import { useCallback, useEffect, useRef, useState } from 'react';
import { CircleDot, Hammer, Loader2, Play, Square } from 'lucide-react';
import { useClient } from 'hooks/useClient';
import { Button } from '@/components/ui/button';
import { readableError } from './errors';
import { Console } from './Console';

/**
 * Production: the built site, and the nginx serving it.
 *
 * ── Two states, not one ──
 *
 * A build can succeed while nothing serves it, and a container can serve a directory built weeks ago.
 * They fail independently and they are fixed differently, so they are reported separately rather than
 * collapsed into "production is up" — which would be true in one of those cases and misleading in the
 * other.
 *
 * ── Build takes minutes ──
 *
 * It renders every route through the real app and copies every referenced file. Said in the button,
 * because a spinner sitting for three minutes with no explanation is indistinguishable from a hang.
 */

type Static = {
  path: string;
  built: boolean;
  entries: number | null;
  builtAt: string | null;
  container: { name: string; state: string | null; forward: string };
};

const when = (iso: string) =>
  new Date(iso).toLocaleString(undefined, { day: 'numeric', month: 'short', hour: '2-digit', minute: '2-digit' });

export const StaticBlock = () => {
  const client = useClient();
  const clientRef = useRef(client);
  clientRef.current = client;

  const [status, setStatus] = useState<Static | null>(null);
  const [busy, setBusy] = useState<'build' | 'start' | 'stop' | null>(null);
  const [output, setOutput] = useState<string | null>(null);
  const [failed, setFailed] = useState(false);

  const load = useCallback(async () => {
    try {
      setStatus(await clientRef.current.get<Static>('/fofos-admin/_config/static'));
    } catch {
      setStatus(null);
    }
  }, []);

  useEffect(() => {
    void load();
  }, [load]);

  const act = async (what: 'build' | 'start' | 'stop') => {
    setBusy(what);
    setFailed(false);
    setOutput(what === 'build' ? 'Rendering every page. This takes a few minutes.' : null);
    try {
      const path = what === 'build' ? '/fofos-admin/_config/static/build' : `/fofos-admin/_config/static/${what}`;
      const result = await clientRef.current.post<{ ok: boolean; output: string; status: Static }>(path, {});
      setStatus(result.status);
      setOutput(result.output);
      setFailed(!result.ok);
    } catch (failure) {
      setOutput(readableError(failure));
      setFailed(true);
      void load();
    } finally {
      setBusy(null);
    }
  };

  if (!status) return null;

  const serving = status.container.state === 'running';

  return (
    <div className="flex flex-col gap-2 border-t border-border pt-3">
      <div className="flex flex-wrap items-center gap-3">
        <div className="min-w-0 flex-1">
          <p className="flex items-center gap-1.5 text-xs">
            <CircleDot
              className={`size-3 ${serving ? 'text-success' : status.container.state ? 'text-destructive' : 'text-muted-foreground/40'}`}
            />
            Production
            <span className="text-muted-foreground/70">
              {status.built ? `${status.entries} files` : 'not built'}
              {status.builtAt ? ` · built ${when(status.builtAt)}` : ''}
              {' · '}
              {status.container.state ?? 'no server'}
            </span>
          </p>
          {/* The forward target, because it is what a domain has to point at and it is not a port. */}
          <p className="font-mono text-xs text-muted-foreground/60">
            {status.container.name} · {serving ? status.container.forward : 'static files, no port'}
          </p>
        </div>

        <div className="flex shrink-0 gap-2">
          <Button
            variant="outline"
            size="sm"
            className="w-24 justify-center"
            onClick={() => void act('build')}
            disabled={busy !== null}
          >
            {busy === 'build' ? <Loader2 className="size-3.5 animate-spin" /> : <Hammer className="size-3.5" />}
            {busy === 'build' ? 'Building' : 'Build'}
          </Button>
          <Button
            variant="outline"
            size="sm"
            className="w-24 justify-center"
            onClick={() => void act('start')}
            // Nothing to serve until something is built, and starting on an empty directory produces a
            // container that returns 404 for everything — which reads as a broken site, not a missing build.
            disabled={busy !== null || !status.built}
            title={status.built ? undefined : 'Build it first'}
          >
            {busy === 'start' ? <Loader2 className="size-3.5 animate-spin" /> : <Play className="size-3.5" />}
            {serving ? 'Restart' : 'Serve'}
          </Button>
          <Button
            variant="outline"
            size="sm"
            className="w-24 justify-center"
            onClick={() => void act('stop')}
            disabled={busy !== null || !status.container.state}
          >
            <Square className="size-3.5" />
            Stop
          </Button>
        </div>
      </div>

      <Console output={output} failed={failed} />
    </div>
  );
};