"use client";

import { useState, useEffect, useCallback } from "react";
import { MessageCircle, Reply, Trash2 } from "lucide-react";
import { toast } from "sonner";
import { useTranslations } from "next-intl";
import { Button } from "@/components/ui/button";
import { Textarea } from "@/components/ui/textarea";
import { Avatar, AvatarFallback, AvatarImage } from "@/components/ui/avatar";
import { Separator } from "@/components/ui/separator";
import { CommentReactions } from "@/components/social/comment-reactions";

type Comment = {
  id: string;
  content: string;
  parentId: string | null;
  createdAt: string;
  userId: string;
  userName: string;
  userUsername: string | null;
  userAvatarUrl: string | null;
};

function timeAgo(dateStr: string) {
  const diff = Date.now() - new Date(dateStr).getTime();
  const mins = Math.floor(diff / 60000);
  if (mins < 1) return "just now";
  if (mins < 60) return `${mins}m ago`;
  const hours = Math.floor(mins / 60);
  if (hours < 24) return `${hours}h ago`;
  return `${Math.floor(hours / 24)}d ago`;
}

function CommentForm({
  recipeId,
  parentId,
  onSubmit,
  placeholder = "Add a comment…",
  onCancel,
}: {
  recipeId: string;
  parentId?: string;
  onSubmit: () => void;
  placeholder?: string;
  onCancel?: () => void;
}) {
  const [content, setContent] = useState("");
  const [submitting, setSubmitting] = useState(false);

  async function submit() {
    if (!content.trim()) return;
    setSubmitting(true);
    try {
      const res = await fetch(`/api/v1/recipes/${recipeId}/comments`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ content: content.trim(), parentId }),
      });
      if (!res.ok) { toast.error("Failed to post comment"); return; }
      setContent("");
      onSubmit();
    } finally {
      setSubmitting(false);
    }
  }

  return (
    <div className="space-y-2">
      <Textarea
        value={content}
        onChange={(e) => setContent(e.target.value)}
        placeholder={placeholder}
        rows={2}
        disabled={submitting}
      />
      <div className="flex gap-2">
        <Button size="sm" onClick={submit} disabled={!content.trim() || submitting}>
          {submitting ? "Posting…" : "Post"}
        </Button>
        {onCancel && <Button size="sm" variant="ghost" onClick={onCancel}>Cancel</Button>}
      </div>
    </div>
  );
}

function CommentItem({
  comment,
  replies,
  currentUserId,
  recipeId,
  onRefresh,
}: {
  comment: Comment;
  replies: Comment[];
  currentUserId?: string;
  recipeId: string;
  onRefresh: () => void;
}) {
  const [showReply, setShowReply] = useState(false);
  const isOwn = comment.userId === currentUserId;
  const t = useTranslations("social");

  async function deleteComment() {
    const res = await fetch(`/api/v1/comments/${comment.id}`, { method: "DELETE" });
    if (res.ok) { toast.success("Deleted"); onRefresh(); }
    else toast.error("Failed to delete");
  }

  return (
    <div className="space-y-3">
      <div className="flex gap-3">
        <Avatar className="h-7 w-7 shrink-0 mt-0.5">
          <AvatarImage src={comment.userAvatarUrl ?? ""} />
          <AvatarFallback className="text-xs">{comment.userName.slice(0, 2).toUpperCase()}</AvatarFallback>
        </Avatar>
        <div className="flex-1 min-w-0 space-y-1">
          <div className="flex items-baseline gap-2">
            <span className="font-medium text-sm">{comment.userName}</span>
            <span className="text-xs text-muted-foreground">{timeAgo(comment.createdAt)}</span>
          </div>
          <p className="text-sm leading-relaxed whitespace-pre-wrap">{comment.content}</p>
          <CommentReactions recipeId={recipeId} commentId={comment.id} initialCounts={{}} initialUserReactions={[]} />
          <div className="flex items-center gap-2">
            {currentUserId && (
              <button
                onClick={() => setShowReply(!showReply)}
                className="text-xs text-muted-foreground hover:text-foreground flex items-center gap-1"
              >
                <Reply className="h-3 w-3" /> Reply
              </button>
            )}
            {isOwn && (
              <button
                onClick={deleteComment}
                className="text-xs text-muted-foreground hover:text-destructive flex items-center gap-1"
              >
                <Trash2 className="h-3 w-3" /> Delete
              </button>
            )}
          </div>
          {showReply && (
            <CommentForm
              recipeId={recipeId}
              parentId={comment.id}
              onSubmit={() => { setShowReply(false); onRefresh(); }}
              placeholder={t("replyPlaceholder")}
              onCancel={() => setShowReply(false)}
            />
          )}
        </div>
      </div>

