// Copyright Epic Games, Inc. All Rights Reserved.

#include "uLang/Semantics/Definition.h"
#include "uLang/Semantics/DataDefinition.h"
#include "uLang/Common/Text/UTF8String.h"
#include "uLang/Semantics/SemanticProgram.h"
#include "uLang/Semantics/SemanticScope.h"
#include "uLang/Semantics/SemanticTypes.h"

namespace uLang
{
SQualifier SQualifier::GetConstrainedQualifier() const
{
    if (_Type == EType::NominalType)
    {
        const CDefinition* ConstrainedDefinition = U._NominalType->Definition()->GetConstrainedDefinition();
        ULANG_ASSERT(ConstrainedDefinition);
        const CLogicalScope* ConstrainedLogicalScope = ConstrainedDefinition->DefinitionAsLogicalScopeNullable();
        ULANG_ASSERT(ConstrainedLogicalScope);
        const CTypeBase* ConstrainedType = ConstrainedLogicalScope->ScopeAsType();
        ULANG_ASSERT(ConstrainedType);
        const CNominalType* ConstrainedNominalType = ConstrainedType->GetNormalType().AsNominalType();
        ULANG_ASSERT(ConstrainedNominalType);
        return SQualifier::NominalType(ConstrainedNominalType);
    }
    if (_Type == EType::LogicalScope)
    {
        const CDefinition* Definition = U._LogicalScope->ScopeAsDefinition();
        ULANG_ASSERT(Definition);
        const CDefinition* ConstrainedDefinition = Definition->GetConstrainedDefinition();
        ULANG_ASSERT(ConstrainedDefinition);
        const CLogicalScope* ConstrainedLogicalScope = ConstrainedDefinition->DefinitionAsLogicalScopeNullable();
        ULANG_ASSERT(ConstrainedLogicalScope);
        return SQualifier::LogicalScope(ConstrainedLogicalScope);
    }
    return *this;
}

CDefinition::CDefinition(EKind Kind, CScope& EnclosingScope, const CSymbol& Name)
    : CNamed(Name)
    , _EnclosingScope(EnclosingScope)
    , _ParentScopeOrdinal(EnclosingScope.GetLogicalScope().AllocateNextDefinitionOrdinal())
    , _Qualifier{SQualifier::Unknown()}
    , _Kind(Kind)
{
    EnclosingScope.GetProgram()._SymbolMap.FindOrInsert(Name)._Value.Add(this);
}

CDefinition::~CDefinition()
{
    // Hack to allow CDefinition to reference a default expression for a non CExprDataDefinition named argument.
    // @JIRA SOL-2695 Named parameter needs to detach double link with AST
    //ULANG_ASSERTF(!GetAstNode(), "Expected %s definition AST node link to be cleared before definition is destroyed", DefinitionKindAsCString(GetKind()));
    //ULANG_ASSERTF(!GetIrNode(true), "Expected %s definition IR node link to be cleared before definition is destroyed", DefinitionKindAsCString(GetKind()));
}

const CDefinition& CDefinition::GetBaseClassOverriddenDefinition() const 
{
    const CDefinition* BaseOverriddenDefinition = this;
    while (BaseOverriddenDefinition->GetOverriddenDefinition() != nullptr && BaseOverriddenDefinition->GetOverriddenDefinition()->_EnclosingScope.GetKind() != CScope::EKind::Interface)
    {
        BaseOverriddenDefinition = BaseOverriddenDefinition->GetOverriddenDefinition();
    }
    return *BaseOverriddenDefinition;
}

SAccessLevel CDefinition::DerivedAccessLevel() const
{
    const CDefinition& DefinitionAccessibilityRoot = GetDefinitionAccessibilityRoot();
    if (DefinitionAccessibilityRoot._AccessLevel.IsSet())
    {
        return DefinitionAccessibilityRoot._AccessLevel.GetValue();
    }
    else
    {
        return DefinitionAccessibilityRoot._EnclosingScope.GetDefaultDefinitionAccessLevel();
    }
}

bool CDefinition::IsInstanceMember() const
{
    return _EnclosingScope.GetKind() == CScope::EKind::Class
        || _EnclosingScope.GetKind() == CScope::EKind::Interface;
}

bool CDefinition::IsDeprecated() const
{
    return HasAttributeClass(_EnclosingScope.GetProgram()._deprecatedClass, _EnclosingScope.GetProgram());
}

