// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System;
using System.Collections.Immutable;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.Editor.Shared.Extensions;
using Microsoft.CodeAnalysis.Editor.Shared.Utilities;
using Microsoft.VisualStudio.Imaging.Interop;
using Microsoft.VisualStudio.Text.Classification;
using Roslyn.Utilities;
 
namespace Microsoft.VisualStudio.LanguageServices.Implementation.InheritanceMargin.MarginGlyph;
 
internal class InheritanceMarginGlyphViewModel
{
    private readonly ClassificationTypeMap _classificationTypeMap;
    private readonly IClassificationFormatMap _classificationFormatMap;
    private readonly InheritanceMarginTag _tag;
    private TextBlock? _lazyToolTipTextBlock;
 
    /// <summary>
    /// ImageMoniker used for the margin.
    /// </summary>
    public ImageMoniker ImageMoniker => _tag.Moniker;
 
    /// <summary>
    /// Tooltip for the margin.
    /// </summary>
    public TextBlock ToolTipTextBlock
    {
        get
        {
            if (_lazyToolTipTextBlock is null)
            {
                var members = _tag.MembersOnLine;
 
                if (members.All(static m => m.TopLevelDisplayText != null))
                {
                    var member = _tag.MembersOnLine[0];
                    Contract.ThrowIfNull(member.TopLevelDisplayText);
 
                    _lazyToolTipTextBlock = new[] { new TaggedText(TextTags.Text, member.TopLevelDisplayText) }.ToTextBlock(_classificationFormatMap, _classificationTypeMap);
                }
                else if (members.Length == 1)
                {
                    var member = _tag.MembersOnLine[0];
 
                    // Here we want to show a classified text with loc text,
                    // e.g. 'Bar' is inherited.
                    // But the classified text are inlines, so can't directly use string.format to generate the string
                    var inlines = member.DisplayTexts.ToInlines(_classificationFormatMap, _classificationTypeMap);
                    var startOfThePlaceholder = ServicesVSResources._0_is_inherited.IndexOf("{0}", StringComparison.Ordinal);
                    var prefixString = ServicesVSResources._0_is_inherited[..startOfThePlaceholder];
                    var suffixString = ServicesVSResources._0_is_inherited[(startOfThePlaceholder + "{0}".Length)..];
                    inlines.Insert(0, new Run(prefixString));
                    inlines.Add(new Run(suffixString));
 
                    _lazyToolTipTextBlock = inlines.ToTextBlock(_classificationFormatMap);
                    _lazyToolTipTextBlock.FlowDirection = FlowDirection.LeftToRight;
 
                }
                else
                {
                    _lazyToolTipTextBlock = new TextBlock
                    {
                        Text = ServicesVSResources.Multiple_members_are_inherited
                    };
                }
            }
 
            return _lazyToolTipTextBlock;
        }
    }
 
    /// <summary>
    /// Text used for automation.
    /// </summary>
    public string AutomationName { get; }
 
    /// <summary>
    /// ViewModels for the context menu items.
    /// </summary>
    public ImmutableArray<MenuItemViewModel> MenuItemViewModels { get; }
 
    /// <summary>
    /// Scale factor for the margin.
    /// </summary>
    public double ScaleFactor { get; }
 
    private InheritanceMarginGlyphViewModel(
        InheritanceMarginTag tag,
        ClassificationTypeMap classificationTypeMap,
        IClassificationFormatMap classificationFormatMap,
        string automationName,
        double scaleFactor,
        ImmutableArray<MenuItemViewModel> menuItemViewModels)
    {
        _classificationTypeMap = classificationTypeMap;
        _classificationFormatMap = classificationFormatMap;
        _tag = tag;
        AutomationName = automationName;
        MenuItemViewModels = menuItemViewModels;
        ScaleFactor = scaleFactor;
    }
 
    public static InheritanceMarginGlyphViewModel Create(
        ClassificationTypeMap classificationTypeMap,
        IClassificationFormatMap classificationFormatMap,
        InheritanceMarginTag tag,
        double zoomLevel)
    {
        var members = tag.MembersOnLine;
 
        // ZoomLevel is 100 based. (e.g. 150%, 100%)
        // ScaleFactor is 1 based. (e.g. 1.5, 1)
        var scaleFactor = zoomLevel / 100;
        if (members.All(m => m.TopLevelDisplayText != null))
        {
            var member = tag.MembersOnLine[0];
            var automationName = member.TopLevelDisplayText;
 
            var menuItemViewModels = members.SelectManyAsArray(m => InheritanceMarginHelpers.CreateModelsForMarginItem(m));
            return new InheritanceMarginGlyphViewModel(tag, classificationTypeMap, classificationFormatMap, automationName!, scaleFactor, menuItemViewModels);
        }
        else if (members.Length == 1)
        {
            var member = tag.MembersOnLine[0];
 
            var automationName = string.Format(ServicesVSResources._0_is_inherited, member.DisplayTexts.JoinText());
            var menuItemViewModels = InheritanceMarginHelpers.CreateModelsForMarginItem(member);
            return new InheritanceMarginGlyphViewModel(tag, classificationTypeMap, classificationFormatMap, automationName, scaleFactor, menuItemViewModels);
        }
        else
        {
            // Same automation name can't be set for control for accessibility purpose. So add the line number info.
            var automationName = string.Format(ServicesVSResources.Multiple_members_are_inherited_on_line_0, tag.LineNumber);
            var menuItemViewModels = InheritanceMarginHelpers.CreateMenuItemViewModelsForMultipleMembers(tag.MembersOnLine);
            return new InheritanceMarginGlyphViewModel(tag, classificationTypeMap, classificationFormatMap, automationName, scaleFactor, menuItemViewModels);
        }
    }
}