"use client";

import { useState, useEffect, useCallback, useMemo } from "react";
import { createClient } from "@/lib/supabase/client";
import { cn } from "@/lib/utils";
import type { Conversation, ConversationStatus } from "@/types";
import { Search, ChevronDown } from "lucide-react";
import { formatDistanceToNow } from "date-fns";
import { Input } from "@/components/ui/input";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
} from "@/components/ui/dropdown-menu";
import { Button } from "@/components/ui/button";
import { ScrollArea } from "@/components/ui/scroll-area";

interface ConversationListProps {
  activeConversationId: string | null;
  onSelect: (conversation: Conversation) => void;
  conversations: Conversation[];
  onConversationsLoaded: (conversations: Conversation[]) => void;
}

const STATUS_COLORS: Record<ConversationStatus, string> = {
  open: "bg-emerald-500",
  pending: "bg-amber-500",
  closed: "bg-slate-500",
};

const FILTER_OPTIONS: { label: string; value: ConversationStatus | "all" }[] = [
  { label: "All", value: "all" },
  { label: "Open", value: "open" },
  { label: "Pending", value: "pending" },
  { label: "Closed", value: "closed" },
];

export function ConversationList({
  activeConversationId,
  onSelect,
  conversations,
  onConversationsLoaded,
}: ConversationListProps) {
  const [search, setSearch] = useState("");
  const [filter, setFilter] = useState<ConversationStatus | "all">("all");
  const [loading, setLoading] = useState(true);

  const fetchConversations = useCallback(async () => {
    const supabase = createClient();
    const { data, error } = await supabase
      .from("conversations")
      .select("*, contact:contacts(*)")
      .order("last_message_at", { ascending: false });

    if (error) {
      // Supabase errors have non-enumerable properties — log fields explicitly
      console.error("Failed to fetch conversations:", {
        message: error.message,
        details: error.details,
        hint: error.hint,
        code: error.code,
      });
      setLoading(false);
      return;
    }

    onConversationsLoaded(data ?? []);
    setLoading(false);
  }, [onConversationsLoaded]);

  useEffect(() => {
    fetchConversations();
  }, [fetchConversations]);

  const filtered = useMemo(() => {
    let result = conversations;

    if (filter !== "all") {
      result = result.filter((c) => c.status === filter);
    }

    if (search.trim()) {
      const q = search.toLowerCase();
      result = result.filter((c) => {
        const name = c.contact?.name?.toLowerCase() ?? "";
        const phone = c.contact?.phone?.toLowerCase() ?? "";
        const lastMsg = c.last_message_text?.toLowerCase() ?? "";
        return name.includes(q) || phone.includes(q) || lastMsg.includes(q);
      });
    }

    return result;
  }, [conversations, filter, search]);

  const handleSearchChange = useCallback(
    (e: React.ChangeEvent<HTMLInputElement>) => {
      setSearch(e.target.value);
    },
    []
  );

  const handleSelect = useCallback(
    (conv: Conversation) => {
      onSelect(conv);
    },
    [onSelect]
  );

  const activeFilter = FILTER_OPTIONS.find((o) => o.value === filter);

  return (
    <div className="flex h-full w-80 flex-col border-r border-slate-800 bg-slate-900">
      {/* Search + Filter */}
      <div className="space-y-2 border-b border-slate-800 p-3">
        <div className="relative">
          <Search className="absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-slate-500" />
          <Input
            value={search}
            onChange={handleSearchChange}
            placeholder="Search conversations..."
            className="border-slate-700 bg-slate-800 pl-9 text-sm text-white placeholder-slate-500 focus:border-emerald-500/50"
          />
        </div>

        <DropdownMenu>
          <DropdownMenuTrigger className="inline-flex items-center justify-center h-7 gap-1 px-2 text-xs text-slate-400 hover:text-white rounded-md hover:bg-slate-800">
              {activeFilter?.label ?? "All"}
              <ChevronDown className="h-3 w-3" />
          </DropdownMenuTrigger>
          <DropdownMenuContent
            align="start"
            className="border-slate-700 bg-slate-800"
          >
            {FILTER_OPTIONS.map((opt) => (
              <DropdownMenuItem
                key={opt.value}
                onClick={() => setFilter(opt.value)}
                className={cn(
                  "text-sm",
                  filter === opt.value
                    ? "text-emerald-400"
                    : "text-slate-300"
                )}
              >
                {opt.label}
              </DropdownMenuItem>
            ))}
          </DropdownMenuContent>
        </DropdownMenu>
      </div>

      {/* Conversation Items */}
      <ScrollArea className="flex-1">
        {loading ? (
          <div className="flex items-center justify-center py-12">
            <div className="h-5 w-5 animate-spin rounded-full border-2 border-emerald-500 border-t-transparent" />
          </div>
        ) : filtered.length === 0 ? (
          <div className="px-4 py-12 text-center">
            <p className="text-sm text-slate-500">No conversations found</p>
          </div>
        ) : (
          <div className="flex flex-col">
            {filtered.map((conv) => (
              <ConversationItem
                key={conv.id}
                conversation={conv}
                isActive={conv.id === activeConversationId}
                onSelect={handleSelect}
              />
            ))}
          </div>
        )}
      </ScrollArea>
    </div>
  );
}

interface ConversationItemProps {
  conversation: Conversation;
  isActive: boolean;
  onSelect: (conversation: Conversation) => void;
}

function ConversationItem({
  conversation,
  isActive,
  onSelect,
}: ConversationItemProps) {
  const contact = conversation.contact;
  const displayName = contact?.name || contact?.phone || "Unknown";
  const initials = displayName.charAt(0).toUpperCase();

  const handleClick = useCallback(() => {
    onSelect(conversation);
  }, [onSelect, conversation]);

  const timeAgo = conversation.last_message_at
    ? formatDistanceToNow(new Date(conversation.last_message_at), {
        addSuffix: false,
      })
    : "";

  return (
    <button
      onClick={handleClick}
      className={cn(
        "flex w-full items-start gap-3 px-3 py-3 text-left transition-colors hover:bg-slate-800/50",
        isActive && "border-l-2 border-emerald-500 bg-slate-800/70"
      )}
    >
      {/* Avatar */}
      <div className="flex h-10 w-10 shrink-0 items-center justify-center rounded-full bg-slate-700 text-sm font-medium text-white">
        {contact?.avatar_url ? (
          <img
            src={contact.avatar_url}
            alt={displayName}
            className="h-10 w-10 rounded-full object-cover"
          />
        ) : (
          initials
        )}
      </div>

      {/* Content */}
      <div className="min-w-0 flex-1">
        <div className="flex items-center justify-between gap-2">
          <span className="truncate text-sm font-medium text-white">
            {displayName}
          </span>
          <span className="shrink-0 text-[10px] text-slate-500">{timeAgo}</span>
        </div>
        <div className="mt-0.5 flex items-center justify-between gap-2">
          <p className="truncate text-xs text-slate-400">
            {conversation.last_message_text || "No messages yet"}
          </p>
          <div className="flex shrink-0 items-center gap-1.5">
            {conversation.unread_count > 0 && (
              <span className="flex h-4 min-w-4 items-center justify-center rounded-full bg-emerald-500 px-1 text-[10px] font-bold text-white">
                {conversation.unread_count}
              </span>
            )}
            <span
              className={cn(
                "h-2 w-2 rounded-full",
                STATUS_COLORS[conversation.status]
              )}
              title={conversation.status}
            />
          </div>
        </div>
      </div>
    </button>
  );
}