// Copyright (C) Stichting Deltares 2017. All rights reserved.
//
// This file is part of Ringtoets.
//
// Ringtoets is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// All names, logos, and references to "Deltares" are registered trademarks of
// Stichting Deltares and remain full property of Stichting Deltares at all times.
// All rights reserved.

using System;
using System.Data;
using System.Data.SQLite;
using Core.Common.Base.IO;
using Core.Common.IO.Readers;
using Core.Common.Utils.Builders;
using Ringtoets.MacroStabilityInwards.IO.Builders;
using Ringtoets.MacroStabilityInwards.IO.Exceptions;
using Ringtoets.MacroStabilityInwards.IO.Properties;
using Ringtoets.MacroStabilityInwards.IO.SoilProfile.Schema;
using Ringtoets.MacroStabilityInwards.Primitives;

namespace Ringtoets.MacroStabilityInwards.IO.SoilProfile
{
    /// <summary>
    /// This class reads a SqLite database file and constructs <see cref="MacroStabilityInwardsSoilProfile1D"/> instances from this database.
    /// </summary>
    public class MacroStabilityInwardsSoilProfileReader : SqLiteDatabaseReaderBase, IRowBasedDatabaseReader
    {
        private const string mechanismName = "Piping";
        private const string mechanismParameterName = "mechanism";

        private IDataReader dataReader;

        /// <summary>
        /// Creates a new instance of <see cref="MacroStabilityInwardsSoilProfileReader"/> which will use the <paramref name="databaseFilePath"/>
        /// as its source. The reader will not point to any record at the start. Use <see cref="MoveNext"/> to start reading
        /// profiles.
        /// </summary>
        /// <param name="databaseFilePath">The path of the database file to open.</param>
        /// <exception cref="CriticalFileReadException">Thrown when:
        /// <list type="bullet">
        /// <item>The <paramref name="databaseFilePath"/> contains invalid characters.</item>
        /// <item>No file could be found at <paramref name="databaseFilePath"/>.</item>
        /// <item>Preparing the queries to read from the database failed.</item>
        /// </list>
        /// </exception>
        public MacroStabilityInwardsSoilProfileReader(string databaseFilePath) : base(databaseFilePath)
        {
            VerifyVersion(databaseFilePath);
            InitializeReader();
        }

        /// <summary>
        /// Gets the total number of profiles that can be read from the database.
        /// </summary>
        public int Count { get; private set; }

        /// <summary>
        /// Gets a value indicating whether or not more soil profiles can be read using 
        /// the <see cref="MacroStabilityInwardsSoilProfileReader"/>.
        /// </summary>
        public bool HasNext { get; private set; }

        /// <summary>
        /// Reads the information for the next profile from the database and creates a 
        /// <see cref="MacroStabilityInwardsSoilProfile1D"/> instance of the information.
        /// </summary>
        /// <returns>The next <see cref="MacroStabilityInwardsSoilProfile1D"/> from the database, or <c>null</c> if no more profiles can be read.</returns>
        /// <exception cref="MacroStabilityInwardsSoilProfileReadException">Thrown when reading the profile in the database contained a non-parsable geometry.</exception>
        /// <exception cref="CriticalFileReadException">Thrown when the database returned incorrect values for required properties.</exception>
        public MacroStabilityInwardsSoilProfile1D ReadProfile()
        {
            if (!HasNext)
            {
                return null;
            }

            try
            {
                return ReadMacroStabilityInwardsSoilProfile();
            }
            catch (InvalidCastException e)
            {
                string message = new FileReaderErrorMessageBuilder(Path).Build(Resources.MacroStabilityInwardsSoilProfileReader_Critical_Unexpected_value_on_column);
                throw new CriticalFileReadException(message, e);
            }
        }

        protected override void Dispose(bool disposing)
        {
            dataReader?.Dispose();
            base.Dispose(disposing);
        }

        /// <summary>
        /// Moves the reader to the next record in the database.
        /// </summary>
        public void MoveNext()
        {
            HasNext = MoveNext(dataReader);
        }

        /// <summary>
        /// Reads the value in the column with name <paramref name="columnName"/> from the 
        /// current row that's being pointed at.
        /// </summary>
        /// <typeparam name="T">The type of object to read.</typeparam>
        /// <param name="columnName">The name of the column to read from.</param>
        /// <returns>The value in the column, or <c>null</c> if the value was <see cref="DBNull.Value"/>.</returns>
        /// <exception cref="InvalidCastException">Thrown when the value in the column could not be casted to type <typeparamref name="T"/>.</exception>
        public T ReadOrDefault<T>(string columnName)
        {
            object valueObject = dataReader[columnName];
            if (valueObject.Equals(DBNull.Value))
            {
                return default(T);
            }
            return (T) valueObject;
        }

