mock_file_source.cpp

// Copyright 2026 Davide Faconti
// SPDX-License-Identifier: Apache-2.0

#include <pj_base/sdk/data_source_patterns.hpp>
#include <string>

namespace {

class MockFileSource : public PJ::FileSourceBase {
 public:
  uint64_t extraCapabilities() const override {
    return PJ::kCapabilityDirectIngest;
  }

  std::string saveConfig() const override {
    return config_;
  }

  PJ::Status loadConfig(std::string_view config_json) override {
    config_ = std::string(config_json);
    return PJ::okStatus();
  }

  PJ::Status importData() override {
    // Test-only failure injection: the host creates the dataset in the live engine
    // before importData() runs, so returning an error here lets tests exercise the
    // host's abandoned-dataset cleanup. config_ is opaque to this example (no JSON
    // dependency), so the marker is matched by substring — safe because only tests
    // set this config.
    if (config_.find("fail_start") != std::string::npos) {
      return PJ::unexpected("mock_file_source: configured start failure");
    }

    if (!runtimeHost().progressStart("Importing", 3, true)) {
      return PJ::unexpected("progress unavailable");
    }

    auto topic = writeHost().ensureTopic("mock/file_data");
    if (!topic) {
      return PJ::unexpected(topic.error());
    }

    for (uint64_t i = 1; i <= 3; ++i) {
      if (runtimeHost().isStopRequested()) {
        return PJ::unexpected("import cancelled");
      }

      auto status = writeHost().appendRecord(
          *topic, PJ::Timestamp{static_cast<int64_t>(i * 100)},
          {{.name = "value", .value = static_cast<double>(i) * 10.0}});
      if (!status) {
        return PJ::unexpected(status.error());
      }

      if (!runtimeHost().progressUpdate(i)) {
        return PJ::unexpected("import cancelled via progress");
      }
    }

    runtimeHost().reportMessage(PJ::DataSourceMessageLevel::kInfo, "imported 3 records");
    return PJ::okStatus();
  }

 private:
  std::string config_ = "{}";
};

}  // namespace

PJ_DATA_SOURCE_PLUGIN(
    MockFileSource, R"({"id":"mock-file-source","name":"Mock File Source","version":"1.0.0",)"
                    R"("description":"Test FileSourceBase lifecycle and progress",)"
                    R"("file_extensions":[".mock"]})")