//******************************************************************************************************
//  IMeasurementExtensions.cs - Gbtc
//
//  Copyright © 2016, Grid Protection Alliance.  All Rights Reserved.
//
//  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See
//  the NOTICE file distributed with this work for additional information regarding copyright ownership.
//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may not use this
//  file except in compliance with the License. You may obtain a copy of the License at:
//
//      http://opensource.org/licenses/MIT
//
//  Unless agreed to in writing, the subject software distributed under the License is distributed on an
//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the
//  License for the specific language governing permissions and limitations.
//
//  Code Modification History:
//  ----------------------------------------------------------------------------------------------------
//  09/02/2010 - J. Ritchie Carroll
//       Generated original version of source code.
//
//******************************************************************************************************

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using GSF.Collections;

namespace GSF.TimeSeries
{
    /// <summary>
    /// Defines static extension functions for <see cref="IMeasurement"/> implementations.
    /// </summary>
    /// <remarks>
    /// These helper functions map to the previously defined corresponding properties to help with the transition of <see cref="MeasurementStateFlags"/>.
    /// </remarks>
    public static class IMeasurementExtensions
    {
        private static readonly ConcurrentDictionary<string, int> s_signalTypeIDs = new ConcurrentDictionary<string, int>();
        private static readonly ConcurrentDictionary<Guid, int> s_signalTypeIDCache = new ConcurrentDictionary<Guid, int>();

        /// <summary>
        /// Returns <c>true</c> if <see cref="MeasurementStateFlags.BadData"/> is not set.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> instance to test.</param>
        /// <returns><c>true</c> if <see cref="MeasurementStateFlags.BadData"/> is not set.</returns>
        public static bool ValueQualityIsGood(this IMeasurement measurement) => (measurement.StateFlags & MeasurementStateFlags.BadData) == 0;

        /// <summary>
        /// Returns <c>true</c> if <see cref="MeasurementStateFlags.BadTime"/> is not set.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> instance to test.</param>
        /// <returns><c>true</c> if <see cref="MeasurementStateFlags.BadTime"/> is not set.</returns>
        public static bool TimestampQualityIsGood(this IMeasurement measurement) => (measurement.StateFlags & MeasurementStateFlags.BadTime) == 0;

        /// <summary>
        /// Gets derived quality flags from a set of source measurements.
        /// </summary>
        /// <param name="measurements">Source measurements.</param>
        /// <returns>Derived quality flags.</returns>
        public static MeasurementStateFlags DeriveQualityFlags(this IEnumerable<IMeasurement> measurements)
        {
            MeasurementStateFlags derivedQuality = MeasurementStateFlags.Normal;
            MeasurementStateFlags[] stateFlags = measurements.Select(measurement => measurement.StateFlags).ToArray();

            bool dataQualityIsBad(MeasurementStateFlags flags) => (flags & MeasurementStateFlags.BadData) > 0;
            bool timeQualityIsBad(MeasurementStateFlags flags) => (flags & MeasurementStateFlags.BadTime) > 0;

            if (stateFlags.Any(dataQualityIsBad))
                derivedQuality |= MeasurementStateFlags.BadData;

            if (stateFlags.Any(timeQualityIsBad))
                derivedQuality |= MeasurementStateFlags.BadTime;

            return derivedQuality;
        }

        /// <summary>
        /// Returns <c>true</c> if <see cref="MeasurementStateFlags.DiscardedValue"/> is set.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> instance to test.</param>
        /// <returns><c>true</c> if <see cref="MeasurementStateFlags.DiscardedValue"/> is not set.</returns>
        public static bool IsDiscarded(this IMeasurement measurement) => (measurement.StateFlags & MeasurementStateFlags.DiscardedValue) > 0;

        /// <summary>
        /// Returns <c>true</c> if <see cref="MeasurementStateFlags.CalculatedValue"/> is set.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> instance to test.</param>
        /// <returns><c>true</c> if <see cref="MeasurementStateFlags.CalculatedValue"/> is not set.</returns>
        public static bool IsCalculated(this IMeasurement measurement) => (measurement.StateFlags & MeasurementStateFlags.CalculatedValue) > 0;

        /// <summary>
        /// Returns the measurement ID if defined, otherwise the run-time signal ID associated with the measurement key.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> instance to test.</param>
        /// <returns>Measurement ID if defined, otherwise the run-time signal ID associated with the measurement key.</returns>
        public static Guid RuntimeSignalID(this IMeasurement measurement) => measurement.ID;

