ocrl/

lib.rs

//! # OCRL Mock Library
//!
//! A mock implementation of the OCRL (Octopus Card Reader Library) C ABI for testing purposes.
//! This library provides a test-friendly simulation of payment terminal operations including
//! card enquiry, deduction, and settlement functions.
//!
//! ## API Compliance
//!
//! This library implements the exact same C API as the official OCRL Linux library:
//! - Function signatures match the official specification exactly
//! - Parameter names use the same camelCase convention as the original API
//! - Return codes follow the official error code specification
//! - Buffer size requirements match the official minimum of 4096 bytes
//!
//! ## Usage
//!
//! The library exports three main C functions:
//! - `Connect(char* com)`: Open serial port and setup security channel with R/W
//! - `CmdExchange(char* requestJSON, char* responseJSON, int maxResponseLen)`: Send requests and receive responses
//! - `Disconnect()`: Close serial port
//!
//! ## Error Codes
//!
//! - `0`: Success (communication succeeded)
//! - `-1`: COM not opened
//! - `-2`: Communication error with R/W
//! - `-3`: responseJSON buffer size not enough
//! - `-6`: Link busy

use std::{sync::Mutex, collections::BTreeMap, ffi::{CStr, CString}};
use std::os::raw::c_char;
use serde::Deserialize;
use serde_json::{json, Value};

static TRANSACTIONS: Mutex<BTreeMap<String, (Command, u64)>> = Mutex::new(BTreeMap::new());

enum Command {
    CardEnquiry(bool),
    Deduct(i32, bool),
    Settle,
}

impl Command {
    fn to_string(&self) -> String {
        match self {
            Command::CardEnquiry(_) => "card.enquiry".to_string(),
            Command::Deduct(_, _) => "deduct".to_string(),
            Command::Settle => "settle".to_string(),
        }
    }
}

/// Open serial port and setup security channel with R/W
///
/// # Parameters
/// - `com`: Name of COM port, e.g. "/dev/ttyS0" (unused in mock implementation)
///
/// # Returns
/// - `0`: Communication with R/W succeeded
/// - `-1`: Cannot open COM
/// - `-2`: Communication error with R/W
///
/// # Safety
/// This function is safe to call from C code.
#[no_mangle]
pub extern "C" fn Connect(_com: *mut c_char) -> i32 {
    0
}

/// Close serial port
///
/// # Safety
/// This function is safe to call from C code.
#[no_mangle]
pub extern "C" fn Disconnect() {}

/// Blocking call to send out request and wait for response from R/W with 1sec timeout
///
/// # Parameters
/// - `requestJSON`: Request to R/W in JSON format
/// - `responseJSON`: Buffer to store response from R/W in JSON format
/// - `maxResponseLen`: Size of responseJSON buffer (minimum size is 4096 bytes)
///
/// # Returns
/// - `0`: Message send/receive succeeded
/// - `-1`: COM not opened
/// - `-2`: Communication error with R/W
/// - `-3`: responseJSON buffer size not enough
/// - `-6`: Link busy
///
/// # Safety
/// The caller must ensure:
/// - `requestJSON` points to a valid null-terminated string
/// - `responseJSON` points to a writable buffer of at least `maxResponseLen` bytes
/// - `maxResponseLen` is positive and represents the actual buffer size (minimum 4096)
#[no_mangle]
#[allow(non_snake_case)]
pub extern "C" fn CmdExchange(requestJSON: *mut c_char, responseJSON: *mut c_char, maxResponseLen: i32) -> i32 {
    if requestJSON.is_null() || responseJSON.is_null() || maxResponseLen <= 0 {
        return -2;
    }

    // Validate minimum buffer size as per API specification
    if maxResponseLen < 4096 {
        return -3;
    }

    let req_str = unsafe {
        match CStr::from_ptr(requestJSON).to_str() {
            Ok(s) => s,
            Err(_) => return -2,
        }
    };

    #[derive(Deserialize)]
    #[serde(rename_all = "camelCase")]
    struct Request {
        command: String,
        transaction_id: Option<String>,
        transaction_data: Option<TransactionData>,
        res_id: Option<String>,
        zh: Option<String>,
    }