        /// <summary>
        /// Reads a value at column <paramref name="columnName"/> from the database.
        /// </summary>
        /// <typeparam name="T">The expected type of value in the column with name <paramref name="columnName"/>.</typeparam>
        /// <param name="columnName">The name of the column to read from.</param>
        /// <returns>The read value from the column with name <paramref name="columnName"/>.</returns>
        /// <exception cref="InvalidCastException">Thrown when the value in the column was not of type <typeparamref name="T"/>.</exception>
        public T Read<T>(string columnName)
        {
            return (T) dataReader[columnName];
        }

        private void VerifyVersion(string databaseFilePath)
        {
            using (var versionReader = new SoilDatabaseVersionReader(databaseFilePath))
            {
                try
                {
                    versionReader.VerifyVersion();
                }
                catch (CriticalFileReadException)
                {
                    CloseConnection();
                    throw;
                }
            }
        }

        /// <summary>
        /// Reads a <see cref="MacroStabilityInwardsSoilProfile1D"/> from the database.
        /// </summary>
        /// <returns>A new <see cref="MacroStabilityInwardsSoilProfile1D"/>.</returns>
        /// <exception cref="MacroStabilityInwardsSoilProfileReadException">Thrown when a recoverable error occurred while reading from the database.</exception>
        /// <exception cref="InvalidCastException">Thrown when recovering from the <see cref="MacroStabilityInwardsSoilProfileReadException"/> failed.</exception>
        private MacroStabilityInwardsSoilProfile1D ReadMacroStabilityInwardsSoilProfile()
        {
            try
            {
                var dimensionValue = Read<long>(SoilProfileTableColumns.Dimension);
                return dimensionValue == 1 ? SoilProfile1DReader.ReadFrom(this) : SoilProfile2DReader.ReadFrom(this);
            }
            catch (MacroStabilityInwardsSoilProfileReadException e)
            {
                MoveToNextProfile(e.ProfileName);
                throw;
            }
        }

        /// <summary>
        /// Steps through the result rows until a row is read which' profile name differs from <paramref name="profileName"/>.
        /// </summary>
        /// <param name="profileName">The name of the profile to skip.</param>
        private void MoveToNextProfile(string profileName)
        {
            while (HasNext && Read<string>(SoilProfileTableColumns.ProfileName).Equals(profileName))
            {
                MoveNext();
            }
        }

        /// <summary>
        /// Prepares a new data reader with queries for obtaining the profiles and updates the reader
        /// so that it points to the first row of the result set.
        /// </summary>
        /// <exception cref="MacroStabilityInwardsSoilProfileReadException">Thrown when the amount of profiles in database could not be read.</exception>
        /// <exception cref="CriticalFileReadException">A query could not be executed on the database schema.</exception>
        private void InitializeReader()
        {
            try
            {
                PrepareReader();
                GetCount();
            }
            catch (SQLiteException e)
            {
                dataReader?.Dispose();
                string message = new FileReaderErrorMessageBuilder(Path).Build(Resources.Error_SoilProfile_read_from_database);
                throw new CriticalFileReadException(message, e);
            }
            MoveNext();
        }

        /// <summary>
        /// Prepares the two queries required for obtaining all the SoilProfile1D and SoilProfile2D with an x defined
        /// to take an intersection from. Since two separate queries are used, the <see cref="dataReader"/> will
        /// have two result sets which the <see cref="MoveNext()"/> method takes into account.
        /// </summary>
        /// <exception cref="SQLiteException">A query could not be executed on the database schema.</exception>
        private void PrepareReader()
        {
            string countQuery = SoilDatabaseQueryBuilder.GetMacroStabilityInwardsSoilProfileCountQuery();

