From 2431fdab21afe19b3729c06eab621f9df1db24c1 Mon Sep 17 00:00:00 2001
From: Sangdae Kim <sangdae.kim@protonmail.com>
Date: Wed, 17 Nov 2021 15:16:36 -0800
Subject: [PATCH 1/4] LocalDone

---
 Library/App.config                 |   6 ++
 Library/EQData.cs                  |  32 +++++++++
 Library/EQDataFrame.cs             | 103 +++++++++++++++++++++++++++++
 Library/Library.csproj             |  55 +++++++++++++++
 Library/Library.sln                |  25 +++++++
 Library/Program.cs                 |  22 ++++++
 Library/Properties/AssemblyInfo.cs |  36 ++++++++++
 7 files changed, 279 insertions(+)
 create mode 100644 Library/App.config
 create mode 100644 Library/EQData.cs
 create mode 100644 Library/EQDataFrame.cs
 create mode 100644 Library/Library.csproj
 create mode 100644 Library/Library.sln
 create mode 100644 Library/Program.cs
 create mode 100644 Library/Properties/AssemblyInfo.cs

diff --git a/Library/App.config b/Library/App.config
new file mode 100644
index 0000000..5754728
--- /dev/null
+++ b/Library/App.config
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<configuration>
+    <startup> 
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
+    </startup>
+</configuration>
\ No newline at end of file
diff --git a/Library/EQData.cs b/Library/EQData.cs
new file mode 100644
index 0000000..24ab0b7
--- /dev/null
+++ b/Library/EQData.cs
@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Library {
+    public class EQData {
+        // https://earthquake.usgs.gov/data/comcat/index.php
+        public DateTime EventTime { get; private set; }
+        public double Latitude { get; private set; }
+        public double Longitude { get; private set; }
+
+        public double Magnitude { get; private set; }
+        public string EventId { get; private set; }
+        public string Place { get; private set; }
+
+        public EQData(string timeStr,
+                       string latitudeStr,
+                       string longitudeStr,
+                       string magnitudeStr,
+                       string idStr,
+                       string placeStr) {
+            EventTime = DateTime.Parse(timeStr);
+            Latitude = double.Parse(latitudeStr);
+            Longitude = double.Parse(longitudeStr);
+            Magnitude = double.Parse(magnitudeStr);
+            EventId = idStr;
+            Place = placeStr;
+        }
+    }
+}
diff --git a/Library/EQDataFrame.cs b/Library/EQDataFrame.cs
new file mode 100644
index 0000000..1d3a755
--- /dev/null
+++ b/Library/EQDataFrame.cs
@@ -0,0 +1,103 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Library {
+    public class EQDataFrame {
+        bool isInitialized;
+        Dictionary<string, EQData> eqMap = new Dictionary<string, EQData>(); // <eqId, EQData>
+        Dictionary<DateTime, List<string>> eqIdsByEventDate = new Dictionary<DateTime, List<string>>(); // <event date, eqId[]>
+
+        // https://en.wikipedia.org/wiki/Haversine_formula
+        double CalcDistBetweenTwoLocationsInMiles(double latA, double longA,
+                                                    double latB, double longB) {
+            double latDiffHalf = (latB - latA) * 0.5;
+            double latSumHalf = (latB + latA) * 0.5;
+            double longDiffHalf = (longB - longA) * 0.5;
+            
+            double sinSqLatDiffHalf = Math.Sin(latDiffHalf) * Math.Sin(latDiffHalf);
+            double sinSqLatSumHalf = Math.Sin(latSumHalf) * Math.Sin(latSumHalf);
+            double sinSqLongDiffHalf = Math.Sin(longDiffHalf) * Math.Sin(longDiffHalf);
+
+            const double EarthRad = 3959.0;
+            double dist = 2.0 * EarthRad * Math.Asin(Math.Sqrt(sinSqLatDiffHalf + (1.0 - sinSqLatDiffHalf - sinSqLatSumHalf) * sinSqLongDiffHalf));
+            return dist;
+        }
+
+        // return null if error
+        public List<EQData> QueryEndpoint(double eq_lat, double eq_long, DateTime eq_start_date, DateTime eq_end_date) {
+            // check lat, long range
+
+            if (eq_end_date < eq_start_date)
+                return null; // error
+
+            List<EQData> ret = new List<EQData>();
+
+            DateTime searchDateStart = eq_start_date.Subtract(eq_start_date.TimeOfDay);
+            DateTime searchDateEnd = eq_end_date.Subtract(eq_end_date.TimeOfDay);
+
+            int durationInDays = (searchDateEnd - searchDateStart).Duration().Days + 1;
+            DateTime searchDate = searchDateStart;
+            for (int i = 0; i < durationInDays; ++ i) {
+                var eqsOnDay = eqIdsByEventDate[searchDate];
+                if (eqsOnDay.Count > 0) {
+                    foreach (var id in eqsOnDay) {
+                        var eqData = eqMap[id];
+                        if (eqData == null)
+                            continue;
+
+                        double dist = CalcDistBetweenTwoLocationsInMiles(eqData.Latitude, eqData.Longitude,
