// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Collections.Generic;
using System.Linq;
using Microsoft.Extensions.Diagnostics.Metrics.Testing;
using TestClasses;
using Xunit;
 
namespace Microsoft.Gen.Metrics.Test;
 
public partial class MetricTests
{
    [Fact]
    public void CounterWithDescription_WorkCorrectly()
    {
        using var collector = new MetricCollector<long>(_meter, nameof(CounterWithDescription));
 
        CounterWithDescription counter = MetricsWithDescription.CreateCounterWithDescription(_meter);
        counter.Add(100L);
 
        var measurement = Assert.Single(collector.GetMeasurementSnapshot());
        Assert.Equal(100L, measurement.Value);
        Assert.Empty(measurement.Tags);
 
        Assert.NotNull(collector.Instrument);
        Assert.Equal("Number of requests processed.", collector.Instrument.Description);
        Assert.Null(collector.Instrument.Unit);
    }
 
    [Fact]
    public void CounterWithUnitAndDescription_WorkCorrectly()
    {
        using var collector = new MetricCollector<long>(_meter, nameof(CounterWithUnitAndDescription));
 
        CounterWithUnitAndDescription counter = MetricsWithDescription.CreateCounterWithUnitAndDescription(_meter);
        counter.Add(12345L, "dim1Value", "dim2Value");
 
        var measurement = Assert.Single(collector.GetMeasurementSnapshot());
        Assert.Equal(12345L, measurement.Value);
        Assert.Equal(new (string, object?)[] { ("s1", "dim1Value"), ("s2", "dim2Value") },
            measurement.Tags.Select(x => (x.Key, x.Value)));
 
        Assert.NotNull(collector.Instrument);
        Assert.Equal("Number of requests processed, by dimension.", collector.Instrument.Description);
        Assert.Equal("{request}", collector.Instrument.Unit);
    }
 
    [Fact]
    public void CounterStrongTypeWithDescription_WorkCorrectly()
    {
        var dimensions = new Dimensions { Dim1 = "s1", Dim2 = "s2" };
 
        using var collector = new MetricCollector<long>(_meter, nameof(CounterStrongTypeWithDescription));
 
        CounterStrongTypeWithDescription counter = MetricsWithDescription.CreateCounterStrongTypeWithDescription(_meter);
        counter.Add(50L, dimensions);
 
        var measurement = Assert.Single(collector.GetMeasurementSnapshot());
        Assert.Equal(50L, measurement.Value);
        Assert.Equal(new (string, object?)[] { ("Dim1", "s1"), ("Dim2", "s2") },
            measurement.Tags.Select(x => (x.Key, x.Value)));
 
        Assert.NotNull(collector.Instrument);
        Assert.Equal("Strongly-typed counter.", collector.Instrument.Description);
        Assert.Null(collector.Instrument.Unit);
    }
 
    [Fact]
    public void GenericCounterWithDescription_WorkCorrectly()
    {
        using var collector = new MetricCollector<double>(_meter, nameof(GenericDoubleCounterWithDescription));
 
        GenericDoubleCounterWithDescription counter = MetricsWithDescription.CreateGenericDoubleCounterWithDescription(_meter);
        counter.Add(3.14);
 
        var measurement = Assert.Single(collector.GetMeasurementSnapshot());
        Assert.Equal(3.14, measurement.Value);
 
        Assert.NotNull(collector.Instrument);
        Assert.Equal("Generic counter.", collector.Instrument.Description);
    }
 
    [Fact]
    public void HistogramWithUnitAndDescription_WorkCorrectly()
    {
        using var collector = new MetricCollector<long>(_meter, nameof(HistogramWithUnitAndDescription));
 
        HistogramWithUnitAndDescription histogram = MetricsWithDescription.CreateHistogramWithUnitAndDescription(_meter);
        histogram.Record(50L);
 
        var measurement = Assert.Single(collector.GetMeasurementSnapshot());
        Assert.Equal(50L, measurement.Value);
 
        Assert.NotNull(collector.Instrument);
        Assert.Equal("Duration of the operation.", collector.Instrument.Description);
        Assert.Equal("ms", collector.Instrument.Unit);
    }
 
    [Fact]
    public void HistogramStrongTypeWithDescription_WorkCorrectly()
    {
        var dimensions = new Dimensions { Dim1 = "s1", Dim2 = "s2" };
 
        using var collector = new MetricCollector<long>(_meter, nameof(HistogramStrongTypeWithDescription));
 
        HistogramStrongTypeWithDescription histogram = MetricsWithDescription.CreateHistogramStrongTypeWithDescription(_meter);
        histogram.Record(50L, dimensions);
 
        var measurement = Assert.Single(collector.GetMeasurementSnapshot());
        Assert.Equal(50L, measurement.Value);
 
        Assert.NotNull(collector.Instrument);
        Assert.Equal("Strongly-typed histogram.", collector.Instrument.Description);
    }
 
    [Fact]
    public void GenericHistogramWithEscapedDescription_PreservesDescription()
    {
        using var collector = new MetricCollector<int>(_meter, nameof(GenericIntHistogramWithEscapedDescription));
 
        GenericIntHistogramWithEscapedDescription histogram = MetricsWithDescription.CreateGenericIntHistogramWithEscapedDescription(_meter);
        histogram.Record(3, "val1");
 
        var measurement = Assert.Single(collector.GetMeasurementSnapshot());
        Assert.Equal(3, measurement.Value);
        Assert.Equal(new KeyValuePair<string, object?>("s1", "val1"), Assert.Single(measurement.Tags));
 
        Assert.NotNull(collector.Instrument);
        Assert.Equal("Contains \"quotes\", a backslash \\, {braces}\tand a\nnew line.", collector.Instrument.Description);
    }
 
    [Fact]
    public void CounterWithEmptyDescription_DescriptionInInstrumentIsNull()
    {
        using var collector = new MetricCollector<long>(_meter, nameof(CounterWithEmptyDescription));
 
        CounterWithEmptyDescription counter = MetricsWithDescription.CreateCounterWithEmptyDescription(_meter);
        counter.Add(1L);
 
        Assert.Single(collector.GetMeasurementSnapshot());
        Assert.NotNull(collector.Instrument);
        Assert.Null(collector.Instrument.Description);
    }
 
    [Fact]
    public void CounterWithNoDescription_DescriptionInInstrumentIsNull()
    {
        using var collector = new MetricCollector<long>(_meter, nameof(Counter0D));
 
        Counter0D counter = CounterTestExtensions.CreateCounter0D(_meter);
        counter.Add(10L);
 
        Assert.Single(collector.GetMeasurementSnapshot());
        Assert.NotNull(collector.Instrument);
        Assert.Null(collector.Instrument.Description);
    }
}