<?php

namespace App\Http\Controllers\api;

use App\Http\Controllers\Controller;
use App\Models\Question;
use App\Models\PvpMatch;
use App\Traits\BaseApiResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Cache;

class PvPQuizController extends Controller
{
    use BaseApiResponse;

    /**
     * STEP 1: Join the Matchmaking Queue
     */
    public function findMatch(Request $request)
    {
        $userId = auth()->id();

        // 1. Check if anyone else is waiting in the cache queue
        $waitingPlayer = Cache::get('pvp_waiting_player');

        // Ensure we don't match the user with themselves
        if ($waitingPlayer && $waitingPlayer != $userId) {

            // MATCH FOUND! Remove the waiting player from the queue
            Cache::forget('pvp_waiting_player');

            // Create the Game Room
            $match = PvpMatch::create([
                'status' => 'in_progress',
                'started_at' => now(),
            ]);

            // Add both players to the match
            $match->players()->createMany([
                ['user_id' => $waitingPlayer, 'score' => 0],
                ['user_id' => $userId, 'score' => 0],
            ]);

            // Select 5 random multiple-choice questions
            $questions = Question::where('type', 'multiple_choice')
                ->inRandomOrder()
                ->limit(5)
                ->pluck('id');

            // Attach questions to the match
            $match->questions()->attach($questions);

            // TODO (Next Step): Fire a WebSocket Event here to tell Player 1 the match started!

            return $this->success([
                'match_id' => $match->id,
                'status' => 'matched',
                'opponent_id' => $waitingPlayer,
                'questions' => $match->questions()->with('options')->get()->makeHidden(['solution_explanation'])->each(function($q) {
                    $q->options->each->makeHidden(['is_correct']);
                })
            ], 'موفق', 'حریف پیدا شد! بازی شروع می‌شود.');
        }

        // NO MATCH FOUND YET. Put this user in the waiting queue for 30 seconds.
        Cache::put('pvp_waiting_player', $userId, 30);

        return $this->success([
            'status' => 'waiting'
        ], 'در حال جستجو', 'در حال یافتن حریف...');
    }

    /**
     * STEP 2: Submit Answer for a single question (Fastest Finger Logic)
     */
    public function submitAnswer(Request $request, PvpMatch $match)
    {
        $request->validate([
            'question_id' => 'required|exists:questions,id',
            'selected_option_id' => 'required|exists:question_options,id',
            'time_taken_seconds' => 'required|numeric|min:0.1|max:15', // Max 15 seconds to answer
        ]);

        // Prevent answering the same question twice!
        $alreadyAnswered = $match->answers()
            ->where('user_id', auth()->id())
            ->where('question_id', $request->question_id)
            ->exists();

        if ($alreadyAnswered) {
            return $this->failed(null, 'خطا', 'شما قبلا به این سوال پاسخ داده‌اید.');
        }

        $player = $match->players()->where('user_id', auth()->id())->firstOrFail();
        $question = Question::with('options')->find($request->question_id);

        $isCorrect = false;
        $pointsEarned = 0;

        // Check if correct
        $correctOption = $question->options->where('is_correct', true)->first();
        if ($correctOption && $correctOption->id == $request->selected_option_id) {
            $isCorrect = true;

            // MATH: Speed Bonus Calculation
            // If base score is 10, and you answer in 2 seconds (out of 15), you get a bonus!
            $baseScore = 10;
            $maxTime = 15;
            $speedBonus = ($maxTime - $request->time_taken_seconds) * 0.5; // Half a point for every second saved

            $pointsEarned = $baseScore + $speedBonus;
        }

        // Save the answer
        $match->answers()->create([
            'user_id' => auth()->id(),
            'question_id' => $question->id,
            'selected_option_id' => $request->selected_option_id,
            'is_correct' => $isCorrect,
            'time_taken' => $request->time_taken_seconds,
            'points_earned' => $pointsEarned
        ]);

        // Update total score for the player
        $player->increment('score', $pointsEarned);

        // ==========================================
        // CHECK IF THE MATCH IS OVER
        // ==========================================
        $totalQuestions = $match->questions()->count(); // Should be 5
        $totalExpectedAnswers = $totalQuestions * 2; // 5 questions * 2 players = 10 answers

        // Count how many answers have been submitted in this match globally
        $currentTotalAnswers = $match->answers()->count();

        $isMatchOver = false;

        if ($currentTotalAnswers >= $totalExpectedAnswers) {
            // The final answer was just submitted! End the game.
            $this->finalizeMatch($match);
            $isMatchOver = true;
        }

        return $this->success([
            'is_correct' => $isCorrect,
            'points_earned' => round($pointsEarned, 2),
            'current_total_score' => round($player->score, 2),
            'is_match_over' => $isMatchOver
        ], 'موفق', 'پاسخ ثبت شد.');
    }

    /**
     * STEP 3: Finalize the Match and Declare Winner (Internal Helper)
     */
    private function finalizeMatch(PvpMatch $match)
    {
        $players = $match->players()->orderByDesc('score')->get();
        $player1 = $players->first();
        $player2 = $players->last();

        $winnerId = null;
        if ($player1->score > $player2->score) {
            $winnerId = $player1->user_id;
        }

        $match->update([
            'status' => 'completed',
            'ended_at' => now(),
            'winner_id' => $winnerId
        ]);

        // --- NEW: UPDATE GAMIFICATION STATS ---
        $user1 = \App\Models\User::find($player1->user_id);
        $user2 = \App\Models\User::find($player2->user_id);

        $user1->increment('duels_played');
        $user2->increment('duels_played');

        // Give XP and Wins
        if ($winnerId) {
            $winner = \App\Models\User::find($winnerId);
            $winner->increment('duels_won');
            $winner->increment('xp', 50); // Winner gets 50 XP

            // NOTE: Here we will later trigger the "duel_win" Daily Quest progress!
        }

        // Loser/Draw gets participation XP
        $loserId = $winnerId === $user1->id ? $user2->id : $user1->id;
        \App\Models\User::find($loserId)->increment('xp', 10);

        // TODO: Fire a WebSocket Event to push "Game Over" screen!
    }
    /**
     * STEP 4: Get Final Match Results
     */
    public function matchResult(PvpMatch $match)
    {
        // Ensure user was actually in this match
        if (!$match->players()->where('user_id', auth()->id())->exists()) {
            return response()->json(['message' => 'دسترسی غیرمجاز'], 403);
        }

        $match->load([
            'players.user:id,name', // Load player names
            'winner:id,name'        // Load winner name
        ]);

        return $this->success([
            'match_id' => $match->id,
            'status' => $match->status,
            'winner_id' => $match->winner_id,
            'winner_name' => $match->winner ? $match->winner->name : 'مساوی (Draw)',
            'players' => $match->players->map(function ($p) {
                return [
                    'user_id' => $p->user_id,
                    'name' => optional($p->user)->name,
                    'final_score' => round($p->score, 2)
                ];
            })
        ], 'موفق', 'نتایج نهایی مسابقه دریافت شد.');
    }
}