"use client";

import { useState, useMemo, useEffect } from "react";
import { useRouter } from "next/navigation";
import AuthGuard from "@/components/auth-guard";
import NavBar from "@/components/nav-bar";
import { useApi } from "@/lib/use-api";

type KnowledgeType = "TEXT" | "WEB" | "YOUTUBE";

interface ModelInfo {
  id: string;
  name: string;
  vendor: string;
}

function extractYouTubeVideoId(url: string): string | null {
  try {
    const u = new URL(url);
    if (u.hostname === "youtu.be") return u.pathname.slice(1);
    if (u.hostname.includes("youtube.com")) return u.searchParams.get("v");
  } catch {
    // invalid URL
  }
  return null;
}

export default function KnowledgeAddPage() {
  const { request } = useApi();
  const router = useRouter();

  const [type, setType] = useState<KnowledgeType>("TEXT");
  const [title, setTitle] = useState("");
  const [url, setUrl] = useState("");
  const [rawText, setRawText] = useState("");
  const [modelId, setModelId] = useState("");
  const [models, setModels] = useState<ModelInfo[]>([]);
  const [submitting, setSubmitting] = useState(false);
  const [fetchingTranscript, setFetchingTranscript] = useState(false);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    request<{ models: ModelInfo[]; defaultModel: string; configured: boolean }>({
      method: "GET",
      url: "/api/models",
    }).then((data) => {
      setModels(data.models);
      setModelId(data.defaultModel);
    }).catch((err) => {
      console.error("Failed to load models:", err);
    });
  }, []);

  const videoId = useMemo(() => (type === "YOUTUBE" ? extractYouTubeVideoId(url) : null), [type, url]);

  const canFetchTranscript = type === "YOUTUBE" && videoId !== null && !fetchingTranscript;

  const handleFetchTranscript = async () => {
    if (!canFetchTranscript) return;
    setError(null);
    setFetchingTranscript(true);
    try {
      const data = await request<{ transcript?: string; error?: string }>({
        method: "GET",
        url: `/api/knowledge/youtube-transcript?url=${encodeURIComponent(url.trim())}`,
      });
      if (data.error) {
        setError(data.error);
      } else if (data.transcript) {
        setRawText(data.transcript);
      }
    } catch (err: unknown) {
      const msg = err instanceof Error ? err.message : "트랜스크립트를 가져올 수 없습니다";
      setError(msg);
    } finally {
      setFetchingTranscript(false);
    }
  };

  const canSubmit =
    !submitting &&
    ((type === "TEXT" && rawText.trim().length > 0) ||
      (type === "WEB" && url.trim().length > 0) ||
      (type === "YOUTUBE" && url.trim().length > 0 && rawText.trim().length > 0));

  const handleSubmit = async () => {
    setError(null);
    setSubmitting(true);
    try {
      await request({
        method: "POST",
        url: "/api/knowledge/ingest",
        data: {
          type,
          title: title.trim() || null,
          url: type !== "TEXT" ? url.trim() : null,
          rawText: type !== "WEB" ? rawText.trim() : null,
          modelId: modelId || null,
        },
      });
      router.push("/knowledge");
    } catch (err: unknown) {
      const msg = err instanceof Error ? err.message : "Failed to submit";
      setError(msg);
      setSubmitting(false);
    }
  };

  const types: { value: KnowledgeType; label: string }[] = [
    { value: "TEXT", label: "Text" },
    { value: "WEB", label: "Web" },
    { value: "YOUTUBE", label: "YouTube" },
  ];

  // 벤더별 그룹화
  const groupedModels = useMemo(() => {
    const groups: Record<string, ModelInfo[]> = {};
    for (const m of models) {
      if (!groups[m.vendor]) groups[m.vendor] = [];
      groups[m.vendor].push(m);
    }
    return groups;
  }, [models]);

  return (
    <AuthGuard>
      <NavBar />
      <main className="max-w-3xl mx-auto px-4 py-8">
        <h1 className="text-2xl font-bold mb-6">Add Knowledge</h1>

        {/* Type Tabs */}
        <div className="flex gap-2 mb-6">
          {types.map((t) => (
            <button
              key={t.value}
              onClick={() => {
                setType(t.value);
                setUrl("");
                setRawText("");
                setError(null);
              }}
              className={`px-4 py-2 rounded-lg text-sm font-medium transition-colors ${
                type === t.value
                  ? "bg-[var(--color-primary)] text-white"
                  : "bg-[var(--color-bg-card)] text-[var(--color-text-muted)] border border-[var(--color-border)] hover:border-[var(--color-primary)]"
              }`}
            >
              {t.label}
            </button>
          ))}
        </div>