    #[derive(Deserialize)]
    #[serde(rename_all = "camelCase")]
    struct TransactionData {
        #[serde(rename = "type")]
        typ: String,
        transaction_value: Option<i32>,
    }

    let request: Request = match serde_json::from_str(req_str) {
        Ok(req) => req,
        Err(_) => return -2,
    };

    if request.command == "config.get" {
        return write_json_response(get_config(), responseJSON, maxResponseLen)
    } else if request.command == "display.img" {
        if let Some(res_id) = request.res_id {
            if let Ok(res_id_value) = res_id.parse::<i32>() {
                if res_id_value > 0 && res_id_value < 9 {
                    return write_json_response(json!({
                        "command": "display.img",
                        "result": "ok",
                    }), responseJSON, maxResponseLen)
                }
            }
        }
        return write_json_response(json!({
            "command": "display.img",
            "result": "fail",
            "errorMessage": [ "Invalid parameter", "設定錯誤" ],
        }), responseJSON, maxResponseLen)
    } else if request.command == "scheme.enquiry" {
        let simplified_chinese = request.zh.unwrap_or_default() == "cn";
        return write_json_response(json!({
            "command": "scheme.enquiry",
            "result": "ok",
            "schemes": [
                { "schemeId":"P01", "schemeDesc": [
                    "JoyYou Promotion",
                    if simplified_chinese {
                        "乐悠卡优惠"
                    } else {
                        "樂悠卡優惠"
                    },
                ] },
                { "schemeId":"P02", "schemeDesc": [
                    "Member's Exclusive Offer x Mobile Octopus Promotion",
                    if simplified_chinese {
                        "会员专属礼遇 x 手机版八达通特别优惠"
                    } else {
                        "會員專屬禮遇 x 手機版八達通特別優惠"
                    },
                ] },
                { "schemeId":"P03", "schemeDesc": [
                    "Festival Promotion x Octopus Special Offer",
                    if simplified_chinese {
                        "节日优惠 x 八达通特别优惠"
                    } else {
                        "節日優惠 x 八達通特別優惠"
                    },
                ] },
                { "schemeId":"P04", "schemeDesc": [
                    "Breakfast Promotion x Octopus Special Offer",
                    if simplified_chinese {
                        "早餐时段 x 八达通特别优惠"
                    } else {
                        "早餐時段 x 八達通特別優惠"
                    },
                ] },
                { "schemeId":"P05", "schemeDesc": [
                    "Birthday Offer",
                    if simplified_chinese {
                        "生日优惠"
                    } else {
                        "生日優惠"
                    },
                ] },
                { "schemeId":"P06", "schemeDesc": [
                    "Public Transport Discount",
                    if simplified_chinese {
                        "公共交通折扣"
                    } else {
                        "公共交通折扣"
                    },
                ] },
                { "schemeId":"P07", "schemeDesc": [
                    "Mobile Octopus Promotion",
                    if simplified_chinese {
                        "手机八达通优惠"
                    } else {
                        "手機八達通優惠"
                    },
                ] },
                { "schemeId":"P08", "schemeDesc": [
                    "Shopping Cashback x Octopus Special Offer",
                    if simplified_chinese {
                        "购物现金回赠 x 八达通特别优惠"
                    } else {
                        "購物現金回贈 x 八達通特別優惠"
                    },
                ] },
                { "schemeId":"P09", "schemeDesc": [
                    "Student Special",
                    if simplified_chinese {
                        "学生优惠"
                    } else {
                        "學生優惠"
                    },
                ] },
                { "schemeId":"P10", "schemeDesc": [
                    "Seasonal Sale x Octopus Special Offer",
                    if simplified_chinese {
                        "季节促销 x 八达通特别优惠"
                    } else {
                        "季節促銷 x 八達通特別優惠"
                    },
                ] },
            ],
        }), responseJSON, maxResponseLen)
    } else if request.command == "trans.request" {
        if let Some(transaction_data) = request.transaction_data {
            if transaction_data.typ == "card.enquiry" {
                let simplified_chinese = request.zh.unwrap_or_default() == "cn";
                return write_json_response(new_transaction(Command::CardEnquiry(simplified_chinese)), responseJSON, maxResponseLen)
            } else if transaction_data.typ == "deduct" {
                let amount = transaction_data.transaction_value.unwrap_or(1);
                let simplified_chinese = request.zh.unwrap_or_default() == "cn";
                return write_json_response(new_transaction(Command::Deduct(amount, simplified_chinese)), responseJSON, maxResponseLen)
            } else if transaction_data.typ == "settle" {
                let mut settle = new_transaction(Command::Settle);
                let settle = settle.as_object_mut().unwrap();
                settle.insert("expiry".to_string(), json!(300));
                return write_json_response(serde_json::Value::Object(settle.clone()), responseJSON, maxResponseLen)
            }
        }
    } else if request.command == "trans.perform" {
        if let Some(transaction_id) = request.transaction_id {
            if let Some((cmd, timestamp)) = TRANSACTIONS.lock().unwrap().get(&transaction_id) {
                match cmd {
                    Command::CardEnquiry(simplified_chinese) => {
                        return write_json_response(enquiry_card(&transaction_id, *simplified_chinese), responseJSON, maxResponseLen)
                    },
                    Command::Deduct(amount, simplified_chinese) => {
                        return write_json_response(deduct(&transaction_id, *amount, *simplified_chinese), responseJSON, maxResponseLen)
                    },
                    Command::Settle => {
                        if get_current_time() - timestamp > 10 {
                            return write_json_response(settle(&transaction_id), responseJSON, maxResponseLen)
                        }
                        std::thread::sleep(std::time::Duration::from_secs(1));
                        return write_json_response(json!({
                            "command": "trans.perform",
                            "transactionId": transaction_id,
                            "result": "processing",
                            "transactionData": {
                                "deviceId": "FFFFFF",
                                "type": "settle",
                            },
                        }), responseJSON, maxResponseLen)
                    },
                }
            }
        }
    } else if request.command == "trans.cancel" {
        if let Some(transaction_id) = request.transaction_id {
            TRANSACTIONS.lock().unwrap().remove(&transaction_id);
            return write_json_response(json!({
                "command": "trans.cancel",
                "result": "ok",
            }), responseJSON, maxResponseLen)
        }
    }
    -2
}

