// MIT License

// Copyright DNN Community

namespace DNN.Modules.UserVoice.Data

{

using DNN.Modules.UserVoice.Data.Entities;

using System;

using System.Configuration;

using System.Data.Common;

using System.Data.Entity;

using System.Diagnostics.CodeAnalysis;

using System.IO;

using System.Web;

/// <summary>

/// The data context for this module.

/// </summary>

[ExcludeFromCodeCoverage] // Very close to the metal configuration code, hard to test without heavy mocking, and low risk of bugs.

public class ModuleDbContext : DbContext

{

/// <summary>

/// Cached connection string, computed lazily and thread-safe.

/// </summary>

private static readonly Lazy<string> CachedConnectionString = new Lazy<string>(ComputeConnectionString);

/// <summary>

/// Initializes a new instance of the <see cref="ModuleDbContext"/> class.

/// </summary>

public ModuleDbContext()

: base(GetConnectionString())

{

Database.SetInitializer(new MigrateDatabaseToLatestVersion<ModuleDbContext, Migrations.Configuration>());

}

/// <summary>

/// Initializes a new instance of the <see cref="ModuleDbContext"/> class.

/// </summary>

/// <param name="connection">An existing <see cref="DbConnection"/>.</param>

public ModuleDbContext(DbConnection connection)

: base(connection, true)

{

Database.SetInitializer(new NullDatabaseInitializer<ModuleDbContext>());

this.Database.CreateIfNotExists();

}

/// <summary>

/// Gets or sets the ideas.

/// </summary>

public virtual DbSet<Idea> Ideas { get; set; }

/// <summary>

/// Gets or sets the collection of user vote entities in the database.

/// </summary>

public virtual DbSet<UserVote> UserVotes { get; set; }

/// <summary>

/// Gets the connection string, using cached value after first call.

/// </summary>

/// <returns>The connection string.</returns>

private static string GetConnectionString()

{

return CachedConnectionString.Value;

}

/// <summary>

/// Computes the connection string by checking runtime context and configuration files.

/// This method is called only once per application lifetime.

/// </summary>

/// <returns>The connection string.</returns>

private static string ComputeConnectionString()

{

// For runtime

if (HttpContext.Current != null)

{

return "name=SiteSqlServer";

}

// For CLI tools, start from the current base directory and move up until we find web.config

string baseDirectory = AppDomain.CurrentDomain.BaseDirectory;

string configFilePath = Path.Combine(baseDirectory, "web.config");

while (!File.Exists(configFilePath) && baseDirectory != null)

{

baseDirectory = Directory.GetParent(baseDirectory)?.FullName;

if (baseDirectory == null)

{

throw new FileNotFoundException("web.config not found in any parent directory.");

}

configFilePath = Path.Combine(baseDirectory, "web.config");

}

// Load the configuration manually from the web.config file

var fileMap = new ExeConfigurationFileMap { ExeConfigFilename = configFilePath };

var config = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);

var connectionString = config.ConnectionStrings.ConnectionStrings["SiteSqlServer"];

return connectionString == null

? throw new NullReferenceException("Connection string 'SiteSqlServer' not found.")

: connectionString.ConnectionString;

}

}

}