+                                                                            eq_lat, eq_long);
+                        if (dist > (eqData.Magnitude * 100.0))
+                            continue;
+                        ret.Add(eqData);
+                    }
+                }
+                searchDate = searchDate.AddDays(1.0);
+            }
+
+            ret.Sort(delegate(EQData x, EQData y) {
+                return x.EventTime.CompareTo(y);
+            });
+            return ret;
+        }
+
+        public void ParseLine(string lineToParse) {
+            if (lineToParse == null)
+                return;
+            string[] splitted = lineToParse.Split(',');
+            if (splitted[14] != "earthquake") // event type
+                return;
+            var eqData = new EQData(timeStr: splitted[0],
+                                    latitudeStr: splitted[1],
+                                    longitudeStr: splitted[2],
+                                    magnitudeStr: splitted[4],
+                                    idStr: splitted[11],
+                                    placeStr: splitted[13]);
+            eqMap.Add(eqData.EventId, eqData);
+
+            DateTime timeToStore = eqData.EventTime.Subtract(eqData.EventTime.TimeOfDay);
+            if (!eqIdsByEventDate.ContainsKey(timeToStore)) {
+                var eqs = new List<string>();
+                eqs.Add(eqData.EventId);
+                eqIdsByEventDate.Add(timeToStore, eqs);
+            } else {
+                var eqs = eqIdsByEventDate[timeToStore];
+                eqs.Add(eqData.EventId);
+                eqIdsByEventDate[timeToStore] = eqs;
+            }
+        }
+
+        public void MarkDone() {
+            isInitialized = true;
+        }
+
+        public void Clear() {
+            eqMap.Clear();
+            eqIdsByEventDate.Clear();
+            isInitialized = false;
+        }
+    }
+}
diff --git a/Library/Library.csproj b/Library/Library.csproj
new file mode 100644
index 0000000..7f1c4a8
--- /dev/null
+++ b/Library/Library.csproj
@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{A4D3553A-6116-476B-B4B2-1CBF70912C23}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <RootNamespace>Library</RootNamespace>
+    <AssemblyName>Library</AssemblyName>
+    <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <Deterministic>true</Deterministic>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="EQData.cs" />
+    <Compile Include="EQDataFrame.cs" />
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="App.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+</Project>
\ No newline at end of file
diff --git a/Library/Library.sln b/Library/Library.sln
new file mode 100644
index 0000000..6901597
--- /dev/null
+++ b/Library/Library.sln
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.31729.503
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Library", "Library.csproj", "{A4D3553A-6116-476B-B4B2-1CBF70912C23}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{A4D3553A-6116-476B-B4B2-1CBF70912C23}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A4D3553A-6116-476B-B4B2-1CBF70912C23}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A4D3553A-6116-476B-B4B2-1CBF70912C23}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A4D3553A-6116-476B-B4B2-1CBF70912C23}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {1B6BBC3F-6E6F-4F13-982E-11EF3EEB0CF4}
+	EndGlobalSection
+EndGlobal
diff --git a/Library/Program.cs b/Library/Program.cs
new file mode 100644
index 0000000..f9eaf36
--- /dev/null
+++ b/Library/Program.cs
@@ -0,0 +1,22 @@
+using System;
+using System.IO;
+
+namespace Library {
+    class Program {
+        static void Main(string[] args) {
+            EQDataFrame dataFrame = new EQDataFrame();
+            using (var sr = new StreamReader("../../../all_month.csv")) {
+                string line;
+                int count = 0;
+                while ((line = sr.ReadLine()) != null) {
+                    if (count > 0)
+                        dataFrame.ParseLine(line);
+                    ++ count;
+                }
+                dataFrame.MarkDone();
+            }
+            var test = dataFrame.QueryEndpoint(64.6648, -147.6137, DateTime.Parse("2021-10-05"), DateTime.Parse("2021-10-05"));
+            int a = 0;
+        }
+    }
+}
diff --git a/Library/Properties/AssemblyInfo.cs b/Library/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000..9fe2d4e
--- /dev/null
+++ b/Library/Properties/AssemblyInfo.cs
@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("Library")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("Library")]
+[assembly: AssemblyCopyright("Copyright ©  2021")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("a4d3553a-6116-476b-b4b2-1cbf70912c23")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

