import { useCallback, useEffect, useRef, useState } from "react";
import { Button, ComposedModal, InlineLoading, InlineNotification, ModalBody, ModalFooter, ModalHeader, Tag } from "@carbon/react";
import { reportToText, runSelfTest, type Check, type SelfTestReport } from "../lib/selfTest";

const STATUS_TAG: Record<Check["status"], { type: "green" | "red" | "gray"; text: string }> = {
  pass: { type: "green", text: "Pass" },
  fail: { type: "red", text: "Fail" },
  info: { type: "gray", text: "Info" },
};

/** Renders the fixtures in this webview's real render client and reports what it found. */
export default function DiagnosticsPanel({ open, onClose }: { open: boolean; onClose: () => void }) {
  const [report, setReport] = useState<SelfTestReport | null>(null);
  const [fatal, setFatal] = useState<string | null>(null);
  const [copied, setCopied] = useState<"ok" | "failed" | null>(null);
  const runId = useRef(0);

  const run = useCallback(async () => {
    const id = ++runId.current;
    setReport(null);
    setFatal(null);
    setCopied(null);
    try {
      // Loaded on demand: the fixtures, goldens and pdf.js are only needed here.
      const { browserSelfTestDeps } = await import("../lib/selfTestBrowser");
      await runSelfTest(browserSelfTestDeps(), (r) => {
        if (runId.current === id) setReport(r);
      });
    } catch (e) {
      if (runId.current === id) setFatal(e instanceof Error ? e.message : String(e));
    }
  }, []);

  useEffect(() => {
    if (open) void run();
    else runId.current++;
  }, [open, run]);

  const copy = async () => {
    if (!report) return;
    try {
      await navigator.clipboard.writeText(reportToText(report));
      setCopied("ok");
    } catch {
      setCopied("failed");
    }
  };

  const running = open && !fatal && !report?.done;

  return (
    <ComposedModal open={open} onClose={onClose} size="md" preventCloseOnClickOutside aria-label="Diagnostics">
      <ModalHeader title="Diagnostics" label="Settings" />
      <ModalBody hasScrollingContent>
        <p className="voiced-muted" style={{ marginBottom: "1rem" }}>
          Renders two sample invoices in this app's own renderer, reads them back and compares them with the reference layouts. Nothing is saved or sent.
        </p>
        {fatal ? <InlineNotification kind="error" lowContrast hideCloseButton title="The self-test could not run" subtitle={fatal} /> : null}
        {report && report.done ? (
          <InlineNotification
            kind={report.passed ? "success" : "error"}
            lowContrast
            hideCloseButton
            title={report.passed ? "All checks passed" : "Some checks failed"}
            subtitle={report.passed ? undefined : "Copy the report and include it when you report the problem."}
          />
        ) : null}
        {report?.sections.map((section) => (
          <section key={section.title} style={{ marginTop: "1.5rem" }} aria-label={section.title}>
            <h4 style={{ marginBottom: "0.5rem" }}>{section.title}</h4>
            {section.checks.map((check, i) => (
              <div key={`${check.label}-${i}`} className="voiced-diagnostics__check">
                <div className="voiced-diagnostics__head">
                  <Tag type={STATUS_TAG[check.status].type} size="sm">
                    {STATUS_TAG[check.status].text}
                  </Tag>
                  <span className="voiced-diagnostics__label">{check.label}</span>
                  {check.ms !== undefined ? <span className="voiced-diagnostics__ms">{check.ms} ms</span> : null}
                </div>
                {check.detail ? <p className="voiced-diagnostics__detail">{check.detail}</p> : null}
              </div>
            ))}
          </section>
        ))}
        {running ? (
          <div style={{ marginTop: "1.5rem" }}>
            <InlineLoading description="Running checks…" />
          </div>
        ) : null}
        {copied ? (
          <div style={{ marginTop: "1rem" }}>
            <InlineNotification
              kind={copied === "ok" ? "success" : "warning"}
              lowContrast
              hideCloseButton
              title={copied === "ok" ? "Report copied" : "Could not copy"}
              subtitle={copied === "ok" ? undefined : "The clipboard is not available here."}
            />
          </div>
        ) : null}
      </ModalBody>
      <ModalFooter>
        <Button kind="secondary" onClick={() => void run()} disabled={running}>
          Run again
        </Button>
        <Button kind="secondary" onClick={() => void copy()} disabled={!report}>
          Copy report
        </Button>
        <Button kind="primary" onClick={onClose}>
          Close
        </Button>
      </ModalFooter>
    </ComposedModal>
  );
}