using System.Net;
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text.Json;
using Dapper;
using FluentAssertions;
using Microsoft.Data.SqlClient;
using Microsoft.Extensions.DependencyInjection;
using SIGCM2.Application.Abstractions.Security;
using SIGCM2.Application.Common;
using SIGCM2.Application.Products.Prices;
using SIGCM2.Domain.Entities;
using SIGCM2.TestSupport;
using Xunit;

namespace SIGCM2.Api.Tests.Products;

/// <summary>
/// PRD-003 — Integration tests for:
///   GET  /api/v1/products/{id}/prices       (requires authentication)
///   POST /api/v1/admin/products/{id}/prices  (requires catalogo:productos:gestionar)
/// DB: SIGCM2_Test_Api (ApiIntegration collection — shared TestWebAppFactory).
///
/// Each test creates its own product (via SQL) to avoid inter-test dependencies.
/// </summary>
[Collection("ApiIntegration")]
public sealed class ProductPricesControllerTests : IAsyncLifetime
{
    private const string ConnectionString = TestConnectionStrings.ApiTestDb;

    private readonly TestWebAppFactory _factory;
    private readonly HttpClient _client;

    // Seeded once per class — valid MedioId and ProductTypeId from canonical data
    private int _medioId;
    private int _productTypeId;

    public ProductPricesControllerTests(TestWebAppFactory factory)
    {
        _factory = factory;
        _client = factory.CreateClient();
    }

    // ── Lifecycle ─────────────────────────────────────────────────────────────

    public async Task InitializeAsync()
    {
        await using var conn = new SqlConnection(ConnectionString);
        await conn.OpenAsync();

        // Resolve a valid MedioId (dbo.Medio uses 'Activo' column)
        _medioId = await conn.QuerySingleAsync<int>(
            "SELECT TOP 1 Id FROM dbo.Medio WHERE Activo = 1 ORDER BY Id");

        // Resolve or seed a valid ProductTypeId (dbo.ProductType uses 'IsActive' column)
        var ptId = await conn.QuerySingleOrDefaultAsync<int?>(
            "SELECT TOP 1 Id FROM dbo.ProductType WHERE IsActive = 1 ORDER BY Id");
        if (ptId is null)
        {
            ptId = await conn.QuerySingleAsync<int>("""
                INSERT INTO dbo.ProductType (Nombre, HasDuration, RequiresText, RequiresCategory, IsBundle, AllowImages, IsActive, FechaCreacion)
                VALUES ('PT_Prices_Test', 0, 0, 0, 0, 0, 1, SYSUTCDATETIME());
                SELECT CAST(SCOPE_IDENTITY() AS INT);
                """);
        }
        _productTypeId = ptId.Value;
    }

    public Task DisposeAsync() => Task.CompletedTask;

    // ── Auth helpers ──────────────────────────────────────────────────────────

    /// <summary>Generates a bearer token for admin (has catalogo:productos:gestionar via 'admin' role).</summary>
    private string GetAdminToken()
    {
        var jwt = _factory.Services.GetRequiredService<IJwtService>();
        return jwt.GenerateAccessToken(new Usuario(
            id: 1, username: "admin", passwordHash: "x",
            nombre: "Admin", apellido: "Sys", email: null,
            rol: "admin", permisosJson: """{"grant":[],"deny":[]}""", activo: true));
    }

    /// <summary>Generates a bearer token for cajero (does NOT have catalogo:productos:gestionar).</summary>
    private string GetCajeroToken()
    {
        var jwt = _factory.Services.GetRequiredService<IJwtService>();
        return jwt.GenerateAccessToken(new Usuario(
            id: 9999, username: "cajero_test", passwordHash: "x",
            nombre: "Cajero", apellido: "Test", email: null,
            rol: "cajero", permisosJson: """{"grant":[],"deny":[]}""", activo: true));
    }

    private HttpRequestMessage BuildRequest(
        HttpMethod method, string url, object? body = null, string? token = null)
    {
        var req = new HttpRequestMessage(method, url);
        if (token is not null)
            req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
        if (body is not null)
            req.Content = JsonContent.Create(body);
        return req;
    }

