using Data.SeaHavenIndustries;
using Data.SeaHavenIndustries.Enums;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Diagnostics;
using SeaHaven.DataServices.Implementation;
using SeaHaven.Services.DTOs;
using SeaHaven.Services.Helpers;
using SeaHaven.Services.Implementation;
using Xunit;

namespace SeaHavenIndustries.Tests;

/// <summary>
/// Cancelling a work order from the board (the lifecycle status PATCH the board and
/// slide-over use) cancels its pending uplift in the same action and commit, with an
/// audit entry of its own.
/// </summary>
public sealed class WorkOrderBoardPatchCancelUpliftTests
{
    private static readonly byte[] Version = { 1, 0, 0, 0, 0, 0, 0, 1 };

    private static async Task<WorkOrderBoardPatchRequestDto> CancelPatchAsync(ApplicationDbContext context)
    {
        var stored = await context.workOrders.AsNoTracking().SingleAsync(w => w.Id == 1);
        return new WorkOrderBoardPatchRequestDto
        {
            Field = WorkOrderBoardFieldNames.LifecycleStatus,
            Value = "Canceled",
            WorkOrderVersion = Convert.ToBase64String(stored.RowVersion ?? Version),
        };
    }

    private static WorkOrderBoardUpdateService NewUpdateService(ApplicationDbContext context)
    {
        var fieldLocks = new WorkOrderFieldLockService(new WorkOrderFieldLockDataService(context));
        var audit = new WorkOrderAuditService(new WorkOrderAuditDataService(context), fieldLocks);
        return WorkOrderAccountTestHelpers.BoardUpdateService(context, audit);
    }

    // Saved in stages: the work order and its primary dispatch reference each other, which a
    // relational provider cannot insert in one statement batch.
    internal static async Task SeedWorkOrderAsync(ApplicationDbContext context)
    {
        context.Accounts.Add(new Accounts { Id = 1, Name = "Acme Corp", IsDeleted = false });
        context.Users.Add(new ApplicationUser { Id = "actor-1", UserName = "actor-1" });
        context.Users.Add(new ApplicationUser { Id = "dispatcher-1", UserName = "dispatcher-1" });
        context.Vendors.Add(new Vendor { Id = 1, CompanyName = "Acme HVAC" });
        var workOrder = new WorkOrder
        {
            Id = 1,
            InternalWONumber = "10000000001",
            ExternalWorkOrderId = "123",
            LifecycleStatus = LifecycleStatus.Incomplete,
            Status = "Incomplete",
            AccountId = 1,
            RowVersion = Version,
        };
        context.workOrders.Add(workOrder);
        await context.SaveChangesAsync();

        context.Dispatches.Add(new Dispatch
        {
            Id = 10,
            VendorId = 1,
            WorkOrderId = 1,
            NTEAmount = 1900m,
            DispatchNumber = "DIS-10",
            Status = "Scheduled",
        });
        await context.SaveChangesAsync();

        workOrder.PrimaryDispatchId = 10;
        await context.SaveChangesAsync();
    }

    internal static DispatchUpliftRequest Uplift(int id, string status, decimal amount) => new()
    {
        Id = id,
        DispatchId = 10,
        CurrentNTE = 1000m,
        RequestedNTE = amount,
        Status = status,
        RequiredTier = status == "NoApprovalRequired" ? 0 : 1,
        NotificationStatus = "Sent",
        createdby = "dispatcher-1",
        CreatedDate = DateTime.UtcNow.AddHours(-id),
    };

    [Fact]
    public async Task PatchToCanceled_CancelsPendingUpliftWithItsOwnAuditAndLeavesDecidedUpliftsAlone()
    {
        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseInMemoryDatabase(Guid.NewGuid().ToString())
            .Options;
        await using (var seed = new ApplicationDbContext(options))
        {
            await SeedWorkOrderAsync(seed);
            seed.DispatchUpliftRequests.AddRange(
                Uplift(100, "Pending", 700m),
                Uplift(101, "Approved", 600m),
                Uplift(102, "NoApprovalRequired", 300m),
                Uplift(103, "Rejected", 900m));
            await seed.SaveChangesAsync();
        }

        await using (var context = new ApplicationDbContext(options))
        {
            var row = await NewUpdateService(context).PatchFieldAsync(1, await CancelPatchAsync(context), "actor-1");
            Assert.Equal(LifecycleStatus.Canceled, row.LifecycleStatus);
        }

        await using var verify = new ApplicationDbContext(options);
        Assert.Equal(LifecycleStatus.Canceled, verify.workOrders.Single().LifecycleStatus);

        var cancelled = verify.DispatchUpliftRequests.Single(u => u.Id == 100);
        Assert.Equal(UpliftStatus.Withdrawn, cancelled.Status);
        Assert.Equal("actor-1", cancelled.DecidedByUserId);
        Assert.NotNull(cancelled.DecidedAt);

