package pl.edu.mimuw.cloudatlas.client;

import com.google.gson.Gson;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.stereotype.Controller;
import pl.edu.mimuw.cloudatlas.api.Api;
import pl.edu.mimuw.cloudatlas.model.*;
import pl.edu.mimuw.cloudatlas.querysigner.QueryData;
import pl.edu.mimuw.cloudatlas.querysignerapi.QuerySignerApi;

import java.net.InetAddress;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.util.*;

/**
 * APIs
 * /
 * /query - displays query submission form
 * /installQuery - posts query installation data
 * /uninstallQuery - posts query uninstallation data
 * /contacts - GET - displays contacts submission form
 * /contacts - POST - posts contacts installation data
 * /attribs - GET - displays attribute submission form
 * /attribs - POST - posts attribute submission data
 * /values - GET - displays attributes values
 * /zones - GET - displays zone change data
 * /zones - POST - posts zone change data
 * /attribNumValues - REST API to get numerical attribute values
 * /attribAllValues - REST API to get all attribute values
 */

@Controller
public class ClientController {
    private Api agentApi;
    private QuerySignerApi querySignerApi;
    private Map<ValueTime, AttributesMap> attributes;
    private String currentZoneName;
    private static final int MAX_ENTRIES = 10;

    ClientController() {
        try {
            String agentHostname = System.getProperty("agent_hostname");
            Registry registry = LocateRegistry.getRegistry(agentHostname);
            this.agentApi = (Api) registry.lookup("Api");
            String querySignerHostname = System.getProperty("query_signer_hostname");
            Registry querySignerRegistry = LocateRegistry.getRegistry(querySignerHostname);
            this.querySignerApi = (QuerySignerApi) querySignerRegistry.lookup("QuerySignerApi");
        } catch (Exception e) {
            System.err.println("Client exception:");
            e.printStackTrace();
        }

        this.attributes = new LinkedHashMap<ValueTime, AttributesMap>() {
            protected boolean removeEldestEntry(Map.Entry<ValueTime, AttributesMap> eldest) {
                return size() > MAX_ENTRIES;
            }
        };
        this.currentZoneName = System.getProperty("zone_path");
        fetchAttributeData(); // fetch attribute data as early as possible
    }

    @GetMapping("/")
    public String homePage(Model model) {
        model.addAttribute("homeMessage", "Welcome to CloudaAtlas client interface");
        return "home";
    }

    @GetMapping("/query")
    public String queryPage(Model model) {
        model.addAttribute("queryObject", new Query());
        return "queryForm";
    }

    @PostMapping("/installQuery")
    public String installQuery(@ModelAttribute Query queryObject, Model model)  {
        boolean success = true;

        try {
            QueryData query = this.querySignerApi.signInstallQuery(queryObject.getName(), queryObject.getValue());
            this.agentApi.installQuery(queryObject.getName(), query);
        } catch (Exception e) {
            success = false;
            System.err.println("Client exception:");
            e.printStackTrace();
        }

        if (success) {
            model.addAttribute(
                    "homeMessage",
                    "Query installed successfully");
        } else {
            model.addAttribute(
                    "homeMessage",
                    "Query submission failed with a remote exception");
        }

        return "home";
    }

    @PostMapping("/uninstallQuery")
    public String uninstallQuery(@ModelAttribute Query queryObject, Model model)  {
        boolean success = true;

        try {
            QueryData query = querySignerApi.signUninstallQuery(queryObject.getName());
            this.agentApi.uninstallQuery(queryObject.getName(), query);
        } catch (Exception e) {
            success = false;
            System.err.println("Client exception:");
            e.printStackTrace();
        }

        if (success) {
            model.addAttribute(
                    "homeMessage",
                    "Query uninstalled successfully");
        } else {
            model.addAttribute(
                    "homeMessage",
                    "Query submission failed with a remote exception");
        }

