using Common;
using Syntax.Parsing;
using Syntax.Parsing.Node;

namespace Syntax;

public class DefinitionTable
{
    private readonly IEnumerable<CompilationUnit> _compilationUnits;

    public DefinitionTable(IEnumerable<CompilationUnit> compilationUnits)
    {
        _compilationUnits = compilationUnits;
    }

    public Optional<IFuncSignature> LookupFunc(string @namespace, string name)
    {
        var definition = _compilationUnits
            .Where(c => c.Namespace == @namespace)
            .SelectMany(c => c.Definitions)
            .OfType<IFuncSignature>()
            .SingleOrDefault(f => f.Name == name);

        return Optional.OfNullable(definition);
    }

    public Optional<StructDefinitionNode> LookupStruct(string @namespace, string name)
    {
        var definition = _compilationUnits
            .Where(c => c.Namespace == @namespace)
            .SelectMany(c => c.Definitions)
            .OfType<StructDefinitionNode>()
            .SingleOrDefault(f => f.Name == name);

        return Optional.OfNullable(definition);
    }

    public IEnumerable<StructDefinitionNode> GetStructs()
    {
        return _compilationUnits
            .SelectMany(c => c.Definitions)
            .OfType<StructDefinitionNode>();
    }
}