using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Elsa.Models;
using Elsa.Serialization;
using Elsa.Services;
using Microsoft.Extensions.Configuration;

public class JsonWorkflowProvider : IWorkflowProvider
{
    private readonly IWorkflowSerializer _serializer;
    private readonly IConfiguration _configuration;

    public JsonWorkflowProvider(IWorkflowSerializer serializer, IConfiguration configuration)
    {
        _serializer = serializer;
        _configuration = configuration;
    }
    
    public async Task<IEnumerable<WorkflowDefinitionVersion>> GetWorkflowDefinitionsAsync(CancellationToken cancellationToken)
    {
        var workflowsDirectoryPath = _configuration["WorkflowPath"];
        var workflowFiles = Directory.GetFiles(workflowsDirectoryPath, "*.json");
        var workflowDefinitionTasks =  workflowFiles.Select(LoadWorkflowDefinition).ToList();
        await Task.WhenAll(workflowDefinitionTasks);
        return workflowDefinitionTasks.Select(x => x.Result);
    }

    private async Task<WorkflowDefinitionVersion> LoadWorkflowDefinition(string path)
    {
        var jsonText = await File.ReadAllTextAsync(path);
        return _serializer.Deserialize<WorkflowDefinitionVersion>(jsonText, JsonTokenFormatter.FormatName);
    }
}