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

namespace WordVersioning.Api.IntegrationTests;

/// <summary>FR-16 — ผูก template ตอน Start Versioning: form field `templateId` ทางเลือกของ upload
/// ใช้เฉพาะตอน auto-create Document · upload แรกของ Document ใหม่ = version 1 เสมอ + field sync เต็มระบบ</summary>
[Collection(IntegrationTestCollection.Name)]
public sealed class TemplateLinkingTests(IntegrationTestFixture fixture)
{
    private static string DefaultFieldsJson() => JsonSerializer.Serialize(TestFlow.DefaultValues);

    [Fact]
    public async Task Upload_WithTemplateId_OnNewDocument_CreatesLinkedDocV1WithFieldSync()
    {
        using var client = fixture.CreateClient();
        var (templateId, _) = await TestFlow.CreateConfiguredTemplateAsync(client, "linking หลัก");

        // Start Versioning ของไฟล์ร่าง: upload แรกพร้อม templateId + fields ที่ extract จาก content controls
        var documentId = Guid.NewGuid();
        using var upload = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(
                TestDocx.BuildTemplateDocx(), "ไฟล์ร่างทดสอบ.docx", Guid.NewGuid().ToString(),
                fieldsJson: DefaultFieldsJson(), templateId: templateId.ToString()));
        Assert.Equal(HttpStatusCode.Created, upload.StatusCode);
        var v1 = (await upload.Content.ReadFromJsonAsync<UploadVersionResult>(IntegrationTestFixture.Json))!;

        // upload แรกของ Document ใหม่ = version 1 เสมอ (ไม่มี v0 ใน flow ไฟล์ร่าง)
        Assert.Equal(1, v1.VersionNumber);

        await using var db = fixture.CreateDb();
        var document = await db.Documents.AsNoTracking()
            .Include(d => d.Versions)
            .SingleAsync(d => d.Id == documentId);
        Assert.Equal(templateId, document.TemplateId); // ผูก template ต้นทาง
        Assert.Equal(string.Empty, document.AddInSignature); // ฝั่ง add-in stamp ในไฟล์เอง — ค่าเดิมของ auto-create

        var version = Assert.Single(document.Versions);
        Assert.Equal(1, version.VersionNumber);
        Assert.NotNull(version.FieldsSnapshotJson); // snapshot แบบมีนิยาม (ไม่ใช่ raw map)

        // field sync เต็มระบบ (FR-11): DocumentFieldValue ครบทุก field ของ template
        var fieldValues = await db.DocumentFieldValues.AsNoTracking()
            .Where(v => v.DocumentId == documentId)
            .ToDictionaryAsync(v => v.FieldKey);
        Assert.Equal(4, fieldValues.Count);
        Assert.Equal("สมหญิง รักงาน", fieldValues["employee_name"].Value);
        Assert.Equal("75000", fieldValues["salary"].Value);
        Assert.All(fieldValues.Values, v => Assert.Equal(v1.VersionId, v.SourceVersionId));
        Assert.All(fieldValues.Values, v => Assert.Equal(fixture.TestUserId, v.UpdatedByUserId));

        // Save & Version ครั้งถัดไป (ไม่ส่ง templateId) = v2 และ TemplateId คงเดิม
        using var second = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(
                TestDocx.BuildTemplateDocx(), "ไฟล์ร่างทดสอบ.docx", Guid.NewGuid().ToString(),
                fieldsJson: DefaultFieldsJson(), message: "แก้ไขรอบสอง"));
        Assert.Equal(HttpStatusCode.Created, second.StatusCode);
        var v2 = (await second.Content.ReadFromJsonAsync<UploadVersionResult>(IntegrationTestFixture.Json))!;
        Assert.Equal(2, v2.VersionNumber);

        await using var db2 = fixture.CreateDb();
        var docAfter = await db2.Documents.AsNoTracking().SingleAsync(d => d.Id == documentId);
        Assert.Equal(templateId, docAfter.TemplateId);
    }

    [Fact]
    public async Task Upload_TemplateIdNotGuid_Returns400()
    {
        using var client = fixture.CreateClient();
        var (templateId, _) = await TestFlow.CreateConfiguredTemplateAsync(client, "linking ไม่ใช่ GUID");

        using var response = await client.PostAsync(
            $"api/documents/{Guid.NewGuid()}/versions",
            ApiExtensions.VersionForm(
                TestDocx.BuildPlainDocx(), "a.docx", Guid.NewGuid().ToString(), templateId: "not-a-guid"));
        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
        var error = await response.Content.ReadAsStringAsync();
        Assert.Contains("templateId", error);
    }

