#include "exception.h"
#include <cstring>
#include <memory>
#include <functional>
namespace panda {
using FrameProducers = std::vector<BacktraceProducer>;
RawTraceProducer  get_default_raw_producer() noexcept;
BacktraceProducer get_default_bt_producer () noexcept;
static RawTraceProducer rawtrace_producer = get_default_raw_producer();
static FrameProducers   frame_producers { get_default_bt_producer() };
BacktraceInfo::~BacktraceInfo() {};
Stackframe::~Stackframe() {};
string BacktraceInfo::to_string() const noexcept {
    string r;
    for(auto& frame: frames) {
        // mimic gdb-style
        r += "0x";
        r += string::from_number(frame->address, 16);
        if (frame->name) {
            r += " in ";
            r += frame->name;
        }
        if (frame->file) {
            r += " at ";
            r += frame->file;
            if (frame->line_no) {
                r += ":";
                r += string::from_number(frame->line_no, 10);
            }
        } else if(frame->library) {
            r += " from ";
            r += frame->library;
        }
        r += "\n";
    }
    return r;
}
void Backtrace::install_producer(const BacktraceProducer &producer_) noexcept {
    frame_producers.push_back(producer_);
}
void Backtrace::uninstall_producer(const BacktraceProducer& producer) noexcept {
    for(auto it = frame_producers.begin(); it != frame_producers.end(); ++it) {
        if (*it == producer) {
            frame_producers.erase(it);
            return;
        }
    }
    assert(0 && "attempt to remove non-exiting backtrace producer");
}
Backtrace::Backtrace (const Backtrace& other) noexcept : buffer(other.buffer) {}
         
Backtrace::Backtrace () noexcept {
    void* temp_buff[max_depth];
    auto depth = rawtrace_producer(temp_buff, max_depth);
    if (depth > 0) {
        buffer.resize(depth);
        std::memcpy(buffer.data(), temp_buff, sizeof(void*) * depth);
    }
}
Backtrace::~Backtrace() {}
iptr<BacktraceInfo> Backtrace::get_backtrace_info() const noexcept {
    StackFrames frames;
    std::vector<BacktraceBackendSP> backends;
    for(auto it = frame_producers.rbegin(); it != frame_producers.rend(); ++it) {
        auto backend = (*it)(*this);
        if (backend) backends.emplace_back(std::move(backend));
    }
    for (size_t i = 0; i < buffer.size(); ++i) {
        bool done = false;
        for (size_t j = 0; j < backends.size() && !done; ++j) {
            done = backends[j]->produce_frame(frames, i);
        }
    }
    return iptr<BacktraceInfo>(new BacktraceInfo(std::move(frames)));
}
string Backtrace::dump_trace() noexcept {
    return Backtrace().get_backtrace_info()->to_string();
}
exception::exception () noexcept {}
exception::exception (const string& whats) noexcept : _whats(whats) {}
exception::exception (const exception& oth) noexcept : Backtrace(oth), _whats(oth._whats) {}
exception& exception::operator= (const exception& oth) noexcept {
    _whats = oth._whats;
    Backtrace::operator=(oth);
    return *this;
}
const char* exception::what () const noexcept {
    _whats = whats();
    return _whats.c_str();
}
string exception::whats () const noexcept {
    return _whats;
}
}