using BuildFlow.Shared.Domain.Errors;
using FluentAssertions;
using Microsoft.EntityFrameworkCore;
using Workflow.Application.Features.WorkflowInstances.Commands;
using Workflow.Application.Features.WorkflowInstances.Handlers;
using Workflow.Domain.Entities;
using Workflow.Domain.Enums;
using Xunit;

namespace BuildFlow.Workflow.Tests.Handlers;

public class UpdateWorkflowInstanceVariablesCommandHandlerTests
{
    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;
    }

    [Fact]
    public async Task UpdateWorkflowInstanceVariables_OverwritesVariables()
    {
        await using var db = CreateDbContext();
        var id = Guid.NewGuid();
        db.WorkflowInstances.Add(new WorkflowInstance
        {
            Id = id,
            DefinitionId = Guid.NewGuid(),
            Title = "Inst",
            Status = InstanceStatus.Running,
            InitiatorId = Guid.NewGuid(),
            Variables = "{}"
        });
        await db.SaveChangesAsync();

        var handler = new UpdateWorkflowInstanceVariablesCommandHandler(db);
        var command = new UpdateWorkflowInstanceVariablesCommand(id, "{\"k\":\"v\"}");

        await handler.Handle(command, CancellationToken.None);

        var stored = await db.WorkflowInstances.FindAsync(id);
        stored!.Variables.Should().Be("{\"k\":\"v\"}");
    }

    [Fact]
    public async Task UpdateWorkflowInstanceVariables_MissingInstance_ThrowsNotFound()
    {
        await using var db = CreateDbContext();
        var handler = new UpdateWorkflowInstanceVariablesCommandHandler(db);
        var command = new UpdateWorkflowInstanceVariablesCommand(Guid.NewGuid(), "{}");

        var act = async () => await handler.Handle(command, CancellationToken.None);

        var ex = await act.Should().ThrowAsync<NotFoundException>();
        ex.Which.Code.Should().Be(ErrorCode.NotFound);
    }

    [Fact]
    public async Task UpdateWorkflowInstanceVariables_NotObject_ThrowsInvalidParam()
    {
        await using var db = CreateDbContext();
        var id = Guid.NewGuid();
        db.WorkflowInstances.Add(new WorkflowInstance
        {
            Id = id,
            DefinitionId = Guid.NewGuid(),
            Title = "Inst",
            Status = InstanceStatus.Running,
            InitiatorId = Guid.NewGuid()
        });
        await db.SaveChangesAsync();

        var handler = new UpdateWorkflowInstanceVariablesCommandHandler(db);
        var command = new UpdateWorkflowInstanceVariablesCommand(id, "[]");

        var act = async () => await handler.Handle(command, CancellationToken.None);

        var ex = await act.Should().ThrowAsync<BusinessException>();
        ex.Which.Code.Should().Be(ErrorCode.InvalidParam);
    }

    [Fact]
    public async Task UpdateWorkflowInstanceVariables_InvalidJson_ThrowsInvalidParam()
    {
        await using var db = CreateDbContext();
        var id = Guid.NewGuid();
        db.WorkflowInstances.Add(new WorkflowInstance
        {
            Id = id,
            DefinitionId = Guid.NewGuid(),
            Title = "Inst",
            Status = InstanceStatus.Running,
            InitiatorId = Guid.NewGuid()
        });
        await db.SaveChangesAsync();

        var handler = new UpdateWorkflowInstanceVariablesCommandHandler(db);
        var command = new UpdateWorkflowInstanceVariablesCommand(id, "{not-json");

        var act = async () => await handler.Handle(command, CancellationToken.None);

        var ex = await act.Should().ThrowAsync<BusinessException>();
        ex.Which.Code.Should().Be(ErrorCode.InvalidParam);
    }
}