import { useState, useEffect, useRef } from "react";
import { AlertCircle, CloudCog, Lock } from "lucide-react";
import { useObservabilityData } from "./hooks/useObservabilityData";
import { IconRail } from "./components/layout/IconRail";
import { AnomalyRadarBar } from "./components/AnomalyRadarBar";
import { TopBar } from "./components/layout/TopBar";
import { CommandAndQueryBar } from "./components/CommandAndQueryBar";
import { WaveformHistogram } from "./components/WaveformHistogram";
import { EntryVisualization } from "./components/EntryVisualization";
import { handleCallback, login } from "./lib/auth";

function AuthCallbackView() {
  const [error, setError] = useState<string | null>(null);
  const handledRef = useRef(false);

  useEffect(() => {
    if (handledRef.current) return;
    handledRef.current = true;

    handleCallback()
      .then(() => {
        window.location.href = "/";
      })
      .catch((err) => {
        console.error("Authentication callback error:", err);
        setError(err instanceof Error ? err.message : String(err));
      });
  }, []);

  return (
    <div className="flex min-h-screen items-center justify-center bg-ds-bg p-6 font-body text-ds-text">
      <main className="w-full max-w-md rounded-[14px] border border-ds-line bg-ds-surface p-8 text-center">
        {error ? (
          <div className="flex flex-col items-center gap-4">
            <div className="flex h-14 w-14 items-center justify-center rounded-full bg-ds-critical-bg text-ds-critical">
              <AlertCircle className="h-7 w-7" aria-hidden="true" />
            </div>
            <div>
              <h2 className="font-[family-name:var(--font-display)] text-lg font-bold text-ds-critical">Authentication failed</h2>
              <p className="mt-1 font-[family-name:var(--font-data)] text-xs text-ds-text-3">{error}</p>
            </div>
            <button
              type="button"
              onClick={() => login()}
              className="mt-2 inline-flex h-9 items-center rounded-[9px] bg-ds-accent px-4 text-[13px] font-semibold text-ds-on-accent"
            >
              Try again
            </button>
          </div>
        ) : (
          <div className="flex flex-col items-center gap-4">
            <div className="flex h-14 w-14 animate-pulse items-center justify-center rounded-full bg-ds-accent-bg text-ds-accent">
              <Lock className="h-7 w-7" aria-hidden="true" />
            </div>
            <div>
              <h2 className="font-[family-name:var(--font-display)] text-lg font-semibold text-ds-text">Completing sign in</h2>
              <p className="mt-1 text-xs text-ds-text-3">Exchanging authorization code with OIDC provider…</p>
            </div>
          </div>
        )}
      </main>
    </div>
  );
}

function App() {
  const { isConnected, traces, logs, metrics, activeTab } = useObservabilityData();

  const hasLoadedAnyData = traces.length > 0 || logs.length > 0 || metrics.length > 0;
  const isCallback =
    typeof window !== "undefined" &&
    (window.location.pathname === "/auth_callback" ||
      window.location.search.includes("code="));
  // The redesigned screens (issues, logs, RUM sessions, rollouts, metrics) own
  // their own filter bar and cards, so the legacy anomaly banner and volume
  // waveform above them would just duplicate that UI in a different visual language.
  const isTriageOverview = activeTab === "tab0" || activeTab === "tab3" || activeTab === "tab7" || activeTab === "tab9" || activeTab === "tab10" || activeTab === "tab2";

  if (isCallback) {
    return <AuthCallbackView />;
  }

  return (
    <div className="bg-ds-bg font-body text-ds-text min-h-screen antialiased selection:bg-ds-accent-bg selection:text-ds-accent">
      {/* Fixed 72px icon rail */}
      <IconRail />

      {/* Main Content Area offset by the rail width */}
      <div className="pl-[72px]">
        {/* Fixed top bar */}
        <TopBar />

        {/* Main Telemetry Console View */}
        <main className="relative w-full bg-ds-bg pb-12 pt-[58px]">
          {!isTriageOverview && <AnomalyRadarBar />}
          <div className="flex w-full flex-col px-6">
            {!isTriageOverview && (
              <>
                {/* Filter Bar */}
                <CommandAndQueryBar />

                {/* Ingest & Incident Waveform Histogram */}
                <WaveformHistogram />
              </>
            )}

            {/* Telemetry Visualizations & Views */}
            <section className="relative flex min-h-0 flex-1 flex-col">
              {isConnected || hasLoadedAnyData ? (
                <EntryVisualization />
              ) : (
                <div className="flex h-full min-h-[360px] flex-col items-center justify-center gap-4 rounded-[14px] border border-dashed border-ds-line bg-ds-surface p-12 text-center">
                  <div className="flex h-16 w-16 items-center justify-center rounded-full bg-ds-accent-bg text-ds-accent">
                    <CloudCog className="h-8 w-8 animate-pulse" aria-hidden="true" />
                  </div>
                  <div>
                    <p className="text-base font-semibold text-ds-text">
                      Establishing telemetry pipeline
                    </p>
                    <p className="mx-auto mt-1 max-w-sm text-xs text-ds-text-3">
                      Connecting to OTLP collector. Listening for incoming traces, logs, and metrics.
                    </p>
                  </div>
                </div>
              )}
            </section>
          </div>
        </main>
      </div>
    </div>
  );

}

export default App;