using System;
using GameAnalyticsSDK.Net.Threading;
using GameAnalyticsSDK.Net.Logging;
using System.Collections.Generic;
using GameAnalyticsSDK.Net.Store;
using GameAnalyticsSDK.Net.Utilities;
using GameAnalyticsSDK.Net.Http;
using GameAnalyticsSDK.Net.State;
using GameAnalyticsSDK.Net.Validators;
using System.Globalization;

namespace GameAnalyticsSDK.Net.Events
{
    internal class GAEvents
    {
        #region Fields and properties

        private static readonly GAEvents _instance = new GAEvents();
        private const string CategorySessionStart = "user";
        private const string CategorySessionEnd = "session_end";
        private const string CategoryDesign = "design";
        private const string CategoryBusiness = "business";
        private const string CategoryProgression = "progression";
        private const string CategoryResource = "resource";
        private const string CategoryError = "error";
        private bool isRunning;
        private bool keepRunning;
        private const double ProcessEventsIntervalInSeconds = 8.0;
        private const int MaxEventCount = 500;

        private static GAEvents Instance
        {
            get
            {
                return _instance;
            }
        }

        #endregion // Fields and properties

        private GAEvents()
        {
        }

        #region Public methods

        public static void StopEventQueue()
        {
            Instance.keepRunning = false;
        }

        public static void EnsureEventQueueIsRunning()
        {
            Instance.keepRunning = true;

            if(!Instance.isRunning)
            {
                Instance.isRunning = true;
                GAThreading.ScheduleTimer(ProcessEventsIntervalInSeconds, "processEventQueue", ProcessEventQueue);
            }
        }

        public static void AddSessionStartEvent()
        {
            if(!GAState.IsEventSubmissionEnabled)
            {
                return;
            }

            string categorySessionStart = CategorySessionStart;

            // Event specific data
            JSONObject eventDict = new JSONObject();
            eventDict["category"] = categorySessionStart;

            // Increment session number  and persist
            GAState.IncrementSessionNum();
            GAStore.SetState(GAState.SessionNumKey, GAState.SessionNum.ToString(CultureInfo.InvariantCulture));

            // Add custom dimensions
            AddDimensionsToEvent(eventDict);

            // Add to store
            AddEventToStore(eventDict);

            // Log
            GALogger.I("Add SESSION START event");

            // Send event right away
            ProcessEvents(categorySessionStart, false);
        }

        public static void AddSessionEndEvent()
        {
            if(!GAState.IsEventSubmissionEnabled)
            {
                return;
            }

            long session_start_ts = GAState.SessionStart;
            long client_ts_adjusted = GAState.GetClientTsAdjusted();
            long sessionLength = client_ts_adjusted - session_start_ts;

            if(sessionLength < 0)
            {
                // Should never happen.
                // Could be because of edge cases regarding time altering on device.
                GALogger.W("Session length was calculated to be less then 0. Should not be possible. Resetting to 0.");
                sessionLength = 0;
            }

            // Event specific data
            JSONObject eventDict = new JSONObject();
            eventDict["category"] = CategorySessionEnd;
            eventDict.Add("length", new JSONNumber(sessionLength));

            // Add custom dimensions
            AddDimensionsToEvent(eventDict);

            // Add to store
            AddEventToStore(eventDict);

            // Log
            GALogger.I("Add SESSION END event.");

            // Send all event right away
            ProcessEvents("", false);
        }

        public static void AddBusinessEvent(
            string currency,
            int amount,
            string itemType,
            string itemId,
            string cartType,
            IDictionary<string, object> fields
        )
        {
            if(!GAState.IsEventSubmissionEnabled)
            {
                return;
            }

            // Validate event params
            if (!GAValidator.ValidateBusinessEvent(currency, amount, cartType, itemType, itemId))
            {
                //GAHTTPApi.Instance.SendSdkErrorEvent(EGASdkErrorType.Rejected);
                return;
            }

            // Create empty eventData
            JSONObject eventDict = new JSONObject();

            // Increment transaction number and persist
            GAState.IncrementTransactionNum();
            GAStore.SetState(GAState.TransactionNumKey, GAState.TransactionNum.ToString(CultureInfo.InvariantCulture));

