import type { GameDTO } from '$lib/api/schema-helpers';

/**
 * The shape the game editor binds to. Every field is present and non-null so the
 * inputs never see `undefined`, and `POST /api/Game` always receives a whole DTO —
 * `AddOrUpdate` replaces every column, so a partial body would blank the rest.
 *
 * `id` 0 marks an unsaved game: the API inserts on 0 and updates otherwise.
 */
export interface Draft {
	id: number;
	name: string;
	longName: string;
	/** Null while the number input sits empty; `Game.Order` is a non-nullable int. */
	order: number | null;
	imgUrl: string;
	wordPressTag: string;
	wordPressTagOs: string;
	smashId: number | null;
}

export const blankDraft: Draft = {
	id: 0,
	name: '',
	longName: '',
	order: 0,
	imgUrl: '',
	wordPressTag: '',
	wordPressTagOs: '',
	smashId: null
};

export function toDraft(game: GameDTO): Draft {
	return {
		id: game.id ?? 0,
		name: game.name ?? '',
		longName: game.longName ?? '',
		order: game.order ?? 0,
		imgUrl: game.imgUrl ?? '',
		wordPressTag: game.wordPressTag ?? '',
		wordPressTagOs: game.wordPressTagOs ?? '',
		smashId: game.smashId ?? null
	};
}

/** Blank text is stored as NULL rather than as an empty string. */
export function toDto(draft: Draft): GameDTO {
	const text = (value: string) => (value.trim() === '' ? null : value.trim());

	return {
		id: draft.id,
		name: text(draft.name),
		longName: text(draft.longName),
		order: draft.order ?? 0,
		imgUrl: text(draft.imgUrl),
		wordPressTag: text(draft.wordPressTag),
		wordPressTagOs: text(draft.wordPressTagOs),
		smashId: draft.smashId
	};
}

/** A new game sorts after the current last one. */
export function nextOrder(games: GameDTO[]): number {
	return games.reduce((max, game) => Math.max(max, game.order ?? 0), 0) + 1;
}

/**
 * Whether the editor holds unsaved changes.
 *
 * Field by field rather than by comparing `JSON.stringify` output, which is
 * key-order dependent: it would report a clean draft as dirty the moment
 * `blankDraft` and `toDraft` listed their keys in a different order.
 */
export function isDirty(a: Draft, b: Draft): boolean {
	return (
		a.id !== b.id ||
		a.name !== b.name ||
		a.longName !== b.longName ||
		a.order !== b.order ||
		a.imgUrl !== b.imgUrl ||
		a.wordPressTag !== b.wordPressTag ||
		a.wordPressTagOs !== b.wordPressTagOs ||
		a.smashId !== b.smashId
	);
}