using Core;
using Core.Events;
using Core.Helpers;
using Core.Templates;
using Generator.Infrastructure.TemplateFiller;
using Microsoft.OpenApi.Exceptions;

namespace Generator.Infrastructure.OpenApi.Builders;

/// <summary>
/// Provides base behavior for generation purpose
/// </summary>
/// <typeparam name="TFile">Derived type from ISpecFile</typeparam>
public abstract class AbstractBuilder<TFile> where TFile : ISpecFile
{
    private readonly ITemplateFactory _templateFactory; 
    protected readonly CommandExecutor Executor;
    protected TFile? SpecFile;
    
    public AbstractBuilder(string invite, DisplayEmitter emitter)
    {
        Executor = new CommandExecutor(invite, emitter);
        _templateFactory = new MustacheTemplateFactory();
        SpecFile = default;
    }

    /// <summary>
    /// Registers file used for generation
    /// </summary>
    /// <param name="specFile"></param>
    public void Load(TFile specFile) => SpecFile = TypeHelper.SafeCast<ISpecFile, TFile>(specFile);
    
    /// <summary>
    /// Launches generation
    /// </summary>
    public async Task ExecuteAllAsync() => await Executor.RunRegistered();
    
    /// <summary>
    /// Registers generation process
    /// </summary>
    public abstract void Generate();

    /// <summary>
    /// Registers build process
    /// </summary>
    public abstract void Build();
  
    /// <summary>
    /// Check if the spec file has been loaded
    /// </summary>
    /// <exception cref="OpenApiException"></exception>
    protected void CheckForNullSpec()
    {
        if (SpecFile == null) throw new OpenApiException("Spec file hasn't been loaded yet.");
    }
    
    protected void MakeTemplate(string inputPath, string outputPath, IDictionary<string, object> data)
    {
        var template = _templateFactory.GetTemplate(inputPath, data);
        var f = new MustacheFiller(template);
        f.Fill();
        f.Write(outputPath);
    }
}