#include "server.hh"

#include "bt.hh"
#include "cfg.hh"
#include "config.h"
#include "http.hh"
#include "json.hh"
#include "logger.hh"
#include "looper.hh"
#include "signals.hh"
#include "uri.hh"
#include "websocket.hh"

#include <cstdint>
#include <format>
#include <functional>
#include <memory>
#include <optional>
#include <string>
#include <string_view>

namespace server {

namespace {

const std::string_view kSignalUpdateAdapter("controller/update");
const std::string kSignalUpdateDevicePrefix("device/update/");

std::optional<bool> match_bool(std::string_view str) {
  if (str == "true")
    return true;
  if (str == "false")
    return false;
  return std::nullopt;
}

class HttpServerDelegate : public http::Server::Delegate {
 public:
  HttpServerDelegate(Api& api, Signaler& signaler)
      : api_(api),
        signaler_(signaler),
        json_writer_(json::writer(json_tmp_)),
        json_mimetype_(http::MimeType::create("application", "json")) {}

  std::unique_ptr<http::Response> handle(
      http::Request const& request) override {
    if (request.path().starts_with("/api/v1/")) {
      auto path = request.path().substr(8);
      if (path == "status") {
        if (request.method() != "GET") {
          return http::Response::status(http::StatusCode::kMethodNotAllowed);
        }

        return status_ok();
      }

      if (path == "controller") {
        if (request.method() != "GET") {
          return http::Response::status(http::StatusCode::kMethodNotAllowed);
        }

        auto const* adapter = api_.adapter();
        json_writer_->clear();
        write_adapter(adapter);

        return http::Response::content(json_tmp_, *json_mimetype_);
      }

      if (path == "controller/discoverable") {
        if (request.method() != "POST") {
          return http::Response::status(http::StatusCode::kMethodNotAllowed);
        }
        std::optional<bool> value = match_bool(request.body());
        auto* adapter = api_.adapter();
        if (adapter && value.has_value()) {
          adapter->set_discoverable(value.value());
          return status_ok();
        }
        return status_error("Bad state");
      }

      if (path.starts_with("device/")) {
        if (request.method() != "GET") {
          return http::Response::status(http::StatusCode::kMethodNotAllowed);
        }

        std::string tmp;
        auto address = uri::decode(path.substr(7), tmp);
        auto const* adapter = api_.adapter();
        if (adapter) {
          for (auto* device : adapter->devices()) {
            if (device->address() == address) {
              json_writer_->clear();
              write_device(*device);
              return http::Response::content(json_tmp_, *json_mimetype_);
            }
          }
        }
        return http::Response::status(http::StatusCode::kNotFound);
      }

      if (path == "events") {
        if (request.method() != "GET") {
          return http::Response::status(http::StatusCode::kMethodNotAllowed);
        }

        auto resp = signaler_.handle(request);
        if (resp)
          return resp;
        return http::Response::status(http::StatusCode::kBadRequest);
      }
    }

    return http::Response::status(http::StatusCode::kNotFound);
  }

 private:
  std::unique_ptr<http::Response> status_ok() {
    json_writer_->clear();
    json_writer_->start_object();
    json_writer_->key("status");
    json_writer_->value("OK");
    json_writer_->end_object();
    return http::Response::content(json_tmp_, *json_mimetype_);
  }

  std::unique_ptr<http::Response> status_error(std::string_view message) {
    json_writer_->clear();
    json_writer_->start_object();
    json_writer_->key("status");
    json_writer_->value("error");
    json_writer_->key("message");
    json_writer_->value(message);
    json_writer_->end_object();
    return http::Response::content(json_tmp_, *json_mimetype_);
  }

