Remove Amplitude analytics integration (#246)

Amplitude is no longer used for product analytics. This removes:
- Go SDK client initialization and event tracking (login, signup, homepage)
- Browser SDK snippet from base.html
- JS init/user identification from akatsuki_src.js
- AmplitudeLogger adapter in app/logging/
- AMPLITUDE_API_KEY from settings, .env.example, and services
- amplitude/analytics-go and mileusna/useragent dependencies from go.mod

Note: web/static/js/dist-*.min.js should be rebuilt via gulp after merge.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: cmyui

.env.example

@@ -51,5 +51,3 @@ RECAPTCHA_SECRET_KEY=
 IP_LOOKUP_URL=http://ip-api.com
 
 PAYPAL_EMAIL_ADDRESS=
-
-AMPLITUDE_API_KEY=

app/handlers/misc/homepage.go

@@ -1,13 +1,8 @@
 package misc
 
 import (
-	"strconv"
-
-	"github.com/amplitude/analytics-go/amplitude"
 	"github.com/gin-gonic/gin"
 	"github.com/osuAkatsuki/hanayo/app/models"
-	"github.com/osuAkatsuki/hanayo/app/sessions"
-	"github.com/osuAkatsuki/hanayo/app/states/services"
 	tu "github.com/osuAkatsuki/hanayo/app/usecases/templates"
 )
 
@@ -17,22 +12,5 @@ func HomepagePageHandler(c *gin.Context) {
 
 	defer tu.Resp(c, 200, "homepage.html", data)
 
-	// Fire a homepage load event
-	ctx := sessions.GetContext(c)
-	if ctx.User.ID != 0 {
-		services.Amplitude.Track(amplitude.Event{
-			EventType: "homepage_load",
-			EventOptions: amplitude.EventOptions{
-				IP:       c.ClientIP(),
-				Country:  c.Request.Header.Get("CF-IPCountry"),
-				City:     c.Request.Header.Get("CF-IPCity"),
-				Region:   c.Request.Header.Get("CF-Region"),
-				Language: c.Request.Header.Get("Accept-Language"),
-				UserID:   strconv.Itoa(ctx.User.ID),
-			},
-			EventProperties: map[string]interface{}{"source": "hanayo"},
-		})
-	}
-
 	data.DisableHH = true
 }

app/handlers/sessions/login/login.go

@@ -5,13 +5,10 @@ import (
 	"html/template"
 	"strconv"
 	"strings"
-	"time"
 
 	"golang.org/x/exp/slog"
 
-	"github.com/amplitude/analytics-go/amplitude"
 	"github.com/gin-gonic/gin"
-	"github.com/mileusna/useragent"
 	"github.com/osuAkatsuki/akatsuki-api/common"
 	eh "github.com/osuAkatsuki/hanayo/app/handlers/errors"
 	msg "github.com/osuAkatsuki/hanayo/app/models/messages"
@@ -123,53 +120,6 @@ func LoginSubmitHandler(c *gin.Context) {
 		return
 	}
 
