/**
 * @file Leaderboard routes for retrieving ranked player statistics.
 * @copyright nhcarrigan
 * @license Naomi's Public License
 * @author Naomi Carrigan
 */
/* eslint-disable max-lines-per-function -- Route handler requires many steps */
/* eslint-disable complexity -- Leaderboard handler has inherent complexity */
import { Hono } from "hono";
import { gameTitles } from "../data/titles.js";
import { prisma } from "../db/client.js";
import { logger } from "../services/logger.js";
import type { HonoEnvironment } from "../types/hono.js";
import type { GameState } from "@elysium/types";

const leaderboardRouter = new Hono<HonoEnvironment>();

const validCategories = new Set([
  "totalGold",
  "bossesDefeated",
  "questsCompleted",
  "achievementsUnlocked",
  "prestigeCount",
  "transcendenceCount",
  "apotheosisCount",
]);

const gameStateCategories = new Set([
  "prestigeCount",
  "transcendenceCount",
  "apotheosisCount",
]);

/**
 * Parses the showOnLeaderboards flag from a player's profile settings blob.
 * @param raw - The raw profile settings value from the database.
 * @returns True if the player should appear on leaderboards, false otherwise.
 */
const parseShowOnLeaderboards = (raw: unknown): boolean => {
  if (raw !== null && typeof raw === "object" && !Array.isArray(raw)) {
    /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions -- Runtime profile shape */
    return (raw as Record<string, unknown>).showOnLeaderboards !== false;
  }
  return true;
};

/**
 * Resolves the display title name for a given title ID.
 * @param titleId - The player's active title ID.
 * @returns The human-readable title name, or empty string if no title.
 */
const resolveTitleName = (titleId: string | null): string => {
  if (titleId === null || titleId === "") {
    return "";
  }
  return gameTitles.find((title) => {
    return title.id === titleId;
  })?.name ?? titleId;
};

leaderboardRouter.get("/", async(context) => {
  try {
    const category = context.req.query("category") ?? "totalGold";
    const limitRaw = Number(context.req.query("limit") ?? "100");
    const limit = Math.min(Math.max(1, limitRaw), 100);

    if (!validCategories.has(category)) {
      return context.json({ error: "Invalid category" }, 400);
    }

    const [ players, gameStates ] = await Promise.all([
      prisma.player.findMany(),
      gameStateCategories.has(category)
        ? prisma.gameState.findMany()
        : Promise.resolve([]),
    ]);

    const stateMap = new Map(
      gameStates.map((gs) => {
        /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions -- Prisma returns JsonValue */
        return [ gs.discordId, gs.state as unknown as GameState ];
      }),
    );

    const entries = players.
      filter((player) => {
        return parseShowOnLeaderboards(player.profileSettings);
      }).
      map((player) => {
        let value = 0;
        if (category === "totalGold") {
          value = player.lifetimeGoldEarned;
        } else if (category === "bossesDefeated") {
          value = player.lifetimeBossesDefeated;
        } else if (category === "questsCompleted") {
          value = player.lifetimeQuestsCompleted;
        } else if (category === "achievementsUnlocked") {
          value = player.lifetimeAchievementsUnlocked;
        } else {
          const state = stateMap.get(player.discordId);
          if (category === "prestigeCount") {
            value = state?.prestige.count ?? 0;
          } else if (category === "transcendenceCount") {
            value = state?.transcendence?.count ?? 0;
          } else if (category === "apotheosisCount") {
            value = state?.apotheosis?.count ?? 0;
          }
        }
        return {
          activeTitle:   resolveTitleName(player.activeTitle),
          avatar:        player.avatar ?? null,
          characterName: player.characterName,
          discordId:     player.discordId,
          username:      player.username,
          value:         value,
        };
      }).
      sort((a, b) => {
        return b.value - a.value;
      }).
      slice(0, limit).
      map((entry, index) => {
        return { ...entry, rank: index + 1 };
      });

    return context.json({ category, entries });
  } catch (error) {
    void logger.error(
      "leaderboards",
      error instanceof Error
        ? error
        : new Error(String(error)),
    );
    return context.json({ error: "Internal server error" }, 500);
  }
});

export { leaderboardRouter };