// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.

#include <vespa/metrics/metrics.h>
#include <vespa/vespalib/gtest/gtest.h>
#include <vespa/vespalib/objects/floatingpointtype.h>

namespace metrics {

namespace {
struct TestMetricVisitor : public MetricVisitor {
    std::ostringstream ost;
    uint32_t setsToVisit;

    TestMetricVisitor(uint32_t setsToVisit_ = 100)
        : ost(), setsToVisit(setsToVisit_) {}

    bool visitMetricSet(const MetricSet& set, bool autoGenerated) override {
        ost << "[" << (autoGenerated ? "*" : "") << set.getName() << "]\n";
        if (setsToVisit > 0) {
            --setsToVisit;
            return true;
        }
        return false;
    }
    bool visitMetric(const Metric& m, bool autoGenerated) override {
        ost << (autoGenerated ? "*" : "") << m.getName() << "\n";
        return true;
    }
};
}

TEST(MetricSetTest, test_normal_usage)
{
    // Set up some metrics to test..
    MetricSet set("a", {{"foo"}}, "");
    DoubleValueMetric v1("c", {{"foo"}}, "", &set);
    LongAverageMetric v2("b", {}, "", &set);
    LongCountMetric v3("d", {{"bar"}}, "", &set);
    MetricSet set2("e", {{"bar"}}, "", &set);
    LongCountMetric v4("f", {{"foo"}}, "", &set2);

    // Give them some values
    v1.addValue(4.2);
    v2.addValue(8);
    v3.inc();
    v4.inc(3);

    // Check that we can register through registerMetric function too.
    LongCountMetric v5("g", {}, "");
    set.registerMetric(v5);
    v5.inc(3);
    v5.dec();

    // Check that getMetric works, and doesn't return copy.
    LongAverageMetric* v2copy(
            dynamic_cast<LongAverageMetric*>(set.getMetric("b")));
    ASSERT_TRUE(v2copy != 0);
    v2copy->addValue(9);
    Metric* nonExistingCopy = set.getMetric("nonexisting");
    EXPECT_TRUE(nonExistingCopy == 0);
    nonExistingCopy = set.getMetric("non.existing");
    EXPECT_TRUE(nonExistingCopy == 0);

    // Check that paths are set
    MetricSet topSet("top", {}, "");
    topSet.registerMetric(set);
    EXPECT_EQ(vespalib::string("a"), set.getPath());
    EXPECT_EQ(vespalib::string("a.c"), v1.getPath());
    EXPECT_EQ(vespalib::string("a.b"), v2.getPath());
    EXPECT_EQ(vespalib::string("a.d"), v3.getPath());
    EXPECT_EQ(vespalib::string("a.e"), set2.getPath());
    EXPECT_EQ(vespalib::string("a.e.f"), v4.getPath());
    EXPECT_EQ(vespalib::string("a.g"), v5.getPath());
    EXPECT_EQ(vespalib::string("a.b"), v2copy->getPath());

    // Verify XML output. Should be in register order.
    std::string expected("'\n"
            "a:\n"
            "  c average=4.2 last=4.2 min=4.2 max=4.2 count=1 total=4.2\n"
            "  b average=8.5 last=9 min=8 max=9 count=2 total=17\n"
            "  d count=1\n"
            "  e:\n"
            "    f count=3\n"
            "  g count=2'"
    );
    EXPECT_EQ(expected, "'\n" + set.toString() + "'");

    // Verify that visiting works. That you get all metrics if you answer
    // true to all sets, and that you don't get members of sets you answer
    // false to get.
    {
        TestMetricVisitor visitor(2);
        set.visit(visitor);
        expected = "[a]\nc\nb\nd\n[e]\nf\ng\n";
        EXPECT_EQ("\n" + expected, "\n" + visitor.ost.str());
    }
    {
        TestMetricVisitor visitor(1);
        set.visit(visitor);
        expected = "[a]\nc\nb\nd\n[e]\ng\n";
        EXPECT_EQ("\n" + expected, "\n" + visitor.ost.str());
    }
    {
        TestMetricVisitor visitor(0);
        set.visit(visitor);
        expected = "[a]\n";
        EXPECT_EQ("\n" + expected, "\n" + visitor.ost.str());
    }
}

TEST(MetricSetTest, support_multiple_metrics_with_same_name_different_dimensions)
{
    MetricSet set("dimset", {{"foo", "bar"}}, "");
    DoubleValueMetric v1("stuff", {{"baz", "blarg"}}, "", &set);
    LongAverageMetric v2("stuff", {{"flarn", "yarn"}}, "", &set);

    EXPECT_EQ(size_t(2), set.getRegisteredMetrics().size());
}

TEST(MetricSetTest, unique_target_metrics_are_added_to_metric_set)
{
    MetricSet set1("a", {{"foo"}}, "");
    LongCountMetric v1("wow", {{"foo"}}, "", &set1);
    MetricSet set2("e", {{"bar"}}, "");
    LongCountMetric v2("doge", {{"foo"}}, "", &set2);

    // Have to actually assign a value to metrics or they won't be carried over.
    v1.inc();
    v2.inc();

    // 'doge' metric in set2 must be preserved even though it does not exist
    // in set1.
    std::vector<Metric::UP> ownerList;
    set1.addToSnapshot(set2, ownerList);

    EXPECT_TRUE(set2.getMetric("wow") != nullptr);
    EXPECT_TRUE(set2.getMetric("doge") != nullptr);
}

}