fn new_transaction(cmd: Command) -> Value {
    let typ = cmd.to_string();
    let id = generate_random_string(22);
    let result = {
        let mut tx = TRANSACTIONS.lock().unwrap();
        if tx.contains_key(&id) {
            "processing"
        } else {
            let timestamp = get_current_time();
            tx.insert(id.clone(), (cmd, timestamp));
            "ok"
        }
    };
    json!({
        "command": "trans.perform",
        "transactionId": id,
        "result": result,
        "transactionData": {
            "deviceId": "FFFFFF",
            "type": typ,
        },
    })
}

fn enquiry_card(id: &str, simplified_chinese: bool) -> Value {
    if let Ok(card) = std::env::var("CARD") {
        if card == "1" {
            return json!({
                "command": "trans.perform",
                "transactionId": id,
                "result": "fail",
                "errorMessage": ["Invalid card", "此卡失效"],
                "transactionData": {
                    "deviceId": "FFFFFF",
                    "type": "card.enquiry",
                },
                "retry": true,
            })
        } else if card == "2" {
            return json!({
                "transactionLogs": [{
                    "amount": 0,
                    "date": "2024-08-01",
                    "machineId": "FFFF",
                    "spName": ["OCL", "OCL"],
                    "spNameLong": ["Octopus Cards Limited", if simplified_chinese {
                        "八达通卡公司"
                    } else {
                        "八達通卡公司"
                    }],
                    "spType": 255,
                    "time": "12:34:56",
                }],
                "command": "trans.perform",
                "transactionId": id,
                "result": "ok",
                "transactionData": {
                    "IDm": "0101010101010101",
                    "availableFund": 2500,
                    "cardId": 25123456,
                    "date": "2025-02-01",
                    "deviceId": "FFFFFF",
                    "identity": 0,
                    "lang": 0,
                    "octopusType": 1,
                    "passenger": 33,
                    "time": "22:33:44",
                    "type": "card.enquiry",
                },
            });
        }
    }
    json!({
        "transactionLogs": [{
            "amount": 0,
            "date": "2024-08-01",
            "machineId": "FFFF",
            "spName": ["OCL", "OCL"],
            "spNameLong": ["Octopus Cards Limited", if simplified_chinese {
                "八达通卡公司"
            } else {
                "八達通卡公司"
            }],
            "spType": 255,
            "time": "12:34:56",
        }],
        "command": "trans.perform",
        "transactionId": id,
        "result": "ok",
        "transactionData": {
            "IDm": "0101010101010101",
            "availableFund": 2500,
            "cardId": 25123456,
            "date": "2025-02-01",
            "deviceId": "FFFFFF",
            "identity": 0,
            "lang": 0,
            "lastAddValueDate": "2025-01-01",
            "lastAddValueDevice": "FFFFFF",
            "lastAddValueType": 1,
            "maxAddValueAllow": 30000,
            "octopusType": 0,
            "passenger": 3,
            "remainingValue": 0,
            "time": "22:33:44",
            "type": "card.enquiry",
        },
    })
}