            // Required
            eventDict["event_id"] = itemType + ":" + itemId;
            eventDict["category"] = CategoryBusiness;
            eventDict["currency"] = currency;
            eventDict.Add("amount", new JSONNumber(amount));
            eventDict.Add(GAState.TransactionNumKey, new JSONNumber(GAState.TransactionNum));

            // Optional
            if (!string.IsNullOrEmpty(cartType))
            {
                eventDict.Add("cart_type", cartType);
            }

            // Add custom dimensions
            AddDimensionsToEvent(eventDict);

            // Add custom fields
            AddFieldsToEvent(eventDict, GAState.ValidateAndCleanCustomFields(fields));

            // Log
            GALogger.I("Add BUSINESS event: {currency:" + currency + ", amount:" + amount + ", itemType:" + itemType + ", itemId:" + itemId + ", cartType:" + cartType + "}");

            // Send to store
            AddEventToStore(eventDict);
        }

        public static void AddResourceEvent(EGAResourceFlowType flowType, string currency, double amount, string itemType, string itemId, IDictionary<string, object> fields)
        {
            if(!GAState.IsEventSubmissionEnabled)
            {
                return;
            }

            // Validate event params
            if (!GAValidator.ValidateResourceEvent(flowType, currency, (long)amount, itemType, itemId))
            {
                //GAHTTPApi.Instance.SendSdkErrorEvent(EGASdkErrorType.Rejected);
                return;
            }

            // If flow type is sink reverse amount
            if (flowType == EGAResourceFlowType.Sink)
            {
                amount *= -1;
            }

            // Create empty eventData
            JSONObject eventDict = new JSONObject();

            // insert event specific values
            string flowTypeString = ResourceFlowTypeToString(flowType);
            eventDict["event_id"] = flowTypeString + ":" + currency + ":" + itemType + ":" + itemId;
            eventDict["category"] = CategoryResource;
            eventDict.Add("amount", new JSONNumber(amount));

            // Add custom dimensions
            AddDimensionsToEvent(eventDict);

            // Add custom fields
            AddFieldsToEvent(eventDict, GAState.ValidateAndCleanCustomFields(fields));

            // Log
            GALogger.I("Add RESOURCE event: {currency:" + currency + ", amount:" + amount + ", itemType:" + itemType + ", itemId:" + itemId + "}");

            // Send to store
            AddEventToStore(eventDict);
        }

        public static void AddProgressionEvent(EGAProgressionStatus progressionStatus, string progression01, string progression02, string progression03, double score, bool sendScore, IDictionary<string, object> fields)
        {
            if(!GAState.IsEventSubmissionEnabled)
            {
                return;
            }

            string progressionStatusString = ProgressionStatusToString(progressionStatus);

            // Validate event params
            if (!GAValidator.ValidateProgressionEvent(progressionStatus, progression01, progression02, progression03))
            {
                //GAHTTPApi.Instance.SendSdkErrorEvent(EGASdkErrorType.Rejected);
                return;
            }

            // Create empty eventData
            JSONObject eventDict = new JSONObject();

            // Progression identifier
            string progressionIdentifier;

            if (string.IsNullOrEmpty(progression02))
            {
                progressionIdentifier = progression01;
            }
            else if (string.IsNullOrEmpty(progression03))
            {
                progressionIdentifier = progression01 + ":" + progression02;
            }
            else
            {
                progressionIdentifier = progression01 + ":" + progression02 + ":" + progression03;
            }

            // Append event specifics
            eventDict["category"] = CategoryProgression;
            eventDict["event_id"] = progressionStatusString + ":" + progressionIdentifier;

            // Attempt
            double attempt_num = 0;

            // Add score if specified and status is not start
            if (sendScore && progressionStatus != EGAProgressionStatus.Start)
            {
                eventDict.Add("score", new JSONNumber(score));
            }

            // Count attempts on each progression fail and persist
            if (progressionStatus == EGAProgressionStatus.Fail)
            {
                // Increment attempt number
                GAState.IncrementProgressionTries(progressionIdentifier);
            }

