import { useMemo, useState } from "react";

import { eventIcon, severityClass } from "../eventDecor";
import type { GameLogEventSnapshot, WorldSnapshot } from "../types";

type GameOverOverlayProps = {
  snapshot: WorldSnapshot;
  events: GameLogEventSnapshot[];
};

const RESULT_COPY: Record<string, { title: string; subtitle: string; tone: string }> = {
  win_population: {
    title: "THE WORLD PREVAILS",
    subtitle: "The countries reached the population goal.",
    tone: "win",
  },
  win_survival: {
    title: "THE WORLD ENDURES",
    subtitle: "The countries survived the pressure of the world.",
    tone: "win",
  },
  lose: {
    title: "THE WORLD HAS FALLEN",
    subtitle: "No citizen drew breath at the end.",
    tone: "lose",
  },
};

export function GameOverOverlay({ snapshot, events }: GameOverOverlayProps) {
  const [isDismissed, setIsDismissed] = useState(false);
  const status = snapshot.simulation.game_status ?? "running";
  const copy = RESULT_COPY[status];
  const stats = snapshot.simulation.stats;
  const totalDeaths = Object.values(stats?.deaths_by_cause ?? {}).reduce(
    (sum, count) => sum + count,
    0,
  );
  const betrayals = useMemo(
    () => events.filter((event) => event.type === "steal" || event.type === "treasury_stolen").length,
    [events],
  );
  const storyEvents = useMemo(
    () =>
      events
        .filter((event) =>
          [
            "npc_born",
            "npc_died",
            "build_completed",
            "house_destroyed",
            "beast_killed",
            "election_completed",
            "policy_updated",
            "cannon_crafted",
            "cannon_fired",
            "game_over",
          ].includes(event.type),
        )
        .slice(-14),
    [events],
  );

  if (!copy || isDismissed) {
    return null;
  }

  return (
    <div className={`gameOverOverlay gameOver-${copy.tone}`} role="dialog" aria-label="Game over">
      <div className="gameOverCard">
        <h1>{copy.title}</h1>
        <p className="gameOverSubtitle">{copy.subtitle}</p>

        <div className="gameOverStats">
          <Stat label="Countries" value={snapshot.countries?.length ?? 0} />
          <Stat label="Births" value={stats?.total_births ?? 0} />
          <Stat label="Deaths" value={totalDeaths} />
          <Stat label="Houses built" value={stats?.houses_built ?? 0} />
          <Stat label="Beasts slain" value={stats?.beasts_killed ?? 0} />
          <Stat label="Treasury raids" value={betrayals} />
          <Stat label="Peak population" value={snapshot.simulation.peak_population ?? 0} />
        </div>

        {Object.keys(stats?.deaths_by_cause ?? {}).length > 0 ? (
          <p className="gameOverCauses">
            Causes of death:{" "}
            {Object.entries(stats?.deaths_by_cause ?? {})
              .map(([cause, count]) => `${cause.replaceAll("_", " ")} x${count}`)
              .join(", ")}
          </p>
        ) : null}

        {storyEvents.length > 0 ? (
          <div className="gameOverStory">
            <h2>The world's story</h2>
            <div className="gameOverStoryList">
              {storyEvents.map((event, index) => (
                <div className={`eventLine ${severityClass(event.severity)}`} key={index}>
                  <span className="eventTick">{event.tick}</span>
                  <span className="eventIcon">{eventIcon(event.type)}</span>
                  <span className="eventText">{event.summary}</span>
                </div>
              ))}
            </div>
          </div>
        ) : null}

        <button type="button" className="gameOverDismiss" onClick={() => setIsDismissed(true)}>
          Inspect the aftermath
        </button>
      </div>
    </div>
  );
}

function Stat({ label, value }: { label: string; value: number }) {
  return (
    <div className="gameOverStat">
      <span className="gameOverStatValue">{value}</span>
      <span className="gameOverStatLabel">{label}</span>
    </div>
  );
}