using Robovoice.Core.Voices;
using System.ComponentModel;

namespace Robovoice.App;

internal sealed partial class VoiceManagerForm : Form
{
    private readonly string _voicesDir;
    private readonly VoiceCatalogue _catalogue;
    private IReadOnlyList<VoiceInfo> _allVoices = Array.Empty<VoiceInfo>();
    private HashSet<string> _installedKeys = new();
    private bool _catalogueLoaded;

    public string? SelectedVoiceKey { get; private set; }

    public VoiceManagerForm(string voicesDir, string? currentVoiceKey)
    {
        InitializeComponent();
        _voicesDir = voicesDir;
        _catalogue = new VoiceCatalogue();
        SelectedVoiceKey = currentVoiceKey;

        txtFilter.TextChanged += (_, _) => ApplyFilter();
        btnDownload.Click += OnDownload;
        btnRemove.Click += OnRemove;
        btnClose.Click += (_, _) => Close();
        gridVoices.SelectionChanged += OnSelectionChanged;
        Load += OnLoad;
        FormClosing += OnFormClosing;
    }

    private async void OnLoad(object? sender, EventArgs e)
    {
        btnDownload.Enabled = false;
        btnRemove.Enabled = false;

        RefreshInstalled();
        lblStatus.Text = "Fetching voice catalogue...";
        progressBar.Visible = true;
        progressBar.Style = ProgressBarStyle.Marquee;

        try
        {
            _allVoices = await _catalogue.GetCatalogueAsync();
            _catalogueLoaded = true;
            PopulateGrid();
            lblStatus.Text = $"{_allVoices.Count} voices available, {_installedKeys.Count} installed";
        }
        catch (Exception ex)
        {
            lblStatus.Text = $"Failed to fetch catalogue: {ex.Message}";
        }
        finally
        {
            progressBar.Visible = false;
        }
    }

    private void RefreshInstalled()
    {
        _installedKeys = VoiceCatalogue
            .GetInstalledVoices(_voicesDir)
            .ToHashSet();
    }

    private void PopulateGrid()
    {
        gridVoices.Rows.Clear();
        gridVoices.Columns.Clear();

        gridVoices.Columns.Add(new DataGridViewTextBoxColumn
        {
            Name = "Key",
            HeaderText = "Key",
            FillWeight = 40,
        });
        gridVoices.Columns.Add(new DataGridViewTextBoxColumn
        {
            Name = "Language",
            HeaderText = "Language",
            FillWeight = 25,
        });
        gridVoices.Columns.Add(new DataGridViewTextBoxColumn
        {
            Name = "Voice",
            HeaderText = "Voice",
            FillWeight = 20,
        });
        gridVoices.Columns.Add(new DataGridViewTextBoxColumn
        {
            Name = "Quality",
            HeaderText = "Quality",
            FillWeight = 15,
        });
        gridVoices.Columns.Add(new DataGridViewTextBoxColumn
        {
            Name = "Size",
            HeaderText = "Size",
            FillWeight = 15,
        });
        gridVoices.Columns.Add(new DataGridViewTextBoxColumn
        {
            Name = "Status",
            HeaderText = "Status",
            FillWeight = 15,
        });

        foreach (var voice in _allVoices)
        {
            bool installed = _installedKeys.Contains(voice.Key);
            int rowIdx = gridVoices.Rows.Add(
                voice.Key,
                voice.Language.NameEnglish,
                voice.Name,
                voice.Quality,
                voice.SizeDisplay,
                installed ? "Installed" : "Available");

            var row = gridVoices.Rows[rowIdx];
            row.Tag = voice.Key;
            if (installed)
            {
                row.DefaultCellStyle.BackColor = Color.FromArgb(235, 245, 235);
                if (voice.Key == SelectedVoiceKey)
                {
                    row.DefaultCellStyle.Font = new Font(gridVoices.Font, FontStyle.Bold);
                    row.Selected = true;
                }
            }
            else
            {
                row.DefaultCellStyle.ForeColor = Color.Gray;
            }
        }

        if (gridVoices.SelectedRows.Count == 0 && gridVoices.Rows.Count > 0)
            gridVoices.Rows[0].Selected = true;
    }

    private void ApplyFilter()
    {
        string filter = txtFilter.Text.Trim().ToLowerInvariant();
        if (string.IsNullOrEmpty(filter))
        {
            foreach (DataGridViewRow row in gridVoices.Rows)
                row.Visible = true;
            return;
        }

