import { useState, useEffect, type ReactNode } from 'react';
import {
  Plus,
  X,
  Radio,
  Inbox,
  HardDrive,
  Ban,
  ArrowDownToLine,
  ArrowUpFromLine,
  type LucideIcon,
} from 'lucide-react';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from '@/components/ui/tooltip';
import { useAppContext } from '@/hooks/useAppContext';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { useNostrPublish } from '@/hooks/useNostrPublish';
import { useToast } from '@/hooks/useToast';
import { useRelayStatus } from '@/hooks/useRelayStatus';
import { isLocalRelay } from '@/lib/relayProbe';
import { cn } from '@/lib/utils';
import { useTranslation } from '@/contexts/language';

interface Relay {
  url: string;
  read: boolean;
  write: boolean;
}

type Tone = 'neutral' | 'cyan' | 'lime' | 'red';

const TONE_ICON: Record<Tone, string> = {
  neutral: 'bg-white/[0.06] text-gray-300',
  cyan: 'bg-cyan-500/12 text-cyan-300',
  lime: 'bg-[#ccff00]/12 text-[#ccff00]',
  red: 'bg-red-500/12 text-red-400',
};

const TONE_CHIP: Record<Tone, string> = {
  neutral: 'border-white/10 bg-white/[0.04] text-gray-300',
  cyan: 'border-cyan-500/25 bg-cyan-500/10 text-cyan-300',
  lime: 'border-[#ccff00]/25 bg-[#ccff00]/10 text-[#ccff00]',
  red: 'border-red-500/30 bg-red-500/10 text-red-400',
};

const TONE_ADD: Record<Tone, string> = {
  neutral: 'border-white/15',
  cyan: 'border-cyan-500/30 text-cyan-300 hover:bg-cyan-500/10',
  lime: 'border-[#ccff00]/30 text-[#ccff00] hover:bg-[#ccff00]/10',
  red: 'border-red-500/30 text-red-400 hover:bg-red-500/10',
};

/** Display-only host, e.g. `wss://relay.example.com/x` → `relay.example.com/x`. */
function formatRelayUrl(url: string): string {
  try {
    const parsed = new URL(url);
    if (parsed.protocol === 'wss:' || parsed.protocol === 'ws:') {
      return parsed.host + (parsed.pathname === '/' ? '' : parsed.pathname);
    }
    return parsed.href;
  } catch {
    return url;
  }
}

/** Live connection dot — green pulsing when connected, breathing while connecting, grey offline. */
function RelayStatusDot({ url }: { url: string }) {
  const { status, reason } = useRelayStatus(url);
  const { t } = useTranslation();

  const label =
    status === 'connected' ? t('settingsUi.relayList.connected') : status === 'connecting' ? t('settingsUi.relayList.connecting') : t('settingsUi.relayList.offline');

  return (
    <TooltipProvider>
      <Tooltip>
        <TooltipTrigger asChild>
          <span className="relative flex h-4 w-4 flex-shrink-0 items-center justify-center">
            <span
              aria-hidden="true"
              className={cn(
                'h-2 w-2 rounded-full motion-reduce:animate-none',
                status === 'connected' && 'bg-[#ccff00] animate-status-live',
                status === 'connecting' && 'bg-[#ccff00]/70 animate-status-breathe',
                status === 'offline' && 'bg-white/25',
              )}
            />
            <span className="sr-only">{label}</span>
          </span>
        </TooltipTrigger>
        <TooltipContent side="left">
          <p className="text-xs font-medium">{label}</p>
          {reason && status === 'offline' && (
            <p className="mt-0.5 font-mono text-[10px] text-muted-foreground">{reason}</p>
          )}
        </TooltipContent>
      </Tooltip>
    </TooltipProvider>
  );
}

