"use client";

import { useCallback, useEffect, useMemo, useRef, useState } from "react";
import { Item, ItemContent, ItemHeader, ItemTitle, ItemDescription } from "@/components/ui/item";
import { BookOpenTextIcon, ScrollTextIcon } from "lucide-react";
import {
  DropdownMenu,
  DropdownMenuCheckboxItem,
  DropdownMenuContent,
  DropdownMenuLabel,
  DropdownMenuTrigger,
} from "@/components/ui/dropdown-menu";

interface LogEntry {
  id: number;
  timestamp: string;
  type: string;
  message: string;
  system?: boolean;
  actor?: { id: number; username: string } | number | null;
  data?: Record<string, unknown>;
}

function formatType(type: string) {
  return type
    .replace(":", " ")
    .split(" ")
    .map((w) => w.charAt(0).toUpperCase() + w.slice(1))
    .join(" ");
}

export function EventLedger({
  structureId,
  refreshKey,
}: {
  structureId: number;
  refreshKey?: number;
}) {
  const [entries, setEntries] = useState<LogEntry[]>([]);
  const [loading, setLoading] = useState(true);
  const [selectedTypes, setSelectedTypes] = useState<Set<string>>(new Set());
  const [currentUserId, setCurrentUserId] = useState<number | null>(null);
  const initialDone = useRef(false);

  const eventTypes = useMemo(() => {
    const set = new Set(entries.map((e) => e.type));
    return Array.from(set).sort();
  }, [entries]);

  const filtered = useMemo(
    () => (selectedTypes.size === 0 ? entries : entries.filter((e) => selectedTypes.has(e.type))),
    [entries, selectedTypes],
  );

  const toggleType = (type: string) => {
    setSelectedTypes((prev) => {
      const next = new Set(prev);
      if (next.has(type)) next.delete(type);
      else next.add(type);
      return next;
    });
  };

  const dropdownLabel = selectedTypes.size === 0 ? "All" : `${selectedTypes.size} selected`;

  const fetchEntries = useCallback(async () => {
    if (!initialDone.current) setLoading(true);
    const params = new URLSearchParams({
      "where[structure.id][equals]": String(structureId),
      sort: "-timestamp",
      limit: "50",
      depth: "1",
    });
    try {
      const r = await fetch(`/api/game-event-logs?${params}`);
      const body = await r.json();
      setEntries(body.docs ?? []);
    } catch {
      setEntries([]);
    } finally {
      initialDone.current = true;
      setLoading(false);
    }
  }, [structureId]);

  useEffect(() => {
    fetch("/api/users/me")
      .then((r) => r.json())
      .then((body) => setCurrentUserId(body?.user?.id ?? null))
      .catch(() => setCurrentUserId(null));
  }, []);

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

  useEffect(() => {
    if (initialDone.current) fetchEntries();
  }, [refreshKey, fetchEntries]);

  useEffect(() => {
    const interval = setInterval(() => {
      if (initialDone.current) fetchEntries();
    }, 30_000);
    return () => clearInterval(interval);
  }, [fetchEntries]);

  if (loading) {
    return (
      <Item variant="outline">
        <ItemHeader>
          <ItemTitle className="flex items-center gap-2 text-muted-foreground">
            <ScrollTextIcon className="size-4" />
            Event Log
          </ItemTitle>
        </ItemHeader>
        <ItemContent>
          <p className="text-sm text-muted-foreground px-1 py-2">Loading...</p>
        </ItemContent>
      </Item>
    );
  }

  return (
    <Item variant="outline">
      <ItemHeader>
        <ItemTitle className="flex items-center gap-2 text-muted-foreground">
          <ScrollTextIcon className="size-4" />
          Event Log
        </ItemTitle>
        <ItemDescription>Recent activity for this structure.</ItemDescription>
      </ItemHeader>
      <ItemContent>
        {eventTypes.length > 1 && (
          <DropdownMenu>
            <span className="text-xs text-muted-foreground">
              Filter event logs...
            </span>
            <DropdownMenuTrigger asChild>
              <button
                type="button"
                className="text-xs px-2.5 py-1 rounded border border-border text-muted-foreground hover:text-foreground transition-colors mb-3 min-w-1/3 w-fit"
              >
                {dropdownLabel}
              </button>
            </DropdownMenuTrigger>
            <DropdownMenuContent align="start">
              <DropdownMenuCheckboxItem
                checked={selectedTypes.size === 0}
                onCheckedChange={() => setSelectedTypes(new Set())}
              >
                All
              </DropdownMenuCheckboxItem>
              {eventTypes.map((t) => (
                <DropdownMenuCheckboxItem
                  key={t}
                  checked={selectedTypes.has(t)}
                  onCheckedChange={() => toggleType(t)}
                >
                  {formatType(t)}
                </DropdownMenuCheckboxItem>
              ))}
            </DropdownMenuContent>
          </DropdownMenu>
        )}
        {filtered.length === 0 ? (
          <p className="text-sm text-muted-foreground px-1 py-2">No events recorded yet.</p>
        ) : (
          <div className="flex flex-col max-h-80 overflow-y-auto">
            {filtered.map((entry, index) => {
              const time = new Date(entry.timestamp);
              const actorId =
                typeof entry.actor === "object" && entry.actor ? entry.actor.id : entry.actor;
              const actorName =
                typeof entry.actor === "object" && entry.actor ? entry.actor.username : null;
              const isYou = actorId != null && actorId === currentUserId;
              const actorLabel = isYou ? "You" : actorName;
              const displayMessage = actorLabel
                ? entry.message.charAt(0).toLowerCase() + entry.message.slice(1)
                : entry.message;
              const isNarrative = entry.system === false;
              return (
                <div key={entry.id}>
                  <div
                    className={`flex items-start gap-3 py-2 text-sm ${isNarrative ? "pl-3 border-l-2 border-amber-500/40" : ""}`}
                  >
                    {isNarrative && (
                      <BookOpenTextIcon className="size-4 text-amber-400 shrink-0 mt-0.5" />
                    )}
                    <span className="text-xs text-muted-foreground shrink-0 w-16 text-right tabular-nums pt-0.5">
                      {time.toLocaleTimeString([], { hour: "2-digit", minute: "2-digit" })}
                    </span>
                    <span className={`flex-1 min-w-0 ${isNarrative ? "text-amber-100/90" : ""}`}>
                      {actorLabel && (
                        <span
                          className={`font-medium ${isYou ? "text-foreground" : "text-muted-foreground"}`}
                        >
                          {actorLabel}
                        </span>
                      )}{" "}
                      {displayMessage}
                    </span>
                    <span className="text-xs text-muted-foreground capitalize shrink-0 pt-0.5">
                      {formatType(entry.type)}
                    </span>
                  </div>
                  {index < filtered.length - 1 && <div className="border-t border-border" />}
                </div>
              );
            })}
          </div>
        )}
      </ItemContent>
    </Item>
  );
}