import type { XOTemplate } from '@xo-cash/types';
import { extendedJsonReplacer, extendedJsonReviver } from '../extended-json.ts';
import { TemplateJsonMalformedError, TemplateSerializationFailedError } from './errors.ts';

/**
 * Serializes an XOTemplate to a JSON string. Encodes `bigint` and `Uint8Array` fields in
 * Extended JSON format so they can be reconstructed by `deserializeTemplate`.
 *
 * @param template The template to serialize.
 * @returns A JSON string representation of the template.
 * @throws {TemplateSerializationFailedError} If the template cannot be serialized to JSON.
 */
export const serializeTemplate = (template: XOTemplate): string => {
    try {
        // Serialize the template to a JSON string.
        return JSON.stringify(template, extendedJsonReplacer);
    } catch (serializationError) {
        const reason = serializationError instanceof Error ? serializationError.message : 'unknown error while serializing template';

        throw new TemplateSerializationFailedError(reason);
    }
};

/**
 * Deserializes a JSON string back into an XOTemplate object. Restores `bigint` and
 * `Uint8Array` fields encoded in Extended JSON format by `serializeTemplate`.
 *
 * @param serializedTemplate - A JSON string of an XOTemplate object.
 * @returns The reconstructed XOTemplate object.
 * @throws {TemplateJsonMalformedError} If the serialized template is not valid JSON.
 */
export const deserializeTemplate = (serializedTemplate: string): XOTemplate => {
    try {
        // Parse the serialized template using the extended JSON reviver.
        return JSON.parse(serializedTemplate, extendedJsonReviver);
    } catch (parsingError) {
        const reason = parsingError instanceof Error ? parsingError.message : 'unknown error while deserializing template';

        throw new TemplateJsonMalformedError(reason);
    }
};