using Explorer.Application;
using Explorer.Domain;
using Explorer.Domain.Abstractions;
using Explorer.Storage.Sqlite;
using Microsoft.Extensions.Logging.Abstractions;

namespace Explorer.Application.Tests;

public class BrowseServiceTests
{
    [Fact]
    public async Task This_pc_shows_indexed_root_aggregate_size()
    {
        var (browse, store) = await CreateAsync(@"C:\", "C: (930.6 GB)");
        var source = (await store.Sources.GetAllAsync()).Single();
        source.LastIndexedUtc = DateTimeOffset.UtcNow;
        await store.Sources.UpsertAsync(source);
        var root = new IndexEntry
        {
            SourceId = source.Id,
            Name = "C:",
            NameNorm = "c:",
            IsDirectory = true,
            PathRel = "",
            LastSeenUtc = DateTimeOffset.UtcNow,
            AggregateSize = 1_073_741_824
        };
        await store.Entries.UpsertAsync(root);

        var listing = await browse.ListThisPcAsync();
        var item = Assert.Single(listing.Items);
        Assert.Equal(1_073_741_824, item.SizeBytes);
        Assert.Equal(250_000_000, item.FreeSpaceBytes);
        Assert.Equal(1_000_000_000, item.CapacityBytes);
        Assert.True(item.IsDirectory);
    }

    [Fact]
    public async Task Live_listing_overlays_folder_aggregate_from_index()
    {
        var (browse, store) = await CreateAsync(@"C:\", "C:");
        var source = (await store.Sources.GetAllAsync()).Single();
        source.LastIndexedUtc = DateTimeOffset.UtcNow;
        await store.Sources.UpsertAsync(source);
        var root = new IndexEntry
        {
            SourceId = source.Id,
            Name = "C:",
            NameNorm = "c:",
            IsDirectory = true,
            PathRel = "",
            LastSeenUtc = DateTimeOffset.UtcNow
        };
        root.Id = await store.Entries.UpsertAsync(root);
        await store.Entries.UpsertAsync(new IndexEntry
        {
            SourceId = source.Id,
            ParentId = root.Id,
            Name = "Movies",
            NameNorm = "movies",
            IsDirectory = true,
            PathRel = "Movies",
            LastSeenUtc = DateTimeOffset.UtcNow,
            AggregateSize = 200
        });

        var listing = await browse.ListAsync(@"C:\");
        var movies = Assert.Single(listing.Items, i => i.Name == "Movies");
        Assert.Equal(200, movies.SizeBytes);
        Assert.Equal(250_000_000, movies.FreeSpaceBytes);
        var loose = Assert.Single(listing.Items, i => i.Name == "loose.txt");
        Assert.Equal(10, loose.SizeBytes);
    }

    private static async Task<(BrowseService Browse, SqliteIndexStore Store)> CreateAsync(string root, string display)
    {
        var db = Path.Combine(Path.GetTempPath(), "ew-browse", Guid.NewGuid().ToString("N"), "index.db");
        var store = new SqliteIndexStore(db, NullLogger<SqliteIndexStore>.Instance);
        await store.OpenAsync();
        var volumes = new BrowseVolumes
        {
            Online =
            [
                new VolumeFingerprint
                {
                    Kind = SourceKind.NtfsLocal,
                    RootPath = root,
                    DisplayName = display,
                    VolumeSerial = 1,
                    CapacityBytes = 1_000_000_000,
                    FreeBytes = 250_000_000
                }
            ]
        };
        var env = new BrowseEnv(Path.GetDirectoryName(db)!);
        var sources = new SourceManager(store, volumes, env, new SystemClock(), NullLogger<SourceManager>.Instance);
        await sources.InitializeAsync();
        var browse = new BrowseService(
            new BrowseEnumerator(),
            volumes,
            store,
            sources,
            new StorageProviderRegistry([], NullLogger<StorageProviderRegistry>.Instance),
            new CloudPlaceStore(env),
            new UiPreferencesStore(env));
        return (browse, store);
    }
}

file sealed class BrowseEnumerator : IFileSystemEnumerator
{
    public IEnumerable<FileSystemItem> EnumerateChildren(string directoryPath)
        => EnumerateChildrenSafe(directoryPath, out _);

    public FileSystemItem? GetItem(string path) => null;

    public IReadOnlyList<FileSystemItem> EnumerateChildrenSafe(string directoryPath, out string? error)
    {
        error = null;
        return
        [
            new FileSystemItem { FullPath = Path.Combine(directoryPath, "Movies"), Name = "Movies", IsDirectory = true },
            new FileSystemItem { FullPath = Path.Combine(directoryPath, "loose.txt"), Name = "loose.txt", SizeBytes = 10 }
        ];
    }
}

file sealed class BrowseVolumes : IVolumeService
{
    public List<VolumeFingerprint> Online { get; set; } = [];
    public IReadOnlyList<VolumeFingerprint> EnumerateOnlineVolumes() => Online;
    public VolumeFingerprint? Probe(string path)
        => Online.FirstOrDefault(v => path.StartsWith(v.RootPath.TrimEnd('\\'), StringComparison.OrdinalIgnoreCase));
    public bool IsPathReachable(string path)
        => Online.Any(v => path.StartsWith(v.RootPath.TrimEnd('\\'), StringComparison.OrdinalIgnoreCase));
    public VolumeSpace GetSpace(string path)
    {
        var fp = Probe(path);
        return new VolumeSpace(fp?.CapacityBytes, fp?.FreeBytes);
    }
}

file sealed class BrowseEnv : IAppEnvironment
{
    public BrowseEnv(string dir)
    {
        DataDirectory = dir;
        Directory.CreateDirectory(dir);
        DatabasePath = Path.Combine(dir, "index.db");
        LogDirectory = Path.Combine(dir, "logs");
        Directory.CreateDirectory(LogDirectory);
    }

    public string DataDirectory { get; }
    public string DatabasePath { get; }
    public string LogDirectory { get; }
}