using System.Net;
using System.Net.Http.Json;
using System.Security.Cryptography;
using System.Text.Json;
using Microsoft.EntityFrameworkCore;

namespace WordVersioning.Api.IntegrationTests;

/// <summary>FR-5 (upload), FR-6 (history), FR-7 (download) — ผ่าน HTTP จริง + ตรวจสถานะใน Postgres ตรงๆ</summary>
[Collection(IntegrationTestCollection.Name)]
public sealed class UploadVersionTests(IntegrationTestFixture fixture)
{
    [Fact]
    public async Task FirstUpload_CreatesDocumentAndVersionRow_FromJwtClaims()
    {
        var documentId = Guid.NewGuid();
        var clientVersionId = Guid.NewGuid();
        var bytes = TestDocx.BuildPlainDocx("version 1 content");

        using var client = fixture.CreateClient();
        using var response = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(bytes, "เอกสารทดสอบ.docx", clientVersionId.ToString()));

        Assert.Equal(HttpStatusCode.Created, response.StatusCode);
        var result = await response.Content.ReadFromJsonAsync<UploadVersionResult>(IntegrationTestFixture.Json);
        Assert.Equal(1, result!.VersionNumber);
        Assert.NotEqual(Guid.Empty, result.VersionId);

        // ตรวจ DB จริง: Document auto-create + ค่า tracking จาก JWT claims (AC-5)
        await using var db = fixture.CreateDb();
        var doc = await db.Documents.AsNoTracking().SingleAsync(d => d.Id == documentId);
        Assert.Equal("เอกสารทดสอบ.docx", doc.FileName);
        Assert.Null(doc.TemplateId); // track เองจาก add-in — ไม่ผูก template

        var version = await db.DocumentVersions.AsNoTracking().SingleAsync(v => v.DocumentId == documentId);
        Assert.Equal(1, version.VersionNumber);
        Assert.Equal(fixture.TestUserId, version.CreatedByUserId); // sub จาก token เท่านั้น
        Assert.Equal(Convert.ToHexString(SHA256.HashData(bytes)).ToLowerInvariant(), version.ContentHash);
        Assert.Equal($"{documentId}/v0001_{clientVersionId}.docx", version.ObjectKey);
    }

    [Fact]
    public async Task SecondUpload_IncrementsVersionNumber_AndHistorySortsNewestFirst()
    {
        var documentId = Guid.NewGuid();
        using var client = fixture.CreateClient();

        var v1 = TestDocx.BuildPlainDocx("v1");
        using var first = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(v1, "doc.docx", Guid.NewGuid().ToString()));
        var firstResult = await first.Content.ReadFromJsonAsync<UploadVersionResult>(IntegrationTestFixture.Json);

        var v2 = TestDocx.BuildPlainDocx("v2 — แก้ไขแล้ว");
        using var second = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(v2, "doc.docx", Guid.NewGuid().ToString()));
        Assert.Equal(HttpStatusCode.Created, second.StatusCode);
        var secondResult = await second.Content.ReadFromJsonAsync<UploadVersionResult>(IntegrationTestFixture.Json);
        Assert.Equal(2, secondResult!.VersionNumber);

        // FR-6: เรียงใหม่ → เก่า
        using var history = await client.GetAsync($"api/documents/{documentId}/versions");
        var items = await history.Content.ReadFromJsonAsync<List<VersionItem>>(IntegrationTestFixture.Json);
        Assert.Equal(2, items!.Count);
        Assert.Equal(secondResult.VersionId, items[0].VersionId);
        Assert.Equal(2, items[0].VersionNumber);
        Assert.Equal(firstResult!.VersionId, items[1].VersionId);
        Assert.Equal(1, items[1].VersionNumber);
        Assert.All(items, i => Assert.Equal(fixture.TestUserId, i.CreatedByUserId));
    }