From 8cdc6b54a5287eebcde30f89219ecfd1ab7d0918 Mon Sep 17 00:00:00 2001
From: Sangdae Kim <sangdae.kim@protonmail.com>
Date: Wed, 17 Nov 2021 16:24:07 -0800
Subject: [PATCH 2/4] Use Nancy

---
 Library/EQDataFrame.cs   | 11 +++++++----
 Library/EQNancyModule.cs | 40 ++++++++++++++++++++++++++++++++++++++++
 Library/Library.csproj   |  8 ++++++++
 Library/Program.cs       | 23 ++++++++++-------------
 Library/packages.config  |  5 +++++
 5 files changed, 70 insertions(+), 17 deletions(-)
 create mode 100644 Library/EQNancyModule.cs
 create mode 100644 Library/packages.config

diff --git a/Library/EQDataFrame.cs b/Library/EQDataFrame.cs
index 1d3a755..814f1a7 100644
--- a/Library/EQDataFrame.cs
+++ b/Library/EQDataFrame.cs
@@ -28,10 +28,13 @@ double CalcDistBetweenTwoLocationsInMiles(double latA, double longA,
 
         // return null if error
         public List<EQData> QueryEndpoint(double eq_lat, double eq_long, DateTime eq_start_date, DateTime eq_end_date) {
-            // check lat, long range
-
-            if (eq_end_date < eq_start_date)
-                return null; // error
+            // https://earthquake.usgs.gov/data/comcat/index.php
+            if (eq_lat < -90.0 || eq_lat > 90.0)
+                return null;
+            else if (eq_long < -180.0 || eq_long > 180.0)
+                return null;
+            else if (eq_end_date < eq_start_date)
+                return null;
 
             List<EQData> ret = new List<EQData>();
 
diff --git a/Library/EQNancyModule.cs b/Library/EQNancyModule.cs
new file mode 100644
index 0000000..0e1a264
--- /dev/null
+++ b/Library/EQNancyModule.cs
@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Nancy;
+using System.IO;
+
+namespace Library {
+    public class EQNancyModule : NancyModule {
+        public EQNancyModule() {
+            EQDataFrame dataFrame = new EQDataFrame();
+            using (var sr = new StreamReader("../../../all_month.csv")) {
+                string line;
+                int count = 0;
+                while ((line = sr.ReadLine()) != null) {
+                    if (count > 0)
+                        dataFrame.ParseLine(line);
+                    ++ count;
+                }
+                dataFrame.MarkDone();
+            }
+
+            Get("/", parameters => {
+                var query = Request.Query;
+                double queryEqLong = (double)query.@long;
+                double queryEqLat = (double)query.lat;
+                string queryEqStartDate = (string)query.start_date;
+                string queryEqEndDate = (string)query.end_date;
+
+                var ret = dataFrame.QueryEndpoint(queryEqLat, queryEqLong, DateTime.Parse(queryEqStartDate), DateTime.Parse(queryEqEndDate));
+                if (ret == null)
+                    return HttpStatusCode.BadRequest;
+                else if (ret.Count == 0)
+                    return HttpStatusCode.NotFound;
+                return Response.AsJson(ret);
+            });
+        }
+    }
+}
diff --git a/Library/Library.csproj b/Library/Library.csproj
index 7f1c4a8..c9bf695 100644
--- a/Library/Library.csproj
+++ b/Library/Library.csproj
@@ -33,6 +33,12 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Nancy, Version=2.0.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>packages\Nancy.2.0.0\lib\net452\Nancy.dll</HintPath>
+    </Reference>
+    <Reference Include="Nancy.Hosting.Self, Version=2.0.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>packages\Nancy.Hosting.Self.2.0.0\lib\net452\Nancy.Hosting.Self.dll</HintPath>
+    </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core" />
     <Reference Include="System.Xml.Linq" />
@@ -45,11 +51,13 @@
   <ItemGroup>
     <Compile Include="EQData.cs" />
     <Compile Include="EQDataFrame.cs" />
+    <Compile Include="EQNancyModule.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />
+    <None Include="packages.config" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>
\ No newline at end of file
diff --git a/Library/Program.cs b/Library/Program.cs
index f9eaf36..2e83bb7 100644
--- a/Library/Program.cs
+++ b/Library/Program.cs
@@ -1,22 +1,19 @@
 using System;
 using System.IO;
+using Nancy;
+using Nancy.Hosting.Self;
 
