using System.Text;
using System.Text.Json;

namespace Strata.SqlTools.SqlBreakdown.Tests;

[TestFixture]
public class JsonTokenReaderTests
{
    [Test]
    public void JsonTokenReader_ReadsJsonTokensCorrectly()
    {
        // Arrange
        var jsonString = """
            {
                "foo": "bar",
                "myList": [1,2,3,4],
                "another": 12
            }
            """;
        var jsonBytes = Encoding.UTF8.GetBytes(jsonString);
        var reader = new Utf8JsonReader(jsonBytes);
        var tokens = new List<(JsonTokenType Type, string Value)>();

        // Act
        while (reader.Read())
        {
            var tokenValue = Encoding.UTF8.GetString(reader.ValueSpan);
            tokens.Add((reader.TokenType, tokenValue));
        }

        // Assert - Validate JSON shape and structure
        Assert.That(tokens, Is.Not.Empty);

        // Validate JSON starts with StartObject and ends with EndObject
        Assert.That(tokens, Has.Count.GreaterThan(2));
        Assert.Multiple(() =>
        {
            Assert.That(tokens[0].Type, Is.EqualTo(JsonTokenType.StartObject));
            Assert.That(tokens[^1].Type, Is.EqualTo(JsonTokenType.EndObject));
            Assert.That(tokens.Count(t => t.Type == JsonTokenType.PropertyName && t.Value == "foo"), Is.EqualTo(1));
            Assert.That(tokens.Count(t => t.Type == JsonTokenType.String && t.Value == "bar"), Is.EqualTo(1));
            Assert.That(tokens.Count(t => t.Type == JsonTokenType.PropertyName && t.Value == "myList"), Is.EqualTo(1));
            Assert.That(tokens.Count(t => t.Type == JsonTokenType.StartArray), Is.EqualTo(1));
            Assert.That(tokens.Count(t => t.Type == JsonTokenType.PropertyName && t.Value == "another"), Is.EqualTo(1));
            Assert.That(tokens.Count(t => t.Type == JsonTokenType.Number && t.Value == "12"), Is.EqualTo(1));
        });

        // Deep validation of JSON content structure
        var tokenIndex = 4;

        Assert.Multiple(() =>
        {
            // Token 4: [
            Assert.That(tokens[tokenIndex++].Type, Is.EqualTo(JsonTokenType.StartArray));

            // Token 5-8: Array elements [1,2,3,4]
            Assert.That(tokens[tokenIndex].Type, Is.EqualTo(JsonTokenType.Number));
            Assert.That(tokens[tokenIndex++].Value, Is.EqualTo("1"));
        });
        Assert.Multiple(() =>
        {
            Assert.That(tokens[tokenIndex].Type, Is.EqualTo(JsonTokenType.Number));
            Assert.That(tokens[tokenIndex++].Value, Is.EqualTo("2"));
        });
        Assert.Multiple(() =>
        {
            Assert.That(tokens[tokenIndex].Type, Is.EqualTo(JsonTokenType.Number));
            Assert.That(tokens[tokenIndex++].Value, Is.EqualTo("3"));
        });
        Assert.Multiple(() =>
        {
            Assert.That(tokens[tokenIndex].Type, Is.EqualTo(JsonTokenType.Number));
            Assert.That(tokens[tokenIndex++].Value, Is.EqualTo("4"));
        });

        // Token 9: ]
        Assert.That(tokens[tokenIndex].Type, Is.EqualTo(JsonTokenType.EndArray));
    }
}