    [Fact]
    public async Task Download_ReturnsExactUploadedBytes_WithDocxContentType()
    {
        var documentId = Guid.NewGuid();
        var bytes = TestDocx.BuildPlainDocx("ไบต์ต้องตรงกันตอนดาวน์โหลด (AC-8 ส่วน backend)");
        using var client = fixture.CreateClient();

        using var upload = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(bytes, "roundtrip.docx", Guid.NewGuid().ToString()));
        var uploaded = await upload.Content.ReadFromJsonAsync<UploadVersionResult>(IntegrationTestFixture.Json);

        using var download = await client.GetAsync(
            $"api/documents/{documentId}/versions/{uploaded!.VersionId}/download");

        Assert.Equal(HttpStatusCode.OK, download.StatusCode);
        Assert.Equal(TestDocx.DocxContentType, download.Content.Headers.ContentType!.MediaType);
        var downloaded = await download.Content.ReadAsByteArrayAsync();
        Assert.Equal(bytes, downloaded); // byte-for-byte ผ่าน MinIO ไป-กลับ
    }

    [Fact]
    public async Task Download_UnknownVersion_Returns404()
    {
        using var client = fixture.CreateClient();
        using var response = await client.GetAsync(
            $"api/documents/{Guid.NewGuid()}/versions/{Guid.NewGuid()}/download");
        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
    }

    [Fact]
    public async Task GetVersions_UnknownDocument_Returns404()
    {
        using var client = fixture.CreateClient();
        using var response = await client.GetAsync($"api/documents/{Guid.NewGuid()}/versions");
        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
    }

    [Fact]
    public async Task Upload_NonDocxFile_Returns400()
    {
        var documentId = Guid.NewGuid();
        using var client = fixture.CreateClient();
        using var form = new MultipartFormDataContent();
        var file = new ByteArrayContent("นี่ไม่ใช่ word"u8.ToArray());
        file.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("text/plain");
        form.Add(file, "file", "notes.txt"); // ชื่อไม่ลงท้าย .docx
        form.Add(new StringContent(Guid.NewGuid().ToString()), "clientVersionId");

        using var response = await client.PostAsync($"api/documents/{documentId}/versions", form);
        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);

        await using var db = fixture.CreateDb();
        Assert.False(await db.Documents.AsNoTracking().AnyAsync(d => d.Id == documentId)); // ไม่มี side effect
    }

    [Fact]
    public async Task Upload_InvalidClientVersionId_Returns400()
    {
        using var client = fixture.CreateClient();
        using var response = await client.PostAsync(
            $"api/documents/{Guid.NewGuid()}/versions",
            ApiExtensions.VersionForm(TestDocx.BuildPlainDocx(), "doc.docx", "ไม่ใช่ GUID"));
        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
    }

    [Fact]
    public async Task Upload_InvalidFieldsJson_Returns400()
    {
        using var client = fixture.CreateClient();
        using var response = await client.PostAsync(
            $"api/documents/{Guid.NewGuid()}/versions",
            ApiExtensions.VersionForm(TestDocx.BuildPlainDocx(), "doc.docx", Guid.NewGuid().ToString(), "not json"));
        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
    }

    /// <summary>เอกสารไม่ผูก template → snapshot เก็บ map ดิบตามที่ส่งมา (behavior ของ Phase 2)</summary>
    [Fact]
    public async Task Upload_WithoutTemplate_StoresRawFieldsMapInSnapshot()
    {
        var documentId = Guid.NewGuid();
        using var client = fixture.CreateClient();

        using var upload = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(
                TestDocx.BuildPlainDocx(), "doc.docx", Guid.NewGuid().ToString(),
                """{"custom_tag":"ค่าที่ส่งมา"}"""));

        Assert.Equal(HttpStatusCode.Created, upload.StatusCode);
        using var history = await client.GetAsync($"api/documents/{documentId}/versions");
        var items = await history.Content.ReadFromJsonAsync<List<VersionItem>>(IntegrationTestFixture.Json);

        var fields = items!.Single().Fields!.Value;
        Assert.Equal(JsonValueKind.Object, fields.ValueKind);
        Assert.Equal("ค่าที่ส่งมา", fields.GetProperty("custom_tag").GetString());
    }
}