'use client';

import { useEffect, useState } from 'react';
import Link from 'next/link';
import { useParams } from 'next/navigation';
import { Skeleton } from '@/components/ui/skeleton';
import { useT } from '@/i18n';
import { API_BASE } from '@/lib/config';

interface SkillTask { label: string; prompt: string }
interface Skill {
  id: string; name: string; description: string; icon: string;
  category: string; difficulty: string; systemPrompt: string;
  starters: string[]; tasks: SkillTask[]; tags: string[];
  prerequisites?: string[];
}
interface AffiliateLink { id: number; title: string; description: string | null; url: string }

export default function SkillDetailPage() {
  const params = useParams();
  const t = useT();
  const [skill, setSkill] = useState<Skill | null>(null);
  const [loading, setLoading] = useState(true);
  const [links, setLinks] = useState<AffiliateLink[]>([]);

  useEffect(() => {
    if (!params.id) return;
    fetch(`${API_BASE}/skills/${params.id}`)
      .then(r => r.json())
      .then(data => { if (data.id) setSkill(data); })
      .finally(() => setLoading(false));
  }, [params.id]);

  useEffect(() => {
    if (!skill?.id) return;
    fetch(`${API_BASE}/affiliate/links?skillId=${skill.id}`)
      .then(r => r.json())
      .then(data => setLinks(data.links || []))
      .catch(() => {});
  }, [skill?.id]);

  async function handlePromote(link: AffiliateLink) {
    try {
      const res = await fetch(`${API_BASE}/affiliate/click/${link.id}`, { method: 'POST' });
      const data = await res.json();
      if (data.redirectUrl) window.open(data.redirectUrl, '_blank', 'noopener,noreferrer');
    } catch {
      window.open(link.url, '_blank', 'noopener,noreferrer');
    }
  }

  if (loading) return (
    <div className="max-w-4xl mx-auto px-4 sm:px-6 lg:px-8 py-12">
      <Skeleton className="h-8 w-48 mb-6" />
      <Skeleton className="h-64 rounded-2xl" />
    </div>
  );

  if (!skill) return (
    <div className="max-w-4xl mx-auto px-4 py-20 text-center">
      <p className="text-muted-foreground">技能不存在</p>
      <Link href="/skills" className="text-brand-600 hover:underline text-sm mt-4 inline-block">返回技能库</Link>
    </div>
  );

  return (
    <div className="max-w-4xl mx-auto px-4 sm:px-6 lg:px-8 py-12">
      <Link href="/skills" className="text-sm text-muted-foreground hover:text-brand-600 mb-4 inline-block">
        &larr; {t.skills.title}
      </Link>

      <div className="bg-card rounded-2xl border border-border p-6 mb-6">
        <div className="flex items-start gap-4 mb-4">
          <span className="text-4xl">{skill.icon}</span>
          <div className="flex-1">
            <h1 className="text-2xl font-bold text-foreground">{skill.name}</h1>
            <p className="text-muted-foreground mt-1">{skill.description}</p>
            <div className="flex items-center gap-3 mt-3">
              <span className={`text-xs px-2 py-0.5 rounded-full ${
                skill.difficulty === 'beginner' ? 'bg-green-100 text-green-700' :
                skill.difficulty === 'intermediate' ? 'bg-yellow-100 text-yellow-700' :
                'bg-red-100 text-red-700'
              }`}>{(t.skills as any)[skill.difficulty]}</span>
              <span className="text-xs text-muted-foreground">{(t.skills.categories as any)[skill.category] || skill.category}</span>
            </div>
          </div>
        </div>

        <Link href={`/sandbox?skill=${skill.id}`}
          className="w-full sm:w-auto inline-flex px-5 py-2.5 bg-brand-600 text-white rounded-xl text-sm font-medium hover:bg-brand-700 transition-colors justify-center">
          {t.skills.apply}
        </Link>
      </div>

      <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
        <div className="bg-card rounded-2xl border border-border p-6">
          <h2 className="text-lg font-semibold text-foreground mb-3">{t.skills.starters}</h2>
          <div className="space-y-2">
            {skill.starters.map((q, i) => (
              <div key={i} className="p-3 bg-muted rounded-xl text-sm text-muted-foreground">{q}</div>
            ))}
          </div>
        </div>

        <div className="bg-card rounded-2xl border border-border p-6">
          <h2 className="text-lg font-semibold text-foreground mb-3">{t.skills.tasks}</h2>
          <div className="space-y-3">
            {skill.tasks.map((task, i) => (
              <div key={i} className="p-3 border border-border rounded-xl">
                <div className="text-sm font-medium text-foreground mb-1">{task.label}</div>
                <div className="text-xs text-muted-foreground font-mono">{task.prompt}</div>
              </div>
            ))}
          </div>
        </div>
      </div>

      {skill.prerequisites && skill.prerequisites.length > 0 && (
        <div className="mt-6 bg-card rounded-2xl border border-border p-6">
          <h2 className="text-lg font-semibold text-foreground mb-3">{t.skills.prerequisites}</h2>
          <div className="flex flex-wrap gap-2">
            {skill.prerequisites.map(pre => (
              <Link key={pre} href={`/skills/${pre}`}
                className="px-3 py-1.5 text-sm bg-muted text-foreground rounded-lg hover:bg-accent transition-colors">
                {pre}
              </Link>
            ))}
          </div>
        </div>
      )}

      {links.length > 0 && (
        <div className="mt-6 bg-card rounded-2xl border border-border p-6">
          <h2 className="text-lg font-semibold text-foreground mb-3">{t.affiliate.recommendForSkill}</h2>
          <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
            {links.map(link => (
              <div key={link.id} className="flex items-center justify-between gap-3 p-3 border border-border rounded-xl">
                <div className="min-w-0">
                  <div className="text-sm font-medium text-foreground truncate">{link.title}</div>
                  {link.description && (
                    <div className="text-xs text-muted-foreground line-clamp-1">{link.description}</div>
                  )}
                </div>
                <button
                  onClick={() => handlePromote(link)}
                  className="shrink-0 px-3 py-1.5 text-xs bg-brand-600 hover:bg-brand-700 text-white rounded-lg transition-colors">
                  {t.affiliate.promoteLink}
                </button>
              </div>
            ))}
          </div>
        </div>
      )}
    </div>
  );
}
