"use client";

import { useState, useEffect, useCallback, useRef } from "react";
import { getStoredPlayer, storePlayer } from "@/lib/player-store";
import { isSupabaseConfigured } from "@/lib/supabase/client";
import {
  getPlayerAchievements,
  upsertAchievementProgress,
  getPlayerGameStats,
} from "@/lib/supabase/achievement-queries";
import { addStarCoins, getPlayerStarCoins, getOrCreatePlayer } from "@/lib/supabase/queries";
import {
  evaluateAchievements,
  type GameResult,
  type AchievementUpdate,
  type CurrentProgress,
  type PlayerStats,
} from "@/lib/achievements/checker";
import {
  calculateCoinsEarned,
  type CoinBreakdown,
} from "@/lib/achievements/coin-calculator";

// ---------------------------------------------------------------------------
// Public interface
// ---------------------------------------------------------------------------

export interface UsePlayerProgressReturn {
  coinBalance: number;
  isLoading: boolean;
  processGameResult: (result: GameResult) => Promise<{
    coinsEarned: CoinBreakdown;
    newAchievements: AchievementUpdate[];
  } | null>;
}

// ---------------------------------------------------------------------------
// Hook
// ---------------------------------------------------------------------------

/**
 * Manages player achievement progress and coin balance.
 *
 * On mount, loads the player's current achievement progress and coin balance
 * from Supabase (when configured). Provides `processGameResult` to evaluate
 * achievements, calculate coins, persist updates, and return the breakdown.
 *
 * When Supabase is not configured, coins are still calculated locally but
 * nothing is persisted.
 */
export function usePlayerProgress(): UsePlayerProgressReturn {
  const [coinBalance, setCoinBalance] = useState(0);
  const [isLoading, setIsLoading] = useState(true);
  const progressRef = useRef<CurrentProgress>({});
  const playerIdRef = useRef<string | null>(null);

  // Load initial achievement progress and coin balance
  useEffect(() => {
    let cancelled = false;

    async function load() {
      const player = getStoredPlayer();
      if (!player || !isSupabaseConfigured) {
        if (!cancelled) setIsLoading(false);
        return;
      }

      // Always verify player exists in DB -- heals stale/reset UUIDs in localStorage
      const dbPlayer = await getOrCreatePlayer(player.anonymousId, player.displayName);
      if (!dbPlayer) {
        if (!cancelled) setIsLoading(false);
        return;
      }
      if (player.id !== dbPlayer.id) {
        storePlayer({ ...player, id: dbPlayer.id });
      }
      playerIdRef.current = dbPlayer.id;

      try {
        const [achievementRows, coins] = await Promise.all([
          getPlayerAchievements(dbPlayer.id),
          getPlayerStarCoins(dbPlayer.id),
        ]);

        if (cancelled) return;

        // Convert DB rows to CurrentProgress map
        const progressMap: CurrentProgress = {};
        for (const row of achievementRows) {
          progressMap[row.achievement_id] = {
            progress: row.progress,
            unlocked: row.unlocked,
          };
        }
        progressRef.current = progressMap;
        setCoinBalance(coins);
      } catch {
        // Silently ignore -- local-only mode still works
      }

      if (!cancelled) setIsLoading(false);
    }

    load();
    return () => {
      cancelled = true;
    };
  }, []);

  // Process a game result: evaluate achievements, calculate coins, persist
  const processGameResult = useCallback(
    async (
      result: GameResult
    ): Promise<{
      coinsEarned: CoinBreakdown;
      newAchievements: AchievementUpdate[];
    } | null> => {
      const player = getStoredPlayer();
      let playerId = playerIdRef.current ?? player?.id ?? null;

      // Always verify player exists in DB -- heals stale/reset UUIDs in localStorage
      if (player && isSupabaseConfigured) {
        const dbPlayer = await getOrCreatePlayer(player.anonymousId, player.displayName);
        if (dbPlayer) {
          if (player.id !== dbPlayer.id) {
            storePlayer({ ...player, id: dbPlayer.id });
          }
          playerId = dbPlayer.id;
          playerIdRef.current = dbPlayer.id;
        }
      }

      // Build player stats from Supabase or use local fallbacks
      let playerStats: PlayerStats;

      if (playerId && isSupabaseConfigured) {
        try {
          const dbStats = await getPlayerGameStats(playerId);
          playerStats = {
            totalGames: dbStats.totalGames + 1, // include current game
            totalCorrectAnswers:
              dbStats.totalCorrectAnswers +
              (result.type === "trivia" ? result.questionsCorrect : 0),
            distinctModesPlayed: dbStats.distinctModes,
            gamesToday: 1, // conservative estimate; refined below
            achievementsUnlocked: Object.values(progressRef.current).filter(
              (p) => p.unlocked
            ).length,
          };

          // Add current mode to distinct modes if not already present
          const currentMode =
            result.type === "trivia" ? result.mode : result.gameId;
          if (!playerStats.distinctModesPlayed.includes(currentMode)) {
            playerStats.distinctModesPlayed = [
              ...playerStats.distinctModesPlayed,
              currentMode,
            ];
          }
        } catch {
          // Fall back to local estimates
          playerStats = buildLocalStats(result, progressRef.current);
        }
      } else {
        playerStats = buildLocalStats(result, progressRef.current);
      }

      // Determine if this is the first game today
      const isFirstGameToday = playerStats.gamesToday <= 1;

      // Evaluate achievements
      const newAchievements = evaluateAchievements(
        result,
        progressRef.current,
        playerStats
      );

      // Calculate coins
      const coinsEarned = calculateCoinsEarned(
        result,
        newAchievements,
        isFirstGameToday
      );

      // Persist to Supabase when available
      if (playerId && isSupabaseConfigured) {
        try {
          // Persist achievement progress
          const upsertPromises = newAchievements.map((update) =>
            upsertAchievementProgress(
              playerId,
              update.achievementId,
              update.newProgress,
              update.justUnlocked
            )
          );
          await Promise.all(upsertPromises);

          // Add coins and update local balance
          if (coinsEarned.total > 0) {
            const newBalance = await addStarCoins(playerId, coinsEarned.total);
            if (newBalance !== null) {
              setCoinBalance(newBalance);
            } else {
              // Optimistic update if DB write failed
              setCoinBalance((prev) => prev + coinsEarned.total);
            }
          }
        } catch {
          // Optimistic local update on persistence failure
          setCoinBalance((prev) => prev + coinsEarned.total);
        }
      } else {
        // No Supabase -- just update local state
        setCoinBalance((prev) => prev + coinsEarned.total);
      }

      // Update local progress cache
      for (const update of newAchievements) {
        progressRef.current[update.achievementId] = {
          progress: update.newProgress,
          unlocked: update.justUnlocked,
        };
      }

      return { coinsEarned, newAchievements };
    },
    []
  );

  return { coinBalance, isLoading, processGameResult };
}

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

/**
 * Builds a conservative PlayerStats object when Supabase is unavailable.
 */
function buildLocalStats(
  result: GameResult,
  currentProgress: CurrentProgress
): PlayerStats {
  return {
    totalGames: 1,
    totalCorrectAnswers:
      result.type === "trivia" ? result.questionsCorrect : 0,
    distinctModesPlayed: [
      result.type === "trivia" ? result.mode : result.gameId,
    ],
    gamesToday: 1,
    achievementsUnlocked: Object.values(currentProgress).filter(
      (p) => p.unlocked
    ).length,
  };
}