import type { AccountPair } from './useJellyfinData';
import { ArrowLeftRight, CircleSlash, KeyRound, Loader2, UserPlus, Users } from 'lucide-react';
import { useJellyfinAccounts } from './useJellyfinData';

// Who exists on each side, shown side by side.
//
// The reason this is worth a screen: provisioning is invisible. Connecting a server can create accounts,
// adopt accounts, and leave accounts alone, and until now the only record of which happened was a JSON
// field in a response nobody reads and rows in a table nobody can see. An owner asking "did it work" had
// no way to find out except to open Jellyfin and count.
//
// Four states, and each one means something different:
//
//   linked          a row in `jellyfin_accounts` says these are the same person
//   matchable       the names fold to the same thing but nothing is recorded — what connecting WOULD adopt
//   Officer only    no Jellyfin account, and no name that matches one — what connecting WOULD create
//   Jellyfin only   somebody with no Officer account. Never touched, and that is deliberate: an absence
//                   in Officer is indistinguishable from a list that has not been told about them yet.
//   this connection the admin account Officer signs in as. It has to be its own state: the owner is
//                   excluded from the provisionable list on purpose, so without this their own account
//                   appears on the Jellyfin side with nothing opposite it and gets labelled as belonging
//                   to nobody — which is what the owner saw, next to their own name.

const TONE = {
  connection: 'text-sky-600',
  linked: 'text-emerald-600',
  matchable: 'text-amber-600',
  officer: 'text-muted-foreground',
  jellyfin: 'text-muted-foreground',
} as const;

const stateOf = (p: AccountPair) => {
  if (p.isConnection) return { key: 'connection' as const, label: 'the account Officer connects with' };
  if (p.linked && p.jellyfin) return { key: 'linked' as const, label: p.adopted ? 'linked (adopted)' : 'linked' };
  if (p.linked) return { key: 'matchable' as const, label: 'linked, but the Jellyfin account is gone' };
  if (p.matchable) return { key: 'matchable' as const, label: 'names match — not linked yet' };
  if (p.officer) return { key: 'officer' as const, label: 'no Jellyfin account' };
  return { key: 'jellyfin' as const, label: 'not an Officer account' };
};

const Cell = ({ name, sub, muted }: { name: string | null; sub?: string | null; muted?: boolean }) =>
  name ? (
    <div className="min-w-0">
      <div className="truncate text-sm text-foreground">{name}</div>
      {sub ? <div className="truncate text-[11px] text-muted-foreground">{sub}</div> : null}
    </div>
  ) : (
    <div className={`text-sm ${muted ? 'text-muted-foreground/40' : 'text-muted-foreground'}`}>—</div>
  );

export const AccountsSection = ({ serverId }: { serverId: number | null }) => {
  const { data, isLoading, error } = useJellyfinAccounts(serverId);

  if (serverId === null) return null;

  return (
    <section className="mt-8">
      <header className="flex items-center gap-2">
        <Users className="h-4 w-4 text-muted-foreground" />
        <h3 className="text-sm font-medium text-foreground">Accounts</h3>
        {data?.known ? (
          <span className="text-[11px] text-muted-foreground">
            {data.counts.linked} linked · {data.counts.officerOnly} Officer only · {data.counts.jellyfinOnly} Jellyfin
            only
          </span>
        ) : null}
      </header>

      {isLoading ? (
        <p className="mt-3 flex items-center gap-2 text-[11px] text-muted-foreground">
          <Loader2 className="h-3 w-3 animate-spin" /> reading both sides…
        </p>
      ) : null}

      {/* Distinct from "there are none". Not knowing means the platform has not sent the account list, or
          this server could not be reached — rendering an empty table for either would state something
          false about the server. */}
      {error || (data && !data.known) ? (
        <p className="mt-3 flex items-start gap-2 text-[11px] text-muted-foreground">
          <CircleSlash className="mt-0.5 h-3 w-3 shrink-0" />
          <span>{data && !data.known ? data.reason : 'could not read the accounts on this server'}</span>
        </p>
      ) : null}

      {data?.known ? (
        <div className="mt-3 overflow-hidden rounded-lg border border-border">
          <div className="grid grid-cols-[1fr_auto_1fr] items-center gap-3 border-b border-border bg-muted/40 px-3 py-1.5 text-[11px] font-medium uppercase tracking-wide text-muted-foreground">
            <span>Officer</span>
            <span className="w-4" />
            <span>Jellyfin</span>
          </div>
          {data.pairs.map((pair) => {
            const state = stateOf(pair);
            return (
              <div
                key={`${pair.officer?.id ?? 'x'}-${pair.jellyfin?.id ?? 'x'}`}
                className="grid grid-cols-[1fr_auto_1fr] items-center gap-3 border-b border-border/60 px-3 py-2 last:border-b-0"
              >
                <Cell
                  name={pair.officer?.username ?? null}
                  sub={pair.officer ? (pair.officer.name ?? pair.officer.role) : null}
                  muted
                />
                <span className={`flex w-4 justify-center ${TONE[state.key]}`} title={state.label}>
                  {state.key === 'connection' ? (
                    <KeyRound className="h-3.5 w-3.5" />
                  ) : state.key === 'linked' || state.key === 'matchable' ? (
                    <ArrowLeftRight className="h-3.5 w-3.5" />
                  ) : (
                    <UserPlus className="h-3.5 w-3.5 opacity-30" />
                  )}
                </span>
                <div className="min-w-0">
                  <Cell name={pair.jellyfin?.name ?? null} muted />
                  <div className={`text-[11px] ${TONE[state.key]}`}>{state.label}</div>
                </div>
              </div>
            );
          })}
        </div>
      ) : null}

      <p className="mt-2 text-[11px] leading-relaxed text-muted-foreground">
        Connecting a server links accounts whose usernames match, creates the ones Officer has and Jellyfin does not,
        and never touches a Jellyfin account with no Officer user — an absence here is indistinguishable from someone
        the list has not been told about yet.
      </p>
    </section>
  );
};