<?php
// points-manager.php - Utility functions for managing user points and rewards

require_once 'config.php';

class PointsManager {
    private $pdo;
    
    public function __construct() {
        $db = new Database();
        $this->pdo = $db->getConnection();
    }
    
    /**
     * Award points to a user
     */
    public function awardPoints($userId, $points, $source, $description, $referenceId = null) {
        try {
            $this->pdo->beginTransaction();
            
            // Update user points
            $stmt = $this->pdo->prepare("INSERT INTO user_points (user_id, points, total_earned) VALUES (?, ?, ?) ON DUPLICATE KEY UPDATE points = points + ?, total_earned = total_earned + ?");
            $stmt->execute([$userId, $points, $points, $points, $points]);
            
            // Add transaction record
            $stmt = $this->pdo->prepare("INSERT INTO point_transactions (user_id, transaction_type, points, source, description, reference_id) VALUES (?, 'earned', ?, ?, ?, ?)");
            $stmt->execute([$userId, $points, $source, $description, $referenceId]);
            
            $this->pdo->commit();
            
            logError('Points awarded', [
                'user_id' => $userId,
                'points' => $points,
                'source' => $source,
                'description' => $description
            ]);
            
            return true;
            
        } catch (Exception $e) {
            $this->pdo->rollback();
            logError('Error awarding points', [
                'user_id' => $userId,
                'points' => $points,
                'source' => $source,
                'error' => $e->getMessage()
            ]);
            return false;
        }
    }
    
    /**
     * Deduct points from a user (for redemptions)
     */
    public function deductPoints($userId, $points, $source, $description, $referenceId = null) {
        try {
            $this->pdo->beginTransaction();
            
            // Check if user has enough points
            $stmt = $this->pdo->prepare("SELECT points FROM user_points WHERE user_id = ?");
            $stmt->execute([$userId]);
            $userPoints = $stmt->fetch();
            
            if (!$userPoints || $userPoints['points'] < $points) {
                $this->pdo->rollback();
                return false;
            }
            
            // Deduct points
            $stmt = $this->pdo->prepare("UPDATE user_points SET points = points - ?, total_redeemed = total_redeemed + ? WHERE user_id = ?");
            $stmt->execute([$points, $points, $userId]);
            
            // Add transaction record
            $stmt = $this->pdo->prepare("INSERT INTO point_transactions (user_id, transaction_type, points, source, description, reference_id) VALUES (?, 'redeemed', ?, ?, ?, ?)");
            $stmt->execute([$userId, $points, $source, $description, $referenceId]);
            
            $this->pdo->commit();
            
            logError('Points deducted', [
                'user_id' => $userId,
                'points' => $points,
                'source' => $source,
                'description' => $description
            ]);
            
            return true;
            
        } catch (Exception $e) {
            $this->pdo->rollback();
            logError('Error deducting points', [
                'user_id' => $userId,
                'points' => $points,
                'source' => $source,
                'error' => $e->getMessage()
            ]);
            return false;
        }
    }
    
    /**
     * Get user's point balance
     */
    public function getUserPoints($userId) {
        try {
            $stmt = $this->pdo->prepare("SELECT points, total_earned, total_redeemed FROM user_points WHERE user_id = ?");
            $stmt->execute([$userId]);
            $result = $stmt->fetch();
            
            if (!$result) {
                return ['points' => 0, 'total_earned' => 0, 'total_redeemed' => 0];
            }
            
            return $result;
            
        } catch (Exception $e) {
            logError('Error fetching user points', ['user_id' => $userId, 'error' => $e->getMessage()]);
            return ['points' => 0, 'total_earned' => 0, 'total_redeemed' => 0];
        }
    }
    
    /**
     * Check and award onboarding points
     */
    public function checkOnboardingPoints($userId) {
        try {
            $stmt = $this->pdo->prepare("SELECT email_verified, onboarding_completed, onboarding_points_awarded FROM users WHERE id = ?");
            $stmt->execute([$userId]);
            $user = $stmt->fetch();
            
            if ($user && $user['email_verified'] && !$user['onboarding_points_awarded']) {
                $this->pdo->beginTransaction();
                
                // Award onboarding points
                $this->awardPoints($userId, 10, 'onboarding', 'Welcome bonus for email verification and first login');
                
                // Mark onboarding as completed
                $stmt = $this->pdo->prepare("UPDATE users SET onboarding_completed = 1, onboarding_points_awarded = 1 WHERE id = ?");
                $stmt->execute([$userId]);
                
                $this->pdo->commit();
                return true;
            }
            
            return false;
            
        } catch (Exception $e) {
            $this->pdo->rollback();
            logError('Error checking onboarding points', ['user_id' => $userId, 'error' => $e->getMessage()]);
            return false;
        }
    }
    
    /**
     * Check and award profiler section completion points
     */
    public function checkProfilerCompletion($userId, $section) {
        try {
            // Get section questions count
            $profilerQuestionCounts = [
                'personal_background' => 6,
                'household_family' => 7,
                'shopping_lifestyle' => 7,
                'technology_digital' => 7,
                'travel_transportation' => 7,
                'health_fitness' => 7,
                'entertainment_media' => 8,
                'food_dining' => 8,
                'financial_services' => 8,
                'communication_payments' => 8
            ];
            
            if (!isset($profilerQuestionCounts[$section])) {
                return false;
            }
            
            $totalQuestions = $profilerQuestionCounts[$section];
            
            // Count answered questions
            $stmt = $this->pdo->prepare("SELECT COUNT(*) as answered FROM user_profiler WHERE user_id = ? AND section = ?");
            $stmt->execute([$userId, $section]);
            $answered = $stmt->fetch()['answered'];
            