-	latitude, err := strconv.ParseFloat(c.Request.Header.Get("CF-IPLatitude"), 64)
-	if err != nil {
-		slog.Error("Error parsing latitude", "error", err.Error())
-		latitude = 0.0
-	}
-
-	longitude, err := strconv.ParseFloat(c.Request.Header.Get("CF-IPLongitude"), 64)
-	if err != nil {
-		slog.Error("Error parsing longitude", "error", err.Error())
-		longitude = 0.0
-	}
-
-	userAgent := useragent.Parse(c.Request.UserAgent())
-
-	services.Amplitude.Track(amplitude.Event{
-		EventType: "web_login",
-		EventOptions: amplitude.EventOptions{
-			UserID:      strconv.Itoa(data.ID),
-			IP:          c.ClientIP(),
-			Country:     c.Request.Header.Get("CF-IPCountry"),
-			City:        c.Request.Header.Get("CF-IPCity"),
-			LocationLat: latitude,
-			LocationLng: longitude,
-			Region:      c.Request.Header.Get("CF-Region"),
-			Language:    c.Request.Header.Get("Accept-Language"),
-			OSName:      userAgent.OS,
-			OSVersion:   userAgent.OSVersion,
-			DeviceModel: userAgent.Device,
-		},
-		EventProperties: map[string]interface{}{"source": "hanayo"},
-	})
-
-	identifyObj := amplitude.Identify{}
-	identifyObj.Set("last_login", time.Now().Unix())
-	identifyObj.Set("last_login_country", data.Country)
-	identifyObj.Set("last_login_ip", c.ClientIP())
-	identifyObj.Set("os_name", userAgent.OS)
-	identifyObj.Set("os_version", userAgent.OSVersion)
-	identifyObj.Set("device_model", userAgent.Device)
-
-	services.Amplitude.Identify(
-		identifyObj,
-		amplitude.EventOptions{
-			UserID: strconv.Itoa(data.ID),
-		},
-	)
-
 	uu.SetYCookie(data.ID, c)
 
 	sess.Set("userid", data.ID)

app/handlers/sessions/register/register.go

@@ -8,9 +8,7 @@ import (
 
 	"golang.org/x/exp/slog"
 
-	"github.com/amplitude/analytics-go/amplitude"
 	"github.com/gin-gonic/gin"
-	"github.com/mileusna/useragent"
 	"github.com/osuAkatsuki/akatsuki-api/common"
 	eh "github.com/osuAkatsuki/hanayo/app/handlers/errors"
 	"github.com/osuAkatsuki/hanayo/app/models"
@@ -192,51 +190,6 @@ func RegisterSubmitHandler(c *gin.Context) {
 	// delete the key c
 	//db.Exec("DELETE FROM beta_keys WHERE beta_key = ?", c.PostForm("key"))
 
-	latitude, err := strconv.ParseFloat(c.Request.Header.Get("CF-IPLatitude"), 64)
-	if err != nil {
-		slog.Error("Error parsing latitude", "error", err.Error())
-		latitude = 0.0
-	}
-
-	longitude, err := strconv.ParseFloat(c.Request.Header.Get("CF-IPLongitude"), 64)
-	if err != nil {
-		slog.Error("Error parsing longitude", "error", err.Error())
-		longitude = 0.0
-	}
-
-	userAgent := useragent.Parse(c.Request.UserAgent())
-
-	services.Amplitude.Track(amplitude.Event{
-		EventType: "web_signup",
-		EventOptions: amplitude.EventOptions{
-			UserID:      strconv.FormatInt(userId, 10),
-			IP:          c.ClientIP(),
-			Country:     c.Request.Header.Get("CF-IPCountry"),
-			City:        c.Request.Header.Get("CF-IPCity"),
-			LocationLat: latitude,
-			LocationLng: longitude,
-			Region:      c.Request.Header.Get("CF-Region"),
-			Language:    c.Request.Header.Get("Accept-Language"),
-			OSName:      userAgent.OS,
-			OSVersion:   userAgent.OSVersion,
-			DeviceModel: userAgent.Device,
-		},
-		EventProperties: map[string]interface{}{"source": "hanayo"},
-	})
-
-	identifyObj := amplitude.Identify{}
-	identifyObj.SetOnce("username", username)
-	identifyObj.SetOnce("email", email)
-	identifyObj.SetOnce("signup_date", time.Now().Unix())
-	identifyObj.SetOnce("signup_ip", c.ClientIP())
-
-	services.Amplitude.Identify(
-		identifyObj,
-		amplitude.EventOptions{
-			UserID: strconv.FormatInt(userId, 10),
-		},
-	)
-
 	uu.SetYCookie(int(userId), c)
 
 	err = uu.LogIP(c, int(userId))