      {replies.length > 0 && (
        <div className="ml-10 space-y-3 border-l pl-4">
          {replies.map((reply) => (
            <div key={reply.id} className="flex gap-3">
              <Avatar className="h-6 w-6 shrink-0 mt-0.5">
                <AvatarImage src={reply.userAvatarUrl ?? ""} />
                <AvatarFallback className="text-xs">{reply.userName.slice(0, 2).toUpperCase()}</AvatarFallback>
              </Avatar>
              <div className="flex-1 min-w-0 space-y-1">
                <div className="flex items-baseline gap-2">
                  <span className="font-medium text-sm">{reply.userName}</span>
                  <span className="text-xs text-muted-foreground">{timeAgo(reply.createdAt)}</span>
                </div>
                <p className="text-sm leading-relaxed">{reply.content}</p>
                {reply.userId === currentUserId && (
                  <button
                    onClick={async () => {
                      const res = await fetch(`/api/v1/comments/${reply.id}`, { method: "DELETE" });
                      if (res.ok) { toast.success("Deleted"); onRefresh(); }
                    }}
                    className="text-xs text-muted-foreground hover:text-destructive flex items-center gap-1"
                  >
                    <Trash2 className="h-3 w-3" /> Delete
                  </button>
                )}
              </div>
            </div>
          ))}
        </div>
      )}
    </div>
  );
}

export function CommentsSection({
  recipeId,
  currentUserId,
}: {
  recipeId: string;
  currentUserId?: string;
}) {
  const [comments, setComments] = useState<Comment[]>([]);
  const [loading, setLoading] = useState(true);
  const t = useTranslations("social");

  const load = useCallback(async () => {
    const res = await fetch(`/api/v1/recipes/${recipeId}/comments`);
    if (res.ok) setComments(await res.json() as Comment[]);
    setLoading(false);
  }, [recipeId]);

  useEffect(() => { void load(); }, [load]);

  const topLevel = comments.filter((c) => !c.parentId);
  const replies = (parentId: string) => comments.filter((c) => c.parentId === parentId);

  return (
    <div className="space-y-6">
      <div className="flex items-center gap-2">
        <MessageCircle className="h-5 w-5" />
        <h2 className="text-xl font-semibold">Comments</h2>
        {!loading && <span className="text-muted-foreground text-sm">({comments.length})</span>}
      </div>

      {currentUserId && (
        <CommentForm recipeId={recipeId} onSubmit={load} placeholder={t("commentPlaceholder")} />
      )}

      {loading ? (
        <p className="text-sm text-muted-foreground">Loading…</p>
      ) : topLevel.length === 0 ? (
        <p className="text-sm text-muted-foreground">No comments yet. Be the first!</p>
      ) : (
        <div className="space-y-6">
          {topLevel.map((comment, i) => (
            <div key={comment.id}>
              {i > 0 && <Separator className="mb-6" />}
              <CommentItem
                comment={comment}
                replies={replies(comment.id)}
                currentUserId={currentUserId}
                recipeId={recipeId}
                onRefresh={load}
              />
            </div>
          ))}
        </div>
      )}
    </div>
  );
}
