import React, { useState, useEffect } from 'react';
import { useApp } from '../../context/AppContext';
import { Cpu, Check, ArrowUp, ArrowDown, X, Plus, Sparkles, Save, Shield, Zap, AlertTriangle } from 'lucide-react';
import { getAiConfig } from '../../services/ai';
import confetti from 'canvas-confetti';

const RENK = {
  blue: 'bg-blue-50 text-blue-700 border-blue-200',
  indigo: 'bg-indigo-50 text-indigo-700 border-indigo-200',
  amber: 'bg-amber-50 text-amber-700 border-amber-200',
  slate: 'bg-slate-100 text-slate-700 border-slate-200',
  emerald: 'bg-emerald-50 text-emerald-700 border-emerald-200',
  orange: 'bg-orange-50 text-orange-700 border-orange-200'
};

const SIRA_ETIKET = ['Birincil (Primary)', '2. Yedek (Fallback)', '3. Yedek (Fallback)', '4. Yedek', '5. Yedek', '6. Yedek'];

export const AiModelSettings = () => {
  const { AI_MODEL_CATALOG, aiModelConfig, setAiModelConfig, getModelById } = useApp();
  const [saved, setSaved] = useState(false);
  const [cfg, setCfg] = useState(null);

  useEffect(() => { getAiConfig().then(setCfg); }, []);
  const aktifYol = cfg?.providers?.[0]?.yol;

  const chain = aiModelConfig.chain;
  const available = AI_MODEL_CATALOG.filter(m => !chain.includes(m.id));

  const update = (newChain) => {
    setAiModelConfig({ ...aiModelConfig, chain: newChain });
    setSaved(false);
  };

  const move = (idx, dir) => {
    const j = idx + dir;
    if (j < 0 || j >= chain.length) return;
    const next = [...chain];
    [next[idx], next[j]] = [next[j], next[idx]];
    update(next);
  };

  const setPrimary = (idx) => {
    if (idx === 0) return;
    const next = [...chain];
    const [item] = next.splice(idx, 1);
    next.unshift(item);
    update(next);
  };

  const remove = (idx) => {
    if (chain.length <= 1) return; // en az bir model kalmalı
    update(chain.filter((_, i) => i !== idx));
  };

  const add = (id) => update([...chain, id]);

  const handleSave = () => {
    // aiModelConfig zaten localStorage'a otomatik yazılıyor; buton kullanıcı geri bildirimi için
    setSaved(true);
    confetti({ particleCount: 60, spread: 70 });
    setTimeout(() => setSaved(false), 3500);
  };

  return (
    <div className="space-y-6 animate-fade-in">
      {/* Canlı AI durumu */}
      {cfg && (
        cfg.configured ? (
          <div className="bg-emerald-50 border border-emerald-200 rounded-xl p-4 flex gap-3">
            <Zap className="w-4 h-4 text-emerald-700 shrink-0 mt-0.5" />
            <div className="text-xs text-emerald-900 leading-relaxed">
              <strong>AI aktif</strong> — {cfg.providers.length} model kullanılabilir
              {aktifYol === 'openrouter' ? ' (OpenRouter üzerinden tek anahtarla)' : ' (doğrudan sağlayıcı anahtarlarıyla)'}.
              <div className="font-mono text-[11px] mt-1 text-emerald-800">
                {cfg.providers.map((p) => `${p.label}: ${p.model}`).join(' · ')}
              </div>
            </div>
          </div>
        ) : (
          <div className="bg-amber-50 border border-amber-200 rounded-xl p-4 flex gap-3">
            <AlertTriangle className="w-4 h-4 text-amber-700 shrink-0 mt-0.5" />
            <p className="text-xs text-amber-900 leading-relaxed">
              <strong>AI anahtarı yok.</strong> Sunucuya tek bir <code className="bg-amber-100 px-1 rounded">OPENROUTER_API_KEY</code> ekleyin —
              aşağıdaki tüm modeller bu tek anahtarla çalışır. Aşağıdaki sıralama yalnızca tercih kaydeder;
              çağrılar anahtar eklendiğinde başlar.
            </p>
          </div>
        )
      )}
      {/* Header */}
      <div className="bg-linear-to-r from-slate-900 via-indigo-950 to-blue-900 text-white p-6 rounded-2xl shadow-lg border border-indigo-800/40 flex items-center justify-between">
        <div className="flex items-center gap-3">
          <div className="w-12 h-12 rounded-2xl bg-indigo-600 text-white flex items-center justify-center font-black shadow-md">
            <Cpu className="w-6 h-6" />
          </div>
          <div>
            <h2 className="font-extrabold text-xl">Yapay Zeka Model Yönetimi</h2>
            <p className="text-xs text-indigo-200 mt-0.5">Şartname analizi ve AI özelliklerinde kullanılacak modeli ve yedek (fallback) sırasını belirleyin.</p>
          </div>
        </div>
        <button type="button"
          onClick={handleSave}
          className={`px-4 py-2.5 rounded-xl font-bold text-sm flex items-center gap-2 transition ${saved ? 'bg-emerald-500 text-white' : 'bg-white text-indigo-900 hover:bg-indigo-50'}`}
        >
          {saved ? <><Check className="w-4 h-4" /> Kaydedildi</> : <><Save className="w-4 h-4" /> Kaydet</>}
        </button>
      </div>

