using FluentAssertions;
using foodmarket.Api.Infrastructure.Invoices;
using Xunit;

namespace foodmarket.UnitTests;

/// <summary>Проверка парсинга ответа Claude CLI. CLI отдаёт конверт
/// <c>{ result: "…json…", usage: {...} }</c>; result иногда обёрнут в
/// <c>```json</c>. Нужно вытащить payload и привести к ParsedInvoice.</summary>
public class ClaudeCliInvoiceExtractorParseTests
{
    [Fact]
    public void Parse_plain_json_payload()
    {
        var json = """{"supplier":"ТОО Фуд","number":"Н-1","date":"2026-10-04","total":1500.00,"lines":[{"barcode":"4870123456789","supplier_code":"ABC","name":"Молоко 3.2%","qty":10,"unit":"шт","price":150.00,"sum":1500.00,"vat":12}]}""";
        var inv = ClaudeCliInvoiceExtractor.Parse(json);
        inv.SupplierName.Should().Be("ТОО Фуд");
        inv.InvoiceNumber.Should().Be("Н-1");
        inv.TotalSum.Should().Be(1500m);
        inv.Lines.Should().HaveCount(1);
        var l = inv.Lines[0];
        l.Barcode.Should().Be("4870123456789");
        l.SupplierCode.Should().Be("ABC");
        l.Quantity.Should().Be(10m);
        l.Price.Should().Be(150m);
    }

    [Fact]
    public void Parse_envelope_with_result_string_and_markdown_fence()
    {
        // Payload wrapped в ```json ``` — Claude иногда так возвращает.
        var fence = "`" + "`" + "`";
        var payloadInside = fence + "json\n{\"supplier\":\"X\",\"lines\":[{\"name\":\"А\",\"qty\":1,\"price\":10}]}\n" + fence;
        var envelope = System.Text.Json.JsonSerializer.Serialize(new
        {
            result = payloadInside,
            usage = new { input_tokens = 123, output_tokens = 45 }
        });
        var inv = ClaudeCliInvoiceExtractor.Parse(envelope);
        inv.SupplierName.Should().Be("X");
        inv.Lines.Should().ContainSingle();
        inv.InputTokens.Should().Be(123);
        inv.OutputTokens.Should().Be(45);
    }

    [Fact]
    public void Parse_barcode_with_spaces_is_stripped()
    {
        var json = """{"lines":[{"name":"X","qty":1,"price":1,"barcode":"4870 123 456 789"}]}""";
        var inv = ClaudeCliInvoiceExtractor.Parse(json);
        inv.Lines[0].Barcode.Should().Be("4870123456789");
    }

    [Fact]
    public void Parse_null_fields_tolerated()
    {
        var json = """{"supplier":null,"number":null,"date":null,"total":null,"lines":[{"name":"X","qty":"2,5","price":"100.5"}]}""";
        var inv = ClaudeCliInvoiceExtractor.Parse(json);
        inv.SupplierName.Should().BeNull();
        inv.TotalSum.Should().BeNull();
        inv.Lines[0].Quantity.Should().Be(2.5m);     // «2,5» → 2.5
        inv.Lines[0].Price.Should().Be(100.5m);
    }

    [Fact]
    public void Parse_empty_raises()
    {
        var act = () => ClaudeCliInvoiceExtractor.Parse("");
        act.Should().Throw<InvoiceExtractionException>();
    }

    [Fact]
    public void Parse_lines_without_name_are_skipped()
    {
        var json = """{"lines":[{"name":"A","qty":1,"price":1},{"name":"","qty":2,"price":2},{"name":null,"qty":3,"price":3}]}""";
        var inv = ClaudeCliInvoiceExtractor.Parse(json);
        inv.Lines.Should().ContainSingle(l => l.Name == "A");
    }
}