using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.U2D;
using UnityObject = UnityEngine.Object;

namespace UnityEditor.U2D.Sprites
{
    /// <summary>An interface that allows Sprite Editor Window to edit Sprite data for user custom importer.</summary>
    /// <remarks> Use this interface to edit Sprite data.
    /// <code>
    /// using UnityEditor;
    /// using UnityEditor.U2D.Sprites;
    /// using UnityEngine;
    ///
    /// public class PivotUpdater : AssetPostprocessor
    /// {
    ///     private void OnPreprocessTexture()
    ///     {
    ///         var factory = new SpriteDataProviderFactories();
    ///         factory.Init();
    ///         var dataProvider = factory.GetSpriteEditorDataProviderFromObject(assetImporter);
    ///         dataProvider.InitSpriteEditorDataProvider();
    ///
    ///         SetPivot(dataProvider, new Vector2(0.5f, 0.5f));
    ///
    ///         dataProvider.Apply();
    ///     }
    ///
    ///     static void SetPivot(ISpriteEditorDataProvider dataProvider, Vector2 pivot)
    ///     {
    ///         var spriteRects = dataProvider.GetSpriteRects();
    ///         foreach (var rect in spriteRects)
    ///         {
    ///             rect.pivot = pivot;
    ///             rect.alignment = SpriteAlignment.Custom;
    ///         }
    ///         dataProvider.SetSpriteRects(spriteRects);
    ///     }
    /// }
    /// </code>
    /// </remarks>
    public interface ISpriteEditorDataProvider
    {
        /// <summary>SpriteImportMode to indicate how Sprite data will be imported.</summary>
        SpriteImportMode spriteImportMode { get; }
        /// <summary>The number of pixels in the sprite that correspond to one unit in world space.</summary>
        float pixelsPerUnit { get; }
        /// <summary>The object that this data provider is acquiring its data from.</summary>
        UnityObject targetObject { get; }
        /// <summary>Returns an array of SpriteRect representing Sprite data the provider has.</summary>
        /// <returns>Array of SpriteRect.</returns>
        SpriteRect[] GetSpriteRects();
        /// <summary>Sets the data provider's current SpriteRect.</summary>
        /// <param name="spriteRects">Updated array of SpriteRect.</param>
        void SetSpriteRects(SpriteRect[] spriteRects);
        /// <summary>Applying any changed data.</summary>
        void Apply();
        /// <summary>Allows the data provider to initialize any data if needed.</summary>
        void InitSpriteEditorDataProvider();
        /// <summary>Gets other data providers that might be supported by ISpriteEditorDataProvider.targetObject.</summary>
        /// <typeparam name="T">The data provider type to acquire.</typeparam>
        /// <returns>Data provider type.</returns>
        T GetDataProvider<T>() where T : class;
        /// <summary>Queries if ISpriteEditorDataProvider.targetObject supports the data provider type.</summary>
        /// <param name="type">Data provider type.</param>
        /// <returns>True if supports, false otherwise.</returns>
        bool HasDataProvider(Type type);
    }

    /// <summary>
    /// Data Provider interface that deals with Sprite Bone data.
    /// </summary>
    public interface ISpriteBoneDataProvider
    {
        /// <summary>
        /// Returns the list of SpriteBone for the corresponding Sprite ID.
        /// </summary>
        /// <param name="guid">Sprite ID.</param>
        /// <returns>The list of SpriteBone associated with the Sprite</returns>
        List<SpriteBone> GetBones(GUID guid);

        /// <summary>Sets a new set of SpriteBone for the corresponding Sprite ID.</summary>
        /// <param name = "guid" > Sprite ID.</param>
        /// <param name = "bones" > List of SpriteBone to associate with the Sprite.</param>
        void SetBones(GUID guid, List<SpriteBone> bones);
    }

    /// <summary>
    /// Data provider that provides data for ID to be used given a SpriteRect's name.
    /// </summary>
    /// <remarks>
    /// The name and ID pair is used to allow mapping back a previous created SpriteRect.
    /// </remarks>
    public interface ISpriteNameFileIdDataProvider
    {
        /// <summary>Returns an IEnumerable of SpriteNameFileIdPair representing the name and file id pairs the provider has.</summary>
        /// <returns>Name and file id pairs.</returns>
        IEnumerable<SpriteNameFileIdPair> GetNameFileIdPairs();
        /// <summary>Sets the data provider's current NameFileIdPair.</summary>
        /// <param name="nameFileIdPairs">Updated IEnumerable of SpriteNameFileIdPair.</param>
        void SetNameFileIdPairs(IEnumerable<SpriteNameFileIdPair> nameFileIdPairs);
    }

    /// <summary>Data provider that provides the outline data for SpriteRect.</summary>
    /// <remarks>The outline data is used to tessellate a Sprite's mesh.</remarks>
    public interface ISpriteOutlineDataProvider
    {
        /// <summary>Given a GUID, returns the outline data used for tessellating the SpriteRect.</summary>
        /// <param name="guid">GUID of the SpriteRect.</param>
        /// <returns>Outline data for theSpriteRect.</returns>
        List<Vector2[]> GetOutlines(GUID guid);
        /// <summary>Given a GUID, sets the outline data used for tessellating the SpriteRect.</summary>
        /// <param name="guid">GUID of the SpriteRect.</param>
        /// <param name="data">Outline data for theSpriteRect.</param>
        void SetOutlines(GUID guid, List<Vector2[]> data);
        /// <summary>Given a GUID, returns the tessellation detail.Tessellation value should be between 0 to 1.</summary>
        /// <param name = "guid" > GUID of the SpriteRect.</param>
        /// <returns>The tessellation value.</returns>
        float GetTessellationDetail(GUID guid);
        /// <summary>Given a GUID, sets the tessellation detail.Tessellation value should be between 0 to 1.</summary>
        /// <param name = "guid" > GUID of the SpriteRect.</param>
        /// <param name="value">The tessellation value.</param>
        void SetTessellationDetail(GUID guid, float value);
    }