      {/* Aktif zincir */}
      <div className="bg-white p-6 rounded-2xl border border-slate-200 shadow-xs space-y-4">
        <div className="flex items-center justify-between border-b border-slate-100 pb-3">
          <div>
            <h3 className="font-extrabold text-sm text-slate-900 flex items-center gap-2">
              <Sparkles className="w-4 h-4 text-indigo-600" /> Aktif Model Sırası (Fallback Zinciri)
            </h3>
            <p className="text-xs text-slate-500">Birincil model yanıt vermezse sıradaki yedeğe otomatik geçilir. Zincirde olmasa bile <strong>Gemini Flash</strong> ücretli yedek olarak her zaman en sonda denenir; yalnız üsttekilerin hepsi başarısız olursa devreye girer.</p>
          </div>
        </div>

        <div className="space-y-3">
          {chain.map((id, idx) => {
            const m = getModelById(id);
            if (!m) return null;
            return (
              <div
                key={id}
                className={`flex items-center gap-4 p-4 rounded-xl border ${idx === 0 ? 'border-indigo-300 bg-indigo-50/40 ring-1 ring-indigo-200' : 'border-slate-200 bg-slate-50/60'}`}
              >
                <div className="flex flex-col items-center gap-1 w-8">
                  <button type="button" onClick={() => move(idx, -1)} disabled={idx === 0} className="text-slate-400 hover:text-indigo-600 disabled:opacity-30">
                    <ArrowUp className="w-4 h-4" />
                  </button>
                  <span className="text-xs font-black text-slate-400">{idx + 1}</span>
                  <button type="button" onClick={() => move(idx, 1)} disabled={idx === chain.length - 1} className="text-slate-400 hover:text-indigo-600 disabled:opacity-30">
                    <ArrowDown className="w-4 h-4" />
                  </button>
                </div>

                <div className="flex-1">
                  <div className="flex items-center gap-2 flex-wrap">
                    <span className="font-extrabold text-sm text-slate-900">{m.label}</span>
                    <span className={`text-[10px] font-bold px-2 py-0.5 rounded-md border ${RENK[m.renk] || RENK.slate}`}>{m.provider}</span>
                    {idx === 0 && (
                      <span className="text-[10px] font-black px-2 py-0.5 rounded-md bg-indigo-600 text-white flex items-center gap-1">
                        <Shield className="w-3 h-3" /> BİRİNCİL
                      </span>
                    )}
                  </div>
                  <div className="text-[11px] text-slate-500 font-mono mt-1">
                    <span className="text-slate-700 font-semibold">{m.or}</span>
                    <span className="text-slate-400"> · doğrudan: </span>{m.model}
                  </div>
                  <div className="text-[10px] text-slate-400 mt-0.5">{SIRA_ETIKET[idx] || `${idx + 1}. sırada`}</div>
                </div>

                <div className="flex items-center gap-2">
                  {idx !== 0 && (
                    <button type="button" onClick={() => setPrimary(idx)} className="text-[11px] font-bold text-indigo-600 hover:text-indigo-800 border border-indigo-200 rounded-lg px-2.5 py-1.5">
                      Birincil yap
                    </button>
                  )}
                  <button type="button" onClick={() => remove(idx)} disabled={chain.length <= 1} className="text-slate-400 hover:text-red-500 disabled:opacity-30 p-1.5">
                    <X className="w-4 h-4" />
                  </button>
                </div>
              </div>
            );
          })}
        </div>
      </div>

      {/* Eklenebilir modeller */}
      {available.length > 0 && (
        <div className="bg-white p-6 rounded-2xl border border-slate-200 shadow-xs space-y-4">
          <div className="border-b border-slate-100 pb-3">
            <h3 className="font-extrabold text-sm text-slate-900">Kullanılabilir Diğer Modeller</h3>
            <p className="text-xs text-slate-500">Zincire eklemek için bir modele tıklayın.</p>
          </div>
          <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-3">
            {available.map(m => (
              <button type="button"
                key={m.id}
                onClick={() => add(m.id)}
                className="text-left p-4 rounded-xl border border-slate-200 hover:border-indigo-300 hover:bg-indigo-50/40 transition group"
              >
                <div className="flex items-center justify-between">
                  <span className="font-extrabold text-sm text-slate-900">{m.label}</span>
                  <Plus className="w-4 h-4 text-slate-300 group-hover:text-indigo-600" />
                </div>
                <span className={`inline-block mt-1 text-[10px] font-bold px-2 py-0.5 rounded-md border ${RENK[m.renk] || RENK.slate}`}>{m.provider}</span>
                <div className="text-[11px] text-slate-500 font-mono mt-2">{m.model}</div>
              </button>
            ))}
          </div>
        </div>
      )}

      <p className="text-[11px] text-slate-400 text-center">
        Seçimler tarayıcınızda saklanır ve tüm AI özelliklerinde (şartname analizi, fiyat/risk değerlendirmesi) kullanılır.
      </p>
    </div>
  );
};