using System;
using System.Data;
using System.Globalization;
using System.Collections;
using System.Collections.Specialized;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using System.Timers;
using System.Diagnostics;

namespace WmData {
    
    /// <summary>
    /// WmDataTransactionManager is the object that is responsible for 
    /// registering and importing data transactions.
    /// Created 2nd of August 2010
    /// </summary>
    public class WmDataTransactionManager {
        protected CultureInfo cultureInfoUs = null;
        protected WmGenericData data = null;
        protected WmIntermediateObjectManager intermediateObjectManager;
        protected System.Timers.Timer removeOldTransactionsTimer;
        protected int removeOldTransactionsAfterHours = 24;
        
        public WmDataTransactionManager(WmGenericData data) {
           cultureInfoUs = new CultureInfo("en-US");
           this.data = data;
        
           intermediateObjectManager = data.IntermediateObjectManager;

           removeOldTransactionsTimer = new System.Timers.Timer(60000);
           removeOldTransactionsTimer.Elapsed += new ElapsedEventHandler(removeOldTransactionsTimer_Elapsed);
           removeOldTransactionsTimer.AutoReset = true;
           removeOldTransactionsTimer.Start();
        }

        public void clearTransactions() {
            data.deleteTableContents(typeof(WmDataTransaction));
            System.Diagnostics.Trace.WriteLine("WmDataTransactionManager: Cleared all transactions.");
        }

        protected void removeOldTransactionsTimer_Elapsed(object sender, ElapsedEventArgs e) {
            removeOldTransactionsTimer.Stop();
            long removalLimitUtcTicks = DateTime.UtcNow.AddHours(-1 * removeOldTransactionsAfterHours).Ticks;

            string select = "localmomentutcticks<" + removalLimitUtcTicks;
            ArrayList tmpRes = data.getObjects(typeof(WmDataTransaction), select);
            WmDataTransaction[] oldTransactions = (WmDataTransaction[])tmpRes.ToArray(typeof(WmDataTransaction));;

            
            for (int t = 0; t < oldTransactions.Length; t++) {
                data.deleteObject(oldTransactions[t]);
            }
            if (oldTransactions.Length > 0) {
                System.Diagnostics.Trace.WriteLine("WmDataTransactionManager: Removed " + oldTransactions.Length + " old transaction(s).");
            }
            removeOldTransactionsTimer.Start();
        }

        public WmDataTransaction[] getTransactionsSince(long momentUtcTicks) {
            string select = "localmomentutcticks>" + momentUtcTicks;
            ArrayList tmpRes = data.getObjects(typeof(WmDataTransaction), select);
            tmpRes.Sort();
            return (WmDataTransaction[])tmpRes.ToArray(typeof(WmDataTransaction));
        }
        public DataRow[] getTransactionsAsDataRowsSince(long momentUtcTicks) {
            string select = "localmomentutcticks>" + momentUtcTicks;
            return data.getDataRows(typeof(WmDataTransaction), select, "localmomentutcticks ASC");
        }
        public long getLastTransactionMomentUtcTicksOnTable(string tableName) {
            string select = "SELECT localmomentutcticks FROM " + data.SqlCatalogName + ".wmdatatransaction WHERE tablename='"+tableName+"' ORDER BY localmomentutcticks DESC LIMIT 1";
            object value = data.getObjectFromSQL(select);

            long lastTransactionMomentTicksUtc = 0;
            if (value != null && !(value is DBNull)) {
                lastTransactionMomentTicksUtc = (long)value;
            }

            return lastTransactionMomentTicksUtc;
        }

        public void registerDeleteTransaction(string tableName, int rowId, long referenceTransactionMomentUtcTicks) {
            if (!tableName.Equals("wmdatatransaction")) {
                createTransactionObject(tableName, rowId, WmDataRowAction.DELETE, referenceTransactionMomentUtcTicks, null);
            }
        }

        public void registerInsertOrUpdateTransaction(string tableName, DataRow dataRow, WmDataRowAction dataRowAction, long referenceTransactionMomentUtcTicks) {
            if (!tableName.Equals("wmdatatransaction")) {

                // Step 1: Set culture to us english to make sure date time and numbers are always formatted correctly
                bool didChangeCulture = false;
                CultureInfo originalCultureInfo = Thread.CurrentThread.CurrentCulture;
                if (!Thread.CurrentThread.CurrentCulture.Name.Equals("en-US")) {
                    Thread.CurrentThread.CurrentCulture = cultureInfoUs;
                }

                // Step 2: Create the Transaction object
                int rowId = (int)dataRow["id"];
                NameValueCollection nameValueCollection = WmDataTools.getNameValueCollectionFromDataRow(dataRow);
                string nameValueString = WmDataTools.getQueryStringFromNameValueCollection(nameValueCollection);
                createTransactionObject(tableName, rowId, dataRowAction, referenceTransactionMomentUtcTicks, nameValueString);

                // Step 4: Restore the culture setting
                if (didChangeCulture) {
                    Thread.CurrentThread.CurrentCulture = originalCultureInfo;
                }

            }
        }

        public void registerInsertOrUpdateTransaction(WmIntermediateObject intermediateObject, int rowId, WmDataRowAction dataRowAction, object objectInstance, long referenceTransactionMomentUtcTicks) {
            if (!intermediateObject.TableName.Equals("wmdatatransaction")) {

