using Logging;
using Newtonsoft.Json;
using Utils;

namespace CodexPlugin
{
    public interface IStoragePurchaseContract
    {
        string PurchaseId { get; }
        StoragePurchaseRequest Purchase { get; }
        ContentId ContentId { get; }
        void WaitForStorageContractSubmitted();
        void WaitForStorageContractStarted();
        void WaitForStorageContractFinished();
    }

    public class StoragePurchaseContract : IStoragePurchaseContract
    {
        private readonly ILog log;
        private readonly CodexAccess codexAccess;
        private readonly TimeSpan gracePeriod = TimeSpan.FromSeconds(30);
        private readonly DateTime contractPendingUtc = DateTime.UtcNow;
        private DateTime? contractSubmittedUtc = DateTime.UtcNow;
        private DateTime? contractStartedUtc;
        private DateTime? contractFinishedUtc;

        public StoragePurchaseContract(ILog log, CodexAccess codexAccess, string purchaseId, StoragePurchaseRequest purchase)
        {
            this.log = log;
            this.codexAccess = codexAccess;
            PurchaseId = purchaseId;
            Purchase = purchase;

            ContentId = new ContentId(codexAccess.GetPurchaseStatus(purchaseId).Request.Content.Cid);
        }

        public string PurchaseId { get; }
        public StoragePurchaseRequest Purchase { get; }
        public ContentId ContentId { get; }

        public TimeSpan? PendingToSubmitted => contractSubmittedUtc - contractPendingUtc;
        public TimeSpan? SubmittedToStarted => contractStartedUtc - contractSubmittedUtc;
        public TimeSpan? SubmittedToFinished => contractFinishedUtc - contractSubmittedUtc;

        public void WaitForStorageContractSubmitted()
        {
            WaitForStorageContractState(gracePeriod, "submitted", sleep: 200);
            contractSubmittedUtc = DateTime.UtcNow;
            LogSubmittedDuration();
            AssertDuration(PendingToSubmitted, gracePeriod, nameof(PendingToSubmitted));
        }

        public void WaitForStorageContractStarted()
        {
            var timeout = Purchase.Expiry + gracePeriod;

            WaitForStorageContractState(timeout, "started");
            contractStartedUtc = DateTime.UtcNow;
            LogStartedDuration();
            AssertDuration(SubmittedToStarted, timeout, nameof(SubmittedToStarted));
        }

        public void WaitForStorageContractFinished()
        {
            if (!contractStartedUtc.HasValue)
            {
                WaitForStorageContractStarted();
            }
            var currentContractTime = DateTime.UtcNow - contractSubmittedUtc!.Value;
            var timeout = (Purchase.Duration - currentContractTime) + gracePeriod;
            WaitForStorageContractState(timeout, "finished");
            contractFinishedUtc = DateTime.UtcNow;
            LogFinishedDuration();
            AssertDuration(SubmittedToFinished, timeout, nameof(SubmittedToFinished));
        }

        public StoragePurchase GetPurchaseStatus(string purchaseId)
        {
            return codexAccess.GetPurchaseStatus(purchaseId);
        }

        private void WaitForStorageContractState(TimeSpan timeout, string desiredState, int sleep = 1000)
        {
            var lastState = "";
            var waitStart = DateTime.UtcNow;

            Log($"Waiting for {Time.FormatDuration(timeout)} to reach state '{desiredState}'.");
            while (lastState != desiredState)
            {
                var purchaseStatus = codexAccess.GetPurchaseStatus(PurchaseId);
                var statusJson = JsonConvert.SerializeObject(purchaseStatus);
                if (purchaseStatus != null && purchaseStatus.State != lastState)
                {
                    lastState = purchaseStatus.State;
                    log.Debug("Purchase status: " + statusJson);
                }

                Thread.Sleep(sleep);

                if (lastState == "errored")
                {
                    FrameworkAssert.Fail("Contract errored: " + statusJson);
                }

                if (DateTime.UtcNow - waitStart > timeout)
                {
                    FrameworkAssert.Fail($"Contract did not reach '{desiredState}' within {Time.FormatDuration(timeout)} timeout. {statusJson}");
                }
            }
        }

        private void LogSubmittedDuration()
        {
            Log($"Pending to Submitted in {Time.FormatDuration(PendingToSubmitted)} " +
                $"( < {Time.FormatDuration(gracePeriod)})");
        }

        private void LogStartedDuration()
        {
            Log($"Submitted to Started in {Time.FormatDuration(SubmittedToStarted)} " +
                $"( < {Time.FormatDuration(Purchase.Expiry + gracePeriod)})");
        }

        private void LogFinishedDuration()
        {
            Log($"Submitted to Finished in {Time.FormatDuration(SubmittedToFinished)} " +
                $"( < {Time.FormatDuration(Purchase.Duration + gracePeriod)})");
        }

        private void AssertDuration(TimeSpan? span, TimeSpan max, string message)
        {
            if (span == null) throw new ArgumentNullException(nameof(MarketplaceAccess) + ": " + message + " (IsNull)");
            if (span.Value.TotalDays >= max.TotalSeconds)
            {
                throw new Exception(nameof(MarketplaceAccess) +
                    $": Duration out of range. Max: {Time.FormatDuration(max)} but was: {Time.FormatDuration(span.Value)} " +
                    message);
            }
        }

        private void Log(string msg)
        {
            log.Log($"[{PurchaseId}] {msg}");
        }
    }
}