import { z } from "zod";
const commandSchema = z
    .object({
    id: z.string(),
    action: z.string()
})
    .passthrough();
export function parseCommand(input) {
    let json;
    try {
        json = JSON.parse(input);
    }
    catch {
        return { success: false, error: "Invalid JSON" };
    }
    const id = typeof json === "object" && json !== null && "id" in json
        ? String(json.id)
        : undefined;
    const result = commandSchema.safeParse(json);
    if (!result.success) {
        const errors = result.error.errors.map((e) => `${e.path.join(".")}: ${e.message}`).join(", ");
        return { success: false, error: `Validation error: ${errors}`, id };
    }
    return { success: true, command: result.data };
}
export function successResponse(id, data) {
    return { id, success: true, data };
}
export function errorResponse(id, error) {
    return { id, success: false, error };
}
/**
 * Serialize a response to JSON string.
 * Replaces lone Unicode surrogates with U+FFFD to avoid serde_json parse errors.
 */
function sanitizeUtf16(input) {
    // Fast path: most strings contain no surrogate code units.
    if (!/[\uD800-\uDFFF]/.test(input))
        return input;
    // Replace lone high/low surrogates. Valid surrogate pairs are preserved.
    // Ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toWellFormed
    return input.replace(/[\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?<![\uD800-\uDBFF])[\uDC00-\uDFFF]/g, "\uFFFD");
}
export function serializeResponse(response) {
    return JSON.stringify(response, (_key, value) => typeof value === "string" ? sanitizeUtf16(value) : value);
}