            // increment and add attempt_num on complete and delete persisted
            if (progressionStatus == EGAProgressionStatus.Complete)
            {
                // Increment attempt number
                GAState.IncrementProgressionTries(progressionIdentifier);

                // Add to event
                attempt_num = GAState.GetProgressionTries(progressionIdentifier);
                eventDict.Add("attempt_num", new JSONNumber(attempt_num));

                // Clear
                GAState.ClearProgressionTries(progressionIdentifier);
            }

            // Add custom dimensions
            AddDimensionsToEvent(eventDict);

            // Add custom fields
            AddFieldsToEvent(eventDict, GAState.ValidateAndCleanCustomFields(fields));

            // Log
            GALogger.I("Add PROGRESSION event: {status:" + progressionStatusString + ", progression01:" + progression01 + ", progression02:" + progression02 + ", progression03:" + progression03 + ", score:" + score + ", attempt:" + attempt_num + "}");

            // Send to store
            AddEventToStore(eventDict);
        }

        public static void AddDesignEvent(string eventId, double value, bool sendValue, IDictionary<string, object> fields)
        {
            if(!GAState.IsEventSubmissionEnabled)
            {
                return;
            }

            // Validate
            if (!GAValidator.ValidateDesignEvent(eventId, value))
            {
                //GAHTTPApi.Instance.SendSdkErrorEvent(EGASdkErrorType.Rejected);
                return;
            }

            // Create empty eventData
            JSONObject eventData = new JSONObject();

            // Append event specifics
            eventData["category"] = CategoryDesign;
            eventData["event_id"] = eventId;

            if(sendValue)
            {
                eventData.Add("value", new JSONNumber(value));
            }

            // Add custom dimensions
            AddDimensionsToEvent(eventData);

            // Add custom fields
            AddFieldsToEvent(eventData, GAState.ValidateAndCleanCustomFields(fields));

            // Log
            GALogger.I("Add DESIGN event: {eventId:" + eventId + ", value:" + value + "}");

            // Send to store
            AddEventToStore(eventData);
        }

        public static void AddErrorEvent(EGAErrorSeverity severity, string message, IDictionary<string, object> fields)
        {
            if(!GAState.IsEventSubmissionEnabled)
            {
                return;
            }

            string severityString = ErrorSeverityToString(severity);

            // Validate
            if (!GAValidator.ValidateErrorEvent(severity, message))
            {
                //GAHTTPApi.Instance.SendSdkErrorEvent(EGASdkErrorType.Rejected);
                return;
            }

            // Create empty eventData
            JSONObject eventData = new JSONObject();

            // Append event specifics
            eventData["category"] = CategoryError;
            eventData["severity"] = severityString;
            eventData["message"] = message;

            // Add custom dimensions
            AddDimensionsToEvent(eventData);

            // Add custom fields
            AddFieldsToEvent(eventData, GAState.ValidateAndCleanCustomFields(fields));

            // Log
            GALogger.I("Add ERROR event: {severity:" + severityString + ", message:" + message + "}");

            // Send to store
            AddEventToStore(eventData);
        }

        #endregion // Public methods

        #region Private methods

        private static void ProcessEventQueue()
        {
            ProcessEvents("", true);
            if(Instance.keepRunning)
            {
                GAThreading.ScheduleTimer(ProcessEventsIntervalInSeconds, "processEventQueue", ProcessEventQueue);
            }
            else
            {
                Instance.isRunning = false;
            }
        }

#if WINDOWS_UWP || WINDOWS_WSA
        private async static void ProcessEvents(string category, bool performCleanUp)
#else
        private static void ProcessEvents(string category, bool performCleanUp)
#endif
        {
            if(!GAState.IsEventSubmissionEnabled)
            {
                return;
            }

            try
            {
                string requestIdentifier = Guid.NewGuid().ToString();

                string selectSql;
                string updateSql;
                string deleteSql = "DELETE FROM ga_events WHERE status = '" + requestIdentifier + "'";
                string putbackSql = "UPDATE ga_events SET status = 'new' WHERE status = '" + requestIdentifier + "';";

                // Cleanup
                if(performCleanUp)
                {
                    CleanupEvents();
                    FixMissingSessionEndEvents();
                }

