import React, { useRef, useState } from 'react'

const DEFAULT_AVATAR = 'https://files.skinbase.org/default/avatar_default.webp'

function CommentItem({ comment }) {
  return (
    <div className="flex gap-3 py-4 border-b border-white/5 last:border-0">
      <a href={comment.author_profile_url} className="shrink-0 mt-0.5">
        <img
          src={comment.author_avatar || DEFAULT_AVATAR}
          alt={comment.author_name}
          className="w-9 h-9 rounded-xl object-cover ring-1 ring-white/10"
          onError={(e) => { e.target.src = DEFAULT_AVATAR }}
          loading="lazy"
        />
      </a>
      <div className="flex-1 min-w-0">
        <div className="flex items-center gap-2 mb-1">
          <a
            href={comment.author_profile_url}
            className="text-sm font-semibold text-slate-200 hover:text-white transition-colors"
          >
            {comment.author_name}
          </a>
          <span className="text-slate-600 text-xs ml-auto whitespace-nowrap">
            {(() => {
              try {
                const d = new Date(comment.created_at)
                const diff = Date.now() - d.getTime()
                const mins = Math.floor(diff / 60000)
                if (mins < 1) return 'just now'
                if (mins < 60) return `${mins}m ago`
                const hrs = Math.floor(mins / 60)
                if (hrs < 24) return `${hrs}h ago`
                const days = Math.floor(hrs / 24)
                if (days < 30) return `${days}d ago`
                return d.toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' })
              } catch { return '' }
            })()}
          </span>
        </div>
        <p className="text-sm text-slate-400 leading-relaxed break-words whitespace-pre-line">
          {comment.body}
        </p>
        {comment.author_signature && (
          <p className="text-xs text-slate-600 mt-2 italic border-t border-white/5 pt-1 truncate">
            {comment.author_signature}
          </p>
        )}
      </div>
    </div>
  )
}

/**
 * TabActivity
 * Profile comments list + comment form for authenticated visitors.
 * Also acts as "Activity" tab.
 */
export default function TabActivity({ profileComments, user, isOwner, isLoggedIn }) {
  const uname = user.username || user.name
  const formRef = useRef(null)
  const [submitted, setSubmitted] = useState(false)

  return (
    <div
      id="tabpanel-activity"
      role="tabpanel"
      aria-labelledby="tab-activity"
      className="pt-6 max-w-2xl"
    >
      <h2 className="text-xs font-semibold uppercase tracking-widest text-slate-500 mb-4 flex items-center gap-2">
        <i className="fa-solid fa-comments text-orange-400 fa-fw" />
        Comments
        {profileComments?.length > 0 && (
          <span className="ml-1 px-1.5 py-0.5 rounded bg-white/5 text-slate-400 font-normal text-[11px]">
            {profileComments.length}
          </span>
        )}
      </h2>

      {/* Comments list */}
      <div className="bg-white/4 ring-1 ring-white/10 rounded-2xl p-5 shadow-xl shadow-black/20 mb-5">
        {!profileComments?.length ? (
          <p className="text-slate-500 text-sm text-center py-8">
            No comments yet. Be the first to leave one!
          </p>
        ) : (
          <div>
            {profileComments.map((comment) => (
              <CommentItem key={comment.id} comment={comment} />
            ))}
          </div>
        )}
      </div>

      {/* Comment form */}
      {!isOwner && (
        <div className="bg-white/4 ring-1 ring-white/10 rounded-2xl p-5 shadow-xl shadow-black/20">
          <h3 className="text-xs font-semibold uppercase tracking-widest text-slate-500 mb-4 flex items-center gap-2">
            <i className="fa-solid fa-pen text-sky-400 fa-fw" />
            Write a Comment
          </h3>

          {isLoggedIn ? (
            submitted ? (
              <div className="flex items-center gap-2 text-green-400 text-sm p-3 rounded-xl bg-green-500/10 ring-1 ring-green-500/20">
                <i className="fa-solid fa-check fa-fw" />
                Your comment has been posted!
              </div>
            ) : (
              <form
                ref={formRef}
                method="POST"
                action={`/@${uname.toLowerCase()}/comment`}
                onSubmit={() => setSubmitted(false)}
              >
                <input type="hidden" name="_token" value={
                  (() => document.querySelector('meta[name="csrf-token"]')?.content ?? '')()
                } />
                <textarea
                  name="body"
                  rows={4}
                  required
                  minLength={2}
                  maxLength={2000}
                  placeholder={`Write a comment for ${uname}…`}
                  className="w-full bg-white/5 border border-white/10 rounded-xl px-3 py-2.5 text-sm text-slate-200 placeholder:text-slate-600 resize-none focus:outline-none focus:ring-2 focus:ring-sky-400/40 focus:border-sky-400/30 transition-all"
                />
                <div className="mt-3 flex justify-end">
                  <button
                    type="submit"
                    className="inline-flex items-center gap-2 px-5 py-2.5 rounded-xl bg-sky-600 hover:bg-sky-500 text-white text-sm font-semibold transition-all shadow-lg shadow-sky-900/30"
                  >
                    <i className="fa-solid fa-paper-plane fa-fw" />
                    Post Comment
                  </button>
                </div>
              </form>
            )
          ) : (
            <p className="text-sm text-slate-400 text-center py-4">
              <a href="/login" className="text-sky-400 hover:text-sky-300 hover:underline transition-colors">
                Log in
              </a>
              {' '}to leave a comment.
            </p>
          )}
        </div>
      )}
    </div>
  )
}