package expo.modules.usbserial

import android.hardware.usb.UsbDevice

// ---------------------------------------------------------------------------
// Internal constants
// ---------------------------------------------------------------------------

internal const val LIBRARY_VERSION = "0.0.1"

/** Read buffer size in bytes. 4 KB is large enough for most serial protocols. */
internal const val READ_BUFFER_SIZE = 4096

/**
 * Timeout for each blocking read() call in milliseconds.
 * Shorter values increase CPU usage; longer values increase latency.
 * 50 ms is a good balance for interactive serial communication.
 */
internal const val READ_TIMEOUT_MS = 50

// ---------------------------------------------------------------------------
// Shared utility functions — internal so unit tests can access without reflection
// ---------------------------------------------------------------------------

/**
 * Builds the typed result map for a discovered USB device.
 * Optional string descriptor fields (manufacturer, product, serial) are only
 * included when the USB device reports them (some devices leave them null).
 */
internal fun buildDeviceMap(
    device: UsbDevice,
    driverName: String,
    portCount: Int,
): Map<String, Any?> {
    val normalizedDriverName = when (driverName) {
        "FtdiSerialDriver" -> "FtdiSerial"
        "CdcAcmSerialDriver" -> "CdcAcmSerial"
        "Ch34xSerialDriver" -> "Ch34xSerial"
        "Cp21xxSerialDriver" -> "Cp21xxSerial"
        "ProlificSerialDriver" -> "ProlificSerial"
        else -> driverName.removeSuffix("Driver")
    }

    val map = mutableMapOf<String, Any?>(
        "deviceId" to device.deviceId,
        "vendorId" to device.vendorId,
        "productId" to device.productId,
        "driverName" to normalizedDriverName,
        "portCount" to portCount,
    )
    device.manufacturerName?.let { map["manufacturerName"] = it }
    device.productName?.let { map["productName"] = it }
    device.serialNumber?.let { map["serialNumber"] = it }
    return map
}