                // Step 1: Set culture to us english to make sure date time and numbers are always formatted correctly
                bool didChangeCulture = false;
                CultureInfo originalCultureInfo = Thread.CurrentThread.CurrentCulture;
                if (!Thread.CurrentThread.CurrentCulture.Name.Equals("en-US")) {
                    Thread.CurrentThread.CurrentCulture = cultureInfoUs;
                }

                // Step 2: Create the Transaction object
                NameValueCollection nameValueCollection = WmDataTools.getNameValueCollectionFromObjectInstance(intermediateObject, objectInstance);
                string nameValueString = WmDataTools.getQueryStringFromNameValueCollection(nameValueCollection);
                createTransactionObject(intermediateObject.TableName, rowId, dataRowAction, referenceTransactionMomentUtcTicks, nameValueString);

                // Step 4: Restore the culture setting
                if (didChangeCulture) {
                    Thread.CurrentThread.CurrentCulture = originalCultureInfo;
                }

            }
        }

        public void registerChecksumTransaction(string tableName) {
            createTransactionObject(tableName, -1, WmDataRowAction.CHECKSUM, -1, null);
        }

        protected void createTransactionObject(string tableName, int objectId, WmDataRowAction dataRowAction, long referenceTransactionMomentUtcTicks, string nameValueString) {
            WmDataTransaction transaction = new WmDataTransaction();
            transaction.DataRowAction = dataRowAction;
            transaction.LocalMomentUtcTicks = DateTime.UtcNow.Ticks;
            transaction.RemoteMomentUtcTicks = referenceTransactionMomentUtcTicks;
            transaction.ObjectId = objectId;
            transaction.TableName = tableName;
            transaction.NameValueQueryString = nameValueString;
            transaction.TableChecksumAfterThisTransaction = data.getChecksum(tableName);
            // Step 3: Save the transaction object
            data.addObject(transaction);
        }

        


        public void importTransaction(WmDataTransaction transaction) {
            // Set culture to us english to make sure date time and numbers are always formatted correctly
            bool didChangeCulture = false;
            CultureInfo originalCultureInfo = Thread.CurrentThread.CurrentCulture;
            if (!Thread.CurrentThread.CurrentCulture.Name.Equals("en-US")) {
                Thread.CurrentThread.CurrentCulture = cultureInfoUs;
            }

            
            switch (transaction.DataRowAction) {
                case WmDataRowAction.ADD:
                    importTransactionAdd(transaction);
                    break;

                case WmDataRowAction.UPDATE:
                    importTransactionUpdate(transaction);
                    break;

                case WmDataRowAction.DELETE:
                    importTransactionDelete(transaction);
                    break;
            }

            // Restore the culture setting
            if (didChangeCulture) {
                Thread.CurrentThread.CurrentCulture = originalCultureInfo;
            }

        }
        protected void importTransactionAdd(WmDataTransaction transaction) {
            WmIntermediateObject intermediateObject = intermediateObjectManager.getExistingIntermediateObjectByTableName(transaction.TableName);
            if (intermediateObject == null) {
                throw new NullReferenceException("WmDataTransactionManager: Attempt to import object that is unknown at the Intermediate Object Manager, try to issue a local get select call first");
            }

            // create an object instance with the given properties
            object objectInstance = intermediateObject.Creator.Invoke();
            NameValueCollection nameValueCollection = transaction.getNameValueCollection();

            foreach (WmIntermediateObjectProperty objectProperty in intermediateObject.Properties) {
                objectProperty.Setter(objectInstance, objectProperty.parseValueFromString(nameValueCollection[objectProperty.DataName]));
            }

            data.addObject(objectInstance, true, transaction.LocalMomentUtcTicks);
        }

        protected void importTransactionUpdate(WmDataTransaction transaction) {
            WmIntermediateObject intermediateObject = intermediateObjectManager.getExistingIntermediateObjectByTableName(transaction.TableName);
            if (intermediateObject == null) {
                throw new NullReferenceException("WmDataTransactionManager: Attempt to update object that is unknown at the Intermediate Object Manager, try to issue a local get select call first");
            }
        
            object objectInstance = null;
            objectInstance = data.getObject(intermediateObject.ObjectType, transaction.ObjectId);

            if (objectInstance != null) {
                NameValueCollection nameValueCollection = transaction.getNameValueCollection();
                foreach (WmIntermediateObjectProperty objectProperty in intermediateObject.Properties) {
                    objectProperty.Setter(objectInstance, objectProperty.parseValueFromString(nameValueCollection[objectProperty.DataName]));
                }
                data.updateObject(objectInstance, transaction.LocalMomentUtcTicks);
            }
        }

        protected void importTransactionDelete(WmDataTransaction transaction) {
            WmIntermediateObject intermediateObject = intermediateObjectManager.getExistingIntermediateObjectByTableName(transaction.TableName);
            if (intermediateObject == null) {
                throw new NullReferenceException("WmDataTransactionManager: Attempt to delete object that is unknown at the Intermediate Object Manager, try to issue a local get select call first");
            }
            Type objectType = intermediateObject.ObjectType;

            data.deleteObject(objectType, transaction.ObjectId, transaction.LocalMomentUtcTicks);
        }
    
    }
}