#include "drivenengine.hpp"


Channel::Channel(DrivenEngine *de, int chid, int port, const std::string &target) {
    driven_ = de;
    chid_ = chid;
    sb_in_.reset(new StreamBuffer);
    sb_out_.reset(new StreamBuffer);
    port_ = port;
    closed_ = false;
    target_ = target;
    assert(driven_->channels_[chid_] == nullptr);
    driven_->channels_[chid_] = this;
}

Channel::~Channel() {
    assert(driven_->channels_[chid_] == this);
    driven_->channels_.erase(chid_);
    if (driven_->recent_channel_ == this) {
        driven_->recent_channel_ = driven_->stdio_channel_.get();
    }
}

double DrivenEngine::get_clock() {
    return clock_;
}

std::unique_ptr<Channel> DrivenEngine::new_outgoing_channel(const std::string &target) {
    return std::unique_ptr<Channel>(new Channel(this, next_channel_id_++, 0, target));
}

std::unique_ptr<Channel> DrivenEngine::new_incoming_channel() {
    if (accepted_channels_.empty()) {
        return nullptr;
    } else {
        std::unique_ptr<Channel> result = std::move(accepted_channels_.back());
        accepted_channels_.pop_back();
        return std::move(result);
    }
}

Channel *DrivenEngine::get_stdio_channel() {
    return stdio_channel_.get();
}

util::LuaSourcePtr DrivenEngine::get_lua_source() {
    return std::move(lua_source_);
}

void DrivenEngine::rescan_lua_source() {
    rescan_lua_source_ = true;
}

void DrivenEngine::stop_driver() {
    stop_driver_ = true;
}

void DrivenEngine::drv_logmode_write(const std::string &filename, int64_t maxsize) {
    // NOT IMPLEMENTED YET, but it's okay as a stub.
}

void DrivenEngine::drv_logmode_replay(const std::string &filename) {
    // NOT IMPLEMENTED YET.
    assert(false);
}
    
void DrivenEngine::drv_logmode_none() {
    // NOT IMPLEMENTED YET, but it's okay as a stub.
}

Channel *DrivenEngine::get_chid(int chid) {
    // We cache the most recently used channel.
    if (recent_channel_->chid_ != chid) {
        auto iter = channels_.find(chid);
        assert(iter != channels_.end());
        recent_channel_ = iter->second;
    }
    return recent_channel_;
}

void DrivenEngine::drv_list_channels(std::vector<int> &channels) {
    channels.clear();
    for (const auto &p : channels_) {
        if (!p.second->closed_) {
            channels.push_back(p.first);
        }
    }
}

const std::string &DrivenEngine::drv_get_target(int chid) {
    return get_chid(chid)->target_;
}

void DrivenEngine::drv_peek_outgoing(int chid, int *nbytes, const char **bytes) {
    Channel *ch = get_chid(chid);
    *nbytes = ch->sb_out_->fill();
    *bytes = ch->sb_out_->data();
}

void DrivenEngine::drv_sent_outgoing(int chid, int nbytes) {
    get_chid(chid)->sb_out_->read_bytes(nbytes);
}

void DrivenEngine::drv_recv_incoming(int chid, int nbytes, char *bytes) {
    if (nbytes > 0) {
        get_chid(chid)->sb_in_->write_bytes(bytes, nbytes);
    }
}

void DrivenEngine::drv_notify_close(int chid) {
    get_chid(chid)->closed_ = true;
}

int DrivenEngine::drv_notify_accept(int port) {
    int chid = next_channel_id_++;
    accepted_channels_.emplace_back(new Channel(this, chid, port, ""));
    return chid;
}

void DrivenEngine::drv_set_clock(double t) {
    clock_ = t;
}

void DrivenEngine::drv_set_lua_source(util::LuaSourcePtr source) {
    lua_source_ = std::move(source);
    rescan_lua_source_ = false;
}

void DrivenEngine::drv_invoke_event_update() {
    event_update();
}

bool DrivenEngine::drv_get_rescan_lua_source() {
    return rescan_lua_source_;
}

bool DrivenEngine::drv_get_stop_driver() {
    return stop_driver_;
}

bool DrivenEngine::drv_step_logfile() {
    // NOT IMPLEMENTED
    assert(false);
    return false;
}

DrivenEngine::DrivenEngine() {
    next_channel_id_ = 1;
    stdio_channel_.reset(new Channel(this, 0, 0, ""));
    recent_channel_ = stdio_channel_.get();
    rescan_lua_source_ = true;
    clock_ = 0.0;
    stop_driver_ = false;
}

DrivenEngine::~DrivenEngine() {
    // Delete the channels that we own.
    stdio_channel_.reset();
    accepted_channels_.clear();
    // At this point, all channels should be gone.
    assert(channels_.empty());
}

static DrivenEngine *engine_;

void DrivenEngine::set(DrivenEngine *de) {
    engine_ = de;
}

DrivenEngine *DrivenEngine::get() {
    return engine_;
}