#include "backtrace_lib.h"

#include <util/generic/hash.h>
#include <util/system/execpath.h>

#include <algorithm>

#if defined(_linux_) && defined(_x86_64_)
    #include <dlfcn.h>
    #include <link.h>
#endif

namespace {
const size_t Limit = 400;
void* Stack[Limit]; // NOLINT(modernize-avoid-c-arrays)

struct TDllInfo {
    const char* Path;
    ui64 BaseAddress;
};

const size_t MaxDLLCnt = 100;
TDllInfo DLLs[MaxDLLCnt]; // NOLINT(modernize-avoid-c-arrays)
size_t DLLCount = 0;

#if defined(_linux_) && defined(_x86_64_)
int DlIterCallback(struct dl_phdr_info* info, size_t, void* data) {
    if (*info->dlpi_name) {
        if (DLLCount + 1 < MaxDLLCnt) {
            reinterpret_cast<std::remove_reference_t<decltype(DLLs[0])>*>(data)[DLLCount++] = {.Path = info->dlpi_name, .BaseAddress = (ui64)info->dlpi_addr};
        }
    }
    return 0;
}
#endif
bool Comp(const TDllInfo& a, const TDllInfo& b) {
    return strcmp(a.Path, b.Path) < 0;
}

} // namespace

namespace NYql::NBacktrace {
TCollectedFrame::TCollectedFrame(uintptr_t addr) {
    File = GetPersistentExecPath().c_str();
    Address = addr;
#if defined(_linux_) && defined(_x86_64_)
    Dl_info dlInfo;
    memset(&dlInfo, 0, sizeof(dlInfo));
    auto ret = dladdr(reinterpret_cast<void*>(addr), &dlInfo);
    if (ret) {
        auto it = std::lower_bound(DLLs, DLLs + DLLCount, std::remove_reference_t<decltype(DLLs[0])>{dlInfo.dli_fname, {}}, Comp);
        if (it != DLLs + DLLCount && !strcmp(it->Path, dlInfo.dli_fname)) {
            File = it->Path;
            Address -= it->BaseAddress;
        }
    }
#endif
}

size_t CollectFrames(TCollectedFrame* frames, void* data) {
#if defined(_linux_) && defined(_x86_64_)
    DLLCount = 0;
    dl_iterate_phdr(DlIterCallback, &DLLs);
#endif
    std::stable_sort(DLLs, DLLs + DLLCount, Comp);
    size_t cnt = CollectBacktrace(Stack, Limit, data);
    return CollectFrames(frames, Stack, cnt);
}

size_t CollectFrames(TCollectedFrame* frames, void** stack, size_t cnt) {
    for (size_t i = 0; i < cnt; ++i) {
        new (frames + i) TCollectedFrame(reinterpret_cast<uintptr_t>(stack[i]));
    }
    return cnt;
}
} // namespace NYql::NBacktrace