  void write_adapter(bt::Adapter const* adapter) {
    json_writer_->start_object();
    json_writer_->key("name");
    json_writer_->value(adapter ? adapter->name() : "unknown");
    json_writer_->key("pairable");
    json_writer_->value(adapter ? adapter->pairable() : false);
    json_writer_->key("discoverable");
    json_writer_->value(adapter ? adapter->discoverable() : false);
    json_writer_->key("discoverable_timeout_seconds");
    json_writer_->value(adapter ? adapter->discoverable_timeout_seconds() : 0);
    json_writer_->key("pairing");
    json_writer_->value(adapter ? adapter->pairing() : false);

    json_writer_->key("devices");
    json_writer_->start_array();

    if (adapter) {
      for (auto* device : adapter->devices()) {
        write_device(*device);
      }
    }

    json_writer_->end_array();
    json_writer_->end_object();
  }

  void write_device(bt::Device const& device) {
    json_writer_->start_object();
    json_writer_->key("name");
    json_writer_->value(device.name());
    json_writer_->key("address");
    json_writer_->value(device.address());
    json_writer_->key("paired");
    json_writer_->value(device.paired());
    json_writer_->key("connected");
    json_writer_->value(device.connected());

    json_writer_->key("playing");
    if (auto* player = device.player()) {
      json_writer_->start_object();
      json_writer_->key("status");
      switch (player->status()) {
        case bt::Player::Status::kPlaying:
        case bt::Player::Status::kForwardSeek:
        case bt::Player::Status::kReverseSeek:
          json_writer_->value("playing");
          break;
        case bt::Player::Status::kStopped:
          json_writer_->value("stopped");
          break;
        case bt::Player::Status::kPaused:
          json_writer_->value("paused");
          break;
        case bt::Player::Status::kError:
          json_writer_->value("error");
          break;
      }
      json_writer_->key("title");
      json_writer_->value(player->track_title());
      json_writer_->key("album");
      json_writer_->value(player->track_album());
      json_writer_->key("artist");
      json_writer_->value(player->track_artist());
      json_writer_->end_object();
    } else {
      json_writer_->value(nullptr);
    }

    json_writer_->end_object();
  }

  Api& api_;
  Signaler& signaler_;
  std::unique_ptr<json::Writer> json_writer_;
  std::string json_tmp_;
  std::unique_ptr<http::MimeType> json_mimetype_;
};

class BluetoothManagerDelegate : public Api {
 public:
  BluetoothManagerDelegate(logger::Logger& logger, Signaler& signaler)
      : logger_(logger), signaler_(signaler) {}

  [[nodiscard]]
  bt::Adapter* adapter() const override {
    return adapter_;
  }

  void new_adapter(bt::Adapter* adapter) override {
    adapter_ = adapter;

    signaler_.send(kSignalUpdateAdapter);

    if (adapter) {
      logger_.info(std::format("New adapter: {} [{}]", adapter->name(),
                               adapter->address()));

      // Assuming pairable doesn't have a timeout - make it so.
      if (adapter_->pairable_timeout_seconds() > 0) {
        adapter_->set_pairable_timeout_seconds(0);
      }

      // Assuming discoverable has one
      if (adapter_->discoverable_timeout_seconds() == 0) {
        adapter_->set_discoverable_timeout_seconds(180);
      }
    } else {
      logger_.info("No adapter");
    }
  }

  void updated_adapter(bt::Adapter& adapter) override {
    if (adapter_ == &adapter)
      signaler_.send(kSignalUpdateAdapter);
  }

  void added_device(bt::Device& device) override {
    logger_.info(
        std::format("New device: {} [{}]", device.name(), device.address()));

    if (adapter_)
      signaler_.send(kSignalUpdateAdapter);
  }

  void removed_device(std::string const& address) override {
    logger_.info(std::format("Remove device: [{}]", address));

    if (adapter_)
      signaler_.send(kSignalUpdateAdapter);
  }

  void added_player(bt::Device& device, bt::Player& /* player */) override {
    logger_.info(std::format("New player for {}", device.name()));