 namespace Library {
     class Program {
         static void Main(string[] args) {
-            EQDataFrame dataFrame = new EQDataFrame();
-            using (var sr = new StreamReader("../../../all_month.csv")) {
-                string line;
-                int count = 0;
-                while ((line = sr.ReadLine()) != null) {
-                    if (count > 0)
-                        dataFrame.ParseLine(line);
-                    ++ count;
-                }
-                dataFrame.MarkDone();
-            }
-            var test = dataFrame.QueryEndpoint(64.6648, -147.6137, DateTime.Parse("2021-10-05"), DateTime.Parse("2021-10-05"));
-            int a = 0;
+            // https://volkanpaksoy.com/archive/2015/11/11/building-a-simple-http-server-with-nancy/
+            string url = "http://localhost";
+            int port = 8000;
+            var server = new NancyHost(new Uri($"{url}:{port}/"));
+            server.Start();
+            Console.WriteLine("Server is running");
+            Console.ReadKey();
+            server.Stop();
         }
     }
 }
diff --git a/Library/packages.config b/Library/packages.config
new file mode 100644
index 0000000..93ef021
--- /dev/null
+++ b/Library/packages.config
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="Nancy" version="2.0.0" targetFramework="net472" />
+  <package id="Nancy.Hosting.Self" version="2.0.0" targetFramework="net472" />
+</packages>
\ No newline at end of file

From 9a73014b1773654dc85efdaaddf69e2739e78c6f Mon Sep 17 00:00:00 2001
From: Sangdae Kim <sangdae.kim@protonmail.com>
Date: Wed, 17 Nov 2021 17:21:20 -0800
Subject: [PATCH 3/4] final

---
 Library/EQDataFrame.cs   | 80 +++++++++++++++++++++++-----------------
 Library/EQNancyModule.cs |  8 ++--
 Library/README.txt       | 14 +++++++
 3 files changed, 64 insertions(+), 38 deletions(-)
 create mode 100644 Library/README.txt

diff --git a/Library/EQDataFrame.cs b/Library/EQDataFrame.cs
index 814f1a7..e182d48 100644
--- a/Library/EQDataFrame.cs
+++ b/Library/EQDataFrame.cs
@@ -1,12 +1,9 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+using System.Text.RegularExpressions;
 
 namespace Library {
     public class EQDataFrame {
-        bool isInitialized;
         Dictionary<string, EQData> eqMap = new Dictionary<string, EQData>(); // <eqId, EQData>
         Dictionary<DateTime, List<string>> eqIdsByEventDate = new Dictionary<DateTime, List<string>>(); // <event date, eqId[]>
 