/** A titled, tinted card grouping one category of relays. */
function Section({
  icon: Icon,
  title,
  count,
  description,
  tone = 'neutral',
  children,
}: {
  icon: LucideIcon;
  title: string;
  count?: number;
  description?: string;
  tone?: Tone;
  children: ReactNode;
}) {
  return (
    <section className="space-y-3 rounded-2xl border border-white/8 bg-white/[0.02] p-4">
      <div className="flex items-start gap-3">
        <div className={cn('mt-0.5 flex h-8 w-8 flex-shrink-0 items-center justify-center rounded-xl', TONE_ICON[tone])}>
          <Icon className="h-4 w-4" />
        </div>
        <div className="min-w-0 flex-1">
          <div className="flex items-center gap-2">
            <h3 className="text-sm font-bold text-white">{title}</h3>
            {count !== undefined && count > 0 && (
              <span className="rounded-full bg-white/[0.08] px-1.5 py-0.5 text-[10px] font-bold text-muted-foreground">
                {count}
              </span>
            )}
          </div>
          {description && (
            <p className="mt-0.5 text-[11px] leading-snug text-muted-foreground">{description}</p>
          )}
        </div>
      </div>
      <div className="space-y-2">{children}</div>
    </section>
  );
}

/** Inline, clickable Read/Write chip. */
function ToggleChip({
  active,
  onClick,
  icon: Icon,
  label,
  hint,
}: {
  active: boolean;
  onClick: () => void;
  icon: LucideIcon;
  label: string;
  hint: string;
}) {
  return (
    <TooltipProvider>
      <Tooltip>
        <TooltipTrigger asChild>
          <button
            type="button"
            onClick={onClick}
            aria-pressed={active}
            className={cn(
              'inline-flex items-center gap-1 rounded-full border px-2 py-0.5 text-[10px] font-bold transition-colors',
              active
                ? 'border-[#ccff00]/30 bg-[#ccff00]/12 text-[#ccff00]'
                : 'border-white/8 bg-white/5 text-white/35 hover:text-white/70',
            )}
          >
            <Icon className="h-2.5 w-2.5" />
            {label}
          </button>
        </TooltipTrigger>
        <TooltipContent className="max-w-xs">
          <p className="text-xs">{hint}</p>
        </TooltipContent>
      </Tooltip>
    </TooltipProvider>
  );
}

/** Removable URL pills. */
function UrlChips({ urls, tone, onRemove }: { urls: string[]; tone: Tone; onRemove: (url: string) => void }) {
  const { t } = useTranslation();
  if (urls.length === 0) return null;
  return (
    <div className="flex flex-wrap gap-1.5">
      {urls.map((url) => (
        <span
          key={url}
          className={cn('inline-flex items-center gap-1 rounded-full border px-2 py-0.5 font-mono text-[11px]', TONE_CHIP[tone])}
        >
          {formatRelayUrl(url)}
          <button
            type="button"
            onClick={() => onRemove(url)}
            className="opacity-60 transition-opacity hover:opacity-100"
            aria-label={t('settingsUi.relayList.removeUrl', { url })}
          >
            <X className="h-3 w-3" />
          </button>
        </span>
      ))}
    </div>
  );
}

/** Input + Add button for a category. */
function AddUrlRow({
  value,
  onChange,
  onAdd,
  placeholder,
  tone = 'neutral',
  primary = false,
}: {
  value: string;
  onChange: (v: string) => void;
  onAdd: () => void;
  placeholder: string;
  tone?: Tone;
  primary?: boolean;
}) {
  const { t } = useTranslation();
  return (
    <div className="flex gap-2">
      <Input
        value={value}
        onChange={(e) => onChange(e.target.value)}
        onKeyDown={(e) => {
          if (e.key === 'Enter') onAdd();
        }}
        placeholder={placeholder}
        className="h-9 rounded-xl border-white/8 bg-white/[0.03] font-mono text-sm focus-visible:ring-[#ccff00]/40"
      />
      <Button
        type="button"
        variant={primary ? 'default' : 'outline'}
        size="sm"
        onClick={onAdd}
        disabled={!value.trim()}
        className={cn(
          'h-9 flex-shrink-0 gap-1.5 rounded-xl font-bold',
          primary ? 'bg-[#ccff00] text-black hover:bg-[#ccff00]/90' : TONE_ADD[tone],
        )}
      >
        <Plus className="h-4 w-4" />
        {t('settingsUi.relayList.add')}
      </Button>
    </div>
  );
}

