using System.Text.Json;
using System.Text.Json.Serialization;
using LindtLeerformPlugin.Models;
using OpenCvSharp;

namespace LindtLeerformPlugin.Services;

public class LeerformRecipeStore
{
    private const string RecipeExtension = ".jleerform";

    public string RecipesDirectory { get; } = Path.Combine("..", "Data", "Recipes");

    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        PropertyNameCaseInsensitive = true,
        WriteIndented = true,
        Converters = { new JsonStringEnumConverter() }
    };

    public IReadOnlyList<string> ListRecipeNames()
    {
        if (!Directory.Exists(RecipesDirectory))
            return Array.Empty<string>();

        return Directory.GetFiles(RecipesDirectory, "*" + RecipeExtension)
            .Select(Path.GetFileNameWithoutExtension)
            .Where(name => !string.IsNullOrEmpty(name))
            .Select(name => name!)
            .OrderBy(name => name, StringComparer.OrdinalIgnoreCase)
            .ToList();
    }

    public LeerformRecipe? Load(string recipeName)
    {
        if (string.IsNullOrWhiteSpace(recipeName))
            return null;

        var path = GetRecipePath(recipeName);
        if (!File.Exists(path))
            return null;

        var json = File.ReadAllText(path);
        return JsonSerializer.Deserialize<LeerformRecipe>(json, JsonOptions);
    }

    public void Save(LeerformRecipe recipe)
    {
        if (string.IsNullOrWhiteSpace(recipe.RecipeName))
            throw new ArgumentException("Recipe must have a name", nameof(recipe));

        Directory.CreateDirectory(RecipesDirectory);
        var path = GetRecipePath(recipe.RecipeName);
        var json = JsonSerializer.Serialize(recipe, JsonOptions);
        File.WriteAllText(path, json);
    }

    public static Mat? DecodeThumbnail(LeerformRecipe recipe)
    {
        if (string.IsNullOrEmpty(recipe.ThumbnailBase64))
            return null;

        try
        {
            var bytes = Convert.FromBase64String(recipe.ThumbnailBase64);
            var mat = Cv2.ImDecode(bytes, ImreadModes.Color);
            return mat.Empty() ? null : mat;
        }
        catch
        {
            return null;
        }
    }

    private string GetRecipePath(string recipeName) =>
        Path.Combine(RecipesDirectory, recipeName + RecipeExtension);
}