fn deduct(id: &str, amount: i32, simplified_chinese: bool) -> Value {
    json!({
        "command": "trans.perform",
        "printData": [
            {
                "type": "line",
                "values": [
                    concat!(
                        "This is program test. If you have any queries on the above transaction, ",
                        "please keep the receipt and call Octopus Customer Service Hotline at ",
                        "2266-2222 or visit www.octopus.com.hk"
                    ),
                    if simplified_chinese {
                        concat!(
                            "程序测试。客户如对上述的交易有任何查询，请保存此存根及致电八达通顾客",
                            "服务热线2266-2222，或浏览www.octopus.com.hk",
                        )
                    } else {
                        concat!(
                            "程序測試。客戶如對上述的交易有任何查詢，請保存此存根及致電八達通顧客",
                            "服務熱線2266-2222，或瀏覽www.octopus.com.hk",
                        )
                    }
                ],
                "format": 0
            },
            {
                "type": "line",
                "values": [
                    "**********************",
                    "**********************"
                ],
                "format": 1
            },
            {
                "type": "line",
                "values": [
                    "* Invalid transaction *",
                    if simplified_chinese {
                        "*      此交易无效     *"
                    } else {
                        "*      此交易無效     *"
                    }
                ],
                "format": 1
            },
            {
                "type": "line",
                "values": [
                    "**********************",
                    "**********************"
                ],
                "format": 1
            },
            {
                "type": "sep",
                "values": [
                    " "
                ]
            },
            {
                "type": "l.r",
                "values": [
                    "Transaction Type",
                    "Terminal",
                    if simplified_chinese {
                        "交易类型"
                    } else {
                        "交易類型"
                    },
                    if simplified_chinese {
                        "终端机"
                    } else {
                        "終端機"
                    },
                ]
            },
            {
                "type": "line",
                "values": [
                    "R/W FW V2.05",
                    "R/W 版本V2.05"
                ],
                "format": 2
            },
            {
                "type": "sep",
                "values": [
                    "-"
                ]
            }
        ],
        "transactionId": id,
        "displayData": [
            {
                "type": "line",
                "values": [
                    "Thank you for using Octopus",
                    if simplified_chinese {
                        "多谢使用八达通"
                    } else {
                        "多謝使用八達通"
                    }
                ],
                "format": 1
            },
            {
                "type": "line",
                "values": [
                    "Remarks",
                    if simplified_chinese {
                        "备注"
                    } else {
                        "備註"
                    }
                ],
                "format": 0
            },
            {
                "type": "l.r",
                "values": [
                    "Transaction Type",
                    "Terminal",
                    if simplified_chinese {
                        "交易类型"
                    } else {
                        "交易類型"
                    },
                    if simplified_chinese {
                        "终端机"
                    } else {
                        "終端機"
                    },
                ]
            },
            {
                "type": "line",
                "values": [
                    "R/W FW V2.05",
                    "R/W 版本V2.05"
                ],
                "format": 2
            }
        ],
        "result": "ok",
        "transactionData": {
            "IDm": "0101010101010101",
            "availableFund": 0,
            "cardId": 25123456,
            "date": "2025-02-28",
            "deviceId": "FFFFFF",
            "identity": 0,
            "lang": 0,
            "lastAddValueDate": "2025-02-28",
            "lastAddValueDevice": "FFFFFF",
            "lastAddValueType": 4,
            "maxAddValueAllow": 30000,
            "octopusType": 0,
            "passenger": 3,
            "remainingValue": 2500 - amount,
            "time": "12:52:57",
            "transactionValue": amount,
            "type": "deduct",
            "schemeName": if amount >= 400 {
                Value::Array(vec![
                    Value::String("VIP x Octopus Offer".to_string()),
                    Value::String("商戶 x 八達通優惠".to_string())
                ])
            } else {
                Value::Null
            },
            "discountAmount": if amount >= 400 {
                json!((amount as f64 * 0.1) as i32)
            } else {
                Value::Null
            },
        }
    })
}

