mirror of
https://github.com/Alexander-D-Karpov/webring.git
synced 2026-03-16 22:07:41 +03:00
331 lines
10 KiB
Go
331 lines
10 KiB
Go
package api
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import (
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"database/sql"
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"encoding/json"
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"errors"
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"fmt"
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"log"
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"net/http"
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"webring/internal/api/middleware"
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"webring/internal/models"
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"github.com/gorilla/mux"
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)
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func RegisterHandlers(r *mux.Router, db *sql.DB) {
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apiRouter := r.PathPrefix("").Subrouter()
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apiRouter.Use(middleware.CORSMiddleware)
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apiRouter.HandleFunc("/{id}/prev/", previousSiteHandler(db)).Methods("GET")
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apiRouter.HandleFunc("/{id}/next/", nextSiteHandler(db)).Methods("GET")
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apiRouter.HandleFunc("/{id}/prev", previousSiteRedirectHandler(db)).Methods("GET")
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apiRouter.HandleFunc("/{id}/next", nextSiteRedirectHandler(db)).Methods("GET")
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apiRouter.HandleFunc("/{id}/data", siteDataHandler(db)).Methods("GET")
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apiRouter.HandleFunc("/{id}/random/", randomSiteHandler(db)).Methods("GET")
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apiRouter.HandleFunc("/{id}/random", randomSiteRedirectHandler(db)).Methods("GET")
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apiRouter.HandleFunc("/sites", listPublicSitesHandler(db)).Methods("GET")
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}
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func previousSiteHandler(db *sql.DB) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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id := mux.Vars(r)["id"]
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site, err := getPreviousSite(db, id)
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if err != nil {
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http.Error(w, "Site not found", http.StatusNotFound)
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return
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}
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response := struct {
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Previous *models.PublicSite `json:"previous"`
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}{
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Previous: site,
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}
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w.Header().Set("Content-Type", "application/json")
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err = json.NewEncoder(w).Encode(response)
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if err != nil {
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http.Error(w, "Error encoding response", http.StatusInternalServerError)
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return
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}
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}
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}
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func nextSiteHandler(db *sql.DB) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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id := mux.Vars(r)["id"]
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site, err := getNextSite(db, id)
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if err != nil {
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http.Error(w, "Site not found", http.StatusNotFound)
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return
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}
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response := struct {
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Next *models.PublicSite `json:"next"`
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}{
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Next: site,
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}
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w.Header().Set("Content-Type", "application/json")
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err = json.NewEncoder(w).Encode(response)
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if err != nil {
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http.Error(w, "Error encoding response", http.StatusInternalServerError)
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return
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}
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}
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}
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func randomSiteHandler(db *sql.DB) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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currentID := mux.Vars(r)["id"]
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site, err := getRandomSite(db, currentID)
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if err != nil {
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if err.Error() == "no available sites found" {
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http.Error(w, "No available sites found", http.StatusNotFound)
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} else {
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log.Printf("Error fetching random site: %v", err)
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http.Error(w, "Error fetching random site", http.StatusInternalServerError)
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}
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return
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}
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response := struct {
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Random *models.PublicSite `json:"random"`
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}{
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Random: site,
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}
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w.Header().Set("Content-Type", "application/json")
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err = json.NewEncoder(w).Encode(response)
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if err != nil {
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return
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}
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}
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}
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func siteDataHandler(db *sql.DB) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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id := mux.Vars(r)["id"]
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data, err := getSiteData(db, id)
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if err != nil {
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http.Error(w, "Error fetching site data", http.StatusInternalServerError)
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return
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}
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w.Header().Set("Content-Type", "application/json")
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err = json.NewEncoder(w).Encode(data)
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if err != nil {
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http.Error(w, "Error encoding response", http.StatusInternalServerError)
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return
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}
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}
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}
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func previousSiteRedirectHandler(db *sql.DB) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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id := mux.Vars(r)["id"]
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site, err := getPreviousSite(db, id)
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if err != nil {