                // Prepare SQL
                string andCategory = "";
                if(!string.IsNullOrEmpty(category))
                {
                    andCategory = " AND category='" + category + "' ";
                }
                selectSql = "SELECT event FROM ga_events WHERE status = 'new' " + andCategory + ";";
                updateSql = "UPDATE ga_events SET status = '" + requestIdentifier + "' WHERE status = 'new' " + andCategory + ";";

                // Get events to process
                JSONArray events = GAStore.ExecuteQuerySync(selectSql);

                // Check for errors or empty
                if(events == null || events.Count == 0)
                {
                    GALogger.I("Event queue: No events to send");
                    UpdateSessionTime();
                    return;
                }

                // Check number of events and take some action if there are too many?
                if(events.Count > MaxEventCount)
                {
                    // Make a limit request
                    selectSql = "SELECT client_ts FROM ga_events WHERE status = 'new' " + andCategory + " ORDER BY client_ts ASC LIMIT 0," + MaxEventCount + ";";
                    events = GAStore.ExecuteQuerySync(selectSql);
                    if(events == null)
                    {
                        return;
                    }

                    // Get last timestamp
                    JSONNode lastItem = events[events.Count - 1];
                    string lastTimestamp = lastItem["client_ts"].Value;

                    // Select again
                    selectSql = "SELECT event FROM ga_events WHERE status = 'new' " + andCategory + " AND client_ts<='" + lastTimestamp + "';";
                    events = GAStore.ExecuteQuerySync(selectSql);
                    if (events == null)
                    {
                        return;
                    }

                    // Update sql
                    updateSql = "UPDATE ga_events SET status='" + requestIdentifier + "' WHERE status='new' " + andCategory + " AND client_ts<='" + lastTimestamp + "';";
                }

                // Log
                GALogger.I("Event queue: Sending " + events.Count + " events.");

                // Set status of events to 'sending' (also check for error)
                if (GAStore.ExecuteQuerySync(updateSql) == null)
                {
                    return;
                }

                // Create payload data from events
                List<JSONNode> payloadArray = new List<JSONNode>();

                for(int i = 0; i < events.Count; ++i)
                {
                    JSONNode ev = events[i];
                    JSONNode eventDict = null;

                    try
                    {
                        eventDict = JSONNode.LoadFromBinaryBase64(ev["event"].Value);
                    }
                    catch(Exception)
                    {
                        //GALogger.E("ProcessEvents: Error decoding json, " + e);
                    }

                    if (eventDict != null && eventDict.Count != 0)
                    {
                        payloadArray.Add(eventDict);
                    }
                }

                // send events
#if WINDOWS_UWP || WINDOWS_WSA
                KeyValuePair<EGAHTTPApiResponse, JSONNode> result = await GAHTTPApi.Instance.SendEventsInArray(payloadArray);
#else
                KeyValuePair<EGAHTTPApiResponse, JSONNode> result = GAHTTPApi.Instance.SendEventsInArray(payloadArray);
#endif

                ProcessEvents(result.Key, result.Value, putbackSql, deleteSql, payloadArray.Count);
            }
            catch (Exception e)
            {
                GALogger.E("Error during ProcessEvents(): " + e);
            }
        }

        public static void ProcessEvents(EGAHTTPApiResponse responseEnum, JSONNode dataDict, string putbackSql, string deleteSql, int eventCount)
        {
            if(responseEnum == EGAHTTPApiResponse.Ok)
            {
                // Delete events
                GAStore.ExecuteQuerySync(deleteSql);
                GALogger.I("Event queue: " + eventCount + " events sent.");
            }
            else
            {
                // Put events back (Only in case of no response)
                if(responseEnum == EGAHTTPApiResponse.NoResponse)
                {
                    GALogger.W("Event queue: Failed to send events to collector - Retrying next time");
                    GAStore.ExecuteQuerySync(putbackSql);
                    // Delete events (When getting some anwser back always assume events are processed)
                }
                else
                {
                    if(dataDict != null)
                    {
                        JSONNode json = null;
                        IEnumerator<JSONNode> enumerator = dataDict.Children.GetEnumerator();
                        if(enumerator.MoveNext())
                        {
                            json = enumerator.Current;
                        }

