package de.opcua.app.service;

import de.opcua.app.model.NodeAction;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Timer;
import java.util.TimerTask;

/**
 * Persists Actions to JSON file.
 */
public class ActionPersistenceService {

    private static final String CONFIG_DIR = System.getProperty("user.home") + "/.opcua-gui";
    private static final String ACTIONS_FILE = CONFIG_DIR + "/actions.json";

    private final ObjectMapper mapper;

    public ActionPersistenceService() {
        this.mapper = new ObjectMapper();
        this.mapper.enable(SerializationFeature.INDENT_OUTPUT);
        ensureConfigDir();
    }

    private void ensureConfigDir() {
        try {
            Path dir = Paths.get(CONFIG_DIR);
            if (!Files.exists(dir)) {
                Files.createDirectories(dir);
                System.out.println("[Persistence] Created config directory: " + CONFIG_DIR);
            }
        } catch (IOException e) {
            System.err.println("[Persistence] Failed to create config directory: " + e.getMessage());
        }
    }

    public void saveActions(Map<String, List<NodeAction>> actions) {
        try {
            List<ActionData> dataList = new ArrayList<>();

            for (Map.Entry<String, List<NodeAction>> entry : actions.entrySet()) {
                String nodeId = entry.getKey();
                for (NodeAction action : entry.getValue()) {
                    ActionData data = new ActionData(
                            nodeId,
                            action.getActionName(),
                            action.getTriggerType().name(),
                            action.getScript(),
                            action.getTriggerValue(),
                            action.getIntervalMs(),
                            action.isEnabled()
                    );
                    data.conditionEnabled = action.isConditionEnabled();
                    data.conditionScript = action.getConditionScript();
                    data.conditionNodeIds = new ArrayList<>(action.getConditionNodeIds());
                    data.nodeAliases = new LinkedHashMap<>(action.getNodeAliases());
                    dataList.add(data);
                }
            }

            mapper.writeValue(new File(ACTIONS_FILE), dataList);
            System.out.println("[Persistence] Saved " + dataList.size() + " actions to " + ACTIONS_FILE);

        } catch (IOException e) {
            System.err.println("[Persistence] Failed to save actions: " + e.getMessage());
        }
    }

    public Map<String, List<NodeAction>> loadActions() {
        Map<String, List<NodeAction>> result = new HashMap<>();

        File file = new File(ACTIONS_FILE);
        if (!file.exists()) {
            System.out.println("[Persistence] No saved actions found");
            return result;
        }

        try {
            ActionData[] dataArray = mapper.readValue(file, ActionData[].class);

            for (ActionData data : dataArray) {
                NodeAction action = new NodeAction();
                action.setNodeId(data.nodeId);
                action.setActionName(data.actionName);
                action.setTriggerType(NodeAction.TriggerType.valueOf(data.triggerType));
                action.setScript(data.script);
                action.setTriggerValue(data.triggerValue);
                action.setIntervalMs(data.intervalMs);
                action.setEnabled(data.enabled);
                action.setConditionEnabled(data.conditionEnabled);
                action.setConditionScript(data.conditionScript);
                action.setConditionNodeIds(data.conditionNodeIds);
                action.setNodeAliases(data.nodeAliases);

                result.computeIfAbsent(data.nodeId, k -> new ArrayList<>()).add(action);
            }

            System.out.println("[Persistence] Loaded " + dataArray.length + " actions from " + ACTIONS_FILE);

        } catch (IOException e) {
            System.err.println("[Persistence] Failed to load actions: " + e.getMessage());
        }

        return result;
    }

    public void startAutoSave(ActionService actionService, int intervalSeconds) {
        Timer timer = new Timer("ActionAutoSave", true);
        timer.scheduleAtFixedRate(new TimerTask() {
            @Override
            public void run() {
                saveActions(actionService.getAllActions());
            }
        }, intervalSeconds * 1000L, intervalSeconds * 1000L);

        System.out.println("[Persistence] Auto-save enabled (every " + intervalSeconds + "s)");
    }

    public static class ActionData {
        public String nodeId;
        public String actionName;
        public String triggerType;
        public String script;
        public String triggerValue;
        public int intervalMs;
        public boolean enabled;

        public boolean conditionEnabled;
        public String conditionScript;
        public List<String> conditionNodeIds = new ArrayList<>();
        public Map<String, String> nodeAliases = new LinkedHashMap<>();

        public ActionData() {}

        public ActionData(String nodeId, String actionName, String triggerType,
                          String script, String triggerValue, int intervalMs, boolean enabled) {
            this.nodeId = nodeId;
            this.actionName = actionName;
            this.triggerType = triggerType;
            this.script = script;
            this.triggerValue = triggerValue;
            this.intervalMs = intervalMs;
            this.enabled = enabled;
        }
    }
}