dpSpec.hpp

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/**
 * @file
 * @ingroup daq_dpm_libmerge
 * @copyright ESO - European Southern Observatory
 */
#ifndef DAQ_DPM_DP_SPEC_HPP
#define DAQ_DPM_DP_SPEC_HPP
#include <filesystem>
#include <optional>
#include <string>
#include <string_view>
#include <variant>
#include <vector>
 
#include <nlohmann/json.hpp>
 
#include <daq/fits/keyword.hpp>
 
namespace daq {
 
struct DpSpecError : std::invalid_argument {
    using std::invalid_argument::invalid_argument;
};
 
/**
 * Close representation of the JSON structure but with stronger types.
 */
struct DpSpec {
    struct Filter {
        std::vector<std::string> selection_patterns;
    };
    struct Transform {
        std::vector<std::string> selection_patterns;
        std::string regex;
        std::string format;
    };
    using KeywordRule = std::variant<Filter, Transform>;
    using KeywordRules = std::vector<KeywordRule>;
 
    struct SourceFitsKeywords {
        std::string source_name;
        fits::KeywordVector keywords;
        KeywordRules keyword_rules;
    };
    struct SourceFitsFile {
        std::string source_name;
        std::string origin;
        KeywordRules keyword_rules;
    };
    struct Target {
        std::string file_id;
        /**
         * Optioal user chosen file prefix to make it easier to identify the produced file.
         */
        std::string file_prefix;
        std::optional<SourceFitsFile> source;
    };
 
    using SourceTypes = std::variant<SourceFitsKeywords, SourceFitsFile>;
 
    std::string id;
    Target target;
    std::vector<SourceTypes> sources;
};
 
/**
 * Parse JSON to construct the DpSpec structure
 *
 * @param spec Data Product Specification to parse.
 * @throw DpSpecError if JSON structure is invalid. Exception may be nested.
 */
DpSpec ParseDpSpec(nlohmann::json const& spec);
 
/**
 * Describes parsed origin string into its components "host" and "path".
 */
struct Origin {
    /**
     * @returns `host:path` if host is not empty, otherwise just `path`
     */
    std::string RsyncPath() const;
    std::string host;
    std::filesystem::path path;
};
 
/**
 * Parse origin string from DpSpec into component parts.
 *
 * Origin string use the format `host:path`, e.g. `10.0.0.1:/path/to/file` with host being optional.
 */
Origin ParseSourceOrigin(std::string const& origin);
 
}  // namespace daq::dpm
 
#endif  // #ifndef DAQ_DPM_DP_SPEC_HPP