using System.CommandLine;
using MycroForge.CLI.CodeGen;
using MycroForge.Core;
using MycroForge.Core.Contract;

namespace MycroForge.CLI.Commands;

public partial class MycroForge
{
    public partial class Db
    {
        public partial class Link
        {
            public class Many : Command, ISubCommandOf<Link>
            {
                private readonly ProjectContext _context;

                private static readonly Argument<string> LeftArgument =
                    new(name: "entity", description: "The left side of the relation");

                private static readonly Option<string> ToOneOption =
                    new(name: "--to-one", description: "The right side of the relation");

                private static readonly Option<string> ToManyOption =
                    new(name: "--to-many", description: "The right side of the relation");

                public Many(ProjectContext context) : base("many", "Define a n:m relation")
                {
                    _context = context;
                    AddArgument(LeftArgument);
                    AddOption(ToOneOption);
                    AddOption(ToManyOption);
                    this.SetHandler(ExecuteAsync, LeftArgument, ToOneOption, ToManyOption);
                }

                private async Task ExecuteAsync(string left, string? toOneOption, string? toManyOption)
                {
                    if (toOneOption is not null && toManyOption is not null)
                        throw new Exception("Cannot set both --to-one and --to-many option.");

                    if (toOneOption is not null)
                        await ToOne(left, toOneOption);

                    else if (toManyOption is not null)
                        await ToMany(left, toManyOption);

                    else throw new Exception("Set --to-one or --to-many option.");
                }

                private async Task ToOne(string left, string toOneOption)
                {
                    await new EntityLinker(_context, left, toOneOption).ManyToOne();
                }

                private async Task ToMany(string left, string toManyOption)
                {
                    await new EntityLinker(_context, left, toManyOption).ManyToMany();
                }
            }
        }
    }
}