/***
    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: Stack.Unix.cpp
    Date: 2022-1-26
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "Stack.hpp"
#include "Stack.Unix.hpp"
#include <libunwind.h>
#include <dlfcn.h>

namespace Aurora::Debug
{
    static void TryComplete(StackTraceEntry &entry)
    {

    }

    static StackTrace DumpContext(unw_context_t *uc)
    {
        StackTrace ret;

        unw_cursor_t cursor;
        unw_word_t ip;

        ::unw_init_local(&cursor, uc);

        while (::unw_step(&cursor) > 0)
        {
            StackTraceEntry entry;

            ::unw_get_reg(&cursor, UNW_REG_IP, &ip);

            // module
            {
                unw_word_t off;
                char procName[512];

                if (unw_get_proc_name(&cursor, procName, AuArraySize(procName), &off) == 0)
                {
                    AuString str;
                    str =  AuString(procName, strlen(procName));
                    str += fmt::format("+0x{:x}", off);
                    entry.label = str;
                }
            }

            {
                Dl_info dlinfo;
                AuSInt originalIP {};
                AuUInt moduleAddress {};

                const char *dllPathName {};

                if (::dladdr((const void *)ip, &dlinfo))
                {
                    dllPathName   = dlinfo.dli_fname;
                    moduleAddress = (AuUInt)dlinfo.dli_fbase;
                    originalIP    = (AuUInt)ip - moduleAddress;
                }

                entry.address = ip;
                entry.relAddress = originalIP;

                if (dllPathName)
                {
                    entry.module = dllPathName;
                }
            }

            AuTryInsert(ret, entry);
        }

        return ret;
    }

    StackTrace DumpContextPlatform(ucontext_t &uc)
    {
        // VALID:
        // Linux: https://github.com/libunwind/libunwind/blob/3be832395426b72248969247a4a66e3c3623578d/include/libunwind-x86.h#L170

        // ???
        // MACOS: https://github.com/JuliaLang/libosxunwind/blob/master/include/libunwind.h#L57
        return DumpContext((unw_context_t *)&uc);
    }

    StackTrace PlatformWalkCallStack()
    {
        #if 0
        StackTrace ret;
        void *ips[1024];

        int count = ::backtrace(ips, AuArraySize(ips));

        auto messages = ::backtrace_symbols(ips, count);
        if (!messages)
        {
            return {};
        }

        for (int i = 0; i < count; i++)
        {
            StackTraceEntry entry;

            entry.address = AuUInt64(ips[i]);
            entry.label = AuUInt64(messages[i]);

            TryComplete(entry);

            AuTryInsert(ret, entry);
        }

        free(messages);

        return ret;
        #endif

        ::unw_context_t uc;
        ::unw_getcontext(&uc);

        return DumpContext(&uc);
    }
}