T> = T extends SchemaItem<infer U> ? U : never

export default class Schema {
	private static registeredModules: Array<SchemaItemStatic> = [
		SchemaArray,
		SchemaBoolean,
		SchemaEnum,
		SchemaLiteral,
		SchemaNullable,
		SchemaObject,
		SchemaString,
		SchemaUnion
	]

	public static register(module: SchemaItemStatic) {
		this.registeredModules.push(module)
	}

	public static getModule(name: string) {
		return this.registeredModules.find((it) => it.name === name)
	}

	public static array<Type extends SchemaItem>(
		...inputs: ConstructorParameters<typeof SchemaArray<Type>>
	): SchemaArray<Type> {
		return new SchemaArray<Type>(...inputs)
	}

	public static boolean(
		...inputs: ConstructorParameters<typeof SchemaBoolean>
	): SchemaBoolean {
		return new SchemaBoolean(...inputs)
	}

	public static enum<Type extends EnumLike>(
		...inputs: ConstructorParameters<typeof SchemaEnum<Type>>
	): SchemaEnum<Type> {
		return new SchemaEnum<Type>(...inputs)
	}

	/**
	*
	* @param input the literal value (note: append `as const` else the typing won't work correctly)
	* @returns
	*/
	public static literal<Type>(
		input: Type
	): SchemaLiteral<Type> {
		return new SchemaLiteral<Type>(input)
	}

	public static nullable<Type extends SchemaItem>(
		...inputs: ConstructorParameters<typeof SchemaNullable<Type>>
	): SchemaNullable<Type> {
		return new SchemaNullable<Type>(...inputs)
	}

	public static number(
		...inputs: ConstructorParameters<typeof SchemaNumber>
	): SchemaNumber {
		return new SchemaNumber(...inputs)
	}

	public static object<Type extends Record<string, SchemaItem<any>>>(
		...inputs: ConstructorParameters<typeof SchemaObject<Type>>
	): SchemaObject<Type> {
		return new SchemaObject<Type>(...inputs)
	}

	/**
	 * See {@link SchemaString}
	 */
	public static string(
		...inputs: ConstructorParameters<typeof SchemaString>
	): SchemaString {
		return new SchemaString(...inputs)
	}

	public static union<Type extends Array<SchemaItem<any>>>(
		...inputs: ConstructorParameters<typeof SchemaUnion<Type>>
	): SchemaUnion<Type> {
		return new SchemaUnion<Type>(...inputs)
	}

	public static fromJSON(json: SchemaJSON): SchemaItem {

		// get the module
		const fn = this.getModule(json.i)

		// handle module not detected
		if (!fn) {
			throw new Error(`Schema cannot parse ${json.i}`)
		}

		// init the module
		const item = new fn(...(json.c?.map((it) => this.isSchemaJSON(it) ? Schema.fromJSON(it) : it) ?? []))

		// handle validations
		for (const validation of (json.f ?? [])) {
			// validation not found in item :(
			if (!(validation.n in item)) {
				throw new Error('validation not available in Schema Item')
			}

			// init the validation
			(item[validation.n] as (...params: Array<unknown>) => void)(...validation.a.map((it) => Schema.isSchemaJSON(it) ? Schema.fromJSON(it) : it))
		}

		// add the attributes
		item.attrs(...json.a ?? [])


		return item
	}

	public static isSchemaJSON(data: unknown): data is SchemaJSON {
		if (typeof data !== 'object' || data === null) {
			return false
		}

		if (!('i' in data)) {
			return false
		}

		return true
	}
}