"use client";

import { useState } from "react";
import { c2api } from "@/lib/c2api";
import { type DiscordAdminOverview, type DiscordGuild, SNOWFLAKE, fmtWhen, guildLabel, parseC2Error } from "@/lib/discord";
import { Button } from "@/components/ui/Button";
import { DIM, Field, INPUT, Panel, Status, Table, TD } from "./ui";

// Linked Discord servers = discord_guilds docs, plus any server that has had a
// radio channel without being linked (it acts for DISCORD_UNLINKED_GUILD_ORG_ID).
// Linking here is PUT /discord/guilds/{id}/link (platform admin, support).
// Org owners link their own from Settings → Organization: "Connect a Discord
// server" (a radio bot's OAuth invite, no DRB server bot needed) or a
// /drb link code (needs the server bot) — server-26#213 item 1, #225.
// The Bots column says which bots are in each server: the DRB server bot is
// optional (server-26#225 S8), one radio bot is enough to stream.
// Remove is DELETE /discord/guilds/{id}: its radio channels are stopped then
// deleted, and the server is unlinked with no fallback org.

function LinkForm({
  overview,
  guild,
  onDone,
  onCancel,
}: {
  overview: DiscordAdminOverview;
  guild?: DiscordGuild;
  onDone: () => void;
  onCancel: () => void;
}) {
  const [guildId, setGuildId] = useState(guild?.guild_id ?? "");
  const [label, setLabel] = useState(guild?.guild_name ?? "");
  const [orgId, setOrgId] = useState(guild?.org_id ?? guild?.acting_org_id ?? "");
  const [saving, setSaving] = useState(false);
  const [error, setError] = useState<string | null>(null);

  async function submit(e: React.FormEvent) {
    e.preventDefault();
    if (!SNOWFLAKE.test(guildId.trim())) {
      setError("Server ID is the 17–20 digit number from Discord (right-click the server icon → Copy Server ID).");
      return;
    }
    const actingNow = guild?.acting_org_id ?? null;
    if (guild && guild.live_streams > 0 && actingNow && actingNow !== orgId) {
      const n = guild.live_streams;
      if (!confirm(`${guildLabel(guild)} has ${n} live radio channel${n === 1 ? "" : "s"} on the current organization's nodes. Moving it stops ${n === 1 ? "it" : "them"}. Continue?`)) return;
    }
    setSaving(true);
    setError(null);
    try {
      await c2api.linkDiscordGuild(guildId.trim(), { org_id: orgId, guild_name: label.trim() || undefined });
      onDone();
    } catch (err) {
      setError(parseC2Error(err).message);
    } finally {
      setSaving(false);
    }
  }

  return (
    <form onSubmit={submit} className="px-4 py-4 border-b border-line grid gap-3 sm:grid-cols-3 bg-raised">
      <Field label="Discord server ID">
        <input
          value={guildId}
          onChange={(e) => setGuildId(e.target.value)}
          required
          readOnly={!!guild}
          inputMode="numeric"
          className={`${INPUT} font-mono ${guild ? "opacity-70" : ""}`}
        />
      </Field>
      <Field label="Label (optional)">
        <input value={label} onChange={(e) => setLabel(e.target.value)} className={INPUT} placeholder="Fire Co. 7" />
      </Field>
      <Field label="Acts for organization">
        <select value={orgId} onChange={(e) => setOrgId(e.target.value)} required className={INPUT}>
          <option value="" disabled>Choose an organization…</option>
          {overview.orgs.map((o) => (
            <option key={o.org_id} value={o.org_id}>{o.name}</option>
          ))}
        </select>
      </Field>
      {error && <p className="sm:col-span-3 text-sev-major text-xs">{error}</p>}
      <div className="sm:col-span-3 flex gap-2">
        <Button type="submit" size="sm" disabled={saving || !orgId}>{saving ? "Saving…" : guild?.linked ? "Save link" : "Link server"}</Button>
        <Button type="button" size="sm" variant="ghost" onClick={onCancel}>Cancel</Button>
      </div>
    </form>
  );
}

