using FluentAssertions;
using Workflow.Application.Form.Schema;
using Xunit;

namespace Workflow.Tests.Form;

public class SchemaDifferTests
{
    private const string OldSchema = """
    {
      "type": "object",
      "properties": {
        "name": { "type": "string", "title": "姓名", "required": true, "x-component": "Input" },
        "age": { "type": "number", "title": "年龄", "x-component": "InputNumber" },
        "gender": { "type": "string", "title": "性别", "x-component": "Select" }
      }
    }
    """;

    [Fact]
    public void Diff_NoChanges_ReturnsEmpty()
    {
        var diff = SchemaDiffer.Diff(OldSchema, OldSchema);

        diff.Added.Should().BeEmpty();
        diff.Removed.Should().BeEmpty();
        diff.Modified.Should().BeEmpty();
    }

    [Fact]
    public void Diff_DetectsAddedField()
    {
        var newSchema = """
        {
          "type": "object",
          "properties": {
            "name": { "type": "string", "title": "姓名", "required": true, "x-component": "Input" },
            "age": { "type": "number", "title": "年龄", "x-component": "InputNumber" },
            "gender": { "type": "string", "title": "性别", "x-component": "Select" },
            "email": { "type": "string", "title": "邮箱", "x-component": "Input" }
          }
        }
        """;

        var diff = SchemaDiffer.Diff(OldSchema, newSchema);

        diff.Added.Should().ContainSingle(f => f.Path == "email");
        diff.Removed.Should().BeEmpty();
        diff.Modified.Should().BeEmpty();
    }

    [Fact]
    public void Diff_DetectsRemovedField()
    {
        var newSchema = """
        {
          "type": "object",
          "properties": {
            "name": { "type": "string", "title": "姓名", "required": true, "x-component": "Input" },
            "age": { "type": "number", "title": "年龄", "x-component": "InputNumber" }
          }
        }
        """;

        var diff = SchemaDiffer.Diff(OldSchema, newSchema);

        diff.Removed.Should().ContainSingle(f => f.Path == "gender");
        diff.Added.Should().BeEmpty();
    }

    [Fact]
    public void Diff_DetectsComponentChange()
    {
        var newSchema = """
        {
          "type": "object",
          "properties": {
            "name": { "type": "string", "title": "姓名", "required": true, "x-component": "Input" },
            "age": { "type": "number", "title": "年龄", "x-component": "Input" },
            "gender": { "type": "string", "title": "性别", "x-component": "Select" }
          }
        }
        """;

        var diff = SchemaDiffer.Diff(OldSchema, newSchema);

        diff.Modified.Should().ContainSingle(f => f.Path == "age" && f.Change!.Contains("组件"));
    }

    [Fact]
    public void Diff_DetectsRequiredChange()
    {
        var newSchema = """
        {
          "type": "object",
          "properties": {
            "name": { "type": "string", "title": "姓名", "x-component": "Input" },
            "age": { "type": "number", "title": "年龄", "x-component": "InputNumber" },
            "gender": { "type": "string", "title": "性别", "x-component": "Select" }
          }
        }
        """;

        var diff = SchemaDiffer.Diff(OldSchema, newSchema);

        diff.Modified.Should().ContainSingle(f => f.Path == "name" && f.Change!.Contains("必填"));
    }

    [Fact]
    public void Diff_HandlesNullInputs()
    {
        var diff = SchemaDiffer.Diff(null, null);

        diff.Added.Should().BeEmpty();
        diff.Removed.Should().BeEmpty();
        diff.Modified.Should().BeEmpty();
    }

    [Fact]
    public void Diff_HandlesInvalidJson()
    {
        var diff = SchemaDiffer.Diff("not json", "{ }");

        // 无效的旧 schema 视为空，新 schema 也空，无差异
        diff.Added.Should().BeEmpty();
        diff.Removed.Should().BeEmpty();
    }

    [Fact]
    public void Diff_HandlesNestedFields()
    {
        var oldNested = """
        {
          "type": "object",
          "properties": {
            "card": {
              "type": "void",
              "x-component": "Card",
              "properties": {
                "name": { "type": "string", "title": "姓名", "x-component": "Input" }
              }
            }
          }
        }
        """;
        var newNested = """
        {
          "type": "object",
          "properties": {
            "card": {
              "type": "void",
              "x-component": "Card",
              "properties": {
                "name": { "type": "string", "title": "姓名", "x-component": "Input" },
                "age": { "type": "number", "title": "年龄", "x-component": "InputNumber" }
              }
            }
          }
        }
        """;

        var diff = SchemaDiffer.Diff(oldNested, newNested);

        diff.Added.Should().ContainSingle(f => f.Path == "card.age");
    }
}