using System.Security.Claims;
using JobTrackerApi.Controllers;
using JobTrackerApi.Models;
using JobTrackerApi.Services;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.Migrations;
using Moq;
using Xunit;

namespace JobTrackerApi.MariaDb.Tests;

public sealed partial class CoverLetterWriterTests
{
    [Fact]
    public async Task Document_schema_upgrade_preserves_legacy_letter_history_and_frozen_rows_on_mariadb()
    {
        await using var connection = await MariaDbDatabase.CreateAsync();
        await using var db = Context(connection);
        var job = await Seed(db, "  old exact letter  ");
        db.CoverLetterVersions.Add(new() { OwnerUserId = Owner, JobApplicationId = job.Id, Version = 7, Text = " old history ", Source = CoverLetterSources.Ai });
        db.SubmittedApplicationPackages.Add(new() { OwnerUserId = Owner, JobApplicationId = job.Id, Version = 1, CoverLetterText = " old frozen letter ", RenderedCvHtml = "<p>unchanged CV</p>" });
        await db.SaveChangesAsync();
        await db.GetService<IMigrator>().MigrateAsync("20261023090000_AddJobRevision");
        db.ChangeTracker.Clear();
        await db.GetService<IMigrator>().MigrateAsync();
        var actual = await db.JobApplications.AsNoTracking().SingleAsync();
        Assert.Equal("  old exact letter  ", actual.CoverLetterText);
        Assert.Equal(1, actual.Version);
        Assert.Null(actual.CoverLetterDocumentSettingsJson);
        var historical = await db.CoverLetterVersions.AsNoTracking().SingleAsync();
        Assert.Equal(7, historical.Version);
        Assert.Equal(" old history ", historical.Text);
        Assert.Equal(CoverLetterSources.Ai, historical.Source);
        Assert.Null(historical.DocumentSettingsJson);
        var frozen = await db.SubmittedApplicationPackages.AsNoTracking().SingleAsync();
        Assert.Equal(" old frozen letter ", frozen.CoverLetterText);
        Assert.Equal("<p>unchanged CV</p>", frozen.RenderedCvHtml);
        Assert.Null(frozen.CoverLetterDocumentSettingsJson);
        Assert.Null(frozen.RenderedCoverLetterHtml);
        Assert.Empty(await db.Database.GetPendingMigrationsAsync());
    }

    [Fact]
    public async Task Document_settings_only_saves_advance_shared_revision_preserve_omission_and_restore_old_defaults()
    {
        await using var connection = await MariaDbDatabase.CreateAsync();
        await using var db = Context(connection);
        var job = await Seed(db, "same body");
        var service = Assets(db);
        var saved = await service.SaveCoverLetterAsync(Owner, job.Id, "same body", CoverLetterSources.Manual, null, job.Version, default,
            new() { SenderName = "Reviewed sender", ThemeId = "minimal", AccentColor = "#123456", SourceCvId = 42 });
        Assert.Equal(2, saved!.Revision);
        Assert.Equal(2, saved.CurrentVersion);
        Assert.Equal("Reviewed sender", saved.DocumentSettings!.SenderName);
        Assert.Equal("same body", saved.Text);
        var baseline = await db.CoverLetterVersions.SingleAsync(x => x.Version == 1);
        Assert.Null(baseline.DocumentSettingsJson);
        Assert.Equal(CoverLetterSources.Legacy, baseline.Source);
        var settingsJson = job.CoverLetterDocumentSettingsJson;
        await Update(db, job, "generic body");
        await Controller(db).SaveApplicationDrafts(job.Id, new SaveApplicationDraftsRequest(null, "notes", null, ExpectedVersion: job.Version), default);
        await service.SaveCoverLetterAsync(Owner, job.Id, "dedicated body", CoverLetterSources.Manual, null, job.Version, default);
        Assert.Equal(settingsJson, job.CoverLetterDocumentSettingsJson);
        var noOpRevision = job.Version;
        var noOp = await service.SaveCoverLetterAsync(Owner, job.Id, "dedicated body", CoverLetterSources.Manual, null, job.Version, default,
            CoverLetterDocumentSettingsJson.Deserialize(settingsJson));
        Assert.Equal(noOpRevision + 1, noOp!.Revision);
        Assert.Equal(4, noOp.CurrentVersion);
        var restored = await service.RestoreCoverLetterAsync(Owner, job.Id, 1, job.Version, default);
        Assert.Equal("same body", restored!.Text);
        Assert.Equal("modern", restored.DocumentSettings!.ThemeId);
        Assert.Equal("", restored.DocumentSettings.SenderName);
        Assert.Null(restored.DocumentSettings.SourceCvId);
        Assert.Equal(5, restored.CurrentVersion);
        Assert.Equal(settingsJson, (await db.CoverLetterVersions.SingleAsync(x => x.Version == 2)).DocumentSettingsJson);
        var restoredDesign = await service.RestoreCoverLetterAsync(Owner, job.Id, 2, job.Version, default);
        Assert.Equal("same body", restoredDesign!.Text);
        Assert.Equal("Reviewed sender", restoredDesign.DocumentSettings!.SenderName);
        Assert.Equal(6, restoredDesign.CurrentVersion);
    }