            string subQueryGetNumberOfLayerProfile1D =
                "SELECT " +
                "SP1D_ID, " +
                $"COUNT(*) as {SoilProfileTableColumns.LayerCount} " +
                "FROM SoilLayer1D " +
                "GROUP BY SP1D_ID";
            string subQueryGetNumberOfLayerProfile2D =
                $"SELECT SP2D_ID, COUNT(*) as {SoilProfileTableColumns.LayerCount} " +
                "FROM SoilLayer2D " +
                "GROUP BY SP2D_ID";
            string subQueryGetMaterialPropertiesOfLayer =
                "SELECT " +
                "mat.MA_ID, " +
                $"mat.MA_Name as {SoilProfileTableColumns.MaterialName}, " +
                $"max(case when pn.PN_Name = 'Color' then pv.PV_Value end) {SoilProfileTableColumns.Color}, " +
                $"max(case when pn.PN_Name = 'BelowPhreaticLevelStochast' then s.ST_Dist_Type end) {SoilProfileTableColumns.BelowPhreaticLevelDistribution}, " +
                $"max(case when pn.PN_Name = 'BelowPhreaticLevelStochast' then s.ST_Shift end) {SoilProfileTableColumns.BelowPhreaticLevelShift}, " +
                $"max(case when pn.PN_Name = 'BelowPhreaticLevelStochast' then s.ST_Mean end) {SoilProfileTableColumns.BelowPhreaticLevelMean}, " +
                $"max(case when pn.PN_Name = 'BelowPhreaticLevelStochast' then s.ST_Deviation end) {SoilProfileTableColumns.BelowPhreaticLevelDeviation}, " +
                $"max(case when pn.PN_Name = 'PermeabKxStochast' then s.ST_Dist_Type end) {SoilProfileTableColumns.PermeabilityDistribution}, " +
                $"max(case when pn.PN_Name = 'PermeabKxStochast' then s.ST_Shift end) {SoilProfileTableColumns.PermeabilityShift}, " +
                $"max(case when pn.PN_Name = 'PermeabKxStochast' then s.ST_Mean end) {SoilProfileTableColumns.PermeabilityMean}, " +
                $"max(case when pn.PN_Name = 'PermeabKxStochast' then s.ST_Variation end) {SoilProfileTableColumns.PermeabilityCoefficientOfVariation}, " +
                $"max(case when pn.PN_Name = 'DiameterD70Stochast' then s.ST_Dist_Type end) {SoilProfileTableColumns.DiameterD70Distribution}, " +
                $"max(case when pn.PN_Name = 'DiameterD70Stochast' then s.ST_Shift end) {SoilProfileTableColumns.DiameterD70Shift}, " +
                $"max(case when pn.PN_Name = 'DiameterD70Stochast' then s.ST_Mean end) {SoilProfileTableColumns.DiameterD70Mean}, " +
                $"max(case when pn.PN_Name = 'DiameterD70Stochast' then s.ST_Variation end) {SoilProfileTableColumns.DiameterD70CoefficientOfVariation} " +
                "FROM ParameterNames AS pn " +
                "LEFT JOIN ParameterValues AS pv USING(PN_ID) " +
                "LEFT JOIN Stochast AS s USING(PN_ID) " +
                "JOIN Materials AS mat " +
                "WHERE pv.MA_ID = mat.MA_ID OR s.MA_ID = mat.MA_ID " +
                "GROUP BY mat.MA_ID ";
            string subQueryGetLayerPropertiesOfLayer1D =
                "SELECT " +
                "SL1D_ID, " +
                $"PV_Value as {SoilProfileTableColumns.IsAquifer} " +
                "FROM ParameterNames " +
                "JOIN LayerParameterValues USING(PN_ID) " +
                $"WHERE PN_NAME = '{SoilProfileTableColumns.IsAquifer}'";
            string subQueryGetLayerPropertiesOfLayer2D =
                "SELECT " +
                "SL2D_ID, " +
                $"PV_Value as {SoilProfileTableColumns.IsAquifer} " +
                "FROM ParameterNames " +
                "JOIN LayerParameterValues USING(PN_ID) " +
                $"WHERE PN_NAME = '{SoilProfileTableColumns.IsAquifer}'";

            string query1D =
                "SELECT " +
                $"1 AS {SoilProfileTableColumns.Dimension}, " +
                $"sp1d.SP1D_Name AS {SoilProfileTableColumns.ProfileName}, " +
                $"layerCount.{SoilProfileTableColumns.LayerCount}, " +
                $"sp1d.BottomLevel AS {SoilProfileTableColumns.Bottom}, " +
                $"sl1d.TopLevel AS {SoilProfileTableColumns.Top}, " +
                $"{SoilProfileTableColumns.MaterialName}, " +
                $"{SoilProfileTableColumns.IsAquifer}, " +
                $"{SoilProfileTableColumns.Color}, " +
                $"{SoilProfileTableColumns.BelowPhreaticLevelDistribution}, " +
                $"{SoilProfileTableColumns.BelowPhreaticLevelShift}, " +
                $"{SoilProfileTableColumns.BelowPhreaticLevelMean}, " +
                $"{SoilProfileTableColumns.BelowPhreaticLevelDeviation}, " +
                $"{SoilProfileTableColumns.DiameterD70Distribution}, " +
                $"{SoilProfileTableColumns.DiameterD70Shift}, " +
                $"{SoilProfileTableColumns.DiameterD70Mean}, " +
                $"{SoilProfileTableColumns.DiameterD70CoefficientOfVariation}, " +
                $"{SoilProfileTableColumns.PermeabilityDistribution}, " +
                $"{SoilProfileTableColumns.PermeabilityShift}, " +
                $"{SoilProfileTableColumns.PermeabilityMean}, " +
                $"{SoilProfileTableColumns.PermeabilityCoefficientOfVariation}, " +
                $"sp1d.SP1D_ID AS {SoilProfileTableColumns.SoilProfileId} " +
                "FROM Mechanism AS m " +
                "JOIN Segment AS segment USING(ME_ID) " +
                "JOIN (SELECT SSM_ID, SP1D_ID, SP2D_ID FROM StochasticSoilProfile GROUP BY SSM_ID, SP1D_ID, SP2D_ID) ssp USING(SSM_ID) " +
                "JOIN SoilProfile1D sp1d USING (SP1D_ID) " +
                "JOIN (" +
                subQueryGetNumberOfLayerProfile1D +
                ") layerCount USING (SP1D_ID) " +
                "JOIN SoilLayer1D sl1d USING (SP1D_ID) " +
                "LEFT JOIN (" +
                subQueryGetMaterialPropertiesOfLayer +
                ") materialProperties USING(MA_ID) " +
                "LEFT JOIN (" +
                subQueryGetLayerPropertiesOfLayer1D +
                ") layerProperties USING(SL1D_ID) " +
                $"WHERE m.{MechanismTableColumns.MechanismName} = @{MechanismTableColumns.MechanismName} " +
                "GROUP BY sp1d.SP1D_ID, sl1d.SL1D_ID;";

