<?php
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Allow-Methods: GET, POST");

// =======================================================================
// CPANEL DATABASE CONNECTIONS CONFIGURATIONS (FILL IN YOUR DETAILS)
// =======================================================================
$db_host = "localhost";
$db_name = "littrea1_nelquaco_erp_db";     // 🔍 Replace with your cPanel Database 
$db_user = "littrea1_George";       // 🔍 Replace with your cPanel User account
$db_pass = "Josphat@2013"; // 🔍 Replace with your secure cPanel password

try {
    $conn = new PDO("mysql:host=$db_host;dbname=$db_name;charset=utf8mb4", $db_user, $db_pass);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch(PDOException $e) {
    echo json_encode(["status" => "error", "message" => "Database Connection Failed: " . $e->getMessage()]);
    exit();
}

$type = isset($_GET['type']) ? $_GET['type'] : '';
$method = $_SERVER['REQUEST_METHOD'];

// =======================================================================
// REQUEST ROUTING CONTROLLER
// =======================================================================

// PATH 1: READ / RETRIEVE ALL DATA BLOCKS ON USER INITIALIZATION LOGIN
if ($method === 'GET' && $type === 'sales') {
    try {
        // 🚀 FIXED: We are querying the full columns and passing them exactly as keys
        $stmt = $conn->prepare("SELECT txn_id, timestamp_string, cashier, customer, summary, total_amount, payment_mode FROM sales_history ORDER BY id DESC LIMIT 500");
        $stmt->execute();
        $sales = $stmt->fetchAll(PDO::FETCH_ASSOC);
        
        // Format properties to clean JSON parameters
        $formattedSales = array_map(function($sale) {
            return [
                "id"        => $sale['txn_id'],
                "txnId"     => $sale['txn_id'],
                "timestamp" => $sale['timestamp_string'],
                "cashier"   => $sale['cashier'],
                "customer"  => $sale['customer'],
                "summary"   => $sale['summary'],
                "total"     => floatval($sale['total_amount']),
                "mode"      => $sale['payment_mode']
            ];
        }, $sales);
        
        echo json_encode($formattedSales);
    } catch(PDOException $e) {
        echo json_encode(["status" => "error", "message" => $e->getMessage()]);
    }
    exit();
}


// PATH 2: COMITTING A COMPLETED POS TRANSACTION INVOICE TO CLOUD
if ($method === 'POST' && $type === 'commit_sale') {
    $inputData = json_decode(file_get_contents("php://input"), true);
    
    if (!$inputData) {
        echo json_encode(["status" => "error", "message" => "Invalid incoming JSON packet payload stream."]);
        exit();
    }

    try {
        $conn->beginTransaction();

        // 1. Insert transaction details into the Sales History table
        $stmt = $conn->prepare("INSERT INTO sales_history (txn_id, timestamp_string, cashier, customer, summary, total_amount, payment_mode) VALUES (:txn_id, :ts, :cashier, :cust, :summary, :total, :mode)");
        $stmt->execute([
            ':txn_id'   => $inputData['txnId'],
            ':ts'       => $inputData['timestamp'],
            ':cashier'  => $inputData['cashier'],
            ':cust'     => $inputData['customer'],
            ':summary'  => $inputData['summary'],
            ':total'    => $inputData['total'],
            ':mode'     => $inputData['mode']
        ]);

        // 2. Adjust financial drawer metrics safely inside double-entry tables row cells
        $modeKey = 'ledger_cash';
        if (strtolower($inputData['mode']) === 'mpesa') $modeKey = 'ledger_mpesa';
        if (strtolower($inputData['mode']) === 'bank') $modeKey = 'ledger_bank';

        $stmt = $conn->prepare("UPDATE system_ledgers SET ledger_value = ledger_value + :amt WHERE ledger_key = :mKey");
        $stmt->execute([':amt' => $inputData['total'], ':mKey' => $modeKey]);

        // 3. Deduct volume from the central tank row if it is a fluid refill item
        if (isset($inputData['deductWaterVolume']) && floatval($inputData['deductWaterVolume']) > 0) {
            $stmt = $conn->prepare("UPDATE system_ledgers SET ledger_value = GREATEST(0, ledger_value - :vol) WHERE ledger_key = 'central_tank_litres'");
            $stmt->execute([':vol' => $inputData['deductWaterVolume']]);
        }

        $conn->commit();
        echo json_encode(["status" => "success", "message" => "Invoice committed successfully to central cloud database row records."]);
    } catch(Exception $e) {
        $conn->rollBack();
        echo json_encode(["status" => "error", "message" => "Transaction Aborted: " . $e->getMessage()]);
    }
    exit();
}

// PATH 3: RETRIEVE SYSTEM DRAWER BALANCES AND WATER RESERVOIRS
if ($method === 'GET' && $type === 'get_balances') {
    try {
        $stmt = $conn->prepare("SELECT ledger_key, ledger_value FROM system_ledgers");
        $stmt->execute();
        $ledgers = $stmt->fetchAll(PDO::FETCH_KEY_PAIR);
        
        echo json_encode([
            "status" => "success",
            "cash" => floatval($ledgers['ledger_cash'] ?? 0),
            "mpesa" => floatval($ledgers['ledger_mpesa'] ?? 0),
            "bank" => floatval($ledgers['ledger_bank'] ?? 0),
            "tank_litres" => floatval($ledgers['central_tank_litres'] ?? 3000)
        ]);
    } catch(PDOException $e) {
        echo json_encode(["status" => "error", "message" => $e->getMessage()]);
    }
    exit();
}
?>