<?php
// packages-backend.php

// Check if session is already started
if (session_status() == PHP_SESSION_NONE) {
    session_start();
}

if (!isset($_SESSION['logged_in']) || $_SESSION['logged_in'] !== true) {
    header('Location: ../../index.php');
    exit;
}

// Database connection
require_once '../../config.php';

// Function to get package details
function getPackageDetails($package_id) {
    global $pdo;
    try {
        $stmt = $pdo->prepare("SELECT * FROM packages WHERE id = ?");
        $stmt->execute([$package_id]);
        return $stmt->fetch(PDO::FETCH_ASSOC);
    } catch (PDOException $e) {
        error_log("Error getting package details: " . $e->getMessage());
        return false;
    }
}

// Function to get all packages
function getAllPackages() {
    global $pdo;
    try {
        $stmt = $pdo->prepare("SELECT * FROM packages ORDER BY min_investment ASC");
        $stmt->execute();
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    } catch (PDOException $e) {
        error_log("Error getting all packages: " . $e->getMessage());
        return [];
    }
}

// Function to check if user can invest in a package
function canUserInvest($user_id, $package_id, $amount) {
    // Get package details
    $package = getPackageDetails($package_id);
    if (!$package) return false;
    
    // Check if amount is within package limits
    if ($amount < $package['min_investment'] || $amount > $package['max_investment']) {
        return false;
    }
    
    return true;
}

// Function to create a new investment
function createInvestment($user_id, $package_id, $amount, $payment_method) {
    global $pdo;
    
    // Start transaction
    $pdo->beginTransaction();
    
    try {
        // Get package details
        $package = getPackageDetails($package_id);
        if (!$package) {
            throw new Exception("Package not found");
        }
        
        // Calculate end date
        $start_date = date('Y-m-d H:i:s');
        $end_date = date('Y-m-d H:i:s', strtotime("+{$package['duration_days']} days"));
        
        // Calculate total expected earnings
        $total_earnings = $amount * ($package['daily_return'] / 100) * $package['duration_days'];
        
        // Insert investment record
        $stmt = $pdo->prepare("INSERT INTO user_investments (user_id, package_id, amount, start_date, end_date, total_earnings) VALUES (?, ?, ?, ?, ?, ?)");
        $stmt->execute([$user_id, $package_id, $amount, $start_date, $end_date, $total_earnings]);
        $investment_id = $pdo->lastInsertId();
        
        // Update user's current package if this is their first or highest investment
        $stmt = $pdo->prepare("SELECT MAX(amount) as max_investment FROM user_investments WHERE user_id = ? AND status = 'active'");
        $stmt->execute([$user_id]);
        $result = $stmt->fetch(PDO::FETCH_ASSOC);
        $max_investment = $result ? $result['max_investment'] : 0;
        
        if ($amount >= $max_investment) {
            $stmt = $pdo->prepare("UPDATE users SET current_package_id = ?, package_start_date = ?, package_end_date = ? WHERE id = ?");
            $stmt->execute([$package_id, $start_date, $end_date, $user_id]);
        }
        
        // Update user's total invested amount
        $stmt = $pdo->prepare("UPDATE users SET total_invested = total_invested + ? WHERE id = ?");
        $stmt->execute([$amount, $user_id]);
        
        // Process payment based on method
        if ($payment_method === 'wallet') {
            // Deduct from user's balance
            $stmt = $pdo->prepare("UPDATE users SET balance = balance - ? WHERE id = ? AND balance >= ?");
            $stmt->execute([$amount, $user_id, $amount]);
            
            if ($stmt->rowCount() === 0) {
                throw new Exception("Insufficient balance");
            }
            
            // Update session balance
            $_SESSION['balance'] -= $amount;
        } else if ($payment_method === 'mpesa') {
            // For demo purposes, we'll just log this
            error_log("M-Pesa payment initiated for user $user_id, amount: $amount");
        } else if ($payment_method === 'bank') {
            // For demo purposes, we'll just log this
            error_log("Bank transfer initiated for user $user_id, amount: $amount");
        }
        
        // Commit transaction
        $pdo->commit();
        
        return $investment_id;
        
    } catch (Exception $e) {
        $pdo->rollBack();
        error_log("Investment creation failed: " . $e->getMessage());
        throw $e;
    }
}

// Function to get user's active investment
function getUserActiveInvestment($user_id) {
    global $pdo;
    try {
        $stmt = $pdo->prepare("
            SELECT ui.*, p.name as package_name, p.daily_return, p.duration_days 
            FROM user_investments ui 
            JOIN packages p ON ui.package_id = p.id 
            WHERE ui.user_id = ? AND ui.status = 'active' AND ui.end_date > NOW() 
            ORDER BY ui.amount DESC 
            LIMIT 1
        ");
        $stmt->execute([$user_id]);
        return $stmt->fetch(PDO::FETCH_ASSOC);
    } catch (PDOException $e) {
        error_log("Error getting user active investment: " . $e->getMessage());
        return false;
    }
}

// Function to get user's daily products
function getUserDailyProducts($user_id) {
    global $pdo;
    try {
        $stmt = $pdo->prepare("
            SELECT up.*, p.name as product_name, p.description, p.value, p.image_url 
            FROM user_products up 
            JOIN products p ON up.product_id = p.id 
            WHERE up.user_id = ? 
            ORDER BY up.assigned_date DESC
        ");
        $stmt->execute([$user_id]);
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    } catch (PDOException $e) {
        error_log("Error getting user daily products: " . $e->getMessage());
        return [];
    }
}

// Handle package investment request
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['action'])) {
    $response = ['success' => false, 'message' => ''];
    
    try {
        if ($_POST['action'] === 'invest') {
            $package_id = intval($_POST['package_id']);
            $amount = floatval($_POST['amount']);
            $payment_method = $_POST['payment_method'];
            $user_id = $_SESSION['user_id'];
            
            // Validate investment
            if (canUserInvest($user_id, $package_id, $amount)) {
                $investment_id = createInvestment($user_id, $package_id, $amount, $payment_method);
                
                $response['success'] = true;
                $response['message'] = 'Investment successful!';
                $response['investment_id'] = $investment_id;
                
                // Update session data
                $_SESSION['total_deposits'] += $amount;
            } else {
                $response['message'] = 'Invalid investment amount or package selection';
            }
        }
    } catch (Exception $e) {
        $response['message'] = $e->getMessage();
    }
    
    header('Content-Type: application/json');
    echo json_encode($response);
    exit;
}
?>