<?php

namespace App\Http\Controllers;

use App\Models\HuntSteps;
use Illuminate\Http\Request;

class HuntStepsController extends Controller
{
    /**
     * Display a listing of the resource.
     */
    public function index()
    {
        //
    }

    /**
     * Show the form for creating a new resource.
     */
    public function create()
    {
        //
    }

    /**
     * Store a newly created resource in storage.
     */
    public function store(\App\Http\Requests\StoreHuntStepRequest $request, \App\Models\Hunts $hunt)
    {
        if ($hunt->creator_id !== auth()->id()) {
            return response()->json(['message' => 'Unauthorized'], 403);
        }

        $validated = $request->validated();

        $step = $hunt->steps()->create($validated);

        return response()->json($step, 201);
    }

    /**
     * Validate a hunt step.
     */
    public function validateStep(\Illuminate\Http\Request $request, \App\Models\Hunts $hunt, \App\Models\HuntSteps $step)
    {
        $request->validate([
            'latitude' => 'required|numeric',
            'longitude' => 'required|numeric',
        ]);

        $user = $request->user();

        // 1. Check participation
        $participation = $user->participations()->where('hunt_id', $hunt->id)->first();

        if (!$participation) {
            return response()->json(['message' => 'Not participating in this hunt'], 403);
        }

        // 2. Check if this is the current step
        if ($participation->pivot->current_step_number !== $step->step_number) {
             return response()->json(['message' => 'This is not your current step'], 400);
        }

         // 3. Check proximity
         // Haversine formula
        $earthRadius = 6371000; // meters

        $latFrom = deg2rad($request->latitude);
        $lonFrom = deg2rad($request->longitude);
        $latTo = deg2rad($step->latitude);
        $lonTo = deg2rad($step->longitude);

        $latDelta = $latTo - $latFrom;
        $lonDelta = $lonTo - $lonFrom;

        $angle = 2 * asin(sqrt(pow(sin($latDelta / 2), 2) +
            cos($latFrom) * cos($latTo) * pow(sin($lonDelta / 2), 2)));
        
        $distance = $angle * $earthRadius;

        if ($distance > $step->radius_m) {
             return response()->json([
                 'success' => false,
                 'message' => 'You are too far from the target.',
                 'distance' => round($distance) . 'm'
             ], 400);
        }

        // 4. Update progress
        // Check if there is a next step
        $nextStepNumber = $step->step_number + 1;
        $nextStep = $hunt->steps()->where('step_number', $nextStepNumber)->first();
        
        $updateData = [];

        if ($nextStep) {
            $updateData['current_step_number'] = $nextStepNumber;
        } else {
             $updateData['status'] = 'completed';
             // Keep current_step_number as is (last step) or increment it to indicate "done"? 
             // Usually keeping it at last step or marking status completed is enough. 
             // Let's verify existing logic in HuntsController::show which filters based on step number.
             // If we increment, show() might need adjustment to show everything if completed.
             // For now, let's just mark completed and maybe keep same step number or increment.
             // If we increment, $nextStep is null, so user matches nothing in filter?
             // Let's increment current_step_number so that in show(), $step->step_number < $currentStepNumber becomes true for all steps.
             $updateData['current_step_number'] = $nextStepNumber; 
        }

        $hunt->participants()->updateExistingPivot($user->id, $updateData);

        // 5. Return response
        $response = [
            'success' => true,
            'message' => 'Step validated!',
        ];

        if ($nextStep) {
            $response['next_step'] = [
                'step_number' => $nextStep->step_number,
                'title' => $nextStep->title,
                'description' => $nextStep->description,
                'hint_text' => $nextStep->hint_text,
                'hint_media_url' => $nextStep->hint_media_url,
                // Do NOT include lat/long
            ];
        } else {
            $response['message'] = 'Hunt completed! Congratulations!';
            $response['completed'] = true;
        }

        return response()->json($response);
    }
}