/* Hook-releated functions.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#include <villas/hook.hpp>
#include <villas/hook_list.hpp>
#include <villas/list.hpp>
#include <villas/plugin.hpp>
#include <villas/sample.hpp>
#include <villas/utils.hpp>

using namespace villas;
using namespace villas::node;

void HookList::parse(json_t *json, int mask, Path *o, Node *n) {
  if (!json_is_array(json))
    throw ConfigError(json, "node-config-hook",
                      "Hooks must be configured as a list of hook objects");

  size_t i;
  json_t *json_hook;
  json_array_foreach(json, i, json_hook) {
    int ret;
    const char *type;
    Hook::Ptr h;
    json_error_t err;
    json_t *json_config;

    switch (json_typeof(json_hook)) {
    case JSON_STRING:
      type = json_string_value(json_hook);
      json_config = json_object();
      break;

    case JSON_OBJECT:
      ret = json_unpack_ex(json_hook, &err, 0, "{ s: s }", "type", &type);
      if (ret)
        throw ConfigError(json_hook, err, "node-config-hook",
                          "Failed to parse hook");
      json_config = json_hook;
      break;

    default:
      throw ConfigError(json_hook, "node-config-hook",
                        "Hook must be configured by simple string or object");
    }

    auto hf = plugin::registry->lookup<HookFactory>(type);
    if (!hf)
      throw ConfigError(json_hook, "node-config-hook", "Unknown hook type '{}'",
                        type);

    if (!(hf->getFlags() & mask))
      throw ConfigError(json_hook, "node-config-hook",
                        "Hook '{}' not allowed here", type);

    h = hf->make(o, n);
    h->parse(json_config);

    push_back(h);
  }
}

void HookList::check() {
  for (auto h : *this)
    h->check();
}

void HookList::prepare(SignalList::Ptr signals, int m, Path *p, Node *n) {
  if (!m)
    goto skip_add;

  // Add internal hooks if they are not already in the list
  for (auto f : plugin::registry->lookup<HookFactory>()) {
    if ((f->getFlags() & m) == m) {
      auto h = f->make(p, n);
      push_back(h);
    }
  }

skip_add:
  // Remove filters which are not enabled
  remove_if([](Hook::Ptr h) { return !h->isEnabled(); });

  // We sort the hooks according to their priority
  sort([](const value_type &a, const value_type b) {
    return a->getPriority() < b->getPriority();
  });

  unsigned i = 0;
  auto sigs = signals;
  for (auto h : *this) {
    h->prepare(sigs);

    sigs = h->getSignals();

    auto logger = h->getLogger();
    logger->debug("Signal list after hook #{}:", i++);
    if (logger->level() <= spdlog::level::debug)
      sigs->dump(logger);
  }
}

int HookList::process(struct Sample *smps[], unsigned cnt) {
  unsigned current, processed = 0;

  if (size() == 0)
    return cnt;

  for (current = 0; current < cnt; current++) {
    struct Sample *smp = smps[current];

    for (auto h : *this) {
      auto ret = h->process(smp);
      smp->signals = h->getSignals();
      switch (ret) {
      case Hook::Reason::ERROR:
        return -1;

      case Hook::Reason::OK:
        continue;

      case Hook::Reason::SKIP_SAMPLE:
        goto skip;

      case Hook::Reason::STOP_PROCESSING:
        goto stop;
      }
    }

  stop:
    SWAP(smps[processed], smps[current]);
    processed++;
  skip : {}
  }

  return processed;
}

void HookList::periodic() {
  for (auto h : *this)
    h->periodic();
}

void HookList::start() {
  for (auto h : *this)
    h->start();
}

void HookList::stop() {
  for (auto h : *this)
    h->stop();
}

SignalList::Ptr HookList::getSignals() const {
  auto h = back();
  if (!h)
    return nullptr;

  return h->getSignals();
}

unsigned HookList::getSignalsMaxCount() const {
  unsigned max_cnt = 0;

  for (auto h : *this) {
    unsigned sigs_cnt = h->getSignals()->size();

    if (sigs_cnt > max_cnt)
      max_cnt = sigs_cnt;
  }

  return max_cnt;
}

json_t *HookList::toJson() const {
  json_t *json_hooks = json_array();

  for (auto h : *this)
    json_array_append(json_hooks, h->getConfig());

  return json_hooks;
}

void HookList::dump(Logger logger, std::string subject) const {
  logger->debug("Hooks of {}:", subject);

  unsigned i = 0;
  for (auto h : *this)
    logger->debug("      {}: {}", i++, h->getFactory()->getName());
}