        return "home";
    }

    @GetMapping("/contacts")
    public String contactPage(Model model) {
        model.addAttribute("contactsObject" , new DataStringInput());
        return "contactsForm";
    }

    public static Set<ValueContact> parseContactsString(String contactsInput) throws Exception {
        Gson gson = new Gson();
        Map<String, ArrayList> contactStrings = gson.fromJson(contactsInput, Map.class);
        Set<ValueContact> contactObjects = new HashSet<ValueContact>();
        ArrayList<Double> cAddr;
        byte[] inetArray = new byte[4];

        for (Map.Entry<String, ArrayList> cursor : contactStrings.entrySet()) {
            cAddr = cursor.getValue(); // gson always reads numerical values as doubles
            for (int i = 0; i < 4; i++) {
                inetArray[i] = (byte) cAddr.get(i).doubleValue();
            }
            contactObjects.add(new ValueContact(
                    new PathName(cursor.getKey()),
                    InetAddress.getByAddress(inetArray))
            );
        }

        return contactObjects;
    }

    @PostMapping("/contacts")
    public String contactPage(@ModelAttribute DataStringInput contactsObject, Model model) {
        boolean success = true;
        Set<ValueContact> contactObjects;

        try {
            contactObjects = parseContactsString(contactsObject.getString());
            this.agentApi.setFallbackContacts(contactObjects);
        } catch (Exception e) {
            success = false;
            System.err.println("Client exception:");
            e.printStackTrace();
        }

        if (success) {
            model.addAttribute("homeMessage", "Contact list submitted successfully");
        } else {
            model.addAttribute("homeMessage", "Contact list submission failed");
        }

        return "home";
    }

    @GetMapping("/attribs")
    public String attribPage(Model model) {
        model.addAttribute("attributeObject", new AttributeInput());
        return "attribForm";
    }

    private List<Value> parseCollectionAttributeValue(List values, ArrayList<String> types) throws Exception {
        List<Value> resultValue = new ArrayList<Value>();
        String currentTypeString = types.get(1);
        AttributeInput attributeInput = new AttributeInput();
        ArrayList<String> newTypes = new ArrayList<>(types.subList(1, types.size()));
        Gson gson = new Gson();

        for (int i = 0; i < values.size(); i++) {
            if (currentTypeString.equals("List")) {
                resultValue.add(parseListAttributeValue((List) values.get(i), newTypes));
            } else if (currentTypeString.equals("Set")) {
                resultValue.add(parseSetAttributeValue((List) values.get(i), newTypes));
            } else {
                attributeInput.setAttributeType(currentTypeString);
                attributeInput.setValueString(gson.toJson(values.get(i)));
                resultValue.add(parseAttributeValue(attributeInput));
            }
        }

        return resultValue;
    }

    private Value parseListAttributeValue(List values, ArrayList<String> types) throws Exception {
        List<Value> listResultValue = parseCollectionAttributeValue(values, types);
        ArrayList<Value> resultValue = new ArrayList<>(listResultValue);

        return new ValueList(resultValue, resultValue.iterator().next().getType());
    }

    private Value parseSetAttributeValue(List values, ArrayList<String> types) throws Exception {
        List<Value> listResultValue = parseCollectionAttributeValue(values, types);
        HashSet<Value> resultValue = new HashSet<>(listResultValue);

        return new ValueSet(resultValue, resultValue.iterator().next().getType());
    }

    private Long parseIntegerAsLong(String value) {
        Double doubleVal;

        try {
            doubleVal = Double.parseDouble(value);
            return doubleVal.longValue();
        } catch (NumberFormatException e) {
            return Long.parseLong(value);
        }
    }

    private Value parseAttributeValue(AttributeInput attributeObject) throws Exception {
        Gson gson = new Gson();
        Value attributeValue = null;