    if (adapter_)
      signaler_.send(kSignalUpdateDevicePrefix + device.address());
  }

  void removed_player(bt::Device& device) override {
    logger_.info(std::format("Remove player for {}", device.name()));

    if (adapter_)
      signaler_.send(kSignalUpdateDevicePrefix + device.address());
  }

  void updated_player(bt::Device& device, bt::Player& /* player */) override {
    if (adapter_)
      signaler_.send(kSignalUpdateDevicePrefix + device.address());
  }

  void agent_request_pincode(
      bt::Device& device,
      std::function<void(std::optional<std::string>)> callback) override {
    logger_.dbg(std::format("Device request pincode: {}", device.name()));
    callback(std::nullopt);
  }

  void agent_display_pincode(bt::Device& device,
                             std::string const& pincode) override {
    logger_.dbg(std::format("Device pincode: {} {}", device.name(), pincode));
  }

  void agent_request_passkey(
      bt::Device& device,
      std::function<void(std::optional<uint32_t>)> callback) override {
    logger_.dbg(std::format("Device request passkey: {}", device.name()));
    callback(std::nullopt);
  }

  void agent_display_passkey(bt::Device& device, uint32_t passkey,
                             uint16_t /* entered */) override {
    logger_.dbg(std::format("Device passkey: {} {}", device.name(), passkey));
  }

  void agent_request_confirmation(bt::Device& device, uint32_t passkey,
                                  std::function<void(bool)> callback) override {
    logger_.dbg(std::format("Device request confirmation: {} {}", device.name(),
                            passkey));
    // Confirm all
    callback(true);
  }

  void agent_request_authorization(
      bt::Device& device, std::function<void(bool)> callback) override {
    logger_.dbg(std::format("Device request authorization: {}", device.name()));
    callback(false);
  }

  void agent_authorize_service(bt::Device& device, std::string const& uuid,
                               std::function<void(bool)> callback) override {
    if (uuid == "0000110d-0000-1000-8000-00805f9b34fb") {
      // Advanced Audio Distribution Profile
      callback(true);
      return;
    }
    if (uuid == "0000111e-0000-1000-8000-00805f9b34fb") {
      // Hands-Free Service Class and Profile
      // Not interrested.
      callback(false);
      return;
    }

    logger_.dbg(std::format("Device request authorize unknown service: {} {}",
                            device.name(), uuid));

    // Do not authorize unknown services.
    callback(false);
  }

  void agent_cancel() override {}

 private:
  logger::Logger& logger_;
  Signaler& signaler_;
  bt::Adapter* adapter_{nullptr};
};

class SignalerImpl : public Signaler, ws::Server::Delegate {
 public:
  SignalerImpl(logger::Logger& logger, cfg::Config const& cfg,
               looper::Looper& looper)
      : server_(ws::create_server(logger, cfg, looper, *this)) {}

  void send(std::string_view signal) override {
    server_->send_text_to_all(signal);
  }

  std::unique_ptr<http::Response> handle(
      http::Request const& request) override {
    return server_->handle(request);
  }

  std::unique_ptr<ws::Message> handle(ws::Message const& /* msg */) override {
    // Ignore anything sent by clients
    return nullptr;
  }

 private:
  std::unique_ptr<ws::Server> server_;
};

}  // namespace

std::unique_ptr<Signaler> create_signaler(logger::Logger& logger,
                                          cfg::Config const& cfg,
                                          looper::Looper& looper) {
  return std::make_unique<SignalerImpl>(logger, cfg, looper);
}

std::unique_ptr<Api> create_bt_delegate(logger::Logger& logger,
                                        Signaler& signaler) {
  return std::make_unique<BluetoothManagerDelegate>(logger, signaler);
}

std::unique_ptr<http::Server::Delegate> create_http_delegate(
    Api& api, Signaler& signaler) {
  return std::make_unique<HttpServerDelegate>(api, signaler);
}

}  // namespace server