#include "dali_comm.hpp"

#include "dali_define.hpp"
#include "log.hpp"

#include <chrono>
#include <cstdio>
#include <string>
#include <thread>

#ifdef ESP_PLATFORM
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#endif

namespace {

constexpr uint32_t kQueryTimeoutMs = 100;

std::string hexByte(uint8_t value) {
  char buffer[5]{};
  std::snprintf(buffer, sizeof(buffer), "0x%02X", static_cast<unsigned>(value));
  return buffer;
}

std::string formatBytes(const std::vector<uint8_t>& bytes) {
  if (bytes.empty()) return "[]";
  std::string out = "[";
  for (size_t i = 0; i < bytes.size(); ++i) {
    if (i > 0) out += ' ';
    out += hexByte(bytes[i]);
  }
  out += ']';
  return out;
}

std::vector<uint8_t> readQueryResponse(const DaliComm::ReadCallback& read_cb, uint32_t timeout_ms) {
  if (!read_cb) return {};

  const auto deadline = std::chrono::steady_clock::now() + std::chrono::milliseconds(timeout_ms);
  std::vector<uint8_t> collected;
  while (std::chrono::steady_clock::now() < deadline && collected.size() < 2) {
    const auto remaining =
        std::chrono::duration_cast<std::chrono::milliseconds>(deadline - std::chrono::steady_clock::now())
            .count();
    if (remaining <= 0) break;

    const auto chunk = read_cb(2 - collected.size(), static_cast<uint32_t>(remaining));
    if (chunk.empty()) break;

    const size_t needed = 2 - collected.size();
    const size_t take = std::min(needed, chunk.size());
    collected.insert(collected.end(), chunk.begin(), chunk.begin() + static_cast<std::ptrdiff_t>(take));

    // Non-prefixed one-byte replies are complete as soon as they arrive.
    if (collected.size() == 1 && collected[0] != 0xFF && collected[0] != 0xFE && collected[0] != 0xFD) {
      break;
    }
  }
  return collected;
}

DaliQueryResult parseQueryResponse(const std::vector<uint8_t>& resp, uint8_t addr) {
  DaliQueryResult result;
  result.raw = resp;
  if (resp.empty()) {
    result.status = DaliQueryStatus::timeout;
    return result;
  }

  // Gateway type 1 returns: 0xFF <data> on success; 0xFE 0x00 on no response;
  // 0xFD xx on invalid frame. COMPARE is special: collisions still mean a match.
  if (resp[0] == 0xFE) {
    result.status = DaliQueryStatus::noResponse;
    return result;
  }
  if (resp[0] == 0xFD) {
    if (addr == DALI_CMD_SPECIAL_COMPARE) {
      result.status = DaliQueryStatus::success;
      result.value = static_cast<uint8_t>(resp.size() >= 2 ? resp[1] : 0xFF);
      return result;
    }
    result.status = DaliQueryStatus::invalidFrame;
    return result;
  }
  if (resp.size() == 1) {
    result.status = DaliQueryStatus::success;
    result.value = resp[0];
    return result;
  }
  if (resp[0] == 0xFF && resp.size() >= 2) {
    result.status = DaliQueryStatus::success;
    result.value = resp[1];
    return result;
  }
  result.status = DaliQueryStatus::unknownFrame;
  return result;
}

void logQueryResult(uint8_t addr, uint8_t cmd, const DaliQueryResult& result) {
  std::string message = "dali:query addr=" + hexByte(addr) + " cmd=" + hexByte(cmd) +
                        " status=" + daliQueryStatusName(result.status);
  if (result.value.has_value()) {
    message += " value=" + hexByte(result.value.value());
  }
  message += " raw=" + formatBytes(result.raw);
  DaliLog::instance().debugLog(message);
}

}  // namespace

const char* daliQueryStatusName(DaliQueryStatus status) {
  switch (status) {
    case DaliQueryStatus::success:
      return "success";
    case DaliQueryStatus::noResponse:
      return "noResponse";
    case DaliQueryStatus::invalidFrame:
      return "invalidFrame";
    case DaliQueryStatus::unknownFrame:
      return "unknownFrame";
    case DaliQueryStatus::sendFailed:
      return "sendFailed";
    case DaliQueryStatus::transportUnavailable:
      return "transportUnavailable";
    case DaliQueryStatus::timeout:
      return "timeout";
  }
  return "unknown";
}

DaliComm::DaliComm(SendCallback send_cb,
                   ReadCallback read_cb,
                   TransactCallback transact_cb,
                   DelayCallback delay_cb)
    : send_(std::move(send_cb)),
      read_(std::move(read_cb)),
      transact_(std::move(transact_cb)),
      delay_(std::move(delay_cb)) {}

void DaliComm::setSendCallback(SendCallback cb) { send_ = std::move(cb); }

void DaliComm::setReadCallback(ReadCallback cb) { read_ = std::move(cb); }

void DaliComm::setTransactCallback(TransactCallback cb) { transact_ = std::move(cb); }

void DaliComm::setDelayCallback(DelayCallback cb) { delay_ = std::move(cb); }

std::vector<uint8_t> DaliComm::checksum(const std::vector<uint8_t>& data) {
  std::vector<uint8_t> out = data;
  uint32_t sum = 0;
  for (const auto b : out) {
    sum += b;
  }
  out.push_back(static_cast<uint8_t>(sum & 0xFF));
  return out;
}

bool DaliComm::write(const std::vector<uint8_t>& data) const { return writeFrame(data); }

std::vector<uint8_t> DaliComm::read(size_t len, uint32_t timeout_ms) const {
  if (!read_) return {};
  return read_(len, timeout_ms);
}

int DaliComm::checkGatewayType(int gateway) const {
  if (!transact_) return 0;