// Which bots are in the server. The DRB server bot is optional (server-26#225):
// "not there" is only a problem when no radio bot is either.
function BotsCell({ guild }: { guild: DiscordGuild }) {
  const radio = guild.radio_bots ?? [];
  const main = guild.main_bot_present;
  return (
    <>
      <div>
        {radio.length > 0 ? (
          <span title={radio.join(", ")}>
            {radio.length} radio bot{radio.length === 1 ? "" : "s"}
          </span>
        ) : (
          <span className={main ? DIM : "text-sev-moderate"}>no radio bot</span>
        )}
      </div>
      <div className={DIM}>
        DRB server bot: {main === true ? "present" : main === false ? "not there" : "never seen"}
        {guild.directory_source === "radio_bot" && " · channels via radio bot"}
      </div>
    </>
  );
}

type RemoveResult = { guild: string; streams: number; bots: { name: string; left: boolean; error: string | null }[] };

function RemoveForm({
  guild,
  onDone,
  onCancel,
}: {
  guild: DiscordGuild;
  onDone: (r: RemoveResult) => void;
  onCancel: () => void;
}) {
  const [leaveBots, setLeaveBots] = useState(false);
  const [saving, setSaving] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const n = guild.live_streams;

  async function submit() {
    setSaving(true);
    setError(null);
    try {
      const r = await c2api.removeDiscordGuild(guild.guild_id, leaveBots);
      onDone({ guild: guildLabel(guild), streams: r.streams_removed.length, bots: r.radio_bots });
    } catch (err) {
      setError(parseC2Error(err).message);
    } finally {
      setSaving(false);
    }
  }

  return (
    <div className="px-4 py-4 border-b border-line bg-raised text-xs text-ink-2 space-y-3">
      <p>
        <b className="text-ink">Remove {guildLabel(guild)} from DRB?</b>{" "}
        {n > 0
          ? `Its ${n} live radio channel${n === 1 ? " is" : "s are"} stopped first, then every radio channel in it is deleted.`
          : "Every radio channel in it is deleted."}{" "}
        It is unlinked and will not fall back to the default organization; linking it again brings it back.
      </p>
      <label className="flex items-start gap-2 cursor-pointer">
        <input type="checkbox" className="mt-0.5" checked={leaveBots} onChange={(e) => setLeaveBots(e.target.checked)} />
        <span>
          Also make the radio bots leave this Discord server (the platform pool and this server&apos;s organization&apos;s
          own bots). They need a new invite to come back.
        </span>
      </label>
      <p className="text-ink-muted">
        The DRB server bot, if it is in the Discord server, stays until someone kicks it there.
      </p>
      {error && <p className="text-sev-major">{error}</p>}
      <div className="flex gap-2">
        <Button size="sm" variant="danger" disabled={saving} onClick={submit}>{saving ? "Removing…" : "Remove server"}</Button>
        <Button size="sm" variant="ghost" onClick={onCancel}>Cancel</Button>
      </div>
    </div>
  );
}

export function ServersPanel({
  overview,
  onChanged,
}: {
  overview: DiscordAdminOverview;
  onChanged: () => Promise<void> | void;
}) {
  // "new" = blank link form; a guild id = editing that row's link.
  const [editing, setEditing] = useState<string | null>(null);
  const [removing, setRemoving] = useState<string | null>(null);
  const [removed, setRemoved] = useState<RemoveResult | null>(null);
  const fallback = overview.limits.unlinked_guild_org_id;
  const fallbackName = overview.limits.unlinked_guild_org_name || fallback;
  const max = overview.limits.guild_max_streams;

  const done = async () => {
    setEditing(null);
    await onChanged();
  };

