"use client";

import { useState, useEffect, useRef, useCallback } from "react";
import { useRouter, useParams } from "next/navigation";
import Image from "next/image";
import { Save, Loader2, Check, ArrowLeft, Upload, AlertCircle } from "lucide-react";
import { InputField, TextareaField, ListField, VictoryListField, VictoryItemListField } from "../../_components/FormField";
import { adminFetch } from "@/lib/csrf";
import type { RichListItem, VictoryItem } from "@/types/content";

function extractUsername(value: string): string {
  if (!value) return "";
  // Strip full URL → username
  const cleaned = value.replace(/^https?:\/\/(www\.)?instagram\.com\//, "").replace(/\/$/, "").replace(/^@/, "");
  return cleaned;
}

interface MemberForm {
  name: string;
  role: string;
  image: string;
  instagram: string;
  shortDescription: string;
  description: string;
  experience: string[];
  victories: VictoryItem[];
  education: RichListItem[];
}

export default function TeamMemberEditorPage() {
  const router = useRouter();
  const { id } = useParams<{ id: string }>();
  const isNew = id === "new";

  const [data, setData] = useState<MemberForm>({
    name: "",
    role: "",
    image: "/images/team/placeholder.webp",
    instagram: "",
    shortDescription: "",
    description: "",
    experience: [],
    victories: [],
    education: [],
  });
  const [loading, setLoading] = useState(!isNew);
  const [saving, setSaving] = useState(false);
  const [saved, setSaved] = useState(false);
  const [uploading, setUploading] = useState(false);

  // Instagram validation
  const [igStatus, setIgStatus] = useState<"idle" | "checking" | "valid" | "invalid">("idle");
  const igTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);

  const validateInstagram = useCallback((username: string) => {
    if (igTimerRef.current) clearTimeout(igTimerRef.current);
    if (!username) { setIgStatus("idle"); return; }
    setIgStatus("checking");
    igTimerRef.current = setTimeout(async () => {
      try {
        const res = await adminFetch(`/api/admin/validate-instagram?username=${encodeURIComponent(username)}`);
        const result = await res.json();
        setIgStatus(result.valid ? "valid" : "invalid");
      } catch {
        setIgStatus("idle");
      }
    }, 800);
  }, []);

  // Link validation for bio
  const [linkErrors, setLinkErrors] = useState<Record<string, string>>({});

  function validateUrl(url: string): boolean {
    if (!url) return true;
    try { new URL(url); return true; } catch { return false; }
  }

  // City validation for victories
  const [cityErrors, setCityErrors] = useState<Record<number, string>>({});
  const [citySuggestions, setCitySuggestions] = useState<{ index: number; items: string[] } | null>(null);
  const cityTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);

  const searchCity = useCallback((index: number, query: string) => {
    if (cityTimerRef.current) clearTimeout(cityTimerRef.current);
    if (!query || query.length < 2) { setCitySuggestions(null); return; }
    cityTimerRef.current = setTimeout(async () => {
      try {
        const res = await fetch(
          `https://nominatim.openstreetmap.org/search?q=${encodeURIComponent(query)}&format=json&addressdetails=1&limit=5&accept-language=ru`,
          { headers: { "User-Agent": "BlackheartAdmin/1.0" } }
        );
        const results = await res.json();
        const cities = results
          .map((r: Record<string, unknown>) => {
            const addr = r.address as Record<string, string> | undefined;
            const city = addr?.city || addr?.town || addr?.village || addr?.state || (r.name as string);
            const country = addr?.country || "";
            return country ? `${city}, ${country}` : city;
          })
          .filter((v: string, i: number, a: string[]) => a.indexOf(v) === i)
          .slice(0, 6);
        setCitySuggestions(cities.length > 0 ? { index, items: cities } : null);
        setCityErrors((prev) => { const n = { ...prev }; delete n[index]; return n; });
      } catch {
        setCitySuggestions(null);
      }
    }, 500);
  }, []);