fn settle(id: &str) -> Value {
    json!({
        "upgrade": "firmware",
        "settlementData": {
            "deductCount": 11,
            "deductTotal": 11,
            "addValueCount": 0,
            "addValueTotal": 0,
            "xfilename": "MPS.00800.FFFFFF.20250309154455.00001",
            "date": "2025-03-09",
            "time": "15:44:56",
        },
        "command": "trans.perform",
        "transactionId": id,
        "result": "ok",
        "transactionData": {
            "date": "2025-03-09",
            "deviceId": "FFFFFF",
            "time": "15:44:56",
            "type": "settle",
        },
    })
}

fn get_config() -> Value {
    json!({
        "alertMessage": 0,
        "hwId": "OR30000000",
        "os": "V12.2.5-2.65",
        "ssid": "",
        "wifi": "off",
        "ip": "192.168.1.100",
        "carrier": "",
        "simId": "454000000000000",
        "network": 3,
        "ocrl": "7100.64",
        "ethDHCP": true,
        "command": "config.get",
        "result": "ok",
        "deviceId": "FFFFFF",
        "readerDate": "23-02-2025",
        "readerTime": "23:00:00",
        "compId": 800,
        "keyVersion": 0,
        "eod": 3000,
        "cobrandwhitelist": 0,
        "blacklist": 0,
        "firmware": "15073485",
        "cchs": 28,
        "interimBlackList": 260000,
        "spbmlist": 0,
        "funcBlacklist": 5000,
        "subsidylist": 0,
        "actionlist": 0,
        "genericResFile": 7,
        "specificResFile": 1,
        "spntlist": 14,
    })
}

#[allow(non_snake_case)]
fn write_json_response(response: Value, responseJSON: *mut c_char, maxResponseLen: i32) -> i32 {
    if responseJSON.is_null() || maxResponseLen <= 0 {
        return -2;
    }

    let resp_str = match serde_json::to_string(&response) {
        Ok(s) => s,
        Err(_) => return -2,
    };

    let c_str = match CString::new(resp_str) {
        Ok(c_str) => c_str,
        Err(_) => return -2,
    };

    if c_str.as_bytes_with_nul().len() > maxResponseLen as usize {
        return -3;
    }

    unsafe {
        std::ptr::copy_nonoverlapping(
            c_str.as_ptr() as *const u8,
            responseJSON as *mut u8,
            c_str.as_bytes_with_nul().len()
        );
    }

    0
}

fn generate_random_string(length: usize) -> String {
    let chars: &[u8] = b"0123456789ABCDEF";
    let now = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap_or_default();
    (0..length)
        .map(|i| {
            let hash = (now.as_micros() as usize)
                .wrapping_add(i)
                .wrapping_mul(0x9E3779B9);
            chars[hash % chars.len()] as char
        })
        .collect()
}

fn get_current_time() -> u64 {
    let start = std::time::SystemTime::now();
    let since_epoch = start.duration_since(std::time::UNIX_EPOCH).expect("Time went backwards");
    since_epoch.as_secs()
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::ffi::CString;
    use std::ptr;

    fn create_c_buffer(size: usize) -> Vec<u8> {
        vec![0u8; size]
    }

    fn get_string_from_buffer(buffer: &[u8]) -> String {
        let null_pos = buffer.iter().position(|&b| b == 0).unwrap_or(buffer.len());
        String::from_utf8_lossy(&buffer[..null_pos]).to_string()
    }

    #[test]
    fn test_connect_success() {
        let com_port = CString::new("/dev/ttyS0").unwrap();
        let result = Connect(com_port.as_ptr() as *mut c_char);
        assert_eq!(result, 0);
    }

    #[test]
    fn test_connect_null_ptr() {
        let result = Connect(ptr::null_mut());
        assert_eq!(result, 0);
    }

    #[test]
    fn test_disconnect() {
        Disconnect();
    }

    #[test]
    fn test_cmd_exchange_null_pointers() {
        let result = CmdExchange(ptr::null_mut(), ptr::null_mut(), 4096);
        assert_eq!(result, -2);
    }