        <div className="space-y-4">
          {/* Title */}
          <div>
            <label className="block text-sm text-[var(--color-text-muted)] mb-1">
              제목 (비워두면 AI가 자동 생성)
            </label>
            <input
              type="text"
              value={title}
              onChange={(e) => setTitle(e.target.value)}
              placeholder="비워두면 내용 기반으로 자동 생성"
              className="w-full px-3 py-2 rounded-lg bg-[var(--color-bg-card)] border border-[var(--color-border)] focus:border-[var(--color-primary)] focus:outline-none"
            />
          </div>

          {/* URL (WEB / YOUTUBE) */}
          {type !== "TEXT" && (
            <div>
              <label className="block text-sm text-[var(--color-text-muted)] mb-1">URL</label>
              <input
                type="url"
                value={url}
                onChange={(e) => setUrl(e.target.value)}
                placeholder={type === "YOUTUBE" ? "https://www.youtube.com/watch?v=..." : "https://example.com/article"}
                className="w-full px-3 py-2 rounded-lg bg-[var(--color-bg-card)] border border-[var(--color-border)] focus:border-[var(--color-primary)] focus:outline-none"
              />
            </div>
          )}

          {/* YouTube Embed */}
          {type === "YOUTUBE" && videoId && (
            <div className="rounded-lg overflow-hidden border border-[var(--color-border)]">
              <div className="relative w-full" style={{ paddingBottom: "56.25%" }}>
                <iframe
                  className="absolute inset-0 w-full h-full"
                  src={`https://www.youtube.com/embed/${videoId}`}
                  allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
                  allowFullScreen
                />
              </div>
            </div>
          )}

          {/* Fetch Transcript Button (YOUTUBE) */}
          {type === "YOUTUBE" && videoId && (
            <button
              onClick={handleFetchTranscript}
              disabled={!canFetchTranscript}
              className="w-full px-4 py-2 bg-[var(--color-bg-card)] border border-[var(--color-border)] hover:border-[var(--color-primary)] disabled:opacity-40 disabled:cursor-not-allowed rounded-lg transition-colors text-sm font-medium"
            >
              {fetchingTranscript ? "트랜스크립트 가져오는 중..." : "트랜스크립트 자동 가져오기"}
            </button>
          )}

          {/* Text Input (TEXT / YOUTUBE) */}
          {type !== "WEB" && (
            <div>
              <label className="block text-sm text-[var(--color-text-muted)] mb-1">
                {type === "YOUTUBE" ? "Transcript / 내용 붙여넣기" : "텍스트 입력"}
              </label>
              <textarea
                value={rawText}
                onChange={(e) => setRawText(e.target.value)}
                placeholder={
                  type === "YOUTUBE"
                    ? "영상의 transcript나 내용을 여기에 붙여넣으세요..."
                    : "텍스트를 직접 입력하세요..."
                }
                rows={12}
                className="w-full px-3 py-2 rounded-lg bg-[var(--color-bg-card)] border border-[var(--color-border)] focus:border-[var(--color-primary)] focus:outline-none resize-y"
              />
            </div>
          )}

          {/* Model Selection */}
          {models.length > 0 && (
            <div>
              <label className="block text-sm text-[var(--color-text-muted)] mb-1">
                AI 모델
              </label>
              <select
                value={modelId}
                onChange={(e) => setModelId(e.target.value)}
                className="w-full px-3 py-2 rounded-lg bg-[var(--color-bg-card)] border border-[var(--color-border)] focus:border-[var(--color-primary)] focus:outline-none"
              >
                {Object.entries(groupedModels).map(([vendor, vendorModels]) => (
                  <optgroup key={vendor} label={vendor}>
                    {vendorModels.map((m) => (
                      <option key={m.id} value={m.id}>
                        {m.name}
                      </option>
                    ))}
                  </optgroup>
                ))}
              </select>
            </div>
          )}

          {/* Error */}
          {error && (
            <p className="text-sm text-red-400">{error}</p>
          )}

          {/* Actions */}
          <div className="flex gap-3 pt-2">
            <button
              onClick={handleSubmit}
              disabled={!canSubmit}
              className="px-6 py-2 bg-[var(--color-primary)] hover:bg-[var(--color-primary-hover)] disabled:opacity-40 disabled:cursor-not-allowed rounded-lg transition-colors"
            >
              {submitting ? "처리 중..." : "추가"}
            </button>
            <button
              onClick={() => router.push("/knowledge")}
              className="px-6 py-2 bg-[var(--color-bg-card)] border border-[var(--color-border)] hover:border-[var(--color-primary)] rounded-lg transition-colors"
            >
              취소
            </button>
          </div>
        </div>
      </main>
    </AuthGuard>
  );
}