Handlers: implement import tags handler

src/tags_handlers/import_tags_handler.cc

@@ -1,27 +1,74 @@
+#include <regex>
 #include "tags_handlers/import_tags_handler.h"
 
 using namespace opustags;
 
 ImportTagsHandler::ImportTagsHandler(std::istream &input_stream)
-    : input_stream(input_stream)
+    : parsed(false), input_stream(input_stream)
 {
 }
 
-bool ImportTagsHandler::relevant(const int streamno)
+bool ImportTagsHandler::relevant(const int)
 {
-    return false;
+    return true;
 }
 
-void ImportTagsHandler::list(const int streamno, const Tags &)
+void ImportTagsHandler::list(const int, const Tags &)
 {
 }
 
-bool ImportTagsHandler::edit(const int streamno, Tags &)
+bool ImportTagsHandler::edit(const int streamno, Tags &tags)
 {
-    return false;
+    // the reason why we do it this way is because the tests indirectly create
+    // this handler with std::cin, and we do not want the constructor to block!
+    parse_input_stream_if_needed();
+
+    const auto old_tags = tags;
+    tags.clear();
+
+    if (tag_map.find(streamno) != tag_map.end())
+    {
+        const auto &source_tags = tag_map.at(streamno);
+        for (const auto &source_tag : source_tags.get_all())
+            tags.add(source_tag.key, source_tag.value);
+    }
+
+    return old_tags != tags;
 }
 
 bool ImportTagsHandler::done()
 {
-    return true;
+    return false;
+}
+
+void ImportTagsHandler::parse_input_stream_if_needed()
+{
+    if (parsed)
+        return;
+    parsed = true;
+
+    const std::regex whitespace_regex("^\\s*$");
+    const std::regex stream_header_regex(
+        "^\\s*\\[stream\\s+(\\d+)\\]\\s*$", std::regex_constants::icase);
+    const std::regex tag_regex(
+        "^\\s*([a-z0-9]+)\\s*=\\s*(.*?)\\s*$", std::regex_constants::icase);
+
+    int current_stream_number = 1;
+    std::string line;
+    while (std::getline(input_stream, line))
+    {
+        std::smatch match;
+        if (std::regex_match(line, match, stream_header_regex))
+        {
+            current_stream_number = std::atoi(match[1].str().c_str());
+        }
+        else if (std::regex_match(line, match, tag_regex))
+        {
+            tag_map[current_stream_number].add(match[1], match[2]);
+        }
+        else if (!std::regex_match(line, match, whitespace_regex))
+        {
+            throw std::runtime_error("Malformed input data near line " + line);
+        }
+    }
 }

src/tags_handlers/import_tags_handler.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <iostream>
+#include <map>
 #include "tags_handler.h"
 
 namespace opustags {
@@ -16,7 +17,11 @@ namespace opustags {
         bool done() override;
 
     private:
+        void parse_input_stream_if_needed();
+
+        bool parsed;
         std::istream &input_stream;
+        std::map<int, Tags> tag_map;
     };
 
