"use client";

// Settings → Organization → "Radio bot per system" (server-26#225, owner
// ruling Q2). The org owner picks which of the org's OWN radio bots plays each
// of the org's systems in Discord. C2 tries that bot first for every new
// radio channel of the system (discord_streams.start_stream); when it can't
// take the stream (busy in that server, no permission, not invited) another
// free bot is used. Shared systems and DRB pool bots stay platform-admin only,
// so they are not offered here. Backend: GET /tokens/org/preferred (list),
// PUT /tokens/{token_id}/prefer/{system_id} (set; "_none" clears).

import { useCallback, useEffect, useState } from "react";
import { c2api } from "@/lib/c2api";
import { parseC2Error, type OrgPreferredBots } from "@/lib/discordPicker";
import { Card, CardHeader } from "@/components/ui/Card";

const SELECT =
  "bg-page border border-line rounded-lg px-2.5 py-1.5 text-ink text-sm focus:outline-none focus:border-accent disabled:opacity-50 max-w-full";

export function PreferredBotsCard({ canEdit }: { canEdit: boolean }) {
  const [data, setData] = useState<OrgPreferredBots | null>(null);
  const [loadError, setLoadError] = useState<string | null>(null);
  const [saving, setSaving] = useState<string | null>(null);
  const [rowError, setRowError] = useState<{ id: string; message: string } | null>(null);
  // A platform admin with no org of their own gets a 403 here: nothing to show
  // (shared systems are set on /systems), so the card hides instead of erroring.
  const [hidden, setHidden] = useState(false);

  const load = useCallback(async () => {
    try {
      setData(await c2api.getOrgPreferredBots());
      setLoadError(null);
    } catch (err) {
      const e = parseC2Error(err);
      if (e.status === 403) setHidden(true);
      // A server error's raw body ("C2 API error 500: ...") means nothing to an owner.
      else setLoadError(e.status !== null && e.status >= 500 ? "DRB couldn't load them just now." : e.message);
    }
  }, []);

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

  async function choose(systemId: string, tokenId: string, currentId: string | null) {
    if (tokenId === (currentId ?? "")) return;
    setSaving(systemId);
    setRowError(null);
    try {
      if (tokenId) await c2api.setPreferredToken(tokenId, systemId);
      else if (currentId) await c2api.setPreferredToken(currentId, "_none");
      await load();
    } catch (err) {
      setRowError({ id: systemId, message: parseC2Error(err).message });
    } finally {
      setSaving(null);
    }
  }

  if (!canEdit || hidden) return null;
  const bots = data?.bots ?? [];
  const botsById = new Map(bots.map((b) => [b.token_id, b]));

  return (
    <Card>
      <CardHeader
        title="Radio bot per system"
        subtitle="Which of your radio bots plays each system in Discord. DRB tries it first for every new radio channel of that system; if it can't (busy in that server, missing a permission, or not invited), another free bot is used."
      />
      {loadError ? (
        <p role="alert" className="text-sm text-sev-major">
          Couldn&apos;t load radio bots: {loadError}{" "}
          <button type="button" onClick={() => load()} className="text-accent hover:underline">
            Try again
          </button>
        </p>
      ) : !data ? (
        <p className="text-sm text-ink-muted">Loading…</p>
      ) : data.systems.length === 0 ? (
        <p className="text-sm text-ink-muted">Your organization has no radio systems yet.</p>
      ) : bots.length === 0 ? (
        <p className="text-sm text-ink-muted">
          Your organization has no radio bots of its own, so DRB picks a free DRB radio bot for each channel. Adding
          your own bot isn&apos;t self-serve yet: DRB support adds it for you, so ask whoever set up your DRB account.
        </p>
      ) : (
        <div className="divide-y divide-line">
          {data.systems.map((s) => {
            const current = s.preferred_token_id ? botsById.get(s.preferred_token_id) : undefined;
            const err = rowError?.id === s.system_id ? rowError.message : null;
            const usedElsewhere = (tokenId: string) => {
              const other = botsById.get(tokenId)?.preferred_for_system_id;
              return other && other !== s.system_id ? data.systems.find((x) => x.system_id === other)?.name ?? "another system" : null;
            };
            return (
              <div key={s.system_id} className="py-3 first:pt-0 last:pb-0 flex flex-wrap items-start gap-x-4 gap-y-1.5">
                <div className="min-w-0 flex-1">
                  <div className="text-sm text-ink font-medium truncate">{s.name}</div>
                  <div className="text-xs text-ink-muted">
                    {current
                      ? `${current.name} is tried first.`
                      : s.preferred_is_platform_bot
                        ? "A DRB radio bot chosen by DRB support is tried first. Pick one of yours to replace it."
                        : "No preference — any free radio bot."}
                    {current?.valid === false && " Discord rejected this bot's token — DRB support has to replace it."}
                    {current && current.server_count === 0 && " It isn't in any Discord server yet — invite it first."}
                  </div>
                  {current?.invite_url && (
                    <a
                      href={current.invite_url}
                      target="_blank"
                      rel="noopener noreferrer"
                      className="text-xs text-accent hover:underline"
                    >
                      Invite {current.name} to a Discord server
                    </a>
                  )}
                  {err && <div role="alert" className="text-xs text-sev-major mt-1">{err}</div>}
                </div>
                <label className="flex items-center gap-2 text-xs text-ink-muted">
                  <span className="sr-only">Preferred radio bot for {s.name}</span>
                  <select
                    value={s.preferred_token_id ?? ""}
                    disabled={saving !== null}
                    onChange={(e) => choose(s.system_id, e.target.value, s.preferred_token_id)}
                    className={SELECT}
                  >
                    <option value="">{s.preferred_is_platform_bot ? "DRB support's choice" : "Any free radio bot"}</option>
                    {bots.map((b) => {
                      const elsewhere = usedElsewhere(b.token_id);
                      return (
                        <option key={b.token_id} value={b.token_id} disabled={b.valid === false}>
                          {b.name}
                          {b.valid === false ? " — token rejected" : elsewhere ? ` — moves it off ${elsewhere}` : ""}
                        </option>
                      );
                    })}
                  </select>
                  {saving === s.system_id && <span>Saving…</span>}
                </label>
              </div>
            );
          })}
        </div>
      )}
    </Card>
  );
}