bool CDefinition::IsExperimental() const
{
    return HasAttributeClass(_EnclosingScope.GetProgram()._experimentalClass, _EnclosingScope.GetProgram());
}

bool CDefinition::IsFinal() const
{
    return HasAttributeClass(_EnclosingScope.GetProgram()._finalClass, _EnclosingScope.GetProgram());
}

const CExpressionBase* CDefinition::GetNativeSpecifierExpression() const
{
    return FindAttributeExpr(_EnclosingScope.GetProgram()._nativeClass, _EnclosingScope.GetProgram());
}

bool CDefinition::IsNative() const
{
    return GetNativeSpecifierExpression() != nullptr;
}

bool CDefinition::IsBuiltIn() const
{
    return _EnclosingScope.IsBuiltInScope();
}

CUTF8String GetQualifiedNameString(const CDefinition& Definition)
{
    return CUTF8String("(%s:)%s", Definition._EnclosingScope.GetScopePath('/', CScope::EPathMode::PrefixSeparator).AsCString(), Definition.AsNameCString());
}

CUTF8String GetCrcNameString(const CDefinition& Definition)
{
    if (Definition.GetKind() == CDefinition::EKind::Data && Definition._EnclosingScope.GetKind() == uLang::CScope::EKind::Interface)
    {
        return GetQualifiedNameString(Definition);
    }
    else
    {
        return Definition.AsNameCString();
    }
}

const char* DefinitionKindAsCString(CDefinition::EKind Kind)
{
    switch(Kind)
    {
#define VISIT_KIND(Name, String) case CDefinition::EKind::Name: return String;
    VERSE_ENUM_DEFINITION_KINDS(VISIT_KIND)
#undef VISIT_KIND
    default: ULANG_UNREACHABLE();
    };
}

bool CDefinition::IsAccessibleFrom(const CScope& Scope) const
{
    const CDefinition& Definition = GetDefinitionAccessibilityRoot();
    return Scope.CanAccess(Definition, Definition.DerivedAccessLevel());
}

const CDefinition* CDefinition::GetEnclosingDefinition() const
{
    for (const CScope* Scope = &_EnclosingScope; Scope; Scope = Scope->GetParentScope())
    {
        if (const CDefinition* EnclosingScopeDefinition = Scope->ScopeAsDefinition())
        {
            return EnclosingScopeDefinition;
        }
    }
    return nullptr;
}

bool CDefinition::IsExplicitlyLocallyQualified() const
{
    return _Qualifier._Type == SQualifier::EType::Local;
}

bool CDefinition::IsLocallyQualified() const
{
    // If it's explicitly `(local:)`-qualified, it's still local.
    if (IsExplicitlyLocallyQualified())
    {
        return true;
    }
    // Anything within a function local-scope and which isn't explicitly-qualified
    // is implicitly `(local:)`.
    return _Qualifier._Type == SQualifier::EType::Unknown && _EnclosingScope.GetScopeOfKind(CScope::EKind::Function) != nullptr;
}

SQualifier CDefinition::GetImplicitQualifier() const
{
    const CDefinition& BaseDefinition = GetBaseOverriddenDefinition();
    return BaseDefinition._EnclosingScope.GetLogicalScope().AsQualifier();
}

void CDefinition::SetName(const CSymbol& NewName)
{
    const CSymbol& OldName = GetName();

    if (CLogicalScope* EnclosingLogicalScope = _EnclosingScope.AsLogicalScopeNullable())
    {
        // Renaming a definition requires that we reindex it into the Name map.
        if (SmallDefinitionArray* ScopeDefinitions = EnclosingLogicalScope->GetDefinitionNameMap().Find(OldName))
        {
            ScopeDefinitions->Remove(this);
            if (ScopeDefinitions->IsEmpty())
            {
                EnclosingLogicalScope->GetDefinitionNameMap().Remove(OldName);
            }
        }
        EnclosingLogicalScope->GetDefinitionNameMap().FindOrInsert(NewName)._Value.Add(this);
    }

    // Update the program-wide CSymbol->Definition map
    if (SSymbolDefinitionArray* SymbolDefinitions = _EnclosingScope.GetProgram()._SymbolMap.Find(OldName))
    {
        SymbolDefinitions->Remove(this);
        if (SymbolDefinitions->IsEmpty())
        {
            _EnclosingScope.GetProgram()._SymbolMap.Remove(OldName);
        }
    }
    _EnclosingScope.GetProgram()._SymbolMap.FindOrInsert(NewName)._Value.Add(this);

    _Name = NewName;
}

}  // namespace uLang