 }

tests/tags_handlers/import_tags_handler_test.cc

@@ -0,0 +1,142 @@
+#include "tags_handlers/import_tags_handler.h"
+#include "catch.h"
+#include <sstream>
+
+using namespace opustags;
+
+TEST_CASE("import tags handler", "[tags_handlers]")
+{
+    SECTION("tags for streams not mentioned in import get emptied")
+    {
+        Tags tags = {{{"remove", "me"}}};
+        std::stringstream ss;
+        ImportTagsHandler handler(ss);
+        REQUIRE(handler.edit(1, tags));
+        REQUIRE(tags.get_all().empty());
+    }
+
+    SECTION("streams that do not exist in the input file are ignored")
+    {
+        // TODO: rather than ignoring, at least print a warning
+        // requires #6
+
+        Tags tags;
+        std::stringstream ss;
+        ss << "[Stream 5]\nkey = value\n";
+        ImportTagsHandler handler(ss);
+        REQUIRE(!handler.edit(1, tags));
+        REQUIRE(tags.get_all().empty());
+    }
+
+    SECTION("adding unique tags")
+    {
+        Tags tags;
+        std::stringstream ss;
+        ss << "[Stream 1]\nkey = value\nkey2 = value2\n";
+        ImportTagsHandler handler(ss);
+        REQUIRE(handler.edit(1, tags));
+        REQUIRE(tags.get_all().size() == 2);
+        REQUIRE(tags.get("key") == "value");
+        REQUIRE(tags.get("key2") == "value2");
+    }
+
+    SECTION("adding tags with the same key")
+    {
+        Tags tags;
+        std::stringstream ss;
+        ss << "[Stream 1]\nkey = value1\nkey = value2\n";
+        ImportTagsHandler handler(ss);
+        REQUIRE(handler.edit(1, tags));
+        REQUIRE(tags.get_all().size() == 2);
+        REQUIRE(tags.get_all().at(0).key == "key");
+        REQUIRE(tags.get_all().at(1).key == "key");
+        REQUIRE(tags.get_all().at(0).value == "value1");
+        REQUIRE(tags.get_all().at(1).value == "value2");
+    }
+
+    SECTION("overwriting existing tags")
+    {
+        Tags tags = {{{"remove", "me"}}};
+        std::stringstream ss;
+        ss << "[Stream 1]\nkey = value\nkey2 = value2\n";
+        ImportTagsHandler handler(ss);
+        REQUIRE(handler.edit(1, tags));
+        REQUIRE(tags.get_all().size() == 2);
+        REQUIRE(tags.get("key") == "value");
+        REQUIRE(tags.get("key2") == "value2");
+    }
+
+    SECTION("various whitespace issues are worked around")
+    {
+        Tags tags;
+        std::stringstream ss;
+        ss << " [StrEaM  1] \n\n  key = value  \nkey2=value2\n";
+        ImportTagsHandler handler(ss);
+        REQUIRE(handler.edit(1, tags));
+        REQUIRE(tags.get_all().size() == 2);
+        REQUIRE(tags.get("key") == "value");
+        REQUIRE(tags.get("key2") == "value2");
+    }
+
+    SECTION("not specifying stream assumes first stream")
+    {
+        Tags tags;
+        std::stringstream ss;
+        ss << "key=value";
+        ImportTagsHandler handler(ss);
+        REQUIRE(handler.edit(1, tags));
+        REQUIRE(tags.get_all().size() == 1);
+        REQUIRE(tags.get("key") == "value");
+    }
+
+    SECTION("multiple streams")
+    {
+        Tags tags1;
+        Tags tags2;
+        std::stringstream ss;
+        ss << "[stream 1]\nkey=value\n[stream 2]\nkey2=value2";
+        ImportTagsHandler handler(ss);
+        REQUIRE(handler.edit(1, tags1));
+        REQUIRE(handler.edit(2, tags2));
+        REQUIRE(tags1.get_all().size() == 1);
+        REQUIRE(tags2.get_all().size() == 1);
+        REQUIRE(tags1.get("key") == "value");
+        REQUIRE(tags2.get("key2") == "value2");
+    }
+
+    SECTION("sections listed twice are concatenated")
+    {
+        Tags tags;
+        std::stringstream ss;
+        ss << "[stream 1]\nkey=value\n"
+            "[stream 2]\nkey=irrelevant\n"
+            "[Stream 1]\nkey2=value2";
+        ImportTagsHandler handler(ss);
+        REQUIRE(handler.edit(1, tags));
+        REQUIRE(tags.get_all().size() == 2);
+        REQUIRE(tags.get("key") == "value");
+        REQUIRE(tags.get("key2") == "value2");
+    }
+
+    SECTION("weird input throws errors - malformed section headers")
+    {
+        Tags tags;
+        std::stringstream ss;
+        ss << "[stream huh]\n";
+        REQUIRE_THROWS({
+            ImportTagsHandler handler(ss);
+            handler.edit(1, tags);
+        });
+    }
+
+    SECTION("weird input throws errors - malformed lines")
+    {
+        Tags tags;
+        std::stringstream ss;
+        ss << "tag huh\n";
+        REQUIRE_THROWS({
+            ImportTagsHandler handler(ss);
+            handler.edit(1, tags);
+        });
+    }
+}