            string query2D =
                "SELECT " +
                $"2 as {SoilProfileTableColumns.Dimension}, " +
                $"sp2d.SP2D_Name as {SoilProfileTableColumns.ProfileName}, " +
                $"layerCount.{SoilProfileTableColumns.LayerCount}, " +
                $"sl2d.GeometrySurface as {SoilProfileTableColumns.LayerGeometry}, " +
                $"mpl.X as {SoilProfileTableColumns.IntersectionX}, " +
                $"{SoilProfileTableColumns.MaterialName}, " +
                $"{SoilProfileTableColumns.IsAquifer}, " +
                $"{SoilProfileTableColumns.Color}, " +
                $"{SoilProfileTableColumns.BelowPhreaticLevelDistribution}, " +
                $"{SoilProfileTableColumns.BelowPhreaticLevelShift}, " +
                $"{SoilProfileTableColumns.BelowPhreaticLevelMean}, " +
                $"{SoilProfileTableColumns.BelowPhreaticLevelDeviation}, " +
                $"{SoilProfileTableColumns.DiameterD70Distribution}, " +
                $"{SoilProfileTableColumns.DiameterD70Shift}, " +
                $"{SoilProfileTableColumns.DiameterD70Mean}, " +
                $"{SoilProfileTableColumns.DiameterD70CoefficientOfVariation}, " +
                $"{SoilProfileTableColumns.PermeabilityDistribution}, " +
                $"{SoilProfileTableColumns.PermeabilityShift}, " +
                $"{SoilProfileTableColumns.PermeabilityMean}, " +
                $"{SoilProfileTableColumns.PermeabilityCoefficientOfVariation}, " +
                $"sp2d.SP2D_ID as {SoilProfileTableColumns.SoilProfileId} " +
                "FROM Mechanism AS m " +
                "JOIN Segment AS segment USING(ME_ID) " +
                "JOIN (SELECT SSM_ID, SP1D_ID, SP2D_ID FROM StochasticSoilProfile GROUP BY SSM_ID, SP1D_ID, SP2D_ID) ssp USING(SSM_ID) " +
                "JOIN SoilProfile2D sp2d USING (SP2D_ID) " +
                "JOIN (" +
                subQueryGetNumberOfLayerProfile2D +
                ") layerCount USING (SP2D_ID) " +
                "JOIN SoilLayer2D sl2d USING (SP2D_ID) " +
                "LEFT JOIN MechanismPointLocation mpl USING(ME_ID, SP2D_ID) " +
                "LEFT JOIN (" +
                subQueryGetMaterialPropertiesOfLayer +
                ") materialProperties USING(MA_ID) " +
                "LEFT JOIN (" +
                subQueryGetLayerPropertiesOfLayer2D +
                ") layerProperties USING(SL2D_ID) " +
                $"WHERE m.{MechanismTableColumns.MechanismName} = @{MechanismTableColumns.MechanismName} " +
                "GROUP BY sp2d.SP2D_ID, sl2d.SL2D_ID;";

            dataReader = CreateDataReader(countQuery + query2D + query1D, new SQLiteParameter
            {
                DbType = DbType.String,
                Value = mechanismName,
                ParameterName = mechanismParameterName
            }, new SQLiteParameter
            {
                DbType = DbType.String,
                ParameterName = $"@{MechanismTableColumns.MechanismName}",
                Value = mechanismName
            });
        }

        private void GetCount()
        {
            dataReader.Read();
            Count = (int) Read<long>(SoilProfileTableColumns.ProfileCount);
            dataReader.NextResult();
        }
    }
}