using FluentAssertions;
using Microsoft.EntityFrameworkCore;
using Workflow.Application.Form.FormDefinition.Commands;
using Workflow.Domain.Entities;
using Workflow.Domain.Enums;
using Workflow.Domain.Exceptions;
using Workflow.Infrastructure.Persistence;
using Xunit;

namespace Workflow.Tests.Form;

/// <summary>
/// 表单设计器与流程设计器耦合关系下的删除边界测试。
///
/// 背景：FormDefinition 被软删除后，全局查询过滤器会让 GetFormDefinitionByIdQuery 等读取路径
/// 直接抛 NotFoundException；StartWorkflowInstanceCommand 也会抛 BusinessException。
/// 因此删除一张仍被流程定义/节点引用的表单，会在运行期产生孤儿引用。
/// 删除前必须阻断并给出明确错误，而不是让下游崩溃。
/// </summary>
[Collection("FormTests")]
public class FormDeletionReferenceTests
{
    private readonly FormTestFixture _fixture;

    public FormDeletionReferenceTests(FormTestFixtureClassFixture fixture)
    {
        _fixture = fixture;
    }

    private const string ValidSchema = """
    {
      "type": "object",
      "properties": {
        "name": { "type": "string", "title": "姓名", "x-decorator": "FormItem", "x-component": "Input" }
      }
    }
    """;

    private static FormDefinition NewForm(Guid id, string code = "REF_FORM") => new()
    {
        Id = id,
        Name = "引用测试表单",
        Code = code,
        Version = 1,
        Status = FormStatus.Published,
        SchemaJson = ValidSchema,
    };

    // ----------------------------------------------------------------
    // 已被流程定义引用：删除必须被阻断
    // ----------------------------------------------------------------
    [Fact]
    public async Task DeleteFormDefinition_ReferencedByWorkflowDefinition_ThrowsBusinessException()
    {
        var formId = Guid.NewGuid();
        await using var db = await _fixture.CreateDbContextWithSeedAsync(
            testName: nameof(DeleteFormDefinition_ReferencedByWorkflowDefinition_ThrowsBusinessException),
            seedAction: ctx =>
            {
                ctx.FormDefinitions.Add(NewForm(formId));
                ctx.WorkflowDefinitions.Add(new WorkflowDefinition
                {
                    Id = Guid.NewGuid(),
                    Name = "引用该表单的流程",
                    Code = "WF_REF_FORM_1",
                    Version = 1,
                    Status = DefinitionStatus.Draft,
                    IsEnabled = true,
                    FormDefinitionId = formId,
                });
            });

        var handler = new DeleteFormDefinitionCommandHandler(db);
        var act = () => handler.Handle(new DeleteFormDefinitionCommand(formId), CancellationToken.None);

        await act.Should().ThrowAsync<BusinessException>()
            .WithMessage("*流程*");

        // 删除被阻断，表单保持可见
        var stillThere = await db.FormDefinitions.FindAsync(formId);
        stillThere.Should().NotBeNull();
        stillThere!.IsDeleted.Should().BeFalse();
    }

    // ----------------------------------------------------------------
    // 已被流程节点引用：删除必须被阻断
    // ----------------------------------------------------------------
    [Fact]
    public async Task DeleteFormDefinition_ReferencedByWorkflowNode_ThrowsBusinessException()
    {
        var formId = Guid.NewGuid();
        var definitionId = Guid.NewGuid();
        await using var db = await _fixture.CreateDbContextWithSeedAsync(
            testName: nameof(DeleteFormDefinition_ReferencedByWorkflowNode_ThrowsBusinessException),
            seedAction: ctx =>
            {
                ctx.FormDefinitions.Add(NewForm(formId));
                ctx.WorkflowDefinitions.Add(new WorkflowDefinition
                {
                    Id = definitionId,
                    Name = "节点引用表单的流程",
                    Code = "WF_REF_FORM_2",
                    Version = 1,
                    Status = DefinitionStatus.Draft,
                    IsEnabled = true,
                });
                ctx.WorkflowNodes.Add(new WorkflowNode
                {
                    Id = Guid.NewGuid(),
                    DefinitionId = definitionId,
                    NodeType = NodeType.Approval,
                    Name = "审批节点",
                    FormDefinitionId = formId,
                });
            });

        var handler = new DeleteFormDefinitionCommandHandler(db);
        var act = () => handler.Handle(new DeleteFormDefinitionCommand(formId), CancellationToken.None);

        await act.Should().ThrowAsync<BusinessException>()
            .WithMessage("*流程*");

        var stillThere = await db.FormDefinitions.FindAsync(formId);
        stillThere.Should().NotBeNull();
        stillThere!.IsDeleted.Should().BeFalse();
    }

    // ----------------------------------------------------------------
    // 仅被已软删除的流程引用：可正常删除（孤儿引用不应永久锁死表单）
    // ----------------------------------------------------------------
    [Fact]
    public async Task DeleteFormDefinition_OnlyReferencedBySoftDeletedDefinition_AllowsDeletion()
    {
        var formId = Guid.NewGuid();
        await using var db = await _fixture.CreateDbContextWithSeedAsync(
            testName: nameof(DeleteFormDefinition_OnlyReferencedBySoftDeletedDefinition_AllowsDeletion),
            seedAction: ctx =>
            {
                ctx.FormDefinitions.Add(NewForm(formId));
                ctx.WorkflowDefinitions.Add(new WorkflowDefinition
                {
                    Id = Guid.NewGuid(),
                    Name = "已删除的流程",
                    Code = "WF_DELETED",
                    Version = 1,
                    Status = DefinitionStatus.Draft,
                    IsEnabled = true,
                    FormDefinitionId = formId,
                    IsDeleted = true,
                });
            });

        var handler = new DeleteFormDefinitionCommandHandler(db);
        await handler.Handle(new DeleteFormDefinitionCommand(formId), CancellationToken.None);

        var normalQuery = await db.FormDefinitions.FirstOrDefaultAsync(f => f.Id == formId);
        normalQuery.Should().BeNull();

        var deleted = await db.FormDefinitions.IgnoreQueryFilters().FirstAsync(f => f.Id == formId);
        deleted.IsDeleted.Should().BeTrue();
    }

    // ----------------------------------------------------------------
    // 无任何引用：可正常删除（回归现有行为，确保不误伤）
    // ----------------------------------------------------------------
    [Fact]
    public async Task DeleteFormDefinition_NotReferenced_Succeeds()
    {
        var formId = Guid.NewGuid();
        await using var db = await _fixture.CreateDbContextWithSeedAsync(
            testName: nameof(DeleteFormDefinition_NotReferenced_Succeeds),
            seedAction: ctx => ctx.FormDefinitions.Add(NewForm(formId, code: "UNREF")));

        var handler = new DeleteFormDefinitionCommandHandler(db);
        await handler.Handle(new DeleteFormDefinitionCommand(formId), CancellationToken.None);

        var normalQuery = await db.FormDefinitions.FirstOrDefaultAsync(f => f.Id == formId);
        normalQuery.Should().BeNull();

        var deleted = await db.FormDefinitions.IgnoreQueryFilters().FirstAsync(f => f.Id == formId);
        deleted.IsDeleted.Should().BeTrue();
    }
}