@@ -44,25 +41,27 @@ public List<EQData> QueryEndpoint(double eq_lat, double eq_long, DateTime eq_sta
             int durationInDays = (searchDateEnd - searchDateStart).Duration().Days + 1;
             DateTime searchDate = searchDateStart;
             for (int i = 0; i < durationInDays; ++ i) {
-                var eqsOnDay = eqIdsByEventDate[searchDate];
-                if (eqsOnDay.Count > 0) {
-                    foreach (var id in eqsOnDay) {
-                        var eqData = eqMap[id];
-                        if (eqData == null)
-                            continue;
+                List<string> eqsOnDay;
+                if (!eqIdsByEventDate.TryGetValue(searchDate, out eqsOnDay)
+                    || eqsOnDay == null
+                    || eqsOnDay.Count == 0)
+                    continue;
+                foreach (var id in eqsOnDay) {
+                    var eqData = eqMap[id];
+                    if (eqData == null)
+                        continue;
 
-                        double dist = CalcDistBetweenTwoLocationsInMiles(eqData.Latitude, eqData.Longitude,
-                                                                            eq_lat, eq_long);
-                        if (dist > (eqData.Magnitude * 100.0))
-                            continue;
-                        ret.Add(eqData);
-                    }
+                    double dist = CalcDistBetweenTwoLocationsInMiles(eqData.Latitude, eqData.Longitude,
+                                                                        eq_lat, eq_long);
+                    if (dist > (eqData.Magnitude * 100.0))
+                        continue;
+                    ret.Add(eqData);
                 }
                 searchDate = searchDate.AddDays(1.0);
             }
 
             ret.Sort(delegate(EQData x, EQData y) {
-                return x.EventTime.CompareTo(y);
+                return y.EventTime.CompareTo(x.EventTime);
             });
             return ret;
         }
@@ -70,15 +69,38 @@ public List<EQData> QueryEndpoint(double eq_lat, double eq_long, DateTime eq_sta
         public void ParseLine(string lineToParse) {
             if (lineToParse == null)
                 return;
-            string[] splitted = lineToParse.Split(',');
+
+            // to handle cases of commas in quote
+            // https://stackoverflow.com/a/48275050
+            //this regular expression splits string on the separator character NOT inside double quotes. 
+            //separatorChar can be any character like comma or semicolon etc. 
+            //it also allows single quotes inside the string value: e.g. "Mike's Kitchen","Jane's Room"
+            Regex regx = new Regex("," + "(?=(?:[^\"]*\"[^\"]*\")*(?![^\"]*\"))"); 
+            string[] splitted = regx.Split(lineToParse);
+            //string[] splitted = lineToParse.Split(',');
             if (splitted[14] != "earthquake") // event type
                 return;
-            var eqData = new EQData(timeStr: splitted[0],
-                                    latitudeStr: splitted[1],
-                                    longitudeStr: splitted[2],
-                                    magnitudeStr: splitted[4],
-                                    idStr: splitted[11],
-                                    placeStr: splitted[13]);
+            
+            string timeStr = splitted[0];
+            string latitudeStr = splitted[1];
+            string longitudeStr = splitted[2];
+            string magnitudeStr = splitted[4];
+            string idStr = splitted[11];
+            string placeStr = splitted[13];
+
+            if (timeStr == string.Empty
+                || latitudeStr == string.Empty 
+                || longitudeStr == string.Empty
+                || magnitudeStr == string.Empty
+                || idStr == string.Empty)
+                return;
+
+            var eqData = new EQData(timeStr: timeStr,
+                                    latitudeStr: latitudeStr,
+                                    longitudeStr: longitudeStr,
+                                    magnitudeStr: magnitudeStr,
+                                    idStr: idStr,
+                                    placeStr: placeStr);
             eqMap.Add(eqData.EventId, eqData);
 
             DateTime timeToStore = eqData.EventTime.Subtract(eqData.EventTime.TimeOfDay);
@@ -92,15 +114,5 @@ public void ParseLine(string lineToParse) {
                 eqIdsByEventDate[timeToStore] = eqs;
             }
         }
-
-        public void MarkDone() {
-            isInitialized = true;
-        }
-
-        public void Clear() {
-            eqMap.Clear();
-            eqIdsByEventDate.Clear();
-            isInitialized = false;
-        }
     }
 }
diff --git a/Library/EQNancyModule.cs b/Library/EQNancyModule.cs
index 0e1a264..b0362ab 100644
--- a/Library/EQNancyModule.cs
+++ b/Library/EQNancyModule.cs
@@ -12,13 +12,13 @@ public EQNancyModule() {
             EQDataFrame dataFrame = new EQDataFrame();
             using (var sr = new StreamReader("../../../all_month.csv")) {
                 string line;
-                int count = 0;
+                bool isFirstLine = true;
                 while ((line = sr.ReadLine()) != null) {
-                    if (count > 0)
+                    if (!isFirstLine)
                         dataFrame.ParseLine(line);
-                    ++ count;
+                    else
+                        isFirstLine = false;
                 }
-                dataFrame.MarkDone();
             }
 
