package com.lanremote.watch;

import android.content.Context;
import android.content.SharedPreferences;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.UUID;

/**
 * 设备与连接信息持久化。
 *
 * 配对成功后保存令牌，下次打开直接从设备列表一键连接，无需再输配对码。
 */
public class DeviceStore {

    private static final String PREFS = "lanremote";
    private static final String KEY_DEVICES = "devices";
    private static final String KEY_DEVICE_ID = "device_id";
    private static final String KEY_DEVICE_NAME = "device_name";
    private static final String KEY_LAST_HOST = "last_host";
    private static final String KEY_LAST_PORT = "last_port";

    private final SharedPreferences prefs;

    public DeviceStore(Context context) {
        this.prefs = context.getApplicationContext()
                .getSharedPreferences(PREFS, Context.MODE_PRIVATE);
    }

    // ---------------- 本机标识 ----------------

    public String deviceId() {
        String id = prefs.getString(KEY_DEVICE_ID, "");
        if (id == null || id.isEmpty()) {
            id = "watch-" + UUID.randomUUID().toString().replace("-", "").substring(0, 16);
            prefs.edit().putString(KEY_DEVICE_ID, id).apply();
        }
        return id;
    }

    public String deviceName() {
        String name = prefs.getString(KEY_DEVICE_NAME, "");
        if (name == null || name.isEmpty()) {
            name = android.os.Build.MODEL;
            if (name == null || name.trim().isEmpty()) {
                name = "手表";
            }
            prefs.edit().putString(KEY_DEVICE_NAME, name).apply();
        }
        return name;
    }

    public void setDeviceName(String name) {
        prefs.edit().putString(KEY_DEVICE_NAME, name == null ? "手表" : name.trim()).apply();
    }

    // ---------------- 上次连接 ----------------

    public String lastHost() {
        return prefs.getString(KEY_LAST_HOST, "");
    }

    public int lastPort() {
        return prefs.getInt(KEY_LAST_PORT, RemoteClient.DEFAULT_PORT);
    }

    public void setLastEndpoint(String host, int port) {
        prefs.edit().putString(KEY_LAST_HOST, host).putInt(KEY_LAST_PORT, port).apply();
    }

    // ---------------- 已配对设备 ----------------

    public List<Map<String, Object>> devices() {
        return readDevices();
    }

    private List<Map<String, Object>> readDevices() {
        String raw = prefs.getString(KEY_DEVICES, "");
        if (raw == null || raw.isEmpty()) {
            return new ArrayList<Map<String, Object>>();
        }
        try {
            Object parsed = Json.parse(raw);
            if (parsed instanceof List) {
                List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();
                for (Object item : (List<?>) parsed) {
                    Map<String, Object> map = Json.asMap(item);
                    if (map != null) {
                        result.add(map);
                    }
                }
                return result;
            }
        } catch (RuntimeException ignored) {
            // 存储损坏时当作空列表，不崩溃
        }
        return new ArrayList<Map<String, Object>>();
    }

    private void writeDevices(List<Map<String, Object>> devices) {
        prefs.edit().putString(KEY_DEVICES, Json.write(devices)).apply();
    }

    /** 保存或更新一台设备（按 key = 地址:端口:设备ID 去重）。 */
    public void saveDevice(String key, String label, String host, int port, String token) {
        List<Map<String, Object>> devices = readDevices();
        List<Map<String, Object>> updated = new ArrayList<Map<String, Object>>();
        for (Map<String, Object> device : devices) {
            if (!key.equals(Json.str(device, "key", ""))) {
                updated.add(device);
            }
        }
        updated.add(0, Json.obj(
                "key", key,
                "label", label,
                "host", host,
                "port", port,
                "token", token,
                "savedAt", System.currentTimeMillis()));
        while (updated.size() > 12) {
            updated.remove(updated.size() - 1);
        }
        writeDevices(updated);
    }

    public void removeDevice(String key) {
        List<Map<String, Object>> devices = readDevices();
        List<Map<String, Object>> updated = new ArrayList<Map<String, Object>>();
        for (Map<String, Object> device : devices) {
            if (!key.equals(Json.str(device, "key", ""))) {
                updated.add(device);
            }
        }
        writeDevices(updated);
    }

    /** 清空所有已配对设备（设置页的清空用）。 */
    public void clearDevices() {
        prefs.edit().remove(KEY_DEVICES).apply();
    }

    public static String deviceKey(String host, int port, String deviceId) {
        return host + ":" + port + ":" + deviceId;
    }
}