using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using System.Threading.Tasks.Dataflow;

namespace Sony.Filtr.Tasks.Tasks
{
    public class ActionTracker
    {
        public readonly string FilePath;

        private readonly BatchBlock<string> actionTrackerBatcher;
        private readonly ActionBlock<IEnumerable<string>> actionTracker;

        public ActionTracker(string filePath, int logsToTrace)
        {
            this.FilePath = filePath;

            this.actionTrackerBatcher = new BatchBlock<string>(logsToTrace);
            this.actionTracker = new ActionBlock<IEnumerable<string>>(
                logs => File.WriteAllLines(this.FilePath, logs.ToArray()),
                new ExecutionDataflowBlockOptions() { MaxDegreeOfParallelism = 1 });

            this.actionTrackerBatcher.LinkTo(this.actionTracker, new DataflowLinkOptions() { PropagateCompletion = true });
        }

        public async Task CompleteAsync()
        {
            this.actionTrackerBatcher.Complete();

            await this.actionTracker.Completion;
        }

        public void AddTrace(string message)
        {
            if (!string.IsNullOrWhiteSpace(message))
            {
                this.actionTrackerBatcher.SendAsync(message);
            }
        }
    }
}