using FluentAssertions;
using Microsoft.EntityFrameworkCore;
using Workflow.Application.Features.WorkflowTasks.Handlers;
using Workflow.Application.Features.WorkflowTasks.Queries;
using Workflow.Domain.Entities;
using Workflow.Domain.Enums;
using Xunit;

using TaskStatus = global::Workflow.Domain.Enums.TaskStatus;

namespace BuildFlow.Workflow.Tests.Handlers;

public class OverdueAndCcTaskQueryHandlerTests
{
    private static WorkflowDbContext CreateDbContext()
    {
        var options = new DbContextOptionsBuilder<WorkflowDbContext>()
            .UseInMemoryDatabase(Guid.NewGuid().ToString())
            .Options;
        var db = new WorkflowDbContext(options);
        db.SavingChanges += AuditStub.OnSave;
        return db;
    }

    private static WorkflowTask SeedTask(WorkflowDbContext db, Guid assigneeId, TaskType type, TaskStatus status, DateTime? dueAt)
    {
        var task = new WorkflowTask
        {
            Id = Guid.NewGuid(),
            InstanceId = Guid.NewGuid(),
            TokenId = Guid.NewGuid(),
            NodeId = Guid.NewGuid(),
            Title = "Task",
            AssigneeId = assigneeId,
            Type = type,
            Status = status,
            DueAt = dueAt
        };
        db.WorkflowTasks.Add(task);
        return task;
    }

    #region GetOverdueTasks

    [Fact]
    public async Task GetOverdueTasks_ReturnsOverduePendingTasks()
    {
        await using var db = CreateDbContext();
        var user = Guid.NewGuid();
        SeedTask(db, user, TaskType.Approval, TaskStatus.Pending, DateTime.UtcNow.AddDays(-1));
        await db.SaveChangesAsync();

        var handler = new GetOverdueTasksQueryHandler(db);
        var result = await handler.Handle(new GetOverdueTasksQuery(null, 1, 10), CancellationToken.None);

        result.Should().NotBeNull();
        result.Items.Should().HaveCount(1);
        result.Total.Should().Be(1);
    }

    [Fact]
    public async Task GetOverdueTasks_FiltersByUser()
    {
        await using var db = CreateDbContext();
        var userA = Guid.NewGuid();
        var userB = Guid.NewGuid();
        SeedTask(db, userA, TaskType.Approval, TaskStatus.Pending, DateTime.UtcNow.AddDays(-1));
        SeedTask(db, userB, TaskType.Approval, TaskStatus.Pending, DateTime.UtcNow.AddDays(-1));
        await db.SaveChangesAsync();

        var handler = new GetOverdueTasksQueryHandler(db);
        var result = await handler.Handle(new GetOverdueTasksQuery(userA, 1, 10), CancellationToken.None);

        result.Items.Should().HaveCount(1);
        result.Items[0].AssigneeId.Should().Be(userA);
    }

    [Fact]
    public async Task GetOverdueTasks_ExcludesFutureDueAndNonPending()
    {
        await using var db = CreateDbContext();
        var user = Guid.NewGuid();
        SeedTask(db, user, TaskType.Approval, TaskStatus.Pending, DateTime.UtcNow.AddDays(1));
        SeedTask(db, user, TaskType.Approval, TaskStatus.Approved, DateTime.UtcNow.AddDays(-1));
        await db.SaveChangesAsync();

        var handler = new GetOverdueTasksQueryHandler(db);
        var result = await handler.Handle(new GetOverdueTasksQuery(null, 1, 10), CancellationToken.None);

        result.Items.Should().BeEmpty();
        result.Total.Should().Be(0);
    }

    #endregion

    #region GetCcTasks

    [Fact]
    public async Task GetCcTasks_ReturnsCcTasksForUser()
    {
        await using var db = CreateDbContext();
        var user = Guid.NewGuid();
        SeedTask(db, user, TaskType.Cc, TaskStatus.Pending, null);
        SeedTask(db, user, TaskType.Approval, TaskStatus.Pending, null);
        await db.SaveChangesAsync();

        var handler = new GetCcTasksQueryHandler(db);
        var result = await handler.Handle(new GetCcTasksQuery(user, 1, 10), CancellationToken.None);

        result.Items.Should().HaveCount(1);
        result.Items[0].Status.Should().Be(TaskStatus.Pending);
    }

    [Fact]
    public async Task GetCcTasks_EmptyForOtherUser()
    {
        await using var db = CreateDbContext();
        SeedTask(db, Guid.NewGuid(), TaskType.Cc, TaskStatus.Pending, null);
        await db.SaveChangesAsync();

        var handler = new GetCcTasksQueryHandler(db);
        var result = await handler.Handle(new GetCcTasksQuery(Guid.NewGuid(), 1, 10), CancellationToken.None);

        result.Items.Should().BeEmpty();
    }

    #endregion
}