using InnovEnergy.App.Backend.Model;
using InnovEnergy.Lib.Utils;

namespace InnovEnergy.App.Backend.Database;

public static partial class Db
{
    public static IEnumerable<Folder> GetChildFolders(this Folder parent)
    {
        return Folders.Where(f => f.ParentId == parent.Id);
    }
        
    public static IEnumerable<Installation> GetChildInstallations(this Folder parent)
    {
        return Installations.Where(f => f.ParentId == parent.Id);
    }
    
    public static IEnumerable<Folder> GetDescendantFolders(this Folder parent)
    {
        return parent.Traverse(GetChildFolders);
    }

    public static Boolean IsDescendantOf(this Folder folder, Int64 ancestorFolderId)
    {
        return Ancestors(folder)
              .Any(u => u.Id == ancestorFolderId);
    }
    
    public static Boolean IsDescendantOf(this Folder folder, Folder ancestor)
    {
        return IsDescendantOf(folder, ancestor.Id);
    }
    
    private static IEnumerable<Folder> Ancestors(this Folder child)
    {
        return child.Unfold(GetParent);
    }

    public static Folder? GetParent(this Folder f)
    {
        return IsRoot(f)    
             ? null 
             : GetFolderById(f.ParentId);
    }

    public static Boolean IsRoot(this Folder f)
    { 
        return f.ParentId == 0; // root has ParentId 0 by definition
    }
    
    public static Int64 CreateFolder(Folder folder)
    {
        return Create(folder);
    }
    
    public static Boolean UpdateFolder(Folder folder)
    {
        // TODO: no circles in path
         
        return Update(folder); 
    }

    // These should not be necessary, just Update folder/installation with new parentId

    // public Boolean ChangeParent(Installation child, Int64 parentId)
    // {
    //     child.ParentId = parentId;
    //     return UpdateInstallation(child);
    // }
    //
    // public Boolean ChangeParent(Folder child, Int64 parentId)
    // {
    //     child.ParentId = parentId;
    //     return UpdateFolder(child);
    // }

    public static Boolean DeleteFolder(Folder folder)
    {
        // Delete direct children
        User2Folder  .Delete(f => f.FolderId == folder.Id);
        Installations.Delete(i => i.ParentId == folder.Id);  
        
        // recursion
        Folders.Where(f => f.ParentId == folder.Id)
               .ForEach(DeleteFolder);
        
        return Delete(folder);
    }
    
}