using DataModel.Database;
using Processor;
using UI_WinForms.Resources;

namespace UI_WinForms.Components;

public sealed partial class Setting : UserControl
{
    public Setting()
    {
        this.InitializeComponent();
    }
    
    private Setting(SettingUIData settingMetaData)
    {
        this.InitializeComponent();
        this.Dock = DockStyle.Top;
        this.labelIcon.Image = settingMetaData.Icon;
        this.labelSettingName.Text = settingMetaData.SettingName();
        this.labelExplanation.Text = settingMetaData.SettingExplanation();

        var dataControl = settingMetaData.SetupDataControl();
        this.tableLayout.Controls.Add(dataControl, 2, 0);
        
        // Ensure, that this data control is vertical centered by calculating the needed margin, considering the outer size of the table layout:
        var margin = (this.tableLayout.GetRowHeights().First() - dataControl.Height) / 2f;
        dataControl.Margin = new Padding(0, (int) margin, 0, (int)margin);
        
        // Calculate the needed height of the explanation label & centering of the data control when the parent window is resized:
        this.tableLayout.Resize += (sender, args) =>
        {
            // Adjust the height of the parent controls (table & user control):
            this.tableLayout.Height = Math.Max((int)this.labelExplanation.CreateGraphics().MeasureString(this.labelExplanation.Text, this.labelExplanation.Font, new SizeF(this.labelExplanation.Width, 1000)).Height, 66);
            this.Height = this.tableLayout.Height + this.tableLayout.Margin.Vertical;
            
            // Ensure, that this data control is vertical centered by calculating the needed margin, considering the outer size of the table layout:
            var margin = (this.tableLayout.GetRowHeights().First() - dataControl.Height) / 2f;
            dataControl.Margin = new Padding(0, (int) margin, 0, (int)margin);
        };
    }

    private readonly record struct SettingUIData(
        Bitmap Icon,
        Func<string> SettingName,
        Func<string> SettingExplanation,
        Func<Control> SetupDataControl
    );

    private static async Task<Setting> ShowDeepLModeSettingAsync()
    {
        var currentSetting = await AppSettings.GetDeepLMode();
        var settingData = new SettingUIData(
            Icon: Icons.deepl_logo_icon_170284,
            SettingName: () => "DeepL Service",
            SettingExplanation: () => "DeepL is a translation service that offers a wide range of translation services. This setting allows you to choose between the free and pro version of DeepL.",
            SetupDataControl: () =>
            {
                var dropdown = new ComboBox();
                dropdown.Items.Add("Disabled");
                dropdown.Items.Add("Free version");
                dropdown.Items.Add("Pro version");
                dropdown.SelectedIndex = currentSetting switch
                {
                    SettingDeepLMode.DISABLED => 0,
                    SettingDeepLMode.USE_FREE_ACCOUNT => 1,
                    SettingDeepLMode.USE_PRO_ACCOUNT => 2,

                    _ => 0,
                };

                // Setup the change event handler:
                dropdown.SelectedValueChanged += async (sender, args) => await AppSettings.SetDeepLMode(dropdown.SelectedIndex switch
                {
                    0 => SettingDeepLMode.DISABLED,
                    1 => SettingDeepLMode.USE_FREE_ACCOUNT,
                    2 => SettingDeepLMode.USE_PRO_ACCOUNT,

                    _ => SettingDeepLMode.DISABLED,
                });

                // Apply the desired layout:
                dropdown.Dock = DockStyle.Fill;
                dropdown.DropDownStyle = ComboBoxStyle.DropDownList;

                return dropdown;
            }
        );

        return new Setting(settingData);
    }
    
    private static async Task<Setting> ShowDeepLAPIKeySettingAsync()
    {
        var currentSetting = await AppSettings.GetDeepLAPIKey();
        var settingData = new SettingUIData(
            Icon: Icons.icons8_key_512,
            SettingName: () => "DeepL API Key",
            SettingExplanation: () => "The API key is required to use the DeepL translation service. You can find your API key on the DeepL website.",
            SetupDataControl: () =>
            {
                var textbox = new TextBox();
                textbox.Text = currentSetting;
                textbox.TextChanged += async (sender, args) => await AppSettings.SetDeepLAPIKey(textbox.Text);
                textbox.Dock = DockStyle.Fill;
                return textbox;
            }
        );