  useEffect(() => {
    if (isNew) return;
    adminFetch(`/api/admin/team/${id}`)
      .then((r) => r.json())
      .then((member) => {
        const username = extractUsername(member.instagram || "");
        setData({
          name: member.name,
          role: member.role,
          image: member.image,
          instagram: username,
          shortDescription: member.shortDescription || "",
          description: member.description || "",
          experience: member.experience || [],
          victories: member.victories || [],
          education: member.education || [],
        });
        if (username) setIgStatus("valid"); // existing data is trusted
      })
      .finally(() => setLoading(false));
  }, [id, isNew]);

  const hasErrors = igStatus === "invalid" || Object.keys(linkErrors).length > 0 || Object.keys(cityErrors).length > 0;

  async function handleSave() {
    if (hasErrors) return;
    setSaving(true);
    setSaved(false);

    // Build instagram as full URL for storage if username is provided
    const payload = {
      ...data,
      instagram: data.instagram ? `https://instagram.com/${data.instagram}` : "",
    };

    if (isNew) {
      const res = await adminFetch("/api/admin/team", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(payload),
      });
      if (res.ok) {
        router.push("/admin/team");
      }
    } else {
      const res = await adminFetch(`/api/admin/team/${id}`, {
        method: "PUT",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(payload),
      });
      if (res.ok) {
        setSaved(true);
        setTimeout(() => setSaved(false), 2000);
      }
    }
    setSaving(false);
  }

  async function handleUpload(e: React.ChangeEvent<HTMLInputElement>) {
    const file = e.target.files?.[0];
    if (!file) return;

    setUploading(true);
    const formData = new FormData();
    formData.append("file", file);
    formData.append("folder", "team");

    try {
      const res = await adminFetch("/api/admin/upload", {
        method: "POST",
        body: formData,
      });
      const result = await res.json();
      if (result.path) {
        setData((prev) => ({ ...prev, image: result.path }));
      }
    } catch {
      // Upload failed silently
    } finally {
      setUploading(false);
    }
  }

  if (loading) {
    return (
      <div className="flex items-center gap-2 text-neutral-400">
        <Loader2 size={18} className="animate-spin" />
        Загрузка...
      </div>
    );
  }

  return (
    <div>
      <div className="flex items-center justify-between gap-4">
        <div className="flex items-center gap-3">
          <button
            onClick={() => router.push("/admin/team")}
            className="rounded-lg p-2 text-neutral-400 hover:text-white transition-colors"
          >
            <ArrowLeft size={20} />
          </button>
          <h1 className="text-2xl font-bold">
            {isNew ? "Новый участник" : data.name}
          </h1>
        </div>
        <button
          onClick={handleSave}
          disabled={saving || !data.name || !data.role || hasErrors || igStatus === "checking"}
          className="flex items-center gap-2 rounded-lg bg-gold px-4 py-2.5 text-sm font-medium text-black transition-opacity hover:opacity-90 disabled:opacity-50"
        >
          {saving ? (
            <Loader2 size={16} className="animate-spin" />
          ) : saved ? (
            <Check size={16} />
          ) : (
            <Save size={16} />
          )}
          {saving ? "Сохранение..." : saved ? "Сохранено!" : "Сохранить"}
        </button>
      </div>

      <div className="mt-6 grid gap-6 lg:grid-cols-[240px_1fr]">
        {/* Photo */}
        <div>
          <p className="text-sm text-neutral-400 mb-2">Фото</p>
          <div className="relative aspect-[3/4] w-full overflow-hidden rounded-xl border border-white/10">
            <Image
              src={data.image}
              alt={data.name || "Фото"}
              fill
              className="object-cover"
              sizes="240px"
            />
          </div>
          <label className="mt-3 flex cursor-pointer items-center justify-center gap-2 rounded-lg border border-dashed border-white/20 px-4 py-2.5 text-sm text-neutral-400 hover:text-white hover:border-white/40 transition-colors">
            {uploading ? (
              <Loader2 size={16} className="animate-spin" />
            ) : (
              <Upload size={16} />
            )}
            {uploading ? "Загрузка..." : "Загрузить фото"}
            <input
              type="file"
              accept="image/*"
              onChange={handleUpload}
              className="hidden"
            />
          </label>
        </div>