            $completionPercentage = ($answered / $totalQuestions) * 100;
            $isCompleted = $completionPercentage >= 100;
            
            // Update completion record
            $stmt = $this->pdo->prepare("INSERT INTO profiler_completion (user_id, section, total_questions, answered_questions, completion_percentage, is_completed, completed_at) VALUES (?, ?, ?, ?, ?, ?, ?) ON DUPLICATE KEY UPDATE answered_questions = ?, completion_percentage = ?, is_completed = ?, completed_at = CASE WHEN ? = 1 THEN NOW() ELSE completed_at END, updated_at = NOW()");
            $completedAt = $isCompleted ? date('Y-m-d H:i:s') : null;
            $stmt->execute([$userId, $section, $totalQuestions, $answered, $completionPercentage, $isCompleted, $completedAt, $answered, $completionPercentage, $isCompleted, $isCompleted]);
            
            // Award points if completed and not already awarded
            if ($isCompleted) {
                $stmt = $this->pdo->prepare("SELECT points_awarded FROM profiler_completion WHERE user_id = ? AND section = ?");
                $stmt->execute([$userId, $section]);
                $completion = $stmt->fetch();
                
                if ($completion && !$completion['points_awarded']) {
                    $pointsToAward = ($section === 'communication_payments') ? 10 : 5;
                    $description = ($section === 'communication_payments') ? 'Mobile verification and UPI details completion' : 'Profiler section completion: ' . ucwords(str_replace('_', ' ', $section));
                    
                    $this->awardPoints($userId, $pointsToAward, 'profiler_' . $section, $description);
                    
                    // Mark points as awarded
                    $stmt = $this->pdo->prepare("UPDATE profiler_completion SET points_awarded = 1 WHERE user_id = ? AND section = ?");
                    $stmt->execute([$userId, $section]);
                    
                    return $pointsToAward;
                }
            }
            
            return false;
            
        } catch (Exception $e) {
            logError('Error checking profiler completion', ['user_id' => $userId, 'section' => $section, 'error' => $e->getMessage()]);
            return false;
        }
    }
    
    /**
     * Get user's transaction history
     */
    public function getTransactionHistory($userId, $limit = 50) {
        try {
            $stmt = $this->pdo->prepare("SELECT * FROM point_transactions WHERE user_id = ? ORDER BY created_at DESC LIMIT ?");
            $stmt->execute([$userId, $limit]);
            return $stmt->fetchAll();
            
        } catch (Exception $e) {
            logError('Error fetching transaction history', ['user_id' => $userId, 'error' => $e->getMessage()]);
            return [];
        }
    }
    
    /**
     * Calculate points needed for next redemption tier
     */
    public function getNextRedemptionTier($currentPoints) {
        $tiers = [200, 500, 1000, 2000, 5000, 10000];
        
        foreach ($tiers as $tier) {
            if ($currentPoints < $tier) {
                return [
                    'next_tier' => $tier,
                    'points_needed' => $tier - $currentPoints,
                    'amount_value' => $tier * 0.5
                ];
            }
        }
        
        // If user has more than highest tier
        return [
            'next_tier' => null,
            'points_needed' => 0,
            'amount_value' => $currentPoints * 0.5
        ];
    }
    
    /**
     * Get points earning summary for admin
     */
    public function getEarningSummary($dateRange = 30) {
        try {
            $stmt = $this->pdo->prepare("
                SELECT 
                    source,
                    COUNT(*) as transaction_count,
                    SUM(points) as total_points,
                    COUNT(DISTINCT user_id) as unique_users
                FROM point_transactions 
                WHERE transaction_type = 'earned' 
                AND created_at >= DATE_SUB(NOW(), INTERVAL ? DAY)
                GROUP BY source
                ORDER BY total_points DESC
            ");
            $stmt->execute([$dateRange]);
            return $stmt->fetchAll();
            
        } catch (Exception $e) {
            logError('Error fetching earning summary', ['error' => $e->getMessage()]);
            return [];
        }
    }
    
    /**
     * Validate redemption request
     */
    public function validateRedemption($userId, $points, $upiId) {
        $errors = [];
        
        // Check minimum points
        if ($points < 200) {
            $errors[] = 'Minimum redemption amount is 200 points (₹100).';
        }
        
        // Check if points are in multiples of 10
        if ($points % 10 !== 0) {
            $errors[] = 'Points must be redeemed in multiples of 10.';
        }
        
        // Check user balance
        $userPoints = $this->getUserPoints($userId);
        if ($points > $userPoints['points']) {
            $errors[] = 'You cannot redeem more points than your available balance.';
        }
        
        // Validate UPI ID
        if (empty($upiId)) {
            $errors[] = 'Please enter your UPI ID.';
        } elseif (!preg_match('/^[\w\.-]+@[\w\.-]+$/', $upiId)) {
            $errors[] = 'Please enter a valid UPI ID (e.g., yourname@paytm).';
        }
        
        return $errors;
    }
}

// Convenience functions for backward compatibility
function awardUserPoints($userId, $points, $source, $description, $referenceId = null) {
    $pm = new PointsManager();
    return $pm->awardPoints($userId, $points, $source, $description, $referenceId);
}

function getUserPointsBalance($userId) {
    $pm = new PointsManager();
    return $pm->getUserPoints($userId);
}

function checkUserOnboarding($userId) {
    $pm = new PointsManager();
    return $pm->checkOnboardingPoints($userId);
}
?>