    [Fact]
    public async Task Upload_TemplateIdUnknown_Returns400()
    {
        using var client = fixture.CreateClient();
        _ = await TestFlow.CreateConfiguredTemplateAsync(client, "linking unknown"); // ตั้ง field defs ไว้ก่อน (ชุดเดียวกับที่ใช้จริง)

        using var response = await client.PostAsync(
            $"api/documents/{Guid.NewGuid()}/versions",
            ApiExtensions.VersionForm(
                TestDocx.BuildPlainDocx(), "a.docx", Guid.NewGuid().ToString(),
                templateId: Guid.NewGuid().ToString()));
        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
    }

    [Fact]
    public async Task Upload_TemplateIdDeactivated_StillLinks()
    {
        using var client = fixture.CreateClient();
        var (templateId, _) = await TestFlow.CreateConfiguredTemplateAsync(client, "linking deactivate");

        using var deactivate = await client.DeleteAsync($"api/templates/{templateId}");
        Assert.Equal(HttpStatusCode.NoContent, deactivate.StatusCode);

        // ไฟล์ร่างถูกสร้างตอน template ยัง active — deactivate หลังจากนั้นต้องไม่ขวางการเริ่ม track (นโยบาย FR-9/FR-12)
        var documentId = Guid.NewGuid();
        using var upload = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(
                TestDocx.BuildTemplateDocx(), "ไฟล์ร่าง.docx", Guid.NewGuid().ToString(),
                fieldsJson: DefaultFieldsJson(), templateId: templateId.ToString()));
        Assert.Equal(HttpStatusCode.Created, upload.StatusCode);

        await using var db = fixture.CreateDb();
        var document = await db.Documents.AsNoTracking().SingleAsync(d => d.Id == documentId);
        Assert.Equal(templateId, document.TemplateId);
    }

    [Fact]
    public async Task Upload_ExistingDocument_IgnoresTemplateId()
    {
        using var client = fixture.CreateClient();
        var (templateId, _) = await TestFlow.CreateConfiguredTemplateAsync(client, "linking เฉย");

        // upload แรกแบบ standalone (ไม่มี templateId) → Document ไม่ผูก template
        var documentId = Guid.NewGuid();
        using var first = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(TestDocx.BuildPlainDocx(), "plain.docx", Guid.NewGuid().ToString()));
        Assert.Equal(HttpStatusCode.Created, first.StatusCode);

        // upload ที่สองส่ง templateId มาด้วย — document มีอยู่แล้วจึงเฉย (TemplateId คง null)
        using var second = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(
                TestDocx.BuildPlainDocx(), "plain.docx", Guid.NewGuid().ToString(), templateId: templateId.ToString()));
        Assert.Equal(HttpStatusCode.Created, second.StatusCode);
        var v2 = (await second.Content.ReadFromJsonAsync<UploadVersionResult>(IntegrationTestFixture.Json))!;
        Assert.Equal(2, v2.VersionNumber);

        await using var db = fixture.CreateDb();
        var document = await db.Documents.AsNoTracking().SingleAsync(d => d.Id == documentId);
        Assert.Null(document.TemplateId);
    }

    [Fact]
    public async Task Upload_ExistingDocument_BadTemplateId_Returns400()
    {
        using var client = fixture.CreateClient();
        _ = await TestFlow.CreateConfiguredTemplateAsync(client, "linking เฉย bad id");

        var documentId = Guid.NewGuid();
        using var first = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(TestDocx.BuildPlainDocx(), "plain.docx", Guid.NewGuid().ToString()));
        Assert.Equal(HttpStatusCode.Created, first.StatusCode);

        // validate ทุกครั้งที่ส่งมา — แม้ document มีอยู่แล้วและค่าจะไม่ถูกใช้ก็ตาม
        using var second = await client.PostAsync(
            $"api/documents/{documentId}/versions",
            ApiExtensions.VersionForm(
                TestDocx.BuildPlainDocx(), "plain.docx", Guid.NewGuid().ToString(), templateId: "not-a-guid"));
        Assert.Equal(HttpStatusCode.BadRequest, second.StatusCode);
    }
}