    [Fact]
    public async Task Preview_is_read_only_and_copied_settings_never_follow_later_cv_changes()
    {
        await using var connection = await MariaDbDatabase.CreateAsync();
        await using var db = Context(connection);
        var job = await Seed(db);
        var cv = new CvVariant { OwnerUserId = Owner, Name = "Source CV", PublicSlug = Guid.NewGuid().ToString("N"), SettingsJson = CvVariantSettingsJson.Serialize(new() { AccentColor = "#123456" }) };
        db.CvVariants.Add(cv);
        await db.SaveChangesAsync();
        var settings = new CoverLetterDocumentSettings { SenderName = "Copied name", SourceCvId = cv.Id, AccentColor = "#123456" };
        var service = Assets(db);
        await service.SaveCoverLetterAsync(Owner, job.Id, "approved body", CoverLetterSources.Manual, null, job.Version, default, settings);
        var revision = job.Version;
        var before = job.CoverLetterDocumentSettingsJson;
        var preview = await service.PreviewCoverLetterAsync(Owner, job.Id, "unapproved preview **bold**", new() { Subject = "Preview only" }, default);
        Assert.Contains("unapproved preview <strong>bold</strong>", preview!.Html);
        cv.SettingsJson = CvVariantSettingsJson.Serialize(new() { AccentColor = "#abcdef" });
        await db.SaveChangesAsync();
        var render = await service.RenderSavedCoverLetterAsync(Owner, job.Id, revision, default);
        Assert.Contains("#123456", render!.Html);
        Assert.Contains("Copied name", render.Html);
        Assert.Contains("approved body", render.Html);
        Assert.DoesNotContain("unapproved preview", render.Html);
        Assert.Equal(before, job.CoverLetterDocumentSettingsJson);
        Assert.Equal(revision, job.Version);
        Assert.Single(await db.CoverLetterVersions.ToListAsync());
        Assert.Null(await service.PreviewCoverLetterAsync("foreign", job.Id, "stolen", settings, default));
        Assert.Null(await service.RenderSavedCoverLetterAsync("foreign", job.Id, revision, default));
    }

    [Theory]
    [InlineData(null)]
    [InlineData(0)]
    [InlineData(-1)]
    [InlineData(99)]
    public async Task Export_requires_current_positive_revision_before_allocating_pdf(int? expectedVersion)
    {
        await using var connection = await MariaDbDatabase.CreateAsync();
        await using var db = Context(connection);
        var job = await Seed(db, "saved body");
        var pdf = new Mock<ICvPdfExporter>(MockBehavior.Strict);
        var user = new ApplicationUser { Id = Owner };
        var users = TestHostFactory.CreateUserManager(user);
        users.Setup(x => x.GetUserAsync(It.IsAny<ClaimsPrincipal>())).ReturnsAsync(user);
        var controller = new ApplicationAssetsController(users.Object, Assets(db), Mock.Of<ISubmittedApplicationPackageService>(), pdf.Object)
        {
            ControllerContext = new() { HttpContext = new DefaultHttpContext() },
        };
        Assert.IsType<ConflictObjectResult>(await controller.ExportCoverLetterPdf(job.Id, default, expectedVersion));
        pdf.VerifyNoOtherCalls();
        pdf.Setup(x => x.ExportAsync(Owner, It.Is<TailoredCvRenderResult>(r => r.Html.Contains("saved body")), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new CvPdfArtifact("cover-letter.pdf", "unused.pdf", [37, 80, 68, 70]));
        Assert.IsType<FileContentResult>(await controller.ExportCoverLetterPdf(job.Id, default, job.Version));
        pdf.Verify(x => x.ExportAsync(Owner, It.IsAny<TailoredCvRenderResult>(), It.IsAny<CancellationToken>()), Times.Once);
        Assert.IsType<NotFoundResult>(await controller.ExportCoverLetterPdf(int.MaxValue, default, job.Version));
        pdf.VerifyNoOtherCalls();
    }