    /// <summary>Data provider that provides the Physics outline data for SpriteRect.</summary>
    /// <remarks>Uses the outline data to generate the Sprite's Physics shape for Polygon Collider 2D.</remarks>
    public interface ISpritePhysicsOutlineDataProvider
    {
        /// <summary>Given a GUID, returns the Physics outline data used for the SpriteRect.</summary>
        /// <param name="guid">GUID of the SpriteRect.</param>
        /// <returns>Physics outline data for the SpriteRect.</returns>
        List<Vector2[]> GetOutlines(GUID guid);
        /// <summary>Given a GUID, sets the Physics outline data used for the SpriteRect.</summary>
        /// <param name="guid">GUID of the SpriteRect.</param>
        /// <param name="data">Physics outline data for the SpriteRect.</param>
        void SetOutlines(GUID guid, List<Vector2[]> data);
        /// <summary>Given a GUID, returns the tessellation detail.Tessellation value should be between 0 to 1.</summary>
        /// <param name = "guid" > GUID of the SpriteRect.</param>
        /// <returns>The tessellation value.</returns>
        float GetTessellationDetail(GUID guid);
        /// <summary>Given a GUID, sets the tessellation detail.Tessellation value should be between 0 to 1.</summary>
        /// <param name = "guid" > GUID of the SpriteRect.</param>
        /// <param name="value">The tessellation value.</param>
        void SetTessellationDetail(GUID guid, float value);
    }

    /// <summary>Data provider that provides texture data needed for Sprite Editor Window.</summary>
    public interface ITextureDataProvider
    {
        /// <summary>Texture2D representation of the data provider.</summary>
        Texture2D texture { get; }
        /// <summary>Texture2D that represents the preview for ITextureDataProvider.texture.</summary>
        Texture2D previewTexture { get; }
        /// <summary>The actual width and height of the texture data.</summary>
        /// <param name="width">Out value for width.</param>
        /// <param name="height">Out value for height.</param>
        void GetTextureActualWidthAndHeight(out int width , out int height);
        /// <summary>Readable version of ITextureProvider.texture.</summary>
        /// <returns>Texture2D that is readable.</returns>
        Texture2D GetReadableTexture2D();
    }

    /// <summary>Data provider that provides secoondary texture data needed for Sprite Editor Window.</summary>
    public interface ISecondaryTextureDataProvider
    {
        /// <summary>
        /// Get set method for an array of SecondarySpriteTexture in the Data Provider
        /// </summary>
        SecondarySpriteTexture[] textures { get; set; }
    }

    /// <summary>A structure that contains meta data about vertices in a Sprite.</summary>
    [Serializable]
    public struct Vertex2DMetaData
    {
        /// <summary>The position of the vertex.</summary>
        public Vector2 position;
        /// <summary>The BoneWeight of the vertex.</summary>
        public BoneWeight boneWeight;
    }

    /// <summary>Data Provider interface that deals with Sprite mesh data.</summary>
    public interface ISpriteMeshDataProvider
    {
        /// <summary>Returns the list of vertex datas for the corresponding Sprite ID.</summary>
        /// <param name = "guid" > Sprite ID.</param>
        Vertex2DMetaData[] GetVertices(GUID guid);
        /// <summary>Sets a new list of vertices for the corresponding Sprite ID.</summary>
        /// <param name = "guid" > Sprite ID.</param>
        void SetVertices(GUID guid, Vertex2DMetaData[] vertices);
        /// <summary>Returns the list of mesh index for the corresponding Sprite ID.</summary>
        /// <param name = "guid" > Sprite ID.</param>
        int[] GetIndices(GUID guid);
        /// <summary>Sets a new list of indices for the corresponding Sprite ID.</summary>
        /// <param name = "guid" > Sprite ID.</param>
        void SetIndices(GUID guid, int[] indices);
        /// <summary>Returns the list of mesh edges for the corresponding Sprite ID.</summary>
        /// <param name = "guid" > Sprite ID.</param>
        Vector2Int[] GetEdges(GUID guid);
        /// <summary>Sets a new list of edges for the corresponding Sprite ID.</summary>
        /// <param name = "guid" > Sprite ID.</param>
        void SetEdges(GUID guid, Vector2Int[] edges);
    }

    /// <summary>
    /// Data Provider interface that allows to get and set custom Sprite data.
    /// </summary>
    internal interface ISpriteCustomDataProvider
    {
        /// <summary>
        /// Gets all available keys.
        /// </summary>
        /// <returns>Collection of all available keys.</returns>
        public IEnumerable<string> GetKeys();

        /// <summary>
        /// Sets the custom data at the given key.
        /// </summary>
        /// <param name="key">Name of the key.</param>
        /// <param name="data">Value.</param>
        public void SetData(string key, string data);

        /// <summary>
        /// Removes the custom data at the given key.
        /// </summary>
        /// <param name="key">Name of the key.</param>
        public void RemoveData(string key);

        /// <summary>
        /// Gets the custom data at the given key.
        /// </summary>
        /// <param name="key">Name of the key.</param>
        /// <param name="data">Value.</param>
        /// <returns>True if the value retrieved successfully.</returns>
        public bool GetData(string key, out string data);
    }
}