export function RelayListManager() {
  const { config, updateConfig } = useAppContext();
  const { user } = useCurrentUser();
  const { mutate: publishEvent } = useNostrPublish();
  const { toast } = useToast();
  const { t } = useTranslation();

  const [relays, setRelays] = useState<Relay[]>(config.relayMetadata.relays);
  const [newRelayUrl, setNewRelayUrl] = useState('');
  const [newLocalUrl, setNewLocalUrl] = useState('');
  const [newBlockedUrl, setNewBlockedUrl] = useState('');
  const [newDmUrl, setNewDmUrl] = useState('');

  const localRelays = config.relayMetadata.localRelays ?? [];
  const blockedRelays = config.relayMetadata.blockedRelays ?? [];
  const dmRelays = config.relayMetadata.dmRelays ?? [];

  // Sync local state with config when it changes (e.g., from NostrProvider sync)
  useEffect(() => {
    setRelays(config.relayMetadata.relays);
  }, [config.relayMetadata.relays]);

  const normalizeRelayUrl = (url: string): string => {
    url = url.trim();
    try {
      return new URL(url).toString();
    } catch {
      try {
        return new URL(`wss://${url}`).toString();
      } catch {
        return url;
      }
    }
  };

  const isValidRelayUrl = (url: string): boolean => {
    const trimmed = url.trim();
    if (!trimmed) return false;
    try {
      new URL(normalizeRelayUrl(trimmed));
      return true;
    } catch {
      return false;
    }
  };

  // ── NIP-65 list (published as kind 10002) ─────────────────────────────────
  const saveRelays = (newRelays: Relay[]) => {
    const now = Math.floor(Date.now() / 1000);
    updateConfig((current) => ({
      ...current,
      relayMetadata: {
        ...(current.relayMetadata ?? { relays: [], updatedAt: 0 }),
        relays: newRelays,
        updatedAt: now,
      },
    }));
    if (user) publishNIP65RelayList(newRelays);
  };

  const publishNIP65RelayList = (relayList: Relay[]) => {
    const tags = relayList
      .map((relay) => {
        if (relay.read && relay.write) return ['r', relay.url];
        if (relay.read) return ['r', relay.url, 'read'];
        if (relay.write) return ['r', relay.url, 'write'];
        return null;
      })
      .filter((tag): tag is string[] => tag !== null);

    publishEvent(
      { kind: 10002, content: '', tags },
      {
        onSuccess: () =>
          toast({ title: t('settingsUi.relayList.publishedTitle'), description: t('settingsUi.relayList.publishedDesc') }),
        onError: (error) => {
          console.error('Failed to publish relay list:', error);
          toast({ title: t('settingsUi.relayList.publishFailedTitle'), variant: 'destructive' });
        },
      },
    );
  };

  const handleAddRelay = () => {
    if (!isValidRelayUrl(newRelayUrl)) {
      toast({
        title: t('settingsUi.relayList.invalidUrlTitle'),
        description: t('settingsUi.relayList.invalidUrlDesc'),
        variant: 'destructive',
      });
      return;
    }
    const normalized = normalizeRelayUrl(newRelayUrl);
    if (relays.some((r) => r.url === normalized)) {
      toast({ title: t('settingsUi.relayList.alreadyInList'), variant: 'destructive' });
      return;
    }
    const newRelays = [...relays, { url: normalized, read: true, write: true }];
    setRelays(newRelays);
    setNewRelayUrl('');
    saveRelays(newRelays);
  };

  const handleRemoveRelay = (url: string) => {
    const newRelays = relays.filter((r) => r.url !== url);
    setRelays(newRelays);
    saveRelays(newRelays);
  };

  const handleToggleRead = (url: string) => {
    const relay = relays.find((r) => r.url === url);
    if (!relay) return;
    if (relay.read && !relay.write) {
      toast({
        title: t('settingsUi.relayList.keepReadWriteTitle'),
        description: t('settingsUi.relayList.keepReadWriteDesc'),
        variant: 'destructive',
      });
      return;
    }
    const newRelays = relays.map((r) => (r.url === url ? { ...r, read: !r.read } : r));
    setRelays(newRelays);
    saveRelays(newRelays);
  };