    // ── DB seed helpers ───────────────────────────────────────────────────────

    /// <summary>Seeds a unique product and returns its Id.</summary>
    private async Task<int> SeedProductAsync(bool activo = true)
    {
        await using var conn = new SqlConnection(ConnectionString);
        await conn.OpenAsync();
        var nombre = $"PP_{Guid.NewGuid():N}"[..35];
        // dbo.Product uses 'IsActive' column (PRD-002 convention)
        return await conn.QuerySingleAsync<int>("""
            INSERT INTO dbo.Product (Nombre, MedioId, ProductTypeId, BasePrice, PriceDurationDays, IsActive, FechaCreacion)
            VALUES (@Nombre, @MedioId, @PtId, 100.00, NULL, @IsActive, SYSUTCDATETIME());
            SELECT CAST(SCOPE_IDENTITY() AS INT);
            """,
            new { Nombre = nombre, MedioId = _medioId, PtId = _productTypeId, IsActive = activo ? 1 : 0 });
    }

    /// <summary>
    /// Inserts a ProductPrice row directly (bypasses SP forward-only guard) to set up test scenarios.
    /// </summary>
    private async Task<long> SeedPriceDirectAsync(
        int productId, decimal price, DateOnly pvf, DateOnly? pvt)
    {
        await using var conn = new SqlConnection(ConnectionString);
        await conn.OpenAsync();
        return await conn.QuerySingleAsync<long>("""
            INSERT INTO dbo.ProductPrices (ProductId, Price, PriceValidFrom, PriceValidTo, FechaCreacion)
            VALUES (@ProductId, @Price, @PriceValidFrom, @PriceValidTo, SYSUTCDATETIME());
            SELECT CAST(SCOPE_IDENTITY() AS BIGINT);
            """,
            new
            {
                ProductId = productId,
                Price = price,
                PriceValidFrom = pvf.ToDateTime(TimeOnly.MinValue),
                PriceValidTo = pvt.HasValue ? (DateTime?)pvt.Value.ToDateTime(TimeOnly.MinValue) : null
            });
    }

    // ── GET /api/v1/products/{id}/prices ─────────────────────────────────────

    /// <summary>§P.8 — No token → 401.</summary>
    [Fact]
    public async Task GetPrices_WithoutAuth_Returns401()
    {
        using var req = BuildRequest(HttpMethod.Get, "/api/v1/products/1/prices");
        var resp = await _client.SendAsync(req);
        resp.StatusCode.Should().Be(HttpStatusCode.Unauthorized);
    }

    /// <summary>§P.8 — Token with no 'catalogo:productos:gestionar' → 403.</summary>
    [Fact]
    public async Task GetPrices_WithoutPermission_Returns403()
    {
        var productId = await SeedProductAsync();
        var token = GetCajeroToken();
        using var req = BuildRequest(HttpMethod.Get, $"/api/v1/products/{productId}/prices", token: token);
        var resp = await _client.SendAsync(req);
        resp.StatusCode.Should().Be(HttpStatusCode.Forbidden);
    }

    /// <summary>§P.6 — Producto sin histórico → 200 con items=[], total=0, page=1, pageSize=20.</summary>
    [Fact]
    public async Task GetPrices_EmptyHistory_Returns200WithPagedResultEmpty()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();

        using var req = BuildRequest(HttpMethod.Get, $"/api/v1/products/{productId}/prices", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.Items.Should().BeEmpty();
        paged.Page.Should().Be(1);
        paged.PageSize.Should().Be(20);
        paged.Total.Should().Be(0);
    }

    /// <summary>§P.1 — 10 precios, sin query params → defaults: page=1, pageSize=20, total=10, items=10.</summary>
    [Fact]
    public async Task GetPrices_TenPrices_NoParams_ReturnsDefaultsPagedResult()
    {
        var productId = await SeedProductAsync();
        // Seed 10 prices — all but the last have explicit PVT to respect UX_ProductPrices_Active
        for (var i = 1; i <= 10; i++)
        {
            var pvt = i < 10 ? (DateOnly?)new DateOnly(2026, 1, i) : null;
            await SeedPriceDirectAsync(productId, i * 10m, new DateOnly(2026, 1, i), pvt);
        }

        var token = GetAdminToken();
        using var req = BuildRequest(HttpMethod.Get, $"/api/v1/products/{productId}/prices", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.Page.Should().Be(1);
        paged.PageSize.Should().Be(20);
        paged.Total.Should().Be(10);
        paged.Items.Should().HaveCount(10);
        // First item must be most recent (Jan 10)
        paged.Items[0].PriceValidFrom.Should().Be(new DateOnly(2026, 1, 10));
    }