    [Fact]
    public async Task Stale_settings_save_and_unsupported_schema_cannot_change_approved_design()
    {
        await using var connection = await MariaDbDatabase.CreateAsync();
        await using var db = Context(connection);
        var job = await Seed(db);
        var service = Assets(db);
        await service.SaveCoverLetterAsync(Owner, job.Id, "approved", CoverLetterSources.Manual, null, 1, default, new() { Subject = "Approved subject" });
        await Assert.ThrowsAsync<DbUpdateConcurrencyException>(() => service.SaveCoverLetterAsync(Owner, job.Id, "stale", CoverLetterSources.Manual, null, 1, default, new() { Subject = "Stale" }));
        Assert.Equal("Approved subject", (await service.GetCoverLetterAsync(Owner, job.Id, default))!.DocumentSettings!.Subject);
        var user = new ApplicationUser { Id = Owner };
        var users = TestHostFactory.CreateUserManager(user);
        users.Setup(x => x.GetUserAsync(It.IsAny<ClaimsPrincipal>())).ReturnsAsync(user);
        var controller = new ApplicationAssetsController(users.Object, service, Mock.Of<ISubmittedApplicationPackageService>());
        Assert.IsType<BadRequestObjectResult>((await controller.SaveCoverLetter(job.Id,
            new("bad", null, null, job.Version, new() { SchemaVersion = 2 }), default)).Result);
        Assert.IsType<BadRequestObjectResult>((await controller.PreviewCoverLetter(job.Id,
            new("bad", new() { SchemaVersion = 2 }), default)).Result);
        Assert.Single(await db.CoverLetterVersions.ToListAsync());
    }

    [Fact]
    public async Task Submitted_letter_html_and_design_remain_exact_after_live_edits_and_old_packages_stay_null()
    {
        await using var connection = await MariaDbDatabase.CreateAsync();
        await using var db = Context(connection);
        var job = await Seed(db);
        var service = Assets(db);
        await service.SaveCoverLetterAsync(Owner, job.Id, "frozen body", CoverLetterSources.Manual, null, job.Version, default,
            new() { SenderName = "Frozen sender", Subject = "Frozen subject" });
        var old = new SubmittedApplicationPackage { OwnerUserId = Owner, JobApplicationId = job.Id, Version = 1, CoverLetterText = "old text-only" };
        db.Add(old);
        await db.SaveChangesAsync();
        var packages = new SubmittedApplicationPackageService(db, Mock.Of<ICvVariantService>(), Mock.Of<IAttachmentStorage>());
        var captured = await packages.CaptureAsync(Owner, job.Id, new("Profile name must not replace sender", null), default);
        var stored = await db.SubmittedApplicationPackages.AsNoTracking().SingleAsync(x => x.Id == captured!.Id);
        Assert.Contains("frozen body", stored.RenderedCoverLetterHtml);
        Assert.Contains("Frozen sender", stored.RenderedCoverLetterHtml);
        Assert.DoesNotContain("Profile name must not replace sender", stored.RenderedCoverLetterHtml);
        await service.SaveCoverLetterAsync(Owner, job.Id, "new body", CoverLetterSources.Manual, null, job.Version, default,
            new() { SenderName = "New sender", Subject = "New subject" });
        var detail = await packages.GetAsync(Owner, job.Id, captured!.Id, default);
        Assert.Equal(stored.RenderedCoverLetterHtml, detail!.RenderedCoverLetterHtml);
        Assert.Equal("Frozen sender", detail.CoverLetterDocumentSettings!.SenderName);
        Assert.Equal("frozen body", detail.CoverLetterText);
        var oldDetail = await packages.GetAsync(Owner, job.Id, old.Id, default);
        Assert.Equal("old text-only", oldDetail!.CoverLetterText);
        Assert.Null(oldDetail.RenderedCoverLetterHtml);
        Assert.Null(oldDetail.CoverLetterDocumentSettings);
    }
}