// [nexus] Phone access onboarding step — Telegram bridge with BotFather guided setup
import { useState } from "react";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { cn } from "@/lib/utils";

interface TelegramStepProps {
  onNext: () => void;
  onBack: () => void;
}

export function TelegramStep({ onNext, onBack }: TelegramStepProps) {
  const [token, setToken] = useState("");
  const [validating, setValidating] = useState(false);
  const [botUsername, setBotUsername] = useState<string | null>(null);
  const [error, setError] = useState<string | null>(null);

  async function handleValidate() {
    if (!token.trim()) return;
    setValidating(true);
    setError(null);
    setBotUsername(null);

    try {
      const res = await fetch("/api/telegram/token", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ token: token.trim() }),
      });

      if (res.ok) {
        const data = await res.json();
        setBotUsername(data.botUsername ?? data.bot_username ?? null);
      } else {
        let msg = "Invalid token";
        try {
          const data = await res.json();
          if (data?.error) msg = data.error;
        } catch {
          // ignore parse errors
        }
        setError(msg);
      }
    } catch {
      setError("Could not reach the server. Check your connection and try again.");
    } finally {
      setValidating(false);
    }
  }

  return (
    <div className="flex flex-col gap-6">
      {/* Telegram as current option */}
      <div className="flex flex-col gap-4">
        <p className="text-sm font-medium">Telegram Bot</p>

        {/* BotFather instructions */}
        <div className="flex flex-col gap-3">
          <p className="text-sm text-muted-foreground">Set up your bot in 4 steps:</p>
          <ol className="flex flex-col gap-3 list-none pl-0">
            {[
              <>Open Telegram and search for <span className="font-mono text-xs bg-muted px-1.5 py-0.5 rounded">@BotFather</span></>,
              <>Send <span className="font-mono text-xs bg-muted px-1.5 py-0.5 rounded">/newbot</span> and follow the prompts to create a bot</>,
              <>Copy the bot token -- it looks like <span className="font-mono text-xs bg-muted px-1.5 py-0.5 rounded">123456:ABC-DEF...</span></>,
              "Paste the token below and click Validate",
            ].map((instruction, i) => (
              <li key={i} className="flex items-start gap-3 text-sm text-muted-foreground">
                <span className="flex h-6 w-6 shrink-0 items-center justify-center rounded-full bg-muted text-xs font-medium text-foreground">
                  {i + 1}
                </span>
                <span className="mt-0.5">{instruction}</span>
              </li>
            ))}
          </ol>
        </div>

        {/* Token input */}
        <div className="flex flex-col gap-2">
          <label htmlFor="telegram-token" className="text-sm font-medium leading-none">
            Bot token
          </label>
          <Input
            id="telegram-token"
            type="text"
            placeholder="Paste bot token here"
            value={token}
            onChange={(e) => {
              setToken(e.target.value);
              setBotUsername(null);
              setError(null);
            }}
            disabled={validating}
            autoComplete="off"
            className="font-mono text-sm"
          />

          {/* Success state */}
          {botUsername && (
            <p className={cn("text-sm", "text-[color:var(--chart-2)]")}>
              Connected to @{botUsername}
            </p>
          )}

          {/* Error state */}
          {error && (
            <p className="text-sm text-destructive bg-destructive/10 rounded-md px-3 py-2">
              {error}
            </p>
          )}
        </div>
      </div>

      {/* Future bridges note */}
      <p className="text-sm text-muted-foreground">
        Discord and WhatsApp bridges coming in a future update.
      </p>

      {/* Actions */}
      <div className="flex flex-col gap-2">
        <Button
          type="button"
          onClick={handleValidate}
          disabled={!token.trim() || validating}
          variant="outline"
          className="w-full"
        >
          {validating ? "Validating..." : "Validate Token"}
        </Button>

        <Button
          type="button"
          onClick={onNext}
          disabled={!botUsername}
          className="w-full"
        >
          Continue
        </Button>

        <Button
          type="button"
          variant="ghost"
          onClick={onNext}
          className="w-full"
        >
          Skip
        </Button>

        <Button
          type="button"
          variant="ghost"
          onClick={onBack}
          className="w-full"
        >
          Back
        </Button>
      </div>
    </div>
  );
}