package chuankou;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;

/**
 * 负责将串口调试相关配置持久化到 set.properties 文件。
 */
public final class SerialPortPreferences {
    private static final String PROPERTIES_FILE = "set.properties";
    private static final String KEY_PORT = "serialPortName";
    private static final String KEY_BAUD = "serialBaudRate";
    private static final String KEY_AUTO = "serialAutoConnect";
    private static final int DEFAULT_BAUD = 115200;

    private SerialPortPreferences() {
    }

    public static String getPortName() {
        return readProperty(KEY_PORT);
    }

    public static void setPortName(String portName) {
        writeProperty(KEY_PORT, sanitizeString(portName));
    }

    public static int getBaudRate() {
        String value = readProperty(KEY_BAUD);
        if (value == null) {
            return DEFAULT_BAUD;
        }
        try {
            return Integer.parseInt(value.trim());
        } catch (NumberFormatException ex) {
            return DEFAULT_BAUD;
        }
    }

    public static void setBaudRate(int baudRate) {
        writeProperty(KEY_BAUD, String.valueOf(baudRate));
    }

    public static boolean isAutoConnectEnabled() {
        String value = readProperty(KEY_AUTO);
        if (value == null) {
            return true; // 默认开启
        }
        return Boolean.parseBoolean(value.trim());
    }

    public static void setAutoConnectEnabled(boolean enabled) {
        writeProperty(KEY_AUTO, Boolean.toString(enabled));
    }

    private static String readProperty(String key) {
        Properties props = new Properties();
        try (FileInputStream in = new FileInputStream(PROPERTIES_FILE)) {
            props.load(in);
            String value = props.getProperty(key);
            if (value == null || value.trim().isEmpty() || "-1".equals(value.trim())) {
                return null;
            }
            return value.trim();
        } catch (IOException ex) {
            return null;
        }
    }

    private static void writeProperty(String key, String value) {
        synchronized (SerialPortPreferences.class) {
            Properties props = new Properties();
            try (FileInputStream in = new FileInputStream(PROPERTIES_FILE)) {
                props.load(in);
            } catch (IOException ignored) {
                // 文件不存在时使用空配置
            }

            if (value == null || value.trim().isEmpty()) {
                props.setProperty(key, "-1");
            } else {
                props.setProperty(key, value.trim());
            }

            try (FileOutputStream out = new FileOutputStream(PROPERTIES_FILE)) {
                props.store(out, "Serial Port Preferences Updated");
            } catch (IOException ex) {
                System.err.println("保存串口配置失败: " + ex.getMessage());
            }
        }
    }

    private static String sanitizeString(String value) {
        if (value == null) {
            return null;
        }
        String trimmed = value.trim();
        return trimmed.isEmpty() ? null : trimmed;
    }
}