using System.Net;
using System.Net.Http.Json;
using System.Text;
using System.Text.Json;
using FluentAssertions;
using Microsoft.Extensions.DependencyInjection;

/// <summary>
/// Tests for cover sheet PDF generation endpoints and the PDF builder.
/// </summary>
[Collection("Database")]
public class CoverSheetPdfTests : IAsyncLifetime
{
    private readonly ApiFixture _fixture;
    private HttpClient _intakeClient = null!;

    public CoverSheetPdfTests(ApiFixture fixture) => _fixture = fixture;

    public async Task InitializeAsync()
    {
        using var scope = _fixture.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
        await DbResetHelper.ResetAsync(db);
        await DataSeeder.SeedAsync(db);
        _intakeClient = await AuthHelper.LoginAsync(_fixture, "intake1");
    }

    public Task DisposeAsync() => Task.CompletedTask;

    [Fact]
    public void Generate_ProducesValidPdfWithCoverSheetMetadata()
    {
        var sheet = new CoverSheet
        {
            Id = Guid.NewGuid(),
            Code = "VCR-CS-A3F7B2D1",
            BatchType = BatchType.VitalsSheet,
            Track = BatchTrack.Backfill,
            CreatedAt = new DateTimeOffset(2026, 6, 27, 12, 0, 0, TimeSpan.Zero),
            Patient = new Patient
            {
                Id = Guid.NewGuid(),
                FullName = "Maria Garcia",
                Mrn = "MRN-12345"
            },
            AssignToUser = new User
            {
                Id = Guid.NewGuid(),
                FullName = "Entry Clerk One"
            }
        };

        var pdf = CoverSheetPdfGenerator.Generate(sheet);

        var text = Encoding.ASCII.GetString(pdf);
        text.Should().StartWith("%PDF-1.4");
        text.Should().Contain("VCR-CS-A3F7B2D1");
        text.Should().Contain("VITALS_SHEET");
        text.Should().Contain("BACKFILL");
        text.Should().Contain("Maria Garcia");
        text.Should().Contain("MRN-12345");
        text.Should().Contain("Entry Clerk One");
        text.Should().Contain("2026-06-27");
        text.Should().Contain("Attach to front of chart section");
        text.Should().Contain("/Subtype /Image");
    }

    [Fact]
    public void GenerateBatch_ProducesMultiPagePdf()
    {
        var sheets = new[]
        {
            new CoverSheet
            {
                Id = Guid.NewGuid(),
                Code = "VCR-CS-11111111",
                BatchType = BatchType.VitalsSheet,
                Track = BatchTrack.Backfill,
                CreatedAt = DateTimeOffset.UtcNow
            },
            new CoverSheet
            {
                Id = Guid.NewGuid(),
                Code = "VCR-CS-22222222",
                BatchType = BatchType.LabResults,
                Track = BatchTrack.Backfill,
                CreatedAt = DateTimeOffset.UtcNow
            }
        };

        var pdf = CoverSheetPdfGenerator.GenerateBatch(sheets);
        var text = Encoding.ASCII.GetString(pdf);

        text.Should().Contain("/Count 2");
        text.Should().Contain("VCR-CS-11111111");
        text.Should().Contain("VCR-CS-22222222");
    }

    [Fact]
    public async Task GeneratePdf_Endpoint_ReturnsPdfForCoverSheetId()
    {
        var sheetId = await GenerateCoverSheetIdAsync();

        var response = await _intakeClient.PostAsync($"/api/v1/cover-sheets/{sheetId}/pdf", null);

        response.StatusCode.Should().Be(HttpStatusCode.OK);
        response.Content.Headers.ContentType!.MediaType.Should().Be("application/pdf");

        var bytes = await response.Content.ReadAsByteArrayAsync();
        var text = Encoding.ASCII.GetString(bytes);
        text.Should().StartWith("%PDF-1.4");
        text.Should().Contain("VCR-CS-");
    }

    [Fact]
    public async Task GenerateBatchPdf_Endpoint_ReturnsMultiPagePdf()
    {
        var ids = new List<Guid>
        {
            await GenerateCoverSheetIdAsync(),
            await GenerateCoverSheetIdAsync()
        };

        var response = await _intakeClient.PostAsJsonAsync(
            "/api/v1/cover-sheets/batch-pdf",
            new { coverSheetIds = ids });

        response.StatusCode.Should().Be(HttpStatusCode.OK);
        response.Content.Headers.ContentType!.MediaType.Should().Be("application/pdf");

        var text = Encoding.ASCII.GetString(await response.Content.ReadAsByteArrayAsync());
        text.Should().Contain("/Count 2");
    }

    [Fact]
    public async Task GeneratePdf_UnknownId_Returns404()
    {
        var response = await _intakeClient.PostAsync(
            $"/api/v1/cover-sheets/{Guid.NewGuid()}/pdf", null);

        response.StatusCode.Should().Be(HttpStatusCode.NotFound);
    }

    private async Task<Guid> GenerateCoverSheetIdAsync()
    {
        var response = await _intakeClient.PostAsJsonAsync(
            "/api/v1/cover-sheets/generate",
            new { count = 1, batchType = "VITALS_SHEET", track = "BACKFILL" });
        response.EnsureSuccessStatusCode();

        var body = await response.Content.ReadFromJsonAsync<JsonElement>();
        return body.GetProperty("data")[0].GetProperty("id").GetGuid();
    }
}