import { Context } from "koa";
import { SimpleInput } from "../controls/controls.js";
import { FormControlContext } from "../controls/form-control.js";
import { FormDataValue } from "../form-types.js";
import { FieldParseResult } from "./field.js";
import { SimpleFormField } from "./simple-form-field.js";

function pad(n: number) {
	return String(n).padStart(2, "0");
}

export class DateTime<Required extends boolean> extends SimpleFormField<
	Required,
	SimpleInput,
	Date | null
> {
	constructor(required: Required) {
		super(required, "datetime-local");
	}

	public getEmptyValue(): Date | null {
		return null;
	}

	async parse(
		ctx: Context,
		raw_value: FormDataValue
	): Promise<FieldParseResult<Date | null>> {
		const parsed_value = new Date(raw_value as string);
		return { parsable: true, error: null, parsed_value };
	}

	async getSealiousCreateValue(
		fctx: FormControlContext
	): Promise<number | null> {
		const { parsed } = await this.getParsedValue(
			fctx.ctx,
			fctx.data.raw_values
		);
		if (parsed == null) {
			return null;
		}
		return new Date(parsed).getTime();
	}

	getControl(): SimpleInput {
		return new SimpleInput(this, {
			label: this.label || this.name,
			type: this.type,
		});
	}

	async sealiousValueToForm(
		ctx: Context,
		value: number | null
	): Promise<FormDataValue> {
		if (value == null) {
			return "";
		}
		const d = new Date(value);

		return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(
			d.getDate()
		)}T${pad(d.getHours())}:${pad(d.getMinutes())}`;
	}
}