    #[test]
    fn test_cmd_exchange_insufficient_buffer() {
        let request = CString::new(r#"{"command": "config.get"}"#).unwrap();
        let mut response_buffer = create_c_buffer(1000);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            1000
        );
        assert_eq!(result, -3);
    }

    #[test]
    fn test_config_get() {
        let request = CString::new(r#"{"command": "config.get"}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        assert_eq!(parsed["command"], "config.get");
        assert_eq!(parsed["result"], "ok");
        assert!(parsed["deviceId"].is_string());
    }

    #[test]
    fn test_display_img_valid() {
        let request = CString::new(r#"{"command": "display.img", "resId": "1"}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        assert_eq!(parsed["command"], "display.img");
        assert_eq!(parsed["result"], "ok");
    }

    #[test]
    fn test_display_img_invalid() {
        let request = CString::new(r#"{"command": "display.img", "resId": "10"}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        assert_eq!(parsed["command"], "display.img");
        assert_eq!(parsed["result"], "fail");
    }

    #[test]
    fn test_scheme_enquiry() {
        let request = CString::new(r#"{"command": "scheme.enquiry"}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        assert_eq!(parsed["command"], "scheme.enquiry");
        assert_eq!(parsed["result"], "ok");
        assert!(parsed["schemes"].is_array());
        assert!(parsed["schemes"].as_array().unwrap().len() > 0);
    }

    #[test]
    fn test_scheme_enquiry_simplified_chinese() {
        let request = CString::new(r#"{"command": "scheme.enquiry", "zh": "cn"}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        assert_eq!(parsed["command"], "scheme.enquiry");
        assert_eq!(parsed["result"], "ok");

        let schemes = parsed["schemes"].as_array().unwrap();
        let first_scheme = &schemes[0];
        let desc = first_scheme["schemeDesc"].as_array().unwrap();
        assert!(desc[1].as_str().unwrap().contains("乐"));
    }

    #[test]
    fn test_trans_request_card_enquiry() {
        let request = CString::new(r#"{"command": "trans.request", "transactionData": {"type": "card.enquiry"}}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        assert_eq!(parsed["command"], "trans.perform");
        assert!(parsed["result"] == "ok" || parsed["result"] == "processing");
        assert!(parsed["transactionId"].is_string());
        assert_eq!(parsed["transactionData"]["type"], "card.enquiry");
    }

    #[test]
    fn test_trans_request_deduct() {
        let request = CString::new(r#"{"command": "trans.request", "transactionData": {"type": "deduct", "transactionValue": 100}}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        assert_eq!(parsed["command"], "trans.perform");
        assert!(parsed["result"] == "ok" || parsed["result"] == "processing");
        assert!(parsed["transactionId"].is_string());
        assert_eq!(parsed["transactionData"]["type"], "deduct");
    }

    #[test]
    fn test_trans_request_settle() {
        let request = CString::new(r#"{"command": "trans.request", "transactionData": {"type": "settle"}}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        assert_eq!(parsed["command"], "trans.perform");
        assert!(parsed["result"] == "ok" || parsed["result"] == "processing");
        assert!(parsed["transactionId"].is_string());
        assert_eq!(parsed["transactionData"]["type"], "settle");
        assert_eq!(parsed["expiry"], 300);
    }

    #[test]
    fn test_trans_perform_card_enquiry() {
        let request = CString::new(r#"{"command": "trans.request", "transactionData": {"type": "card.enquiry"}}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        let transaction_id = parsed["transactionId"].as_str().unwrap();

        let perform_request = format!(r#"{{"command": "trans.perform", "transactionId": "{}"}}"#, transaction_id);
        let perform_cstr = CString::new(perform_request).unwrap();
        let mut perform_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            perform_cstr.as_ptr() as *mut c_char,
            perform_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let perform_response = get_string_from_buffer(&perform_buffer);
        let perform_parsed: serde_json::Value = serde_json::from_str(&perform_response).unwrap();
        assert_eq!(perform_parsed["command"], "trans.perform");
        assert_eq!(perform_parsed["result"], "ok");
        assert!(perform_parsed["transactionData"]["IDm"].is_string());
        assert!(perform_parsed["transactionData"]["availableFund"].is_number());
    }