                        if(responseEnum == EGAHTTPApiResponse.BadRequest && json is JSONArray)
                        {
                            GALogger.W("Event queue: " + eventCount + " events sent. " + dataDict.Count + " events failed GA server validation.");
                        }
                        else
                        {
                            GALogger.W("Event queue: Failed to send events.");
                        }
                    }
                    else
                    {
                        GALogger.W("Event queue: Failed to send events.");
                    }

                    GAStore.ExecuteQuerySync(deleteSql);
                }
            }
        }

        private static void CleanupEvents()
        {
            GAStore.ExecuteQuerySync("UPDATE ga_events SET status = 'new';");
        }

        private static void FixMissingSessionEndEvents()
        {
            if(!GAState.IsEventSubmissionEnabled)
            {
                return;
            }

            // Get all sessions that are not current
            Dictionary<string, object> parameters = new Dictionary<string, object>();
            parameters.Add("$session_id", GAState.SessionId);


            string sql = "SELECT timestamp, event FROM ga_session WHERE session_id != $session_id;";
            JSONArray sessions = GAStore.ExecuteQuerySync(sql, parameters);

            if (sessions == null || sessions.Count == 0)
            {
                return;
            }

            GALogger.I(sessions.Count + " session(s) located with missing session_end event.");

            // Add missing session_end events
            for (int i = 0; i < sessions.Count; ++i)
            {
                JSONNode session = sessions[i];
                JSONNode sessionEndEvent = null;

                try
                {
                    sessionEndEvent = JSONNode.LoadFromBinaryBase64(session["event"].Value);
                }
                catch(Exception)
                {
                    //GALogger.E("FixMissingSessionEndEvents: Error decoding json, " + e);
                }

                if(sessionEndEvent != null)
                {
                    long event_ts = sessionEndEvent["client_ts"].AsLong;
                    long start_ts = session["timestamp"].AsLong;

                    long length = event_ts - start_ts;
                    length = Math.Max(0, length);

                    GALogger.D("fixMissingSessionEndEvents length calculated: " + length);

                    sessionEndEvent["category"] = CategorySessionEnd;
                    sessionEndEvent.Add("length", new JSONNumber(length));

                    // Add to store
                    AddEventToStore(sessionEndEvent.AsObject);
                }
                else
                {
                    GALogger.I("Problem decoding session_end event. Skipping  this session_end event.");
                }
            }
        }

#if WINDOWS_WSA
        private async static void AddEventToStore(JSONObject eventData)
#else
        private static void AddEventToStore(JSONObject eventData)
#endif
        {
            // Check if datastore is available
            if (!GAStore.IsTableReady)
            {
                GALogger.W("Could not add event: SDK datastore error");
                return;
            }

            // Check if we are initialized
            if (!GAState.Initialized)
            {
                GALogger.W("Could not add event: SDK is not initialized");
                return;
            }

            try
            {
                // Check db size limits (10mb)
                // If database is too large block all except user, session and business
                if (GAStore.IsDbTooLargeForEvents && !GAUtilities.StringMatch(eventData["category"].Value, "^(user|session_end|business)$"))
                {
                    GALogger.W("Database too large. Event has been blocked.");
                    return;
                }

                // Get default annotations
                JSONObject ev = GAState.GetEventAnnotations();

                // Create json with only default annotations
                string jsonDefaults = ev.SaveToBinaryBase64();

                // Merge with eventData
                foreach(KeyValuePair<string,JSONNode> pair in eventData)
                {
                    ev.Add(pair.Key, pair.Value);
                }

                // Create json string representation
                string json = ev.ToString();

                // output if VERBOSE LOG enabled

                GALogger.II("Event added to queue: " + json);

                // Add to store
                Dictionary<string, object> parameters = new Dictionary<string, object>();
                parameters.Add("$status", "new");
                parameters.Add("$category", ev["category"].Value);
                parameters.Add("$session_id", ev["session_id"].Value);
                parameters.Add("$client_ts", ev["client_ts"].Value);
                parameters.Add("$event", ev.SaveToBinaryBase64());
                string sql = "INSERT INTO ga_events (status, category, session_id, client_ts, event) VALUES($status, $category, $session_id, $client_ts, $event);";