    /// <summary>§P.2 — 30 precios, page=2, pageSize=10 → items 11-20 ordenados DESC.</summary>
    [Fact]
    public async Task GetPrices_ThirtyPrices_Page2PageSize10_ReturnsCorrectPage()
    {
        var productId = await SeedProductAsync();
        // Seed 30 prices — all but the last have explicit PVT to respect UX_ProductPrices_Active
        for (var i = 1; i <= 30; i++)
        {
            var pvt = i < 30 ? (DateOnly?)new DateOnly(2026, 1, i) : null;
            await SeedPriceDirectAsync(productId, i * 5m, new DateOnly(2026, 1, i), pvt);
        }

        var token = GetAdminToken();
        using var req = BuildRequest(
            HttpMethod.Get, $"/api/v1/products/{productId}/prices?page=2&pageSize=10", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.Page.Should().Be(2);
        paged.PageSize.Should().Be(10);
        paged.Total.Should().Be(30);
        paged.Items.Should().HaveCount(10);
        // Ordered DESC by PVF: rank 11-20 from newest = Jan 20 down to Jan 11
        paged.Items[0].PriceValidFrom.Should().Be(new DateOnly(2026, 1, 20));
        paged.Items[9].PriceValidFrom.Should().Be(new DateOnly(2026, 1, 11));
    }

    /// <summary>§P.3 — 30 precios, page=10, pageSize=10 → items=[], total=30.</summary>
    [Fact]
    public async Task GetPrices_ThirtyPrices_PageBeyondTotal_ReturnsEmptyItems()
    {
        var productId = await SeedProductAsync();
        for (var i = 1; i <= 30; i++)
        {
            var pvt = i < 30 ? (DateOnly?)new DateOnly(2026, 1, i) : null;
            await SeedPriceDirectAsync(productId, i * 5m, new DateOnly(2026, 1, i), pvt);
        }

        var token = GetAdminToken();
        using var req = BuildRequest(
            HttpMethod.Get, $"/api/v1/products/{productId}/prices?page=10&pageSize=10", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.Page.Should().Be(10);
        paged.PageSize.Should().Be(10);
        paged.Total.Should().Be(30);
        paged.Items.Should().BeEmpty();
    }

    /// <summary>§P.4 — pageSize=500 → clamp to 100 en la respuesta.</summary>
    [Fact]
    public async Task GetPrices_PageSizeOver100_ClampsTo100()
    {
        var productId = await SeedProductAsync();
        // Seed 5 prices — all but the last have explicit PVT to respect UX_ProductPrices_Active
        for (var i = 1; i <= 5; i++)
        {
            var pvt = i < 5 ? (DateOnly?)new DateOnly(2026, 1, i) : null;
            await SeedPriceDirectAsync(productId, i * 10m, new DateOnly(2026, 1, i), pvt);
        }

        var token = GetAdminToken();
        using var req = BuildRequest(
            HttpMethod.Get, $"/api/v1/products/{productId}/prices?pageSize=500", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.PageSize.Should().Be(100, "pageSize must be clamped to max 100");
        paged.Items.Should().HaveCount(5);
    }

    /// <summary>§P.5 — page=0 → clamp to 1.</summary>
    [Fact]
    public async Task GetPrices_PageZero_ClampsToOne()
    {
        var productId = await SeedProductAsync();
        await SeedPriceDirectAsync(productId, 100m, new DateOnly(2026, 1, 1), null); // single active row

        var token = GetAdminToken();
        using var req = BuildRequest(
            HttpMethod.Get, $"/api/v1/products/{productId}/prices?page=0", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.Page.Should().Be(1, "page=0 must be clamped to 1");
    }

