using System.Collections.ObjectModel;
using System.ComponentModel;
using ClaudeDo.Data;
using ClaudeDo.Data.Models;
using ClaudeDo.Data.Repositories;
using ClaudeDo.Ui.Services;
using CommunityToolkit.Mvvm.Input;
using Microsoft.EntityFrameworkCore;

namespace ClaudeDo.Ui.ViewModels.Modals;

public sealed partial class RepoImportModalViewModel : ViewModelBase
{
    private readonly IDbContextFactory<ClaudeDoDbContext> _dbFactory;
    private readonly HashSet<string> _existingDirs = new(StringComparer.OrdinalIgnoreCase);

    public ObservableCollection<RepoImportItemViewModel> Repos { get; } = new();

    public Action? CloseAction { get; set; }

    public int CreateCount => Repos.Count(r => r.IsChecked && !r.AlreadyAdded);
    public bool CanCreate => CreateCount > 0;
    public string CreateButtonText => $"Create {CreateCount} list(s)";

    public RepoImportModalViewModel(IDbContextFactory<ClaudeDoDbContext> dbFactory)
    {
        _dbFactory = dbFactory;
    }

    public async Task LoadAsync(CancellationToken ct = default)
    {
        Repos.Clear();
        _existingDirs.Clear();

        await using var ctx = await _dbFactory.CreateDbContextAsync(ct);
        var lists = new ListRepository(ctx);
        foreach (var l in await lists.GetAllAsync(ct))
        {
            if (!string.IsNullOrWhiteSpace(l.WorkingDir))
                _existingDirs.Add(l.WorkingDir!);
        }
        NotifyCreateState();
    }

    public void AddFolders(IEnumerable<string> folders)
    {
        var current = new HashSet<string>(
            Repos.Select(r => r.FullPath), StringComparer.OrdinalIgnoreCase);

        foreach (var folder in folders)
        {
            var found = RepoScanner.Scan(folder);
            foreach (var item in BuildCandidates(found, current, _existingDirs))
            {
                item.PropertyChanged += OnItemChanged;
                Repos.Add(item);
                current.Add(item.FullPath);
            }
        }
        NotifyCreateState();
    }

    public static List<RepoImportItemViewModel> BuildCandidates(
        IEnumerable<RepoCandidate> found,
        IReadOnlySet<string> currentPaths,
        IReadOnlySet<string> existingDirs)
    {
        var items = new List<RepoImportItemViewModel>();
        foreach (var c in found)
        {
            if (currentPaths.Contains(c.FullPath)) continue;
            items.Add(new RepoImportItemViewModel
            {
                Name = c.Name,
                FullPath = c.FullPath,
                AlreadyAdded = existingDirs.Contains(c.FullPath),
                IsChecked = true,
            });
        }
        return items;
    }

    private void OnItemChanged(object? sender, PropertyChangedEventArgs e)
    {
        if (e.PropertyName == nameof(RepoImportItemViewModel.IsChecked))
            NotifyCreateState();
    }

    private void NotifyCreateState()
    {
        OnPropertyChanged(nameof(CreateCount));
        OnPropertyChanged(nameof(CanCreate));
        OnPropertyChanged(nameof(CreateButtonText));
    }

    [RelayCommand]
    private async Task CreateAsync()
    {
        var toCreate = Repos.Where(r => r.IsChecked && !r.AlreadyAdded).ToList();
        if (toCreate.Count > 0)
        {
            await using var ctx = await _dbFactory.CreateDbContextAsync();
            var lists = new ListRepository(ctx);
            foreach (var r in toCreate)
            {
                await lists.AddAsync(new ListEntity
                {
                    Id = Guid.NewGuid().ToString("N"),
                    Name = r.Name,
                    WorkingDir = r.FullPath,
                    DefaultCommitType = CommitTypeRegistry.DefaultType,
                    CreatedAt = DateTime.UtcNow,
                });
            }
        }
        CloseAction?.Invoke();
    }

    [RelayCommand]
    private void Cancel() => CloseAction?.Invoke();
}