const fs = require("node:fs");
const path = require("node:path");
const vm = require("node:vm");
const sources = require("./sources.cjs");
const vendorSources = { content: ["src/vendor/fullcalendar/index.global.min.js"], background: [] };

const root = path.resolve(__dirname, "..");

/** Compose classic scripts at build time; never load or evaluate code at runtime. */
function composeScript(target, { bootstrap = true } = {}) {
  const files = sources[target];
  if (!files) throw new Error(`Unknown script target: ${target}`);
  if (new Set(files).size !== files.length) throw new Error(`Duplicate source in ${target}`);
  const parts = files.map(file => {
    const source = fs.readFileSync(path.join(root, file), "utf8");
    new vm.Script(source, { filename: file });
    return `// Source: ${file}\n${source}`;
  });
  if (target === "content") {
    const calendarLibrary = fs.readFileSync(path.join(root, vendorSources.content[0]), "utf8");
    const calendarLicense = fs.readFileSync(path.join(root, "src/vendor/fullcalendar/LICENSE.md"), "utf8");
    parts.unshift(`function loadOpportunityCalendarLibrary() {\n/* ${calendarLicense} */\n${calendarLibrary}\nreturn FullCalendar;\n}`);
    const css = ["src/content/styles/redwood.css", "src/features/debug/styles.css", "src/features/opportunities/styles.css", "src/features/install-base/styles.css", "src/features/service-requests/styles.css", "src/features/consumption/plan-detail.css", "src/features/ratecard/styles.css", "src/features/opportunities/customer-table-search.css", "src/features/opportunities/calendar.css"]
      .map(file => fs.readFileSync(path.join(root, file), "utf8")).join("\n");
    parts.unshift(`const redwoodStyles = ${JSON.stringify(css)};`);
  }
  const factory = target === "content" ? "createContentApplication" : "createBackgroundApplication";
  const ending = bootstrap ? `${factory}().start();` : `return ${factory};`;
  const output = `(function () {\n  "use strict";\n${parts.join("\n")}\n${ending}\n})();\n`;
  new vm.Script(output, { filename: `${target}.js` });
  return output;
}

module.exports = { composeScript, sources, vendorSources };