    /// <summary>§P.4 boundary — pageSize=100 exacto → no clamping, boundary inclusivo.</summary>
    [Fact]
    public async Task GetPrices_PageSize100_Exact_Returns200()
    {
        var productId = await SeedProductAsync();
        // Seed 3 prices — all but the last have explicit PVT
        for (var i = 1; i <= 3; i++)
        {
            var pvt = i < 3 ? (DateOnly?)new DateOnly(2026, 1, i) : null;
            await SeedPriceDirectAsync(productId, i * 10m, new DateOnly(2026, 1, i), pvt);
        }

        var token = GetAdminToken();
        using var req = BuildRequest(
            HttpMethod.Get, $"/api/v1/products/{productId}/prices?pageSize=100", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.PageSize.Should().Be(100, "pageSize=100 is the upper boundary — must NOT be clamped further");
        paged.Items.Should().HaveCount(3);
    }

    /// <summary>§P.4 boundary — pageSize=101 → clamp to 100.</summary>
    [Fact]
    public async Task GetPrices_PageSize101_ClampsTo100()
    {
        var productId = await SeedProductAsync();
        await SeedPriceDirectAsync(productId, 50m, new DateOnly(2026, 2, 1), null);

        var token = GetAdminToken();
        using var req = BuildRequest(
            HttpMethod.Get, $"/api/v1/products/{productId}/prices?pageSize=101", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.PageSize.Should().Be(100, "pageSize=101 must be clamped to 100");
    }

    /// <summary>§P.4 boundary — pageSize=1000 → clamp to 100.</summary>
    [Fact]
    public async Task GetPrices_PageSize1000_ClampsTo100()
    {
        var productId = await SeedProductAsync();
        await SeedPriceDirectAsync(productId, 75m, new DateOnly(2026, 3, 1), null);

        var token = GetAdminToken();
        using var req = BuildRequest(
            HttpMethod.Get, $"/api/v1/products/{productId}/prices?pageSize=1000", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.PageSize.Should().Be(100, "pageSize=1000 must be clamped to max 100");
    }

    /// <summary>§P.5 boundary — page=-5 → clamp to 1.</summary>
    [Fact]
    public async Task GetPrices_PageNegative_ClampsToOne()
    {
        var productId = await SeedProductAsync();
        await SeedPriceDirectAsync(productId, 120m, new DateOnly(2026, 4, 1), null);

        var token = GetAdminToken();
        using var req = BuildRequest(
            HttpMethod.Get, $"/api/v1/products/{productId}/prices?page=-5", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.Page.Should().Be(1, "page=-5 must be clamped to 1");
    }

    /// <summary>§P.4 boundary — pageSize=0 → clamp to 1 (minimum).</summary>
    [Fact]
    public async Task GetPrices_PageSizeZero_ClampsToOne()
    {
        var productId = await SeedProductAsync();
        await SeedPriceDirectAsync(productId, 90m, new DateOnly(2026, 5, 1), null);

        var token = GetAdminToken();
        using var req = BuildRequest(
            HttpMethod.Get, $"/api/v1/products/{productId}/prices?pageSize=0", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.PageSize.Should().Be(1, "pageSize=0 must be clamped to minimum 1");
    }

    /// <summary>§P.7 — Producto inexistente → 404.</summary>
    [Fact]
    public async Task GetPrices_ProductNotFound_Returns404()
    {
        var token = GetAdminToken();
        using var req = BuildRequest(HttpMethod.Get, "/api/v1/products/999999999/prices", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.NotFound);
        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
        body.GetProperty("error").GetString().Should().Be("product_not_found");
    }

    /// <summary>
    /// §P.1 compat — 3 prices, no params → PagedResult with items ordered DESC.
    /// Replaces the old GetPrices_WithHistory_Returns200OrderedDescending.
    /// </summary>
    [Fact]
    public async Task GetPrices_WithHistory_Returns200OrderedDescendingPaged()
    {
        var productId = await SeedProductAsync();

