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

#pragma once

#if ! defined(_MSC_VER)

#include <cxxabi.h>

#endif

#include <array>

#include <cstdlib>

#include <memory>

#include <string>

#include <vector>

namespace hilti::rt {

/** Captures a stack backtrace at construction time. */

class Backtrace {

public:

    Backtrace();

    Backtrace(const Backtrace& other) = default;

    Backtrace(Backtrace&& other) = default;

    ~Backtrace() = default;

    // Returns pointer to save stack space.

    std::unique_ptr<std::vector<std::string>> backtrace() const;

    friend bool operator==(const Backtrace& a, const Backtrace& b);

    friend bool operator!=(const Backtrace& a, const Backtrace& b) { return ! (a == b); }

    Backtrace& operator=(const Backtrace& other) = default;

    Backtrace& operator=(Backtrace&& other) = default;

private:

    using Callstack = std::array<void*, 32>;

    std::shared_ptr<Callstack> _callstack = nullptr;

    int _frames = -1;

};

bool operator==(const Backtrace& a, const Backtrace& b);

/** Wrapper around the ABI's C++ demangle function. */

inline std::string demangle(const std::string& symbol) {

#if defined(_MSC_VER)

    // MSVC's typeid().name() returns "class X" or "struct X" prefixed names.

    if ( symbol.starts_with("class ") )

        return symbol.substr(6);

    if ( symbol.starts_with("struct ") )

        return symbol.substr(7);

    if ( symbol.starts_with("enum ") )

        return symbol.substr(5);

    return symbol;

#else

    int status;

    char* dname = abi::__cxa_demangle(symbol.c_str(), nullptr, nullptr, &status);

    std::string x = (dname && status == 0) ? dname : symbol;

    if ( dname )

        free(dname); // NOLINT

    return x;

#endif

}

} // namespace hilti::rt