                GAStore.ExecuteQuerySync(sql, parameters);

                // Add to session store if not last
                if (eventData["category"].Value.Equals(CategorySessionEnd))
                {
                    parameters.Clear();
                    parameters.Add("$session_id", ev["session_id"].Value);
                    sql = "DELETE FROM ga_session WHERE session_id = $session_id;";
                    GAStore.ExecuteQuerySync(sql, parameters);
                }
                else
                {
                    sql = "INSERT OR REPLACE INTO ga_session(session_id, timestamp, event) VALUES($session_id, $timestamp, $event);";
                    parameters.Clear();
                    parameters.Add("$session_id", ev["session_id"].Value);
                    parameters.Add("$timestamp", GAState.SessionStart);
                    parameters.Add("$event", jsonDefaults);
                    GAStore.ExecuteQuerySync(sql, parameters);
                }
            }
            catch (Exception e)
            {
                GALogger.E("addEventToStoreWithEventData: error using json");
                GALogger.E(e.ToString());
            }
        }

        private static void AddDimensionsToEvent(JSONObject eventData)
        {
            if (eventData == null)
            {
                return;
            }
            // add to dict (if not nil)
            if (!string.IsNullOrEmpty(GAState.CurrentCustomDimension01))
            {
                eventData["custom_01"] = GAState.CurrentCustomDimension01;
            }
            if (!string.IsNullOrEmpty(GAState.CurrentCustomDimension02))
            {
                eventData["custom_02"] = GAState.CurrentCustomDimension02;
            }
            if (!string.IsNullOrEmpty(GAState.CurrentCustomDimension03))
            {
                eventData["custom_03"] = GAState.CurrentCustomDimension03;
            }
        }

        private static void AddFieldsToEvent(JSONObject eventData, JSONObject fields)
        {
            if (eventData == null)
            {
                return;
            }

            if(fields != null && fields.Count > 0)
            {
                eventData["custom_fields"] = fields;
            }
        }

        private static string ResourceFlowTypeToString(EGAResourceFlowType value)
        {
            switch(value)
            {
                case EGAResourceFlowType.Source:
                    {
                        return "Source";
                    }

                case EGAResourceFlowType.Sink:
                    {
                        return "Sink";
                    }

                default:
                    {
                        return "";
                    }
            }
        }

        private static string ProgressionStatusToString(EGAProgressionStatus value)
        {
            switch(value)
            {
                case EGAProgressionStatus.Start:
                    {
                        return "Start";
                    }

                case EGAProgressionStatus.Complete:
                    {
                        return "Complete";
                    }

                case EGAProgressionStatus.Fail:
                    {
                        return "Fail";
                    }

                default:
                    {
                        return "";
                    }
            }
        }

        private static void UpdateSessionTime()
        {
            if(GAState.SessionIsStarted())
            {
                JSONObject ev = GAState.GetEventAnnotations();
                string jsonDefaults = ev.SaveToBinaryBase64();
                string sql = "INSERT OR REPLACE INTO ga_session(session_id, timestamp, event) VALUES($session_id, $timestamp, $event);";
                Dictionary<string, object> parameters = new Dictionary<string, object>();
                parameters.Add("$session_id", ev["session_id"].Value);
                parameters.Add("$timestamp", GAState.SessionStart);
                parameters.Add("$event", jsonDefaults);
                GAStore.ExecuteQuerySync(sql, parameters);
            }
        }

        private static string ErrorSeverityToString(EGAErrorSeverity value)
        {
            switch(value)
            {
                case EGAErrorSeverity.Debug:
                    {
                        return "debug";
                    }

                case EGAErrorSeverity.Info:
                    {
                        return "info";
                    }

                case EGAErrorSeverity.Warning:
                    {
                        return "warning";
                    }

                case EGAErrorSeverity.Error:
                    {
                        return "error";
                    }

                case EGAErrorSeverity.Critical:
                    {
                        return "critical";
                    }

                default:
                    {
                        return "";
                    }
            }
        }

#endregion // Private methods
    }
}