import { invoke } from "@tauri-apps/api/core";
import type { SelfTestReport } from "./lib/selfTest";
import type { StepResult } from "./lib/selfTestSteps";

/**
 * Unattended self-test mode, enabled by the VOICED_SELFTEST_OUT environment variable (the backend
 * returns the report path, or null in normal use). It runs the diagnostics and an end-to-end invoice
 * flow in this very webview, writes a JSON report and makes the process exit with the verdict.
 */

const WATCHDOG_MS = 120_000;

export async function maybeRunSelfTest(): Promise<void> {
  let reportPath: string | null;
  try {
    reportPath = await invoke<string | null>("selftest_config");
  } catch {
    return; // Not running inside Tauri (plain browser dev server).
  }
  if (!reportPath) return;
  const path = reportPath;

  const start = performance.now();
  const startedAt = new Date().toISOString();
  let diagnostics: SelfTestReport | null = null;
  let steps: StepResult[] = [];
  let renderMode: () => string = () => "unknown";
  let finished = false;

  const finish = async (ok: boolean, error?: string) => {
    if (finished) return;
    finished = true;
    const body = {
      ok,
      ...(error ? { error } : {}),
      startedAt,
      totalMs: Math.round(performance.now() - start),
      userAgent: navigator.userAgent,
      renderMode: renderMode(),
      steps,
      diagnostics,
    };
    try {
      await invoke("selftest_report", { json: JSON.stringify(body, null, 2), ok });
    } catch (e) {
      console.error("self-test report could not be written", e);
    }
  };

  const failWith = (what: string) => void finish(false, what);
  const timer = window.setTimeout(() => {
    if (finished) return;
    void finish(false, "timeout");
  }, WATCHDOG_MS);
  window.addEventListener("error", (e) => failWith(`uncaught error: ${e.message}`));
  window.addEventListener("unhandledrejection", (e) => failWith(`unhandled rejection: ${String(e.reason)}`));

  try {
    const [{ createStepLog }, { runSelfTest }, { browserSelfTestDeps }, { runE2eSteps }, { getRenderClient }] = await Promise.all([
      import("./lib/selfTestSteps"),
      import("./lib/selfTest"),
      import("./lib/selfTestBrowser"),
      import("./lib/selfTestE2e"),
      import("./lib/renderClient"),
    ]);
    renderMode = () => getRenderClient().mode;
    const log = createStepLog();
    steps = log.steps;

    await log.run("diagnostics: render, rasterise, fingerprint, flatten", async () => {
      const report = await runSelfTest(browserSelfTestDeps(), (r) => {
        diagnostics = r;
      });
      diagnostics = report;
      const failed = report.sections.flatMap((s) => s.checks.filter((c) => c.status === "fail").map((c) => `${s.title} / ${c.label}: ${c.detail ?? ""}`));
      return { ok: report.passed, detail: failed.length ? failed.join("\n") : "all checks passed" };
    });
    await runE2eSteps(log, path);

    window.clearTimeout(timer);
    await finish(log.steps.every((s) => s.ok));
  } catch (e) {
    window.clearTimeout(timer);
    await finish(false, e instanceof Error ? `${e.name}: ${e.message}\n${e.stack ?? ""}` : String(e));
  }
}