1 /**

     2  * Relational pipes

     3  * Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)

     4  *

     5  * This program is free software: you can redistribute it and/or modify

     6  * it under the terms of the GNU General Public License as published by

     7  * the Free Software Foundation, version 3 of the License.

     8  *

     9  * This program is distributed in the hope that it will be useful,

    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

    12  * GNU General Public License for more details.

    13  *

    14  * You should have received a copy of the GNU General Public License

    15  * along with this program. If not, see <http://www.gnu.org/licenses/>.

    16  */

    17 #pragma once

    18 

    19 #include <vector>

    20 #include <filesystem>

    21 

    22 #include <relpipe/writer/typedefs.h>

    23 #include <relpipe/writer/AttributeMetadata.h>

    24 #include <relpipe/writer/RelationalWriter.h>

    25 #include <regex>

    26 

    27 #include "RequestedField.h"

    28 #include "SystemProcess.h"

    29 #include "AttributeFinder.h"

    30 

    31 namespace relpipe {

    32 namespace in {

    33 namespace filesystem {

    34 

    35 namespace fs = std::filesystem;

    36 using namespace relpipe::writer;

    37 

    38 class ScriptAttributeFinder : public AttributeFinder {

    39 private:

    40 	std::wstring_convert<codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.

    41 

    42 	std::string getScriptCommand(const RequestedField& field) {

    43 		return SCRIPT_PREFIX + convertor.to_bytes(field.name);

    44 	}

    45 

    46 	std::vector<std::string> toEnvironmentalVariables(const std::vector<string_t>& vector) {

    47 		std::vector<std::string> result;

    48 		for (int i = 0; i < vector.size();) {

    49 			string_t name = vector[i++];

    50 			string_t value = vector[i++];

    51 			if (name.rfind(L"env:" == 0)) {

    52 				result.push_back(convertor.to_bytes(name.substr(4)));

    53 				result.push_back(convertor.to_bytes(value));

    54 			}

    55 		}

    56 		return result;

    57 	}

    58 

    59 	TypeId getAttributeType(const RequestedField& field, const string_t& alias) {

    60 		// TODO: put latest supported version in the environmental variable

    61 		// TODO: put alias in the environmental variable

    62 		SystemProcess process({getScriptCommand(field)}, toEnvironmentalVariables(field.options));

    63 		std::string output = process.execute();

    64 		std::regex pattern("(.*)\\n(.*)\\n");

    65 		std::smatch match;

    66 		std::regex_match(output, match, pattern);

    67 		if (match.ready() && match[1] == "1") {

    68 			// TODO: move to a common library

    69 			if (match[2] == "boolean") return TypeId::BOOLEAN;

    70 			if (match[2] == "integer") return TypeId::INTEGER;

    71 			if (match[2] == "string") return TypeId::STRING;

    72 			throw RelpipeWriterException(L"Unsupported script data type – field: „" + field.name + L"“ type: „" + convertor.from_bytes(match[2]) + L"“");

    73 		} else {

    74 			throw RelpipeWriterException(L"Unsupported script version – field: „" + field.name + L"“ output: „" + convertor.from_bytes(output) + L"“");

    75 		}

    76 

    77 	}

    78 

    79 	string_t getScriptOutput(const fs::path& file, const RequestedField& field, const string_t& alias) {

    80 		try {

    81 			// TODO: put alias in the environmental variable

    82 			SystemProcess process({getScriptCommand(field), currentFileRaw}, toEnvironmentalVariables(field.options));

    83 			return convertor.from_bytes(process.execute());

    84 		} catch (relpipe::cli::RelpipeCLIException& e) {

    85 			// TODO: print warnings?

    86 			// TODO: do not fork/exec if the file is not readable

    87 			return L"";

    88 		}

    89 	}

    90 protected:

    91 

    92 	virtual void writeFieldOfExistingFile(RelationalWriter* writer, const RequestedField& field) override {

    93 		// TODO: paralelization?

    94 		if (field.group == RequestedField::GROUP_SCRIPT) {

    95 			for (string_t alias : field.getAliases()) {

    96 				writer->writeAttribute(getScriptOutput(currentFile, field, alias));

    97 			}

    98 		}

    99 	}

   100 

   101 public:

   102 

   103 	static const std::string SCRIPT_PREFIX;

   104 

   105 	virtual vector<AttributeMetadata> toMetadata(const RequestedField& field) override {

   106 		if (field.group == RequestedField::GROUP_SCRIPT) {

   107 			vector<AttributeMetadata> metadata;

   108 			for (string_t alias : field.getAliases()) metadata.push_back(AttributeMetadata{alias, getAttributeType(field, alias)});

   109 			return metadata;

   110 		} else {

   111 			return {};

   112 		}

   113 	}

   114 

   115 	virtual ~ScriptAttributeFinder() override {

   116 	}

   117 };

   118 

   119 const std::string ScriptAttributeFinder::SCRIPT_PREFIX = "__relpipe_in_filesystem_script_";

   120 

   121 }

   122 }

   123 }