using System;
using System.CodeDom;
using System.Linq;
using System.Runtime.InteropServices.ComTypes;
using Kaitai;

namespace CodeGenerator;

public static class BlendExt {
    //TODO: Add an bool IsPrincipal extension method to kaitai structs lib
    //A principal (or root) block is defined by having a two digit code and by the fact that its dna_index is always valid.
    //If we have a pointer to a principal block, we can ignore the type of the pointer and use the block type.
    //Subsidiary blocks are defined by having the code "DATA", which is ommited here. Their dna_index is not
    // always correct and is only used when whichever field points to them has an "invalid" type (like void*).
    public static bool IsPrincipal(this BlendFile.FileBlock block) {
        string[] dataTypes = ["REND", "TEST", "GLOB", "DATA", "DNA1"];
        bool isPrincipal = !dataTypes.Contains(block.Code);
        if (isPrincipal && block.Count > 1)
            throw new("Corrupt File detected. Principal block has more than one data type");
        return isPrincipal;
    }
}