        switch (attributeObject.getAttributeType()) {
            case "Boolean":
                if (attributeObject.getValueString().toLowerCase().equals("true")) {
                    attributeValue = new ValueBoolean(true);
                } else if (attributeObject.getValueString().toLowerCase().equals("false")) {
                    attributeValue = new ValueBoolean(false);
                } else {
                    String errMsg = "Incorrect boolean value: " + attributeObject.getValueString();
                    throw new UnsupportedOperationException(errMsg);
                }
                break;
            case "Double":
                attributeValue = new ValueDouble(Double.parseDouble(attributeObject.getValueString()));
                break;
            case "Int":
                attributeValue = new ValueInt(parseIntegerAsLong(attributeObject.getValueString()));
                break;
            case "String":
                attributeValue = new ValueString(attributeObject.getValueString());
                break;
            case "Time":
                attributeValue = new ValueTime(parseIntegerAsLong(attributeObject.getValueString()));
                break;
            case "Duration":
                attributeValue = new ValueDuration(parseIntegerAsLong(attributeObject.getValueString()));
                break;
            case "Contact":
                DataStringInput contactsString = new DataStringInput();
                contactsString.setString(attributeObject.getValueString());
                attributeValue = parseContactsString(contactsString.getString()).iterator().next();
                break;
            case "List":
                List parsedListValue = gson.fromJson(attributeObject.getValueString(), List.class);
                ArrayList<String> parsedListTypes = new ArrayList<>(Arrays.asList(
                        attributeObject.getAttributeComplexType().replaceAll("\\s","").split(",")));
                attributeValue = parseListAttributeValue(parsedListValue, parsedListTypes);
                break;
            case "Set":
                List parsedSetValue = gson.fromJson(attributeObject.getValueString(), List.class);
                ArrayList<String> parsedSetTypes = new ArrayList<>(Arrays.asList(
                        attributeObject.getAttributeComplexType(). replaceAll("\\s","").split(",")));
                attributeValue = parseSetAttributeValue(parsedSetValue, parsedSetTypes);
                break;
            default:
                String errMsg = "Value type not supported: " + attributeObject.getAttributeType();
                throw new UnsupportedOperationException(errMsg);
        }

        return attributeValue;
    }

    @PostMapping("/attribs")
    public String attribPage(@ModelAttribute AttributeInput attributeObject, Model model) {
        boolean success = true;
        Value attributeValue;

        try {
            attributeValue = parseAttributeValue(attributeObject);
            agentApi.setAttributeValue(
                    attributeObject.getZoneName(),
                    attributeObject.getAttributeName(),
                    attributeValue);
        } catch (Exception e) {
            success = false;
            System.err.println("Client exception:");
            e.printStackTrace();
        }

        if (success) {
            model.addAttribute("homeMessage", "Attribute submitted successfully");
        } else {
            model.addAttribute("homeMessage", "Attribute submission failed");
        }

        return "home";
    }

    private String getAvailableZonesString() {
        boolean success = true;
        Set<String> availableZones;
        String availableZonesString = "";

        try {
            availableZones = agentApi.getZoneSet();
            availableZonesString = availableZones.toString().substring(1, availableZones.toString().length() - 1);
        } catch (Exception e) {
            success = false;
            System.err.println("Client exception:");
            e.printStackTrace();
        }

        if (success) {
            return "Available zones are: " + availableZonesString;
        } else {
            return "No zones available, error occured during fetch";
        }
    }

    @GetMapping("/values")
    public String valuesPage(Model model) {
        return "attribChart";
    }

    @Scheduled(fixedRate = 5000)
    private void fetchAttributeData() {
        AttributesMap attribData;
        ValueTime currentTime;

        try {
            if (!this.currentZoneName.isEmpty()) {
                attribData = agentApi.getZoneAttributeValues(this.currentZoneName);
                currentTime = new ValueTime(System.currentTimeMillis());
                this.attributes.put(currentTime, attribData);
            }
        } catch (Exception e) {
            System.err.println("Client exception:");
            e.printStackTrace();
        }
    }

    private ArrayList getAllAttributeValues(AttributesMap attribs, Boolean justNumerical) {
        ArrayList valuesList = new ArrayList<>();
        Value val;

