Report helper is added.

helper/README.md

@@ -76,6 +76,13 @@ The information provided on this project is strictly for informational purposes
 - [type Float](<#Float>)
 - [type Integer](<#Integer>)
 - [type Number](<#Number>)
+- [type Report](<#Report>)
+  - [func NewReport\(title string, date \<\-chan time.Time\) \*Report](<#NewReport>)
+  - [func \(r \*Report\) AddColumn\(column ReportColumn\)](<#Report.AddColumn>)
+  - [func \(r \*Report\) WriteToFile\(fileName string\) error](<#Report.WriteToFile>)
+  - [func \(r \*Report\) WriteToWriter\(writer io.Writer\) error](<#Report.WriteToWriter>)
+- [type ReportColumn](<#ReportColumn>)
+  - [func NewNumericReportColumn\[T Number\]\(name string, values \<\-chan T\) ReportColumn](<#NewNumericReportColumn>)
 - [type Ring](<#Ring>)
   - [func NewRing\[T any\]\(size int\) \*Ring\[T\]](<#NewRing>)
   - [func \(r \*Ring\[T\]\) Insert\(t T\) T](<#Ring[T].Insert>)
@@ -831,6 +838,82 @@ type Number interface {
 }
 ```
 
+<a name="Report"></a>
+## type [Report](<https://github.com/cinar/indicator/blob/v2/helper/report.go#L80-L82>)
+
+Report generates an HTML file containing an interactive chart that visually represents the provided data and annotations.
+
+The generated HTML file can be opened in a web browser to explore the data visually, interact with the chart elements, and view the associated annotations.
+
+```go
+type Report struct {
+    // contains filtered or unexported fields
+}
+```
+
+<a name="NewReport"></a>
+### func [NewReport](<https://github.com/cinar/indicator/blob/v2/helper/report.go#L87>)
+
+```go
+func NewReport(title string, date <-chan time.Time) *Report
+```
+
+NewReport takes a channel of time as the time axis and returns a new instance of the Report struct. This instance can later be used to add data and annotations and subsequently generate a report.
+
+<a name="Report.AddColumn"></a>
+### func \(\*Report\) [AddColumn](<https://github.com/cinar/indicator/blob/v2/helper/report.go#L98>)
+
+```go
+func (r *Report) AddColumn(column ReportColumn)
+```
+
+AddColumn adds a new data column to the report.
+
+<a name="Report.WriteToFile"></a>
+### func \(\*Report\) [WriteToFile](<https://github.com/cinar/indicator/blob/v2/helper/report.go#L117>)
+
+```go
+func (r *Report) WriteToFile(fileName string) error
+```
+
+WriteToFile writes the generated report content to a file with the specified name. This allows users to conveniently save the report for later viewing or analysis.
+
+<a name="Report.WriteToWriter"></a>
+### func \(\*Report\) [WriteToWriter](<https://github.com/cinar/indicator/blob/v2/helper/report.go#L105>)
+
+```go
+func (r *Report) WriteToWriter(writer io.Writer) error
+```
+
+WriteToWriter writes the report content to the provided io.Writer. This allows the report to be sent to various destinations, such as a file, a network socket, or even the standard output.
+
+<a name="ReportColumn"></a>
+## type [ReportColumn](<https://github.com/cinar/indicator/blob/v2/helper/report.go#L24-L33>)
+
+ReportColumn defines the interface that all report data columns must implement. This interface ensures that different types of data columns can be used consistently within the report generation process.
+
+```go
+type ReportColumn interface {
+    // Name returns the name of the report column.
+    Name() string
+
+    // Type returns the data type of the report column.
+    Type() string
+
+    // Value returns the next data value for the report column.
+    Value() string
+}
+```
+
+<a name="NewNumericReportColumn"></a>
+### func [NewNumericReportColumn](<https://github.com/cinar/indicator/blob/v2/helper/report.go#L43>)
+
+```go
+func NewNumericReportColumn[T Number](name string, values <-chan T) ReportColumn
+```
+
+NewNumericReportColumn returns a new instance of a numeric data column for a report.
+
 <a name="Ring"></a>
 ## type [Ring](<https://github.com/cinar/indicator/blob/v2/helper/ring.go#L18-L21>)
 

helper/report.go

@@ -0,0 +1,126 @@
+// Copyright (c) 2023 Onur Cinar. All Rights Reserved.
+// The source code is provided under MIT License.
+// https://github.com/cinar/indicator
+
+package helper
+
+import (
+	// Go embed report template.
+	_ "embed"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"text/template"
+	"time"
+)
+
+//go:embed "report.tmpl"
+var reportTmpl string
+
+// ReportColumn defines the interface that all report data columns must implement.
+// This interface ensures that different types of data columns can be used
+// consistently within the report generation process.
+type ReportColumn interface {
+	// Name returns the name of the report column.
+	Name() string
+
+	// Type returns the data type of the report column.
+	Type() string
+
+	// Value returns the next data value for the report column.
+	Value() string
+}
+
+// numericReportColumn is the number report column struct.
+type numericReportColumn[T Number] struct {
+	ReportColumn
+	name   string
+	values <-chan T
+}
+
+// NewNumericReportColumn returns a new instance of a numeric data column for a report.
+func NewNumericReportColumn[T Number](name string, values <-chan T) ReportColumn {
+	return &numericReportColumn[T]{
+		name:   name,
+		values: values,
+	}
+}
+
+// Name returns the name of the report column.
+func (c *numericReportColumn[T]) Name() string {
+	return c.name
+}
+
+// Type returns number as the data type.
+func (c *numericReportColumn[T]) Type() string {
+	return "number"
+}
+
+// Value returns the next data value for the report column.