        // Seed 3 prices: 2 closed + 1 active (ascending order to verify API returns DESC)
        await SeedPriceDirectAsync(productId, 50m,  new DateOnly(2026, 1, 1), new DateOnly(2026, 1, 31));
        await SeedPriceDirectAsync(productId, 75m,  new DateOnly(2026, 2, 1), new DateOnly(2026, 2, 28));
        await SeedPriceDirectAsync(productId, 100m, new DateOnly(2026, 3, 1), null);

        var token = GetAdminToken();
        using var req = BuildRequest(HttpMethod.Get, $"/api/v1/products/{productId}/prices", token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.OK);
        var paged = await resp.Content.ReadFromJsonAsync<PagedResult<ProductPriceDto>>();
        paged.Should().NotBeNull();
        paged!.Total.Should().Be(3);
        paged.Items.Should().HaveCount(3);

        // First item = most recent (active, March)
        paged.Items[0].PriceValidFrom.Should().Be(new DateOnly(2026, 3, 1));
        paged.Items[0].IsActive.Should().BeTrue();
        paged.Items[0].PriceValidTo.Should().BeNull();

        // Last item = oldest (January)
        paged.Items[2].PriceValidFrom.Should().Be(new DateOnly(2026, 1, 1));
        paged.Items[2].IsActive.Should().BeFalse();
        paged.Items[2].PriceValidTo.Should().Be(new DateOnly(2026, 1, 31));
    }

    // ── POST /api/v1/admin/products/{id}/prices ───────────────────────────────

    [Fact]
    public async Task PostPrice_WithoutAuth_Returns401()
    {
        using var req = BuildRequest(HttpMethod.Post, "/api/v1/admin/products/1/prices",
            body: new { price = 200m, priceValidFrom = "2026-05-01" });
        var resp = await _client.SendAsync(req);
        resp.StatusCode.Should().Be(HttpStatusCode.Unauthorized);
    }

    [Fact]
    public async Task PostPrice_WithoutPermission_Returns403()
    {
        var productId = await SeedProductAsync();
        var token = GetCajeroToken();
        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");

        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = 200m, priceValidFrom = pvf },
            token: token);
        var resp = await _client.SendAsync(req);
        resp.StatusCode.Should().Be(HttpStatusCode.Forbidden);
    }

    [Fact]
    public async Task PostPrice_FirstPrice_Returns201WithClosedNull()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();
        // Use tomorrow to ensure >= hoy_AR passes FluentValidation
        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");

        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = 250m, priceValidFrom = pvf },
            token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.Created);

        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
        body.TryGetProperty("created", out var created).Should().BeTrue();
        body.TryGetProperty("closed", out var closed).Should().BeTrue();

        created.GetProperty("price").GetDecimal().Should().Be(250m);
        created.GetProperty("priceValidFrom").GetString().Should().Be(pvf);
        created.GetProperty("isActive").GetBoolean().Should().BeTrue();
        closed.ValueKind.Should().Be(JsonValueKind.Null);

        // Location header must be present
        resp.Headers.Location.Should().NotBeNull();
    }

    [Fact]
    public async Task PostPrice_SecondPrice_Returns201WithClosedNotNull()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();

        // Seed an existing active price at a past date (direct insert bypasses SP)
        await SeedPriceDirectAsync(productId, 100m, new DateOnly(2026, 4, 1), null);

        // New price must be strictly greater than active PVF
        var newPvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(2).ToString("yyyy-MM-dd");
        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = 300m, priceValidFrom = newPvf },
            token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.Created);

        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
        var closed = body.GetProperty("closed");
        closed.ValueKind.Should().NotBe(JsonValueKind.Null);
        closed.GetProperty("price").GetDecimal().Should().Be(100m);

        // PriceValidTo of closed = newPvf - 1 day
        var expectedPvt = DateOnly.ParseExact(newPvf, "yyyy-MM-dd").AddDays(-1).ToString("yyyy-MM-dd");
        closed.GetProperty("priceValidTo").GetString().Should().Be(expectedPvt);

        var created = body.GetProperty("created");
        created.GetProperty("price").GetDecimal().Should().Be(300m);
        created.GetProperty("priceValidFrom").GetString().Should().Be(newPvf);
        created.GetProperty("isActive").GetBoolean().Should().BeTrue();
    }

    [Fact]
    public async Task PostPrice_PriceZero_Returns400()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();
        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");

        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = 0m, priceValidFrom = pvf },
            token: token);
        var resp = await _client.SendAsync(req);
        resp.StatusCode.Should().Be(HttpStatusCode.BadRequest);
    }

