using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Text.Json.Nodes;
using System.Text.Json.Serialization;
using ModelContextProtocol.Server;

namespace ModelContextProtocol.Protocol;

/// <summary>
/// Represents a known resource that the server is capable of reading.
/// </summary>
/// <remarks>
/// See the <see href="https://github.com/modelcontextprotocol/specification/blob/main/schema/">schema</see> for details.
/// </remarks>
[DebuggerDisplay("Name = {Name}, Uri = {Uri}")]
public sealed class Resource : IBaseMetadata
{
    /// <inheritdoc />
    [JsonPropertyName("name")]
    public required string Name { get; set; }

    /// <inheritdoc />
    [JsonPropertyName("title")]
    public string? Title { get; set; }

    /// <summary>
    /// Gets or sets the URI of this resource.
    /// </summary>
    [JsonPropertyName("uri")]
    [StringSyntax(StringSyntaxAttribute.Uri)]
    public required string Uri { get; set; }

    /// <summary>
    /// Gets or sets a description of what this resource represents.
    /// </summary>
    /// <remarks>
    /// <para>
    /// This can be used by clients to improve the LLM's understanding of available resources. It can be thought of like a \"hint\" to the model.
    /// </para>
    /// <para>
    /// The description should provide clear context about the resource's content, format, and purpose.
    /// This helps AI models make better decisions about when to access or reference the resource.
    /// </para>
    /// <para>
    /// Client applications can also use this description for display purposes in user interfaces
    /// or to help users understand the available resources.
    /// </para>
    /// </remarks>
    [JsonPropertyName("description")]
    public string? Description { get; set; }

    /// <summary>
    /// Gets or sets the MIME type of this resource.
    /// </summary>
    /// <remarks>
    /// <para>
    /// <see cref="MimeType"/> specifies the format of the resource content, helping clients to properly interpret and display the data.
    /// Common MIME types include "text/plain" for plain text, "application/pdf" for PDF documents,
    /// "image/png" for PNG images, and "application/json" for JSON data.
    /// </para>
    /// <para>
    /// This property can be <see langword="null"/> if the MIME type is unknown or not applicable for the resource.
    /// </para>
    /// </remarks>
    [JsonPropertyName("mimeType")]
    public string? MimeType { get; set; }

    /// <summary>
    /// Gets or sets optional annotations for the resource.
    /// </summary>
    /// <remarks>
    /// These annotations can be used to specify the intended audience (<see cref="Role.User"/>, <see cref="Role.Assistant"/>, or both)
    /// and the priority level of the resource. Clients can use this information to filter or prioritize resources for different roles.
    /// </remarks>
    [JsonPropertyName("annotations")]
    public Annotations? Annotations { get; set; }

    /// <summary>
    /// Gets or sets the size of the raw resource content (before base64 encoding), in bytes, if known.
    /// </summary>
    /// <remarks>
    /// This can be used by applications to display file sizes and estimate context window usage.
    /// </remarks>
    [JsonPropertyName("size")]
    public long? Size { get; set; }

    /// <summary>
    /// Gets or sets an optional list of icons for this resource.
    /// </summary>
    /// <remarks>
    /// This can be used by clients to display the resource's icon in a user interface.
    /// </remarks>
    [JsonPropertyName("icons")]
    public IList<Icon>? Icons { get; set; }

    /// <summary>
    /// Gets or sets metadata reserved by MCP for protocol-level metadata.
    /// </summary>
    /// <remarks>
    /// Implementations must not make assumptions about its contents.
    /// </remarks>
    [JsonPropertyName("_meta")]
    public JsonObject? Meta { get; set; }

    /// <summary>
    /// Gets or sets the callable server resource corresponding to this metadata if any.
    /// </summary>
    [JsonIgnore]
    public McpServerResource? McpServerResource { get; set; }
}