inital impl

.gitignore

@@ -0,0 +1,115 @@
+# Created by https://www.toptal.com/developers/gitignore/api/goland+all,go
+# Edit at https://www.toptal.com/developers/gitignore?templates=goland+all,go
+
+### Go ###
+# If you prefer the allow list template instead of the deny list, see community template:
+# https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore
+#
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
+# Go workspace file
+go.work
+
+### GoLand+all ###
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio, WebStorm and Rider
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/**/usage.statistics.xml
+.idea/**/dictionaries
+.idea/**/shelf
+
+# AWS User-specific
+.idea/**/aws.xml
+
+# Generated files
+.idea/**/contentModel.xml
+
+# Sensitive or high-churn files
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.local.xml
+.idea/**/sqlDataSources.xml
+.idea/**/dynamic.xml
+.idea/**/uiDesigner.xml
+.idea/**/dbnavigator.xml
+
+# Gradle
+.idea/**/gradle.xml
+.idea/**/libraries
+
+# Gradle and Maven with auto-import
+# When using Gradle or Maven with auto-import, you should exclude module files,
+# since they will be recreated, and may cause churn.  Uncomment if using
+# auto-import.
+# .idea/artifacts
+# .idea/compiler.xml
+# .idea/jarRepositories.xml
+# .idea/modules.xml
+# .idea/*.iml
+# .idea/modules
+# *.iml
+# *.ipr
+
+# CMake
+cmake-build-*/
+
+# Mongo Explorer plugin
+.idea/**/mongoSettings.xml
+
+# File-based project format
+*.iws
+
+# IntelliJ
+out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Cursive Clojure plugin
+.idea/replstate.xml
+
+# SonarLint plugin
+.idea/sonarlint/
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+
+# Editor-based Rest Client
+.idea/httpRequests
+
+# Android studio 3.1+ serialized cache file
+.idea/caches/build_file_checksums.ser
+
+### GoLand+all Patch ###
+# Ignore everything but code style settings and run configurations
+# that are supposed to be shared within teams.
+
+.idea/*
+
+!.idea/codeStyles
+!.idea/runConfigurations
+
+# End of https://www.toptal.com/developers/gitignore/api/goland+all,go

go.mod

@@ -0,0 +1,3 @@
+module gositemap
+
+go 1.20

sitemap.go

@@ -0,0 +1,102 @@
+package gositemap
+
+import (
+	"encoding/xml"
+	"fmt"
+	"math"
+)
+
+type ChangeFrequency string
+
+const (
+	Always  ChangeFrequency = "always"
+	Hourly  ChangeFrequency = "hourly"
+	Daily   ChangeFrequency = "daily"
+	Weekly  ChangeFrequency = "weekly"
+	Monthly ChangeFrequency = "monthly"
+	Yearly  ChangeFrequency = "yearly"
+	Never   ChangeFrequency = "never"
+)
+
+func (f ChangeFrequency) String() string {
+	return string(f)
+}
+
+type urlSetXML struct {
+	XMLName xml.Name  `xml:"http://www.sitemaps.org/schemas/sitemap/0.9 urlset"`
+	URLs    []*urlXML `xml:"url"`
+}
+
+type urlXML struct {
+	Loc        string           `xml:"loc"`
+	LastMod    *string          `xml:"lastmod,omitempty"`
+	ChangeFreq *ChangeFrequency `xml:"changefreq,omitempty"`
+	Priority   *float64         `xml:"priority,omitempty"`
+}
+
+type siteMapIndexXML struct {
+	XMLName  xml.Name      `xml:"http://www.sitemaps.org/schemas/sitemap/0.9 sitemapindex"`
+	SiteMaps []*sitemapXML `xml:"sitemap"`
+}
+
+type sitemapXML struct {
+	Loc     string  `xml:"loc"`
+	LastMod *string `xml:"lastmod,omitempty"`
+}
+
+type SiteMap struct {
+	urls    []*urlXML
+	BaseURL string
+}
+
+func (m *SiteMap) AddURL(url string, lastMod *string, freq *ChangeFrequency, prio *float64) {
+	m.urls = append(m.urls, &urlXML{
+		Loc:        fmt.Sprintf("https://%s/%s", m.BaseURL, url),
+		LastMod:    lastMod,
+		ChangeFreq: freq,
+		Priority:   prio,
+	})
+}
+
+func prefixXML(content []byte) []byte {
+	return append([]byte(xml.Header), content...)
+}
+
+func (m *SiteMap) SiteMapIndex() ([]byte, error) {
+	nSiteMaps := int(math.Floor(float64(len(m.urls))/50000 + 1))
+
+	index := &siteMapIndexXML{}
+
+	for i := 0; i < nSiteMaps; i++ {
+		index.SiteMaps = append(index.SiteMaps, &sitemapXML{
+			Loc: fmt.Sprintf("https://%s/sitemap%d.xml", m.BaseURL, i),
+		})
+	}
+
+	res, err := xml.Marshal(index)
+	if err != nil {
+		return nil, err
+	}
+
+	return prefixXML(res), nil
+}
+
+func (m *SiteMap) SiteMap(id int) ([]byte, error) {
+	siteMap := &urlSetXML{}
+
+	var urls []*urlXML
+	if 50000*(id+1) >= len(m.urls) {
+		urls = m.urls[50000*id:]
+	} else {
+		urls = m.urls[50000*id : 50000*(id+1)]
+	}
+
+	siteMap.URLs = append(siteMap.URLs, urls...)
+
+	res, err := xml.Marshal(siteMap)
+	if err != nil {
+		return nil, err
+	}
+
+	return prefixXML(res), nil
+}