+func (c *numericReportColumn[T]) Value() string {
+	return fmt.Sprintf("%v", <-c.values)
+}
+
+// reportModel struct holds the data that is exposed to the template renderer
+// for generating the report. It encapsulates all the information necessary
+// to render the report's content, including data, and annotations.
+type reportModel struct {
+	Title   string
+	Date    <-chan time.Time
+	Columns []ReportColumn
+}
+
+// Report generates an HTML file containing an interactive chart that
+// visually represents the provided data and annotations.
+//
+// The generated HTML file can be opened in a web browser to explore
+// the data visually, interact with the chart elements, and view
+// the associated annotations.
+type Report struct {
+	model reportModel
+}
+
+// NewReport takes a channel of time as the time axis and returns a new
+// instance of the Report struct. This instance can later be used to
+// add data and annotations and subsequently generate a report.
+func NewReport(title string, date <-chan time.Time) *Report {
+	return &Report{
+		model: reportModel{
+			Title:   title,
+			Date:    date,
+			Columns: []ReportColumn{},
+		},
+	}
+}
+
+// AddColumn adds a new data column to the report.
+func (r *Report) AddColumn(column ReportColumn) {
+	r.model.Columns = append(r.model.Columns, column)
+}
+
+// WriteToWriter writes the report content to the provided io.Writer.
+// This allows the report to be sent to various destinations, such
+// as a file, a network socket, or even the standard output.
+func (r *Report) WriteToWriter(writer io.Writer) error {
+	tmpl, err := template.New("report").Parse(reportTmpl)
+	if err != nil {
+		return err
+	}
+
+	return tmpl.Execute(writer, r.model)
+}
+
+// WriteToFile writes the generated report content to a file with
+// the specified name. This allows users to conveniently save the
+// report for later viewing or analysis.
+func (r *Report) WriteToFile(fileName string) error {
+	file, err := os.Create(filepath.Clean(fileName))
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+
+	return r.WriteToWriter(file)
+}

helper/report.tmpl

@@ -0,0 +1,86 @@
+<!DOCTYPE html>
+<html>
+
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <title>{{ .Title }}</title>
+    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/css/bulma.min.css">
+</head>
+
+<body>
+    <section class="section">
+        <div class="container">
+            <h1 class="title">
+                {{ .Title }}
+            </h1>
+
+            <div id="dashboard">
+                <div id="chart"></div>
+                <div id="controls"></div>
+            </div>
+        </div>
+    </section>
+
+    <script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
+    <script type="text/javascript">
+        // Load the Visualization API and the corechart and controls packages.
+        google.charts.load("current", { "packages": ["corechart", "controls"] });
+
+        // Set a callback to run when the Google Visualization API is loaded.
+        google.charts.setOnLoadCallback(drawDashboard);
+
+        // Callback that creates and populates a data table,
+        // instantiates the pie chart, passes in the data and
+        // draws it.
+        function drawDashboard() {
+            var dashboard = new google.visualization.Dashboard(document.getElementById("dashboard"));
+
+            var chart = new google.visualization.ChartWrapper({
+                "chartType": "LineChart",
+                "containerId": "chart",
+                "options": {
+                    "title": "{{ .Title }}",
+                    "curveType": "function",
+                    "legend": {
+                        "position": "right",
+                    }
+                }
+            });
+
+            var rangeFilter = new google.visualization.ControlWrapper({
+                "controlType": "ChartRangeFilter",
+                "containerId": "controls",
+                "options": {
+                    "filterColumnLabel": "Date",
+                    "ui": {
+                        "chartOptions": {
+                            "height": 50
+                        }
+                    }
+                }
+            });
+
+            // Create the data table.
+            var data = new google.visualization.DataTable();
+            data.addColumn("date", "Date");
+            {{ range.Columns }}
+            data.addColumn("{{ .Type }}", "{{ .Name }}");
+            {{ end }}
+
+            {{ range.Date }}
+            data.addRow([
+                new Date({{ .Format "2006, 1, 2" }}),
+                {{ range $.Columns }}
+                {{ .Value }},
+                {{ end }}
+            ]);
+            {{ end }}
+
+            dashboard.bind(rangeFilter, chart);
+            dashboard.draw(data);
+        }
+    </script>
+</body>
+
+</html>

helper/report_test.go

@@ -0,0 +1,46 @@
+// Copyright (c) 2023 Onur Cinar. All Rights Reserved.
+// The source code is provided under MIT License.
+// https://github.com/cinar/indicator
+
+package helper_test
+
+import (
+	"os"
+	"testing"
+	"time"
+
+	"github.com/cinar/indicator/helper"
+)
+
+func TestReportWriteToFile(t *testing.T) {
+	type Row struct {
+		Date  time.Time `format:"2006-01-02"`
+		High  float64
+		Low   float64
+		Close float64
+	}
+
+	input, err := helper.ReadFromCsvFile[Row]("testdata/report.csv", true)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	inputs := helper.Duplicate(input, 4)
+	dates := helper.Map(inputs[0], func(row *Row) time.Time { return row.Date })
+	highs := helper.Map(inputs[1], func(row *Row) float64 { return row.High })
+	lows := helper.Map(inputs[2], func(row *Row) float64 { return row.Low })
+	closes := helper.Map(inputs[3], func(row *Row) float64 { return row.Close })
+
+	report := helper.NewReport("Test Report", dates)
+	report.AddColumn(helper.NewNumericReportColumn("High", highs))
+	report.AddColumn(helper.NewNumericReportColumn("Low", lows))
+	report.AddColumn(helper.NewNumericReportColumn("Close", closes))
+
+	fileName := "report.html"
+	defer os.Remove(fileName)
+
+	err = report.WriteToFile("report.html")
+	if err != nil {
+		t.Fatal(err)
+	}
+}