  const std::vector<uint8_t> usbProbe{0x01, 0x00, 0x00};
  const std::vector<uint8_t> legacyProbe{0x28, 0x01, static_cast<uint8_t>(gateway), 0x11, 0x00, 0x00,
                                         0xFF};
  const std::vector<uint8_t> newProbe{0x28, 0x01, static_cast<uint8_t>(gateway), 0x11, 0x00,
                                      0x00, 0x00, 0x00, 0x00, 0xFF};

  prepareForQuery();
  const auto usbResp = transact_(usbProbe.data(), usbProbe.size());
  if (!usbResp.empty() && usbResp[0] > 0) return 1;

  prepareForQuery();
  const auto legacyResp = transact_(legacyProbe.data(), legacyProbe.size());
  if (legacyResp.size() >= 2 && legacyResp[0] == gateway) return 2;

  prepareForQuery();
  const auto newResp = transact_(newProbe.data(), newProbe.size());
  if (newResp.size() >= 2 && newResp[0] == gateway) return 3;

  return 0;
}

void DaliComm::flush() const {
  if (!read_) return;
  for (int i = 0; i < 10; i++) {
    const auto data = read_(2, 100);
    if (data.empty()) break;
  }
}

bool DaliComm::resetBus() const {
  const std::vector<uint8_t> frame{0x00, 0x00, 0x00};
  if (!write(frame)) return false;
  sleepMs(100);
  if (!write(frame)) return false;
  sleepMs(100);
  return true;
}

bool DaliComm::sendRaw(uint8_t addr, uint8_t cmd) const { return sendCmd(addr, cmd); }

bool DaliComm::sendRawNew(uint8_t addr, uint8_t cmd, bool needVerify) const {
  if (!needVerify) return sendCmd(addr, cmd);
  return queryCmd(addr, cmd).has_value();
}

bool DaliComm::sendExtRaw(uint8_t addr, uint8_t cmd) const { return sendExtCmd(addr, cmd); }

bool DaliComm::sendExtRawNew(uint8_t addr, uint8_t cmd) const { return sendExtCmd(addr, cmd); }

std::optional<uint8_t> DaliComm::queryRaw(uint8_t addr, uint8_t cmd) const { return queryCmd(addr, cmd); }

std::optional<uint8_t> DaliComm::queryRawNew(uint8_t addr, uint8_t cmd) const {
  return queryCmd(addr, cmd);
}

DaliQueryResult DaliComm::queryRawResult(uint8_t addr, uint8_t cmd) const {
  return queryCmdResult(addr, cmd);
}

DaliQueryResult DaliComm::queryRawNewResult(uint8_t addr, uint8_t cmd) const {
  return queryCmdResult(addr, cmd);
}

bool DaliComm::send(int dec_addr, uint8_t cmd) const { return sendCmd(toCmdAddr(dec_addr), cmd); }

std::optional<uint8_t> DaliComm::query(int dec_addr, uint8_t cmd) const {
  return queryCmd(toCmdAddr(dec_addr), cmd);
}

bool DaliComm::getBusStatus() const { return checkGatewayType(0) > 0; }

uint8_t DaliComm::toCmdAddr(int dec_addr) { return static_cast<uint8_t>(dec_addr * 2 + 1); }

uint8_t DaliComm::toArcAddr(int dec_addr) { return static_cast<uint8_t>(dec_addr * 2); }

bool DaliComm::writeFrame(const std::vector<uint8_t>& frame) const {
  if (!send_) return false;
  return send_(frame.data(), frame.size());
}

void DaliComm::prepareForQuery() const {
  if (!read_) return;
  for (int i = 0; i < 8; ++i) {
    const auto data = read_(64, 1);
    if (data.empty()) {
      break;
    }
  }
}

void DaliComm::sleepMs(uint32_t ms) const {
  if (delay_) {
    delay_(ms);
    return;
  }
#ifdef ESP_PLATFORM
  vTaskDelay(pdMS_TO_TICKS(ms));
#else
  std::this_thread::sleep_for(std::chrono::milliseconds(ms));
#endif
}

bool DaliComm::sendCmd(uint8_t addr, uint8_t cmd) const {
  const std::vector<uint8_t> frame{0x10, addr, cmd};
  return writeFrame(frame);
}

// Send extended command frame (0x11). Gateway will send twice for 0x11, but we only need to send once.
bool DaliComm::sendExtCmd(uint8_t addr, uint8_t cmd) const {
  const std::vector<uint8_t> frame{0x11, addr, cmd};
  const bool ret = writeFrame(frame);
  sleepMs(100);
  return ret;
}

std::optional<uint8_t> DaliComm::queryCmd(uint8_t addr, uint8_t cmd) const {
  const auto result = queryCmdResult(addr, cmd);
  if (!result.hasValue()) return std::nullopt;
  return result.value;
}

DaliQueryResult DaliComm::queryCmdResult(uint8_t addr, uint8_t cmd) const {
  const std::vector<uint8_t> frame{0x12, addr, cmd};
  DaliQueryResult result;
  if (send_ && read_) {
    prepareForQuery();
    if (!writeFrame(frame)) {
      result.status = DaliQueryStatus::sendFailed;
      logQueryResult(addr, cmd, result);
      return result;
    }
    result = parseQueryResponse(readQueryResponse(read_, kQueryTimeoutMs), addr);
    logQueryResult(addr, cmd, result);
    return result;
  }

  prepareForQuery();
  if (!transact_) {
    result.status = DaliQueryStatus::transportUnavailable;
    logQueryResult(addr, cmd, result);
    return result;
  }
  result = parseQueryResponse(transact_(frame.data(), frame.size()), addr);
  logQueryResult(addr, cmd, result);
  return result;
}