  return (
    <Panel
      title="Linked Discord servers"
      description="Every bot command in a server is scoped to the organization it is linked to."
      action={<Button size="sm" onClick={() => setEditing(editing === "new" ? null : "new")}>+ Link a server</Button>}
      note={
        fallback ? (
          <>
            <b className="text-ink">Unlinked servers act for {fallbackName}</b> (DISCORD_UNLINKED_GUILD_ORG_ID). Any
            server the DRB server bot is invited to can use that org&apos;s systems until it is linked here (a radio
            bot alone never puts an unlinked server here). Set the variable to an empty string once every real server
            is linked.
          </>
        ) : (
          <>Unlinked servers can&apos;t use radio commands until they are linked here.</>
        )
      }
    >
      {editing === "new" && <LinkForm overview={overview} onDone={done} onCancel={() => setEditing(null)} />}
      {removed && (
        <div className="px-4 py-3 border-b border-line text-xs text-ink-2">
          Removed {removed.guild}: {removed.streams} radio channel{removed.streams === 1 ? "" : "s"} deleted.
          {removed.bots.length > 0 && (
            <>
              {" "}Radio bots:{" "}
              {removed.bots.map((b) => `${b.name} ${b.left ? "left" : `did not leave (${b.error ?? "unknown error"})`}`).join("; ")}.
            </>
          )}{" "}
          The DRB server bot, if it was there, stays in that Discord server until someone kicks it.
          <button className="ml-3 text-accent hover:underline" onClick={() => setRemoved(null)}>Dismiss</button>
        </div>
      )}
      {overview.guilds.length === 0 ? (
        <p className="px-4 py-6 text-sm text-ink-muted">
          No Discord servers yet. Link one here, or an organization owner connects one under Settings → Organization.
        </p>
      ) : (
        <Table head={["Server", "Acts for", "Bots", "Radio channels", "Linked", "Status", ""]}>
          {overview.guilds.flatMap((g) => {
            const row = (
              <tr key={g.guild_id}>
                <td className={TD}>
                  <b>{guildLabel(g)}</b>
                  <div className={`${DIM} font-mono`}>{g.guild_id}</div>
                </td>
                <td className={TD}>
                  {g.acting_org_name || g.acting_org_id || <span className={DIM}>nobody</span>}
                  {!g.linked && g.acting_org_id && <div className={DIM}>fallback, not linked</div>}
                </td>
                <td className={TD}>
                  <BotsCell guild={g} />
                </td>
                <td className={TD}>
                  {g.live_streams} / {max}
                </td>
                <td className={TD}>{g.linked ? fmtWhen(g.linked_at) : <span className={DIM}>—</span>}</td>
                <td className={TD}>
                  {g.linked ? (
                    <Status health="ok">Linked</Status>
                  ) : g.acting_org_id ? (
                    <Status health="warn">Unlinked · fallback org</Status>
                  ) : (
                    <Status health="bad">Unlinked</Status>
                  )}
                </td>
                <td className={`${TD} text-right whitespace-nowrap`}>
                  <Button
                    size="sm"
                    variant="secondary"
                    onClick={() => {
                      setRemoving(null);
                      setEditing(editing === g.guild_id ? null : g.guild_id);
                    }}
                  >
                    {g.linked ? "Change org" : "Link"}
                  </Button>
                  <Button
                    size="sm"
                    variant="danger"
                    className="ml-1"
                    onClick={() => {
                      setEditing(null);
                      setRemoved(null);
                      setRemoving(removing === g.guild_id ? null : g.guild_id);
                    }}
                  >
                    Remove
                  </Button>
                </td>
              </tr>
            );
            if (removing === g.guild_id) {
              return [
                row,
                <tr key={`${g.guild_id}-remove`}>
                  <td colSpan={7} className="p-0 border-b border-line">
                    <RemoveForm
                      guild={g}
                      onCancel={() => setRemoving(null)}
                      onDone={async (r) => {
                        setRemoving(null);
                        setRemoved(r);
                        await onChanged();
                      }}
                    />
                  </td>
                </tr>,
              ];
            }
            if (editing !== g.guild_id) return [row];
            return [
              row,
              <tr key={`${g.guild_id}-edit`}>
                <td colSpan={7} className="p-0 border-b border-line">
                  <LinkForm overview={overview} guild={g} onDone={done} onCancel={() => setEditing(null)} />
                </td>
              </tr>,
            ];
          })}
        </Table>
      )}
    </Panel>
  );
}