        {/* Fields */}
        <div className="space-y-4">
          <InputField
            label="Имя"
            value={data.name}
            onChange={(v) => setData({ ...data, name: v })}
          />
          <InputField
            label="Роль / Специализация"
            value={data.role}
            onChange={(v) => setData({ ...data, role: v })}
          />
          <div>
            <label className="block text-sm text-neutral-400 mb-1.5">Instagram</label>
            <div className="relative">
              <span className="absolute left-4 top-1/2 -translate-y-1/2 text-neutral-500 text-sm select-none">@</span>
              <input
                type="text"
                value={data.instagram}
                onChange={(e) => {
                  const username = extractUsername(e.target.value);
                  setData({ ...data, instagram: username });
                  validateInstagram(username);
                }}
                placeholder="username"
                className={`w-full rounded-lg border bg-neutral-800 pl-8 pr-10 py-2.5 text-white placeholder-neutral-500 outline-none transition-colors ${
                  igStatus === "invalid"
                    ? "border-red-500 focus:border-red-500"
                    : igStatus === "valid"
                    ? "border-green-500/50 focus:border-green-500"
                    : "border-white/10 focus:border-gold"
                }`}
              />
              <span className="absolute right-3 top-1/2 -translate-y-1/2">
                {igStatus === "checking" && <Loader2 size={14} className="animate-spin text-neutral-400" />}
                {igStatus === "valid" && <Check size={14} className="text-green-400" />}
                {igStatus === "invalid" && <AlertCircle size={14} className="text-red-400" />}
              </span>
            </div>
            {igStatus === "invalid" && (
              <p className="mt-1 text-xs text-red-400">Аккаунт не найден</p>
            )}
            {data.instagram && igStatus !== "invalid" && (
              <p className="mt-1 text-xs text-neutral-500">instagram.com/{data.instagram}</p>
            )}
          </div>
          <TextareaField
            label="Краткое описание (для карточки)"
            value={data.shortDescription}
            onChange={(v) => setData({ ...data, shortDescription: v })}
            rows={2}
            placeholder="1-2 предложения для карусели"
          />
          <TextareaField
            label="Полное описание (для страницы тренера)"
            value={data.description}
            onChange={(v) => setData({ ...data, description: v })}
            rows={6}
          />

          <div className="border-t border-white/5 pt-4 mt-4">
            <p className="text-sm font-medium text-neutral-300 mb-4">Биография</p>
            <div className="space-y-4">
              <ListField
                label="Опыт"
                items={data.experience}
                onChange={(items) => setData({ ...data, experience: items })}
                placeholder="Например: 10 лет в танцах"
              />
              <VictoryItemListField
                label="Достижения"
                items={data.victories}
                onChange={(items) => setData({ ...data, victories: items })}
                cityErrors={cityErrors}
                citySuggestions={citySuggestions}
                onCitySearch={searchCity}
                onCitySelect={(i, v) => {
                  const updated = data.victories.map((item, idx) => idx === i ? { ...item, location: v } : item);
                  setData({ ...data, victories: updated });
                  setCitySuggestions(null);
                  setCityErrors((prev) => { const n = { ...prev }; delete n[i]; return n; });
                }}
                onLinkValidate={(key, error) => {
                  setLinkErrors((prev) => {
                    if (error) return { ...prev, [key]: error };
                    const n = { ...prev }; delete n[key]; return n;
                  });
                }}
              />
              <VictoryListField
                label="Образование"
                items={data.education}
                onChange={(items) => setData({ ...data, education: items })}
                placeholder="Например: Сертификат IPSF"
                onLinkValidate={(key, error) => {
                  setLinkErrors((prev) => {
                    if (error) return { ...prev, [key]: error };
                    const n = { ...prev }; delete n[key]; return n;
                  });
                }}
              />
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}