        for (Map.Entry<Attribute, Value> entry : attribs) {
            val = entry.getValue();
            // casting to ValueDouble and ValueInt caused some errors
            // and gson turns all numerical values into doubles anyway
            if (justNumerical && isValueNumerical(val)) {
                valuesList.add(Double.parseDouble(val.toString()));
            } else if (!justNumerical) {
                valuesList.add(val.toString());
            }
        }

        return valuesList;
    }

    private boolean isValueNumerical(Value val) {
        Type valType = val.getType();

        if (TypePrimitive.DOUBLE.isCompatible(valType) || TypePrimitive.INTEGER.isCompatible(valType)) {
            return true;
        } else {
            return false;
        }
    }

    private AttributesMap getLastAttributesMap() {
        ArrayList<Map.Entry<ValueTime, AttributesMap>> attribsMap = new ArrayList<>(this.attributes.entrySet());
        return attribsMap.get(attribsMap.size() - 1).getValue();
    }

    private ArrayList<String> getAttributesColumnNames(Boolean justNumerical) {
        ArrayList<String> chartValueNames = new ArrayList<>();
        AttributesMap lastAttribMap = getLastAttributesMap();

        for (Map.Entry<Attribute, Value> e : lastAttribMap) {
            if (!justNumerical || isValueNumerical(e.getValue())) {
                chartValueNames.add(e.getKey().getName());
            }
        }
        chartValueNames.add(0, "Timestamp");
        return chartValueNames;
    }

    // data format compatible with Google Charts Table and Google Line Chart input
    // but it's a generic 2d array table representation
    // https://developers.google.com/chart/interactive/docs/gallery/table
    private ArrayList<ArrayList> getValuesTable(Boolean justNumerical) {
        ArrayList valueRow;
        ArrayList<ArrayList> allValues = new ArrayList<>();
        ArrayList<String> valueNames = getAttributesColumnNames(justNumerical);

        for (Map.Entry<ValueTime, AttributesMap> attribMapEntry : this.attributes.entrySet()) {
            valueRow = getAllAttributeValues(attribMapEntry.getValue(), justNumerical);
            while (valueRow.size() < valueNames.size() - 1) {
                valueRow.add(null);
            }
            valueRow.add(0, attribMapEntry.getKey().toString().substring(11, 19));
            allValues.add(valueRow);
        }

        // optional trimming of table length
        // if (allValues.size() > 10) {
        //     allValues =  new ArrayList<ArrayList>(allValues.subList(allValues.size() - 11, allValues.size() - 1));
        // }
        allValues.add(0, valueNames);
        return allValues;
    }

    private String processAttribValues(ArrayList<ArrayList> valuesTable) {
        String jsonAttributes = "";
        Gson gson = new Gson();
        jsonAttributes = gson.toJson(valuesTable);
        // System.out.println(jsonAttributes);
        return jsonAttributes;
    }

    @GetMapping("/attribNumValues")
    @ResponseBody
    public String attribNumValuesApi() {
        return processAttribValues(getValuesTable(true));
    }

    @GetMapping("/attribAllValues")
    @ResponseBody
    public String attribAllValuesApi() {
        return processAttribValues(getValuesTable(false));
    }

    @GetMapping("/zones")
    public String zonesGetPage(Model model) {
        model.addAttribute("availableZones", getAvailableZonesString());
        model.addAttribute("currentZone", "Current zone: " + this.currentZoneName);
        model.addAttribute("zoneName", new DataStringInput());
        return "zoneForm";
    }

    @PostMapping("/zones")
    public String zonesPostPage(@ModelAttribute DataStringInput zoneName, Model model) {
        this.currentZoneName = zoneName.getString();
        this.attributes.clear();
        model.addAttribute("currentZone", "Current zone: " + this.currentZoneName);
        model.addAttribute("availableZones", getAvailableZonesString());
        model.addAttribute("zoneName", new DataStringInput());
        return "zoneForm";
    }
}