  const handleToggleWrite = (url: string) => {
    const relay = relays.find((r) => r.url === url);
    if (!relay) return;
    if (!relay.read && relay.write) {
      toast({
        title: t('settingsUi.relayList.keepReadWriteTitle'),
        description: t('settingsUi.relayList.keepReadWriteDesc'),
        variant: 'destructive',
      });
      return;
    }
    const newRelays = relays.map((r) => (r.url === url ? { ...r, write: !r.write } : r));
    setRelays(newRelays);
    saveRelays(newRelays);
  };

  // ── Local / Blocked (app-only, never published) ───────────────────────────
  const updateCategory = (key: 'localRelays' | 'blockedRelays', list: string[]) => {
    updateConfig((c) => ({
      ...c,
      relayMetadata: { ...(c.relayMetadata ?? { relays: [], updatedAt: 0 }), [key]: list },
    }));
  };

  const addCategoryRelay = (key: 'localRelays' | 'blockedRelays', value: string, reset: () => void) => {
    if (!isValidRelayUrl(value)) {
      toast({ title: t('settingsUi.relayList.invalidUrlTitle'), variant: 'destructive' });
      return;
    }
    const normalized = normalizeRelayUrl(value);
    const existing = config.relayMetadata[key] ?? [];
    if (existing.includes(normalized)) {
      toast({ title: t('settingsUi.relayList.alreadyInThisList'), variant: 'destructive' });
      return;
    }
    updateCategory(key, [...existing, normalized]);
    reset();
  };

  const removeCategoryRelay = (key: 'localRelays' | 'blockedRelays', url: string) => {
    updateCategory(key, (config.relayMetadata[key] ?? []).filter((u) => u !== url));
  };

  // ── DM relays (kind 10050, published) ─────────────────────────────────────
  const publishDmRelayList = (urls: string[]) => {
    if (!user) return;
    publishEvent(
      { kind: 10050, content: '', tags: urls.map((url) => ['relay', url]) },
      {
        onSuccess: () => toast({ title: t('settingsUi.relayList.dmPublishedTitle'), description: t('settingsUi.relayList.dmPublishedDesc') }),
        onError: (error) => {
          console.error('Failed to publish DM relay list:', error);
          toast({ title: t('settingsUi.relayList.dmPublishFailedTitle'), variant: 'destructive' });
        },
      },
    );
  };

  const setDmRelays = (urls: string[], publish = true) => {
    updateConfig((c) => ({
      ...c,
      relayMetadata: { ...(c.relayMetadata ?? { relays: [], updatedAt: 0 }), dmRelays: urls },
    }));
    if (publish) publishDmRelayList(urls);
  };

  const addDmRelay = () => {
    if (!isValidRelayUrl(newDmUrl)) {
      toast({ title: t('settingsUi.relayList.invalidUrlTitle'), variant: 'destructive' });
      return;
    }
    const normalized = normalizeRelayUrl(newDmUrl);
    if (dmRelays.includes(normalized)) {
      toast({ title: t('settingsUi.relayList.alreadyInThisList'), variant: 'destructive' });
      return;
    }
    setDmRelays([...dmRelays, normalized]);
    setNewDmUrl('');
  };

