using System.Net;
using System.Net.Http.Json;
using FluentAssertions;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using PageManager.Api.Api.Dtos;
using PageManager.Api.Data;
using PageManager.Api.Data.Models;
using PageManager.Api.Tests.Integration.Fixtures;

namespace PageManager.Api.Tests.Integration;

[Collection("Postgres")]
public class FilesControllerTests : IAsyncLifetime
{
    private readonly TestWebAppFactory _factory;
    private readonly HttpClient _client;

    public FilesControllerTests(PostgresFixture postgres)
    {
        _factory = new TestWebAppFactory(postgres);
        _client  = _factory.CreateClient();
    }

    public async Task InitializeAsync()
    {
        using var scope = _factory.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
        await db.Database.ExecuteSqlRawAsync(
            "TRUNCATE book_files, book_authors, series_entries, editions, books, authors, series, import_sources RESTART IDENTITY CASCADE");
    }

    public Task DisposeAsync()
    {
        _client.Dispose();
        _factory.Dispose();
        return Task.CompletedTask;
    }

    // ── GET /api/books/{id}/files ─────────────────────────────────────────────

    [Fact]
    public async Task GetBookFiles_NoFiles_Returns200WithEmptyArray()
    {
        var bookId = await SeedBookAsync();

        var response = await _client.GetAsync($"/api/books/{bookId}/files");

        response.StatusCode.Should().Be(HttpStatusCode.OK);
        var files = await response.Content.ReadFromJsonAsync<BookFileDto[]>();
        files.Should().BeEmpty();
    }

    [Fact]
    public async Task GetBookFiles_WithFiles_Returns200WithCorrectData()
    {
        var bookId = await SeedBookAsync("Dune");
        await SeedFileAsync(filename: "dune.epub", format: FileFormat.Epub, bookId: bookId);
        await SeedFileAsync(filename: "dune.mobi", format: FileFormat.Mobi, bookId: bookId);

        var response = await _client.GetAsync($"/api/books/{bookId}/files");

        response.StatusCode.Should().Be(HttpStatusCode.OK);
        var files = await response.Content.ReadFromJsonAsync<BookFileDto[]>();
        files.Should().HaveCount(2);
        files!.Select(f => f.Filename).Should().BeEquivalentTo(["dune.epub", "dune.mobi"]);
        files.First(f => f.Filename == "dune.epub").Format.Should().Be("epub");
    }

    // ── GET /api/files?unmatched=true ─────────────────────────────────────────

    [Fact]
    public async Task GetUnmatchedFiles_MixedFiles_ReturnsOnlyUnmatched()
    {
        var bookId = await SeedBookAsync();
        await SeedFileAsync(filename: "unmatched.epub", bookId: null);
        await SeedFileAsync(filename: "matched.epub",   bookId: bookId);

        var response = await _client.GetAsync("/api/files?unmatched=true");

        response.StatusCode.Should().Be(HttpStatusCode.OK);
        var files = await response.Content.ReadFromJsonAsync<BookFileDto[]>();
        files.Should().ContainSingle(f => f.Filename == "unmatched.epub");
        files.Should().NotContain(f => f.Filename == "matched.epub");
    }

    [Fact]
    public async Task GetFiles_NoUnmatchedParam_Returns400()
    {
        var response = await _client.GetAsync("/api/files");

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

    // ── PATCH /api/files/{id} ─────────────────────────────────────────────────

    [Fact]
    public async Task AssignFile_Exists_Returns200WithUpdatedBookId()
    {
        var bookId = await SeedBookAsync();
        var fileId = await SeedFileAsync(filename: "orphan.epub", bookId: null);

        var response = await _client.PatchAsJsonAsync($"/api/files/{fileId}", new { bookId });

        response.StatusCode.Should().Be(HttpStatusCode.OK);
        var file = await response.Content.ReadFromJsonAsync<BookFileDto>();
        file!.BookId.Should().Be(bookId);
    }

    [Fact]
    public async Task AssignFile_NotFound_Returns404()
    {
        var response = await _client.PatchAsJsonAsync("/api/files/99999", new { bookId = 1 });

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

    [Fact]
    public async Task AssignFile_ClearsBookId_WhenSetToNull()
    {
        var bookId = await SeedBookAsync();
        var fileId = await SeedFileAsync(filename: "book.epub", bookId: bookId);

        var response = await _client.PatchAsJsonAsync($"/api/files/{fileId}", new { bookId = (int?)null });

        response.StatusCode.Should().Be(HttpStatusCode.OK);
        var file = await response.Content.ReadFromJsonAsync<BookFileDto>();
        file!.BookId.Should().BeNull();
    }

    // ── DELETE /api/files/{id} ────────────────────────────────────────────────

    [Fact]
    public async Task DeleteFile_Exists_Returns204AndRemovesRecord()
    {
        var fileId = await SeedFileAsync();

        var response = await _client.DeleteAsync($"/api/files/{fileId}");

        response.StatusCode.Should().Be(HttpStatusCode.NoContent);

        using var scope = _factory.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
        var exists = await db.BookFiles.AnyAsync(f => f.Id == fileId);
        exists.Should().BeFalse();
    }

    [Fact]
    public async Task DeleteFile_NotFound_Returns404()
    {
        var response = await _client.DeleteAsync("/api/files/99999");

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

    // ── Helpers ───────────────────────────────────────────────────────────────

    private async Task<int> SeedBookAsync(string title = "Test Book")
    {
        using var scope = _factory.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
        var book = new Book { Title = title, Formats = [], Genres = [] };
        db.Books.Add(book);
        await db.SaveChangesAsync();
        return book.Id;
    }

    private async Task<int> SeedFileAsync(
        string filename = "test.epub",
        FileFormat format = FileFormat.Epub,
        int? bookId = null,
        long sizeBytes = 1024)
    {
        using var scope = _factory.Services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
        var file = new BookFile
        {
            Filename  = filename,
            Path      = filename,
            Format    = format,
            SizeBytes = sizeBytes,
            BookId    = bookId,
            AddedAt   = DateTime.UtcNow,
        };
        db.BookFiles.Add(file);
        await db.SaveChangesAsync();
        return file.Id;
    }
}