    [Fact]
    public async Task PostPrice_NegativePrice_Returns400()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();
        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");

        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = -5m, priceValidFrom = pvf },
            token: token);
        var resp = await _client.SendAsync(req);
        resp.StatusCode.Should().Be(HttpStatusCode.BadRequest);
    }

    [Fact]
    public async Task PostPrice_PastDate_Returns400()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();
        // Clearly in the past
        const string pastDate = "2020-01-01";

        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = 100m, priceValidFrom = pastDate },
            token: token);
        var resp = await _client.SendAsync(req);
        resp.StatusCode.Should().Be(HttpStatusCode.BadRequest);
    }

    [Fact]
    public async Task PostPrice_ProductNotFound_Returns404()
    {
        var token = GetAdminToken();
        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");

        using var req = BuildRequest(HttpMethod.Post, "/api/v1/admin/products/999999999/prices",
            body: new { price = 100m, priceValidFrom = pvf },
            token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.NotFound);
        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
        body.GetProperty("error").GetString().Should().Be("product_not_found");
    }

    [Fact]
    public async Task PostPrice_ForwardOnlyViolation_Returns409()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();

        // Seed active price at a far-future date
        await SeedPriceDirectAsync(productId, 200m, new DateOnly(2099, 12, 1), null);

        // Try to add price with a date BEFORE the active one
        const string retroPvf = "2099-11-01";
        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = 150m, priceValidFrom = retroPvf },
            token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.Conflict);
        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
        body.GetProperty("error").GetString().Should().Be("product_price_forward_only");
    }

    [Fact]
    public async Task PostPrice_SamePvfAsActive_Returns409()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();

        // Seed active price at a far-future date
        await SeedPriceDirectAsync(productId, 200m, new DateOnly(2099, 12, 1), null);

        // Try to add price with the SAME date — also rejected (forward-only: must be strictly greater)
        const string samePvf = "2099-12-01";
        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = 250m, priceValidFrom = samePvf },
            token: token);
        var resp = await _client.SendAsync(req);

        resp.StatusCode.Should().Be(HttpStatusCode.Conflict);
        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
        body.GetProperty("error").GetString().Should().Be("product_price_forward_only");
    }

    // ── Audit Event ───────────────────────────────────────────────────────────

    [Fact]
    public async Task PostPrice_Success_CreatesAuditEvent()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();
        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");

        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = 500m, priceValidFrom = pvf },
            token: token);
        var resp = await _client.SendAsync(req);
        resp.StatusCode.Should().Be(HttpStatusCode.Created);

        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
        var newId = body.GetProperty("created").GetProperty("id").GetInt64();

        // Verify audit event row in SIGCM2_Test_Api
        await using var conn = new SqlConnection(ConnectionString);
        await conn.OpenAsync();
        var auditCount = await conn.QuerySingleAsync<int>("""
            SELECT COUNT(1) FROM dbo.AuditEvent
            WHERE Action = 'product_price.created'
              AND TargetType = 'ProductPrice'
              AND TargetId = @TargetId
            """, new { TargetId = newId.ToString() });

        auditCount.Should().Be(1, because: "IAuditLogger must record product_price.created after a successful POST");
    }

    // ── DateOnly JSON format ──────────────────────────────────────────────────

    [Fact]
    public async Task PostPrice_DateOnly_SerializesAsYyyyMmDd()
    {
        var productId = await SeedProductAsync();
        var token = GetAdminToken();
        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");

        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
            body: new { price = 999m, priceValidFrom = pvf },
            token: token);
        var resp = await _client.SendAsync(req);
        resp.StatusCode.Should().Be(HttpStatusCode.Created);

        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
        var returnedPvf = body.GetProperty("created").GetProperty("priceValidFrom").GetString();

        // DateOnlyJsonConverter must produce "yyyy-MM-dd" — no time, no TZ suffix
        returnedPvf.Should().MatchRegex(@"^\d{4}-\d{2}-\d{2}$",
            because: "DateOnlyJsonConverter (UDT-011) must serialize DateOnly as yyyy-MM-dd");
        returnedPvf.Should().Be(pvf);
    }
}