    #[test]
    fn test_trans_cancel() {
        let request = CString::new(r#"{"command": "trans.request", "transactionData": {"type": "card.enquiry"}}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        let transaction_id = parsed["transactionId"].as_str().unwrap();

        let cancel_request = format!(r#"{{"command": "trans.cancel", "transactionId": "{}"}}"#, transaction_id);
        let cancel_cstr = CString::new(cancel_request).unwrap();
        let mut cancel_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            cancel_cstr.as_ptr() as *mut c_char,
            cancel_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, 0);
        let cancel_response = get_string_from_buffer(&cancel_buffer);
        let cancel_parsed: serde_json::Value = serde_json::from_str(&cancel_response).unwrap();
        assert_eq!(cancel_parsed["command"], "trans.cancel");
        assert_eq!(cancel_parsed["result"], "ok");
    }

    #[test]
    fn test_invalid_json() {
        let request = CString::new(r#"{"invalid": json}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, -2);
    }

    #[test]
    fn test_unknown_command() {
        let request = CString::new(r#"{"command": "unknown.command"}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        let result = CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        assert_eq!(result, -2);
    }

    #[test]
    fn test_generate_random_string() {
        let str1 = generate_random_string(10);
        let str2 = generate_random_string(10);

        assert_eq!(str1.len(), 10);
        assert_eq!(str2.len(), 10);

        for ch in str1.chars() {
            assert!(ch.is_ascii_hexdigit());
        }
        for ch in str2.chars() {
            assert!(ch.is_ascii_hexdigit());
        }

        let mut strings = std::collections::HashSet::new();
        for _ in 0..100 {
            let s = generate_random_string(10);
            assert_eq!(s.len(), 10);
            strings.insert(s);
        }
        assert!(strings.len() > 10);
    }

    #[test]
    fn test_get_current_time() {
        let time1 = get_current_time();
        std::thread::sleep(std::time::Duration::from_millis(10));
        let time2 = get_current_time();

        assert!(time2 >= time1);
    }

    #[test]
    fn test_card() {
        test_card_invalid_scenario();
        test_card_with_history_scenario();
    }

    fn test_card_invalid_scenario() {
        std::env::remove_var("CARD");
        std::env::set_var("CARD", "1");

        assert_eq!(std::env::var("CARD").unwrap(), "1");

        let request = CString::new(r#"{"command": "trans.request", "transactionData": {"type": "card.enquiry"}}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        let transaction_id = parsed["transactionId"].as_str().unwrap();

        let perform_request = format!(r#"{{"command": "trans.perform", "transactionId": "{}"}}"#, transaction_id);
        let perform_cstr = CString::new(perform_request).unwrap();
        let mut perform_buffer = create_c_buffer(4096);

        CmdExchange(
            perform_cstr.as_ptr() as *mut c_char,
            perform_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        let perform_response = get_string_from_buffer(&perform_buffer);
        let perform_parsed: serde_json::Value = serde_json::from_str(&perform_response).unwrap();

        assert!(perform_parsed["result"] == "fail");
        assert!(perform_parsed["errorMessage"].is_array());
        assert_eq!(perform_parsed["retry"], true);

        std::env::remove_var("CARD");
    }

    fn test_card_with_history_scenario() {
        std::env::remove_var("CARD");
        std::env::set_var("CARD", "2");

        let request = CString::new(r#"{"command": "trans.request", "transactionData": {"type": "card.enquiry"}}"#).unwrap();
        let mut response_buffer = create_c_buffer(4096);

        CmdExchange(
            request.as_ptr() as *mut c_char,
            response_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        let response = get_string_from_buffer(&response_buffer);
        let parsed: serde_json::Value = serde_json::from_str(&response).unwrap();
        let transaction_id = parsed["transactionId"].as_str().unwrap();

        let perform_request = format!(r#"{{"command": "trans.perform", "transactionId": "{}"}}"#, transaction_id);
        let perform_cstr = CString::new(perform_request).unwrap();
        let mut perform_buffer = create_c_buffer(4096);

        CmdExchange(
            perform_cstr.as_ptr() as *mut c_char,
            perform_buffer.as_mut_ptr() as *mut c_char,
            4096
        );

        let perform_response = get_string_from_buffer(&perform_buffer);
        let perform_parsed: serde_json::Value = serde_json::from_str(&perform_response).unwrap();
        assert_eq!(perform_parsed["result"], "ok");
        assert!(perform_parsed["transactionLogs"].is_array());
        assert!(perform_parsed["transactionData"]["octopusType"].is_number());

        std::env::remove_var("CARD");
    }
}