// Copyright (c) 2020-now by the Zeek Project. See LICENSE for details.

#pragma once

#include <string>
#include <string_view>
#include <utility>

#include <hilti/ast/attribute.h>
#include <hilti/ast/forward.h>
#include <hilti/ast/node.h>
#include <hilti/ast/statement.h>
#include <hilti/ast/type.h>
#include <hilti/ast/types/function.h>

namespace hilti {

namespace function {

/** A function's calling convention. */
enum class CallingConvention {
    Extern,          /**< function can be called from external C++ code */
    ExternNoSuspend, /**< function can be called from external C++ code, and is guaranteed to not suspend. */
    Standard         /**< default, nothing special */
};

namespace detail {
constexpr util::enum_::Value<CallingConvention> Conventions[] = {
    {CallingConvention::Extern, "extern"},
    {CallingConvention::ExternNoSuspend, "extern-no-suspend"},
    {CallingConvention::Standard, "<standard>"},
};
} // namespace detail

constexpr auto to_string(CallingConvention cc) { return util::enum_::to_string(cc, detail::Conventions); }

namespace calling_convention {
constexpr auto from_string(std::string_view s) {
    return util::enum_::from_string<CallingConvention>(s, detail::Conventions);
}
} // namespace calling_convention

} // namespace function
/** Base class for function nodes. */
class Function : public Node {
public:
    const auto& id() const { return _id; }
    auto type() const { return child<QualifiedType>(0); }
    auto ftype() const { return child<QualifiedType>(0)->type()->as<type::Function>(); }
    auto body() const { return child<Statement>(1); }
    auto attributes() const { return child<AttributeSet>(2); }
    auto callingConvention() const { return _cc; }
    auto isStatic() const { return attributes()->find(hilti::attribute::kind::Static) != nullptr; }

    void setBody(ASTContext* ctx, Statement* b) { setChild(ctx, 1, b); }
    void setID(ID id) { _id = std::move(id); }
    void setResultType(ASTContext* ctx, QualifiedType* t) { ftype()->setResultType(ctx, t); }

    node::Properties properties() const override {
        auto p = node::Properties{{"id", _id}, {"cc", to_string(_cc)}};
        return Node::properties() + std::move(p);
    }

    static auto create(ASTContext* ctx, const ID& id, type::Function* ftype, Statement* body,
                       function::CallingConvention cc = function::CallingConvention::Standard,
                       AttributeSet* attrs = nullptr, const Meta& meta = {}) {
        if ( ! attrs )
            attrs = AttributeSet::create(ctx);

        return ctx->make<Function>(ctx, {QualifiedType::create(ctx, ftype, Constness::Const, meta), body, attrs}, id,
                                   cc, meta);
    }

protected:
    Function(ASTContext* ctx, Nodes children, ID id, function::CallingConvention cc, Meta meta = {})
        : Node(ctx, NodeTags, std::move(children), std::move(meta)), _id(std::move(id)), _cc(cc) {}

    std::string _dump() const override;

    HILTI_NODE_0(Function, final);

private:
    ID _id;
    function::CallingConvention _cc;
};

} // namespace hilti