// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

using System.Text.Json.Serialization;
using Microsoft.Teams.Apps.Schema.Entities;
using Microsoft.Teams.Core.Schema;

namespace Microsoft.Teams.Apps.Schema;

/// <summary>
/// Represents a message activity.
/// </summary>
public class MessageActivity : TeamsActivity
{

    /// <summary>
    /// Convenience method to create a MessageActivity from a CoreActivity.
    /// </summary>
    /// <param name="activity">The CoreActivity to convert.</param>
    /// <returns>A MessageActivity instance.</returns>
    public static new MessageActivity FromActivity(CoreActivity activity)
    {
        ArgumentNullException.ThrowIfNull(activity);
        return new MessageActivity(activity);
    }

    /// <summary>
    /// Default constructor.
    /// </summary>
    [JsonConstructor]
    public MessageActivity() : base(TeamsActivityTypes.Message)
    {
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="MessageActivity"/> class with the specified text.
    /// </summary>
    /// <param name="text">The text content of the message.</param>
    public MessageActivity(string text) : base(TeamsActivityTypes.Message)
    {
        Text = text;
    }


    /// <summary>
    /// Initializes a new instance of the <see cref="MessageActivity"/> class with the specified text.
    /// </summary>
    /// <param name="attachments">The list of attachments for the message.</param>
    public MessageActivity(IList<TeamsAttachment> attachments) : base(TeamsActivityTypes.Message)
    {
        Attachments = attachments;
    }

    /// <summary>
    /// Internal constructor to create MessageActivity from CoreActivity.
    /// </summary>
    /// <param name="activity">The CoreActivity to convert.</param>
    internal MessageActivity(CoreActivity activity) : base(activity)
    {
        Attachments = activity.Properties.Extract<IList<TeamsAttachment>>("attachments");
        Text = activity.Properties.Extract<string>("text");
        TextFormat = activity.Properties.Extract<string>("textFormat");
        AttachmentLayout = activity.Properties.Extract<string>("attachmentLayout");
        SuggestedActions = activity.Properties.Extract<SuggestedActions>("suggestedActions");
    }

    /// <summary>
    /// Gets or sets the attachments for the message.
    /// </summary>
    [JsonPropertyName("attachments")]
    public IList<TeamsAttachment>? Attachments { get; set; }

    /// <summary>
    /// Gets or sets the text content of the message.
    /// </summary>
    [JsonPropertyName("text")]
    public string? Text { get; set; }

    /// <summary>
    /// Gets the message text with the bot (recipient) @mention removed and trimmed.
    /// In group chats, Teams prepends "&lt;at&gt;botname&lt;/at&gt;" to the text when the bot is mentioned.
    /// This property strips that mention so handlers can match on the user's intent alone.
    /// </summary>
    [JsonIgnore]
    public string? TextWithoutMentions
    {
        get
        {
            string? text = Text;
            if (text is null) return null;

            foreach (MentionEntity mention in this.GetMentions())
            {
                if (mention.Mentioned?.Id == Recipient?.Id && mention.Text is not null)
                {
                    text = text.Replace(mention.Text, string.Empty, StringComparison.OrdinalIgnoreCase);
                }
            }
            return text.Trim();
        }
    }
    /// <summary>
    /// Gets or sets the text format. See <see cref="TextFormats"/> for common values (plain, markdown, xml, extendedmarkdown).
    /// </summary>
    [JsonPropertyName("textFormat")]
    public string? TextFormat { get; set; }

    /// <summary>
    /// Gets or sets the attachment layout.
    /// </summary>
    [JsonPropertyName("attachmentLayout")]
    public string? AttachmentLayout { get; set; }

}

/// <summary>
/// String constants for text formats.
/// </summary>
public static class TextFormats
{
    /// <summary>
    /// Plain text format.
    /// </summary>
    public const string Plain = "plain";

    /// <summary>
    /// Markdown text format.
    /// </summary>
    public const string Markdown = "markdown";

    /// <summary>
    /// XML text format.
    /// </summary>
    public const string Xml = "xml";

    /// <summary>
    /// Extended markdown text format. Supports GFM tables, LaTeX math blocks,
    /// and other rich content beyond standard markdown.
    /// </summary>
    public const string ExtendedMarkdown = "extendedmarkdown";
}