import { useState } from 'react'
import { useWritingHistory } from '@/hooks/use-writing-history'
import { useAuthStore } from '@/store/auth-store'
import type { WritingSubmission } from '@/types'

function scoreColor(score: string) {
  const n = parseFloat(score)
  if (n >= 7) return 'bg-green-100 text-green-700'
  if (n >= 5) return 'bg-amber-100 text-amber-700'
  return 'bg-red-100 text-red-700'
}

function relativeTime(iso: string) {
  const diff = Date.now() - new Date(iso).getTime()
  const mins = Math.floor(diff / 60_000)
  if (mins < 1) return 'vừa xong'
  if (mins < 60) return `${mins} phút trước`
  const hours = Math.floor(mins / 60)
  if (hours < 24) return `${hours} giờ trước`
  return `${Math.floor(hours / 24)} ngày trước`
}

function SubmissionCard({ item }: { item: WritingSubmission }) {
  const [open, setOpen] = useState(false)
  const fb = item.feedback

  return (
    <div className="bg-white rounded-xl border border-slate-200 overflow-hidden">
      <button
        onClick={() => setOpen((v) => !v)}
        className="w-full text-left p-4 flex items-start gap-3 hover:bg-slate-50 transition-colors"
      >
        <span className={`text-xs font-bold px-2 py-1 rounded-lg flex-shrink-0 mt-0.5 ${scoreColor(fb?.score ?? '0')}`}>
          {fb?.score ?? '–'}
        </span>
        <div className="flex-1 min-w-0">
          <p className="text-sm text-slate-700 line-clamp-1">{item.content}</p>
          <p className="text-xs text-slate-400 mt-0.5">{relativeTime(item.created_at)}</p>
        </div>
        <span className="material-symbols-outlined text-slate-400 flex-shrink-0 mt-0.5" style={{ fontSize: 18 }}>
          {open ? 'expand_less' : 'expand_more'}
        </span>
      </button>

      {open && fb && (
        <div className="border-t border-slate-100 p-4 space-y-4">
          <div>
            <p className="text-xs text-slate-400 mb-2">Bài viết gốc</p>
            <p className="text-xs text-slate-600 leading-relaxed whitespace-pre-wrap">{item.content}</p>
          </div>

          {fb.grammar?.length > 0 && (
            <div>
              <p className="text-xs font-semibold text-slate-600 mb-1.5 flex items-center gap-1.5">
                <span className="w-1.5 h-1.5 rounded-full bg-red-500 inline-block" />
                Ngữ pháp
              </p>
              <ul className="space-y-1">
                {fb.grammar.map((g, i) => (
                  <li key={i} className="text-xs text-slate-600 flex gap-1.5">
                    <span className="text-red-400 flex-shrink-0">•</span>{g}
                  </li>
                ))}
              </ul>
            </div>
          )}

          {fb.vocabulary?.length > 0 && (
            <div>
              <p className="text-xs font-semibold text-slate-600 mb-1.5 flex items-center gap-1.5">
                <span className="w-1.5 h-1.5 rounded-full bg-amber-500 inline-block" />
                Từ vựng
              </p>
              <ul className="space-y-1">
                {fb.vocabulary.map((v, i) => (
                  <li key={i} className="text-xs text-slate-600 flex gap-1.5">
                    <span className="text-amber-400 flex-shrink-0">•</span>{v}
                  </li>
                ))}
              </ul>
            </div>
          )}

          {fb.structure && (
            <div>
              <p className="text-xs font-semibold text-slate-600 mb-1">Cấu trúc</p>
              <p className="text-xs text-slate-600">{fb.structure}</p>
            </div>
          )}

          {fb.summary && (
            <div className="bg-green-50 rounded-lg p-3">
              <p className="text-xs font-semibold text-green-700 mb-1">Tổng nhận xét</p>
              <p className="text-xs text-slate-600">{fb.summary}</p>
            </div>
          )}
        </div>
      )}
    </div>
  )
}

export function WritingHistory() {
  const user = useAuthStore((s) => s.user)
  const { data: history, isLoading } = useWritingHistory()

  if (!user) return null

  return (
    <section className="px-4 lg:px-6 pb-10 max-w-6xl mx-auto">
      <h2 className="text-lg font-bold text-slate-800 mb-4">Lịch sử chấm bài</h2>

      {isLoading && (
        <div className="flex items-center gap-2 text-sm text-slate-400">
          <div className="w-4 h-4 border-2 border-slate-200 border-t-blue-500 rounded-full animate-spin" />
          Đang tải...
        </div>
      )}

      {!isLoading && !history?.length && (
        <div className="text-center py-10 text-slate-400">
          <span className="material-symbols-outlined mb-2 block" style={{ fontSize: 36 }}>history</span>
          <p className="text-sm">Chưa có bài nào được chấm.</p>
        </div>
      )}

      {!!history?.length && (
        <div className="space-y-2">
          {history.map((item) => <SubmissionCard key={item.id} item={item} />)}
        </div>
      )}
    </section>
  )
}
