// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System.Collections.Concurrent;
using Microsoft.CodeAnalysis.Shared.Utilities;
using Microsoft.CodeAnalysis.SQLite.v2.Interop;
using Microsoft.CodeAnalysis.Storage;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.SQLite.v2
{
    internal partial class SQLitePersistentStorage
    {
        /// <summary>
        /// Mapping from the workspace's ID for a project, to the ID we use in the DB for the project.
        /// Kept locally so we don't have to hit the DB for the common case of trying to determine the 
        /// DB id for a project.
        /// </summary>
        private readonly ConcurrentDictionary<ProjectId, ProjectPrimaryKey> _projectIdToPrimaryKeyMap = new();
 
        /// <summary>
        /// Given a project, and the name of a stream to read/write, gets the integral DB ID to 
        /// use to find the data inside the ProjectData table.
        /// </summary>
        private ProjectPrimaryKey? TryGetProjectPrimaryKey(SqlConnection connection, ProjectKey projectKey, bool allowWrite)
        {
            // First see if we've cached the ID for this value locally.  If so, just return
            // what we already have.
            if (!_projectIdToPrimaryKeyMap.TryGetValue(projectKey.Id, out var existingId))
            {
                // Store the project as its folder and project name.  The folder is relative to the solution path so
                // that we're not dependent on file-system location.
                var projectPath =
                    projectKey.FilePath != null && PathUtilities.GetRelativePath(_solutionDirectory, projectKey.FilePath) is { Length: > 0 } relativePath
                        ? relativePath
                        : projectKey.FilePath;
 
                // Key the project off both its path and name.  That way we work properly
                // in host and test scenarios.
                if (TryGetStringId(connection, projectPath, allowWrite) is not int projectPathId ||
                    TryGetStringId(connection, projectKey.Name, allowWrite) is not int projectNameId)
                {
                    return null;
                }
 
                // Cache the value locally so we don't need to go back to the DB in the future.
                existingId = new ProjectPrimaryKey(projectPathId, projectNameId);
                _projectIdToPrimaryKeyMap.TryAdd(projectKey.Id, existingId);
            }
 
            return existingId;
        }
    }
}