app/logging/logging.go

@@ -1,7 +1,6 @@
 package services
 
 import (
-	"github.com/amplitude/analytics-go/amplitude"
 	"github.com/jmoiron/sqlx"
 	csrf "github.com/osuAkatsuki/hanayo/internal/csrf"
 	"github.com/thehowl/qsql"
@@ -15,6 +14,5 @@ var (
 	QB        *qsql.DB
 	MG        mailgun.Mailgun
 	RD        *redis.Client
-	Amplitude amplitude.Client
 	CSRF      csrf.CSRF
 )

app/states/services/services.go

@@ -82,8 +82,6 @@ type Settings struct {
 	IP_LOOKUP_URL string
 
 	PAYPAL_EMAIL_ADDRESS string
-
-	AMPLITUDE_API_KEY string
 }
 
 var settings = Settings{}
@@ -146,8 +144,6 @@ func LoadSettings() Settings {
 
 	settings.PAYPAL_EMAIL_ADDRESS = getEnv("PAYPAL_EMAIL_ADDRESS")
 
-	settings.AMPLITUDE_API_KEY = getEnv("AMPLITUDE_API_KEY")
-
 	return settings
 }
 

app/states/settings/settings.go

@@ -3,7 +3,6 @@ module github.com/osuAkatsuki/hanayo
 go 1.21
 
 require (
-	github.com/amplitude/analytics-go v1.0.1
 	github.com/aws/aws-sdk-go v1.47.3
 	github.com/dustin/go-humanize v1.0.0
 	github.com/fatih/structs v1.1.0
@@ -15,7 +14,6 @@ require (
 	github.com/johnniedoe/contrib v0.0.0-20150821124612-d553224621be
 	github.com/joho/godotenv v1.5.1
 	github.com/microcosm-cc/bluemonday v1.0.26
-	github.com/mileusna/useragent v1.3.3
 	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646
 	github.com/pariz/gountries v0.1.6
 	github.com/rjeczalik/notify v0.9.3-0.20181126183243-629144ba06a1