             Get("/", parameters => {
diff --git a/Library/README.txt b/Library/README.txt
new file mode 100644
index 0000000..5b2fd8d
--- /dev/null
+++ b/Library/README.txt
@@ -0,0 +1,14 @@
+This is README file for explanations of the challenge.
+
+* How to Test
+1. Open the Library.sln file in Adminstrator and Build the solution.
+	You may need to install Nancy and Nancy.Hosting.Self from NuGet.
+2. Run the application.
+3. Send GET request by using the program like Postman
+ex) http://localhost:8000/?lat=68.6647&long=-147.6137&start_date=2021/10/06&end_date=2021/10/05
+
+
+
+
+The program uses NancyFx(Http Server) to handle request and return the response(port:8000, localhost).
+When the server is up, the program parses the csv file and 
\ No newline at end of file

From 2161831e09e7856c6acc7cad1510407a707abdda Mon Sep 17 00:00:00 2001
From: Sangdae Kim <sangdae.kim@protonmail.com>
Date: Wed, 17 Nov 2021 17:30:12 -0800
Subject: [PATCH 4/4] done

---
 Library/EQDataFrame.cs |  3 ++-
 Library/README.txt     | 14 +++++++++-----
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/Library/EQDataFrame.cs b/Library/EQDataFrame.cs
index e182d48..badf3de 100644
--- a/Library/EQDataFrame.cs
+++ b/Library/EQDataFrame.cs
@@ -35,6 +35,7 @@ public List<EQData> QueryEndpoint(double eq_lat, double eq_long, DateTime eq_sta
 
             List<EQData> ret = new List<EQData>();
 
+            // to store the day of the date
             DateTime searchDateStart = eq_start_date.Subtract(eq_start_date.TimeOfDay);
             DateTime searchDateEnd = eq_end_date.Subtract(eq_end_date.TimeOfDay);
 
@@ -57,7 +58,7 @@ public List<EQData> QueryEndpoint(double eq_lat, double eq_long, DateTime eq_sta
                         continue;
                     ret.Add(eqData);
                 }
-                searchDate = searchDate.AddDays(1.0);
+                searchDate = searchDate.AddDays(1.0); // walk through the days
             }
 
             ret.Sort(delegate(EQData x, EQData y) {
diff --git a/Library/README.txt b/Library/README.txt
index 5b2fd8d..c6058f1 100644
--- a/Library/README.txt
+++ b/Library/README.txt
@@ -5,10 +5,14 @@ This is README file for explanations of the challenge.
 	You may need to install Nancy and Nancy.Hosting.Self from NuGet.
 2. Run the application.
 3. Send GET request by using the program like Postman
-ex) http://localhost:8000/?lat=68.6647&long=-147.6137&start_date=2021/10/06&end_date=2021/10/05
-
-
-
+ex) http://localhost:8000/?lat=-5.0888&long=146.3141&start_date=2021/10/05&end_date=2021/10/08
+4. The result would be in json.
 
+* Description
 The program uses NancyFx(Http Server) to handle request and return the response(port:8000, localhost).
-When the server is up, the program parses the csv file and 
\ No newline at end of file
+When the server is up, the program parses the csv file per each line and convert the line to EQData which holds data we interest(time, lat, long, mag, place).
+The collection I used is a dictionary with id as key(eqMap).
+To save time, I put the ids in a dictionary by date(eqIdsByEventDate).
+
+When the program gets a query, it computes the range of date and search the endpoints by each day of the date.
+If the event matches, add to the list to return and then sort from newest to oldest date when return the list.