  return (
    <div className="space-y-4">
      {/* NIP-65 */}
      <Section
        icon={Radio}
        title={t('settingsUi.relayList.nip65Title')}
        count={relays.length}
        tone="lime"
        description={
          user
            ? t('settingsUi.relayList.nip65DescUser')
            : t('settingsUi.relayList.nip65DescLoggedOut')
        }
      >
        {relays.length === 0 ? (
          <p className="rounded-xl border border-dashed border-white/10 px-3 py-4 text-center text-xs text-muted-foreground">
            {t('settingsUi.relayList.noRelays')}
          </p>
        ) : (
          relays.map((relay) => (
            <div
              key={relay.url}
              className="flex items-center gap-3 rounded-xl border border-white/8 bg-white/[0.03] p-3 transition-colors hover:border-white/12"
            >
              <RelayStatusDot url={relay.url} />
              <div className="min-w-0 flex-1">
                <div className="flex items-center gap-2">
                  <span className="truncate font-mono text-sm text-white" title={relay.url}>
                    {formatRelayUrl(relay.url)}
                  </span>
                  {isLocalRelay(relay.url) && (
                    <span className="flex-shrink-0 rounded-full border border-[#ccff00]/25 bg-[#ccff00]/12 px-1.5 py-0.5 text-[9px] font-black uppercase tracking-[0.15em] text-[#ccff00]">
                      {t('settingsUi.relayList.local')}
                    </span>
                  )}
                </div>
                <div className="mt-1.5 flex gap-1.5">
                  <ToggleChip
                    active={relay.read}
                    onClick={() => handleToggleRead(relay.url)}
                    icon={ArrowDownToLine}
                    label={t('settingsUi.relayList.read')}
                    hint={t('settingsUi.relayList.readHint')}
                  />
                  <ToggleChip
                    active={relay.write}
                    onClick={() => handleToggleWrite(relay.url)}
                    icon={ArrowUpFromLine}
                    label={t('settingsUi.relayList.write')}
                    hint={t('settingsUi.relayList.writeHint')}
                  />
                </div>
              </div>
              <Button
                variant="ghost"
                size="icon"
                onClick={() => handleRemoveRelay(relay.url)}
                disabled={relays.length <= 1}
                className="size-7 flex-shrink-0 rounded-full text-muted-foreground hover:bg-white/5 hover:text-destructive"
                aria-label={t('settingsUi.relayList.removeUrl', { url: relay.url })}
              >
                <X className="h-4 w-4" />
              </Button>
            </div>
          ))
        )}
        <AddUrlRow
          value={newRelayUrl}
          onChange={setNewRelayUrl}
          onAdd={handleAddRelay}
          placeholder="wss://relay.example.com"
          primary
        />
      </Section>

      {/* DM inbox */}
      <Section
        icon={Inbox}
        title={t('settingsUi.relayList.dmTitle')}
        count={dmRelays.length}
        tone="cyan"
        description={t('settingsUi.relayList.dmDesc')}
      >
        <UrlChips urls={dmRelays} tone="cyan" onRemove={(u) => setDmRelays(dmRelays.filter((x) => x !== u))} />
        <AddUrlRow
          value={newDmUrl}
          onChange={setNewDmUrl}
          onAdd={addDmRelay}
          placeholder="wss://inbox.relay.example"
          tone="cyan"
        />
      </Section>

      {/* Local */}
      <Section
        icon={HardDrive}
        title={t('settingsUi.relayList.localTitle')}
        count={localRelays.length}
        tone="lime"
        description={t('settingsUi.relayList.localDesc')}
      >
        <UrlChips urls={localRelays} tone="lime" onRemove={(u) => removeCategoryRelay('localRelays', u)} />
        <AddUrlRow
          value={newLocalUrl}
          onChange={setNewLocalUrl}
          onAdd={() => addCategoryRelay('localRelays', newLocalUrl, () => setNewLocalUrl(''))}
          placeholder="ws://192.168.1.10:7777"
          tone="lime"
        />
      </Section>

      {/* Blocked */}
      <Section
        icon={Ban}
        title={t('settingsUi.relayList.blockedTitle')}
        count={blockedRelays.length}
        tone="red"
        description={t('settingsUi.relayList.blockedDesc')}
      >
        <UrlChips urls={blockedRelays} tone="red" onRemove={(u) => removeCategoryRelay('blockedRelays', u)} />
        <AddUrlRow
          value={newBlockedUrl}
          onChange={setNewBlockedUrl}
          onAdd={() => addCategoryRelay('blockedRelays', newBlockedUrl, () => setNewBlockedUrl(''))}
          placeholder="wss://relay.example.com"
          tone="red"
        />
      </Section>
    </div>
  );
}