        return new Setting(settingData);
    }
    
    private static async Task<Setting> ShowDeepLActionSettingAsync()
    {
        var currentSetting = await AppSettings.GetDeepLAction();
        var settingData = new SettingUIData(
            Icon: Icons.icons8_play_512__2_,
            SettingName: () => "DeepL Operation",
            SettingExplanation: () => "Should the missing translations be automatically completed by DeepL? This can lead to higher costs. By default, DeepL is only applied manually.",
            SetupDataControl: () =>
            {
                // We set up a combo box with the available actions:
                var dropdown = new ComboBox();
                dropdown.Items.Add("Manual");
                dropdown.Items.Add("Automatic");
                dropdown.SelectedIndex = currentSetting switch
                {
                    SettingDeepLAction.MANUAL => 0,
                    SettingDeepLAction.AUTOMATIC_ALL => 1,
                    
                    _ => 0,
                };
                
                // Setup the change event handler:
                dropdown.SelectedValueChanged += async (sender, args) => await AppSettings.SetDeepLAction(dropdown.SelectedIndex switch
                {
                    0 => SettingDeepLAction.MANUAL,
                    1 => SettingDeepLAction.AUTOMATIC_ALL,
                    
                    _ => SettingDeepLAction.MANUAL,
                });
                
                // Apply the desired layout:
                dropdown.Dock = DockStyle.Fill;
                dropdown.DropDownStyle = ComboBoxStyle.DropDownList;

                return dropdown;
            }
        );

        return new Setting(settingData);
    }

    private static IEnumerable<Task<Setting>> ShowCultureSettingsAsync()
    {
        var isFirstCulture = true; // We need this flag to distinguish the first task from the others.
        var cultureIndices = new List<int>(new []{ -1 });
        while (cultureIndices.Count > 0)
        {
            var innerLoopIndex = cultureIndices.Last(); // needed to avoid closure issues.
            yield return Task.Run(async () =>
            {
                var localCultureIndex = innerLoopIndex;
                
                // Get a list of culture indices. Thus, we know the number of cultures. We cannot do this in the outer loop,
                // because we cannot await there. The AppSettings is caching the answer, though. The list of indices is ordered
                // ascending.
                var localCultureIndices = await AppSettings.GetCultureIndices();
                
                // Update the number of cultures in the outer loop for the first call:
                if(isFirstCulture)
                {
                    localCultureIndex = localCultureIndices.Last();
                    innerLoopIndex = localCultureIndices.Last();
                    
                    cultureIndices.Clear();
                    cultureIndices.AddRange(localCultureIndices);
                    isFirstCulture = false;
                }

                // Get the current culture code:
                var currentCultureCode = await AppSettings.GetCultureCode(localCultureIndex);
                
                // Construct the setting:
                return new Setting(new()
                {
                    Icon = Icons.icons8_chat_bubble_512,
                    SettingName = () => $"{localCultureIndex}. Culture",
                    SettingExplanation = () => "The culture according to RFC 4646: First comes the ISO 639-1 language code in lower case, followed by a hyphen, followed by the ISO 3166-1 alpha-2 country code in upper case. Example: en-US for English in the USA, de-DE for German in Germany.",
                    SetupDataControl = () =>
                    {
                        var textbox = new TextBox();
                        textbox.Text = currentCultureCode;
                        textbox.TextChanged += async (sender, args) =>
                        {
                            await AppSettings.SetCultureCode(localCultureIndex, textbox.Text);
                        };
                        textbox.Dock = DockStyle.Fill;
                        return textbox;
                    }
                });
            });
            
            cultureIndices.Remove(innerLoopIndex);
        }
    }

    public static IEnumerable<Task<Setting>> GetAllSettings()
    {
        foreach (var setting in ShowCultureSettingsAsync())
        {
            yield return setting;
        }
        
        yield return ShowDeepLActionSettingAsync();
        yield return ShowDeepLAPIKeySettingAsync();
        yield return ShowDeepLModeSettingAsync();
    }
}