        Assert.Equal(UpliftStatus.Approved, verify.DispatchUpliftRequests.Single(u => u.Id == 101).Status);
        Assert.Equal(UpliftStatus.NoApprovalRequired, verify.DispatchUpliftRequests.Single(u => u.Id == 102).Status);
        Assert.Equal(UpliftStatus.Rejected, verify.DispatchUpliftRequests.Single(u => u.Id == 103).Status);
        Assert.Equal(1900m, verify.Dispatches.Single().NTEAmount);

        var upliftAudit = Assert.Single(verify.WorkOrderAuditLogs, log => log.Action == "uplift_cancel");
        Assert.Equal(1, upliftAudit.WorkOrderId);
        Assert.Equal("actor-1", upliftAudit.UserId);
        Assert.Equal("Dispatch DIS-10 Uplift", upliftAudit.FieldName);
        Assert.Equal(UpliftStatus.Pending, upliftAudit.OldValue);
        Assert.Equal(UpliftStatus.Withdrawn, upliftAudit.NewValue);

        var statusAudit = Assert.Single(verify.WorkOrderAuditLogs, log => log.Action == "StatusChanged");
        Assert.Equal(LifecycleStatus.Canceled.ToString(), statusAudit.NewValue);
        Assert.NotEqual(upliftAudit.Id, statusAudit.Id);
    }

    [Fact]
    public async Task PatchToOtherStatus_LeavesPendingUpliftPending()
    {
        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseInMemoryDatabase(Guid.NewGuid().ToString())
            .Options;
        await using (var seed = new ApplicationDbContext(options))
        {
            await SeedWorkOrderAsync(seed);
            seed.DispatchUpliftRequests.Add(Uplift(100, "Pending", 700m));
            await seed.SaveChangesAsync();
        }

        await using (var context = new ApplicationDbContext(options))
        {
            var patch = await CancelPatchAsync(context);
            patch.Value = "Pending";
            await NewUpdateService(context).PatchFieldAsync(1, patch, "actor-1");
        }

        await using var verify = new ApplicationDbContext(options);
        Assert.Equal(LifecycleStatus.Pending, verify.workOrders.Single().LifecycleStatus);
        Assert.Equal(UpliftStatus.Pending, verify.DispatchUpliftRequests.Single().Status);
        Assert.DoesNotContain(verify.WorkOrderAuditLogs, log => log.Action == "uplift_cancel");
    }

    [Fact]
    public async Task PatchToCanceled_FailureAfterTheWrites_RollsBackWorkOrderAndUpliftTogether()
    {
        await using var connection = new SqliteConnection("DataSource=:memory:");
        await connection.OpenAsync();
        var failAfterSave = new FailAfterSaveInterceptor();
        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseSqlite(connection)
            .AddInterceptors(failAfterSave)
            .Options;

        await using (var seed = new SqliteRowVersionDbContext(options))
        {
            await seed.Database.EnsureCreatedAsync();
            await SeedWorkOrderAsync(seed);
            seed.DispatchUpliftRequests.Add(Uplift(100, "Pending", 700m));
            await seed.SaveChangesAsync();
        }

        failAfterSave.Armed = true;
        await using (var context = new SqliteRowVersionDbContext(options))
        {
            var patch = await CancelPatchAsync(context);
            await Assert.ThrowsAsync<InvalidOperationException>(
                () => NewUpdateService(context).PatchFieldAsync(1, patch, "actor-1"));
        }

        // The failing save did write both the cancelled work order and the withdrawn
        // uplift inside the transaction; the failure after it must undo both.
        Assert.True(failAfterSave.SawWithdrawnUpliftInSave);

        failAfterSave.Armed = false;
        await using var verify = new SqliteRowVersionDbContext(options);
        Assert.Equal(LifecycleStatus.Incomplete, (await verify.workOrders.AsNoTracking().SingleAsync()).LifecycleStatus);
        Assert.Equal(UpliftStatus.Pending, (await verify.DispatchUpliftRequests.AsNoTracking().SingleAsync()).Status);
        Assert.False(await verify.WorkOrderAuditLogs.AnyAsync());
    }

    private sealed class FailAfterSaveInterceptor : SaveChangesInterceptor
    {
        public bool Armed { get; set; }
        public bool SawWithdrawnUpliftInSave { get; private set; }

        public override ValueTask<InterceptionResult<int>> SavingChangesAsync(
            DbContextEventData eventData,
            InterceptionResult<int> result,
            CancellationToken cancellationToken = default)
        {
            if (Armed && eventData.Context is not null)
            {
                SawWithdrawnUpliftInSave = eventData.Context.ChangeTracker
                    .Entries<DispatchUpliftRequest>()
                    .Any(entry => entry.State == EntityState.Modified
                        && entry.Entity.Status == UpliftStatus.Withdrawn);
            }

            return base.SavingChangesAsync(eventData, result, cancellationToken);
        }

        public override ValueTask<int> SavedChangesAsync(
            SaveChangesCompletedEventData eventData,
            int result,
            CancellationToken cancellationToken = default)
        {
            if (Armed)
                throw new InvalidOperationException("Simulated failure after the rows were written");

            return base.SavedChangesAsync(eventData, result, cancellationToken);
        }
    }

    internal sealed class SqliteRowVersionDbContext : ApplicationDbContext
    {
        public SqliteRowVersionDbContext(DbContextOptions<ApplicationDbContext> options)
            : base(options)
        {
        }

        protected override void OnModelCreating(ModelBuilder builder)
        {
            base.OnModelCreating(builder);

            // SQLite has no rowversion type; store the seeded blobs as plain values.
            foreach (var entityType in new[] { typeof(WorkOrder), typeof(Dispatch), typeof(DispatchUpliftRequest) })
            {
                var property = builder.Entity(entityType).Property("RowVersion").Metadata;
                property.ValueGenerated = Microsoft.EntityFrameworkCore.Metadata.ValueGenerated.Never;
                property.IsConcurrencyToken = false;
            }
        }
    }
}