        foreach (DataGridViewRow row in gridVoices.Rows)
        {
            if (row.Tag is not string key)
            {
                row.Visible = false;
                continue;
            }

            var voice = _allVoices.FirstOrDefault(v => v.Key == key);
            if (voice is null)
            {
                row.Visible = false;
                continue;
            }

            string haystack = $"{key} {voice.Name} {voice.Language.NameEnglish} {voice.Language.Code} {voice.Language.Family} {voice.Quality}".ToLowerInvariant();
            row.Visible = haystack.Contains(filter);
        }
    }

    private void OnSelectionChanged(object? sender, EventArgs e)
    {
        if (gridVoices.SelectedRows.Count == 0) return;
        var row = gridVoices.SelectedRows[0];
        if (row.Tag is not string key) return;

        bool installed = _installedKeys.Contains(key);
        btnDownload.Enabled = !installed && _catalogueLoaded;
        btnRemove.Enabled = installed;
    }

    private async void OnDownload(object? sender, EventArgs e)
    {
        if (gridVoices.SelectedRows.Count == 0) return;
        var row = gridVoices.SelectedRows[0];
        if (row.Tag is not string key) return;

        var voice = _allVoices.FirstOrDefault(v => v.Key == key);
        if (voice is null) return;

        btnDownload.Enabled = false;
        btnRemove.Enabled = false;
        progressBar.Visible = true;
        progressBar.Style = ProgressBarStyle.Continuous;
        progressBar.Value = 0;
        lblStatus.Text = $"Downloading {key} ({voice.SizeDisplay})...";

        try
        {
            var progress = new Progress<(long downloaded, long total)>(p =>
            {
                if (p.total > 0)
                {
                    progressBar.Value = (int)(p.downloaded * 100 / p.total);
                    lblStatus.Text = $"Downloading {key}... {p.downloaded / (1024 * 1024)} / {p.total / (1024 * 1024)} MB";
                }
            });

            await _catalogue.DownloadVoiceAsync(voice, _voicesDir, progress);
            RefreshInstalled();
            UpdateRowStatus(key, installed: true);
            lblStatus.Text = $"Downloaded {key} successfully.";
        }
        catch (Exception ex)
        {
            lblStatus.Text = $"Download failed: {ex.Message}";
        }
        finally
        {
            progressBar.Visible = false;
            OnSelectionChanged(null, EventArgs.Empty);
        }
    }

    private void OnRemove(object? sender, EventArgs e)
    {
        if (gridVoices.SelectedRows.Count == 0) return;
        var row = gridVoices.SelectedRows[0];
        if (row.Tag is not string key) return;

        var dlgResult = MessageBox.Show(
            $"Remove voice '{key}'?\nThis will delete the .onnx and .onnx.json files.",
            "Confirm Remove",
            MessageBoxButtons.YesNo,
            MessageBoxIcon.Question);

        if (dlgResult != DialogResult.Yes) return;

        try
        {
            VoiceCatalogue.RemoveVoice(_voicesDir, key);
            RefreshInstalled();
            UpdateRowStatus(key, installed: false);
            if (SelectedVoiceKey == key)
                SelectedVoiceKey = null;
            lblStatus.Text = $"Removed {key}.";
        }
        catch (Exception ex)
        {
            lblStatus.Text = $"Remove failed: {ex.Message}";
        }

        OnSelectionChanged(null, EventArgs.Empty);
    }

    private void UpdateRowStatus(string key, bool installed)
    {
        foreach (DataGridViewRow row in gridVoices.Rows)
        {
            if (row.Tag is string rowKey && rowKey == key)
            {
                row.Cells["Status"].Value = installed ? "Installed" : "Available";
                row.DefaultCellStyle.BackColor = installed
                    ? Color.FromArgb(235, 245, 235)
                    : Color.White;
                row.DefaultCellStyle.ForeColor = installed
                    ? Color.Black
                    : Color.Gray;
                break;
            }
        }

        lblStatus.Text = $"{_allVoices.Count} voices available, {_installedKeys.Count} installed";
    }

    private void OnFormClosing(object? sender, FormClosingEventArgs e)
    {
        if (gridVoices.SelectedRows.Count > 0 && gridVoices.SelectedRows[0].Tag is string key)
        {
            if (_installedKeys.Contains(key))
                SelectedVoiceKey = key;
        }

        _catalogue.DisposeAsync().AsTask().Wait();
    }
}