import { readFile } from "node:fs/promises";
import nunjucks from "nunjucks";
import { contentTypes } from "./content-types";
import { executionContext } from "./execution-context";
import { httpCodes } from "./http-codes";
import type { Result } from "./types";

// FIXME: Handle the error here
const loadFile = async (path: string): Promise<string> => {
    // Specifying 'utf8' returns a string; otherwise, it returns a Buffer
    const data = await readFile(path, "utf8");

    return data;
};

const render = async (path: string, ctx: object): Promise<string> => {
    const fullPath = `${executionContext.diachron_root}/templates/${path}.html.njk`;

    const template = await loadFile(fullPath);

    const retval = nunjucks.renderString(template, ctx);

    return retval;
};

const html = (payload: string): Result => {
      const retval: Result = {
        code: httpCodes.success.OK,
        result: payload,
        contentType: contentTypes.text.html,
    };

    return retval;
};

export { render, html };