        /// <summary>
        /// Returns the <see cref="MeasurementKey"/> values of a <see cref="IMeasurement"/> enumeration.
        /// </summary>
        /// <param name="measurements"><see cref="IMeasurement"/> enumeration to convert.</param>
        /// <returns><see cref="MeasurementKey"/> values of the <see cref="IMeasurement"/> enumeration.</returns>
        public static MeasurementKey[] MeasurementKeys(this IEnumerable<IMeasurement> measurements) => measurements == null ? new MeasurementKey[0] : measurements.Select(m => m.Key).ToArray();

        /// <summary>
        /// Gets a unique (run-time only) signal type ID for the given <paramref name="measurement"/> useful for sorting.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> to obtain signal type for.</param>
        /// <param name="dataSource"><see cref="DataSet"/> that contains measurement metadata.</param>
        /// <returns>Unique (run-time only) signal type ID for the given <paramref name="measurement"/>.</returns>
        // This uses string hash code over something like item count + 1 to generate a unique run-time ID of the signal type since chances of a hash code collision
        // over a small set of signal types is much smaller than the possibility of duplicates due to possible race conditions when using item count + 1
        public static int GetSignalType(this IMeasurement measurement, DataSet dataSource) => s_signalTypeIDCache.GetOrAdd(measurement.ID, signalID => s_signalTypeIDs.GetOrAdd(LookupSignalType(signalID, dataSource), signalType => signalType.GetHashCode()));

        /// <summary>
        /// Sets the tag name for a <see cref="IMeasurement"/>.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> to create new <see cref="MeasurementMetadata"/> for.</param>
        /// <param name="tagName">New tag name value to assign to measurement's metadata.</param>
        public static void SetTagName(this IMeasurement measurement, string tagName) => measurement.Metadata = measurement.Metadata.ChangeTagName(tagName);

        /// <summary>
        /// Sets the associated <see cref="MeasurementKey"/> for a <see cref="IMeasurement"/>.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> to create new <see cref="MeasurementMetadata"/> for.</param>
        /// <param name="key">New measurement key value to assign to measurement's metadata.</param>
        public static void SetKey(this IMeasurement measurement, MeasurementKey key) => measurement.Metadata = measurement.Metadata.ChangeKey(key);

        /// <summary>
        /// Sets the adder (i.e., "b" of y = mx + b) for a <see cref="IMeasurement"/>.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> to create new <see cref="MeasurementMetadata"/> for.</param>
        /// <param name="adder">New adder value to assign to measurement's metadata.</param>
        public static void SetAdder(this IMeasurement measurement, double adder) => measurement.Metadata = measurement.Metadata.ChangeAdder(adder);

        /// <summary>
        /// Sets the multiplier (i.e., "m" of y = mx + b) for a <see cref="IMeasurement"/>.
        /// </summary>
        /// <param name="measurement"><see cref="IMeasurement"/> to create new <see cref="MeasurementMetadata"/> for.</param>
        /// <param name="multiplier">New multiplier value to assign to measurement's metadata.</param>
        public static void SetMultiplier(this IMeasurement measurement, double multiplier) => measurement.Metadata = measurement.Metadata.ChangeMultiplier(multiplier);

        /// <summary>
        /// Gets a single column of measurement data from a two dimensional data window.
        /// </summary>
        /// <param name="dataWindow">Target data window.</param>
        /// <param name="columnIndex">Index of column to return.</param>
        /// <returns>All values from <paramref name="columnIndex"/> in <paramref name="dataWindow"/>.</returns>
        public static IMeasurement[] GetDataColumn(this IMeasurement[,] dataWindow, int columnIndex) => dataWindow.GetColumn(columnIndex).ToArray();

        // Lookup signal type for given measurement ID
        private static string LookupSignalType(Guid signalID, DataSet dataSource)
        {
            try
            {
                DataRow[] filteredRows = dataSource.Tables["ActiveMeasurements"].Select($"SignalID = '{signalID}'");
                return filteredRows.Length > 0 ? filteredRows[0]["SignalType"].ToString().ToUpper().Trim() : "NONE";
            }
            catch
            {
                return "NONE";
            }
        }
    }
}