go.mod

@@ -35,8 +35,6 @@ github.com/allegro/bigcache v1.2.1 h1:hg1sY1raCwic3Vnsvje6TT7/pnZba83LeFck5NrFKS
 github.com/allegro/bigcache v1.2.1/go.mod h1:Cb/ax3seSYIx7SuZdm2G2xzfwmv3TPSk2ucNfQESPXM=
 github.com/allegro/bigcache/v2 v2.2.5 h1:mRc8r6GQjuJsmSKQNPsR5jQVXc8IJ1xsW5YXUYMLfqI=
 github.com/allegro/bigcache/v2 v2.2.5/go.mod h1:FppZsIO+IZk7gCuj5FiIDHGygD9xvWQcqg1uIPMb6tY=
-github.com/amplitude/analytics-go v1.0.1 h1:rrdC5VBctlJigSk0kw7ktwSijob/wyH4bop2SqWduCU=
-github.com/amplitude/analytics-go v1.0.1/go.mod h1:kAQG8OQ6aPOxZrEZ3+/NFCfxdYSyjqXZhgkjWFD3/vo=
 github.com/andybalholm/brotli v1.1.0 h1:eLKJA0d02Lf0mVpIDgYnqXcUn0GqVmEFny3VuID1U3M=
 github.com/andybalholm/brotli v1.1.0/go.mod h1:sms7XGricyQI9K10gOSf56VKKWS4oLer58Q+mhRPtnY=
 github.com/apache/thrift v0.12.0/go.mod h1:cp2SuWMxlEZw2r+iP2GNCdIi4C1qmUzdZFSVb+bacwQ=
@@ -335,8 +333,6 @@ github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5
 github.com/microcosm-cc/bluemonday v1.0.26 h1:xbqSvqzQMeEHCqMi64VAs4d8uy6Mequs3rQ0k/Khz58=
 github.com/microcosm-cc/bluemonday v1.0.26/go.mod h1:JyzOCs9gkyQyjs+6h10UEVSe02CGwkhd72Xdqh78TWs=
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
-github.com/mileusna/useragent v1.3.3 h1:hrIVmPevJY3ICS1Ob4yjqJToQiv2eD9iHaJBjxMihWY=
-github.com/mileusna/useragent v1.3.3/go.mod h1:3d8TOmwL/5I8pJjyVDteHtgDGcefrFUX4ccGOMKNYYc=
 github.com/mitchellh/cli v1.0.0/go.mod h1:hNIlj7HEI86fIcpObd7a0FcrxTWetlwJDGcceTlRvqc=
 github.com/mitchellh/go-homedir v1.0.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/go-testing-interface v1.0.0/go.mod h1:kRemZodwjscx+RGhAo8eIhFbs2+BFgRtFPeD/KE+zxI=
@@ -492,17 +488,16 @@ github.com/streadway/amqp v0.0.0-20190404075320-75d898a42a94/go.mod h1:AZpEONHx3
 github.com/streadway/amqp v0.0.0-20190827072141-edfb9018d271/go.mod h1:AZpEONHx3DKn8O/DFsRAY58/XVQiIPMTMB1SddzLXVw=
 github.com/streadway/handy v0.0.0-20190108123426-d5acb3125c2a/go.mod h1:qNTQ5P5JnDBl6z3cMAg/SywNDC5ABu5ApDIw6lUbRmI=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.1.1 h1:2vfRuCMp5sSVIDSqO8oNnWJq7mPa6KVP3iPIwFBuy8A=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.5.0 h1:1zr/of2m5FGMsad5YfcqgdqdWrIhu+EBEJRhR1U7z/c=
-github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
 github.com/stretchr/testify v0.0.0-20151208002404-e3a8ff8ce365/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
-github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/tevino/abool v1.2.0 h1:heAkClL8H6w+mK5md9dzsuohKeXHUpY7Vw0ZCKW+huA=
 github.com/tevino/abool v1.2.0/go.mod h1:qc66Pna1RiIsPa7O4Egxxs9OqkuxDX55zznh9K07Tzg=
 github.com/thehowl/cieca v0.0.0-20161122163418-3d95e04c9b12 h1:qRwhooiSbYeP3Bb951Ji6PvT5/94Xdbe7B6+IYLj5So=

go.sum

@@ -14,7 +14,6 @@ import (
 
 	"golang.org/x/exp/slog"
 
-	"github.com/amplitude/analytics-go/amplitude"
 	"github.com/fatih/structs"
 	"github.com/gin-gonic/contrib/sessions"
 	"github.com/gin-gonic/gin"
@@ -35,7 +34,6 @@ import (
 	loginHandlers "github.com/osuAkatsuki/hanayo/app/handlers/sessions/login"
 	logoutHandlers "github.com/osuAkatsuki/hanayo/app/handlers/sessions/logout"
 	registerHandlers "github.com/osuAkatsuki/hanayo/app/handlers/sessions/register"
-	logging "github.com/osuAkatsuki/hanayo/app/logging"
 	middleware "github.com/osuAkatsuki/hanayo/app/middleware"
 	msg "github.com/osuAkatsuki/hanayo/app/models/messages"
 	sessionsmanager "github.com/osuAkatsuki/hanayo/app/sessions"
@@ -125,11 +123,6 @@ func main() {
 	})
 	services.RD = rd
 
-	amplitudeConfig := amplitude.NewConfig(settings.AMPLITUDE_API_KEY)
-	amplitudeConfig.MinIDLength = 4 // our user ids start from 1000
-	amplitudeConfig.Logger = (*logging.AmplitudeLogger)(logger)
-	services.Amplitude = amplitude.NewClient(amplitudeConfig)
-
 	// even if it's not release, we say that it's release
 	// so that gin doesn't spam
 	gin.SetMode(gin.ReleaseMode)