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http.Error(w, "Site not found", http.StatusNotFound)
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return
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}
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http.Redirect(w, r, site.URL, http.StatusFound)
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}
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}
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func nextSiteRedirectHandler(db *sql.DB) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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id := mux.Vars(r)["id"]
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site, err := getNextSite(db, id)
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if err != nil {
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http.Error(w, "Site not found", http.StatusNotFound)
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return
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}
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http.Redirect(w, r, site.URL, http.StatusFound)
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}
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}
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func randomSiteRedirectHandler(db *sql.DB) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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currentID := mux.Vars(r)["id"]
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site, err := getRandomSite(db, currentID)
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if err != nil {
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if err.Error() == "no available sites found" {
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http.Error(w, "No available sites found", http.StatusNotFound)
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} else {
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log.Printf("Error fetching random site: %v", err)
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http.Error(w, "Error fetching random site", http.StatusInternalServerError)
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}
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return
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}
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http.Redirect(w, r, site.URL, http.StatusFound)
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}
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}
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func listPublicSitesHandler(db *sql.DB) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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sites, err := getRespondingSites(db)
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if err != nil {
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http.Error(w, "Error fetching sites", http.StatusInternalServerError)
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return
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}
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w.Header().Set("Content-Type", "application/json")
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err = json.NewEncoder(w).Encode(sites)
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if err != nil {
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http.Error(w, "Error encoding response", http.StatusInternalServerError)
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return
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}
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}
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}
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func getRespondingSites(db *sql.DB) ([]models.PublicSite, error) {
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rows, err := db.Query("SELECT id, name, url, favicon FROM sites WHERE is_up = true ORDER BY id")
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if err != nil {
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return nil, err
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}
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defer func(rows *sql.Rows) {
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err := rows.Close()
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if err != nil {
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log.Printf("Error closing rows: %v", err)
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}
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}(rows)
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var sites []models.PublicSite
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for rows.Next() {
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var site models.PublicSite
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if err := rows.Scan(&site.ID, &site.Name, &site.URL, &site.Favicon); err != nil {
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return nil, err
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}
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sites = append(sites, site)
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}
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return sites, nil
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}
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func getNextSite(db *sql.DB, currentID string) (*models.PublicSite, error) {
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var site models.PublicSite
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err := db.QueryRow(`
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WITH ring AS (
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SELECT id, name, url, favicon, is_up,
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LEAD(id) OVER (ORDER BY id) AS next_id,
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LAG(id) OVER (ORDER BY id) AS prev_id
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FROM sites
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WHERE is_up = true
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)
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SELECT id, name, url, favicon
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FROM ring
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WHERE (id = $1 AND next_id IS NOT NULL AND next_id = (SELECT MIN(id) FROM ring))
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OR (id > $1 AND is_up = true)
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OR (id = (SELECT MIN(id) FROM ring WHERE is_up = true) AND $1 = (SELECT MAX(id) FROM ring WHERE is_up = true))
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ORDER BY CASE
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WHEN id > $1 THEN id
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ELSE (SELECT MAX(id) FROM ring) + 1
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END
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LIMIT 1
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`, currentID).Scan(&site.ID, &site.Name, &site.URL, &site.Favicon)
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if err != nil {
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return nil, err
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}
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return &site, nil
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}
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func getPreviousSite(db *sql.DB, currentID string) (*models.PublicSite, error) {
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var site models.PublicSite
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err := db.QueryRow(`
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WITH ring AS (
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SELECT id, name, url, favicon, is_up,
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LEAD(id) OVER (ORDER BY id) AS next_id,
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LAG(id) OVER (ORDER BY id) AS prev_id
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FROM sites
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WHERE is_up = true
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)
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SELECT id, name, url, favicon
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FROM ring
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WHERE (id = $1 AND prev_id IS NOT NULL AND prev_id = (SELECT MAX(id) FROM ring))
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OR (id < $1 AND is_up = true)
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OR (id = (SELECT MAX(id) FROM ring WHERE is_up = true) AND $1 = (SELECT MIN(id) FROM ring WHERE is_up = true))
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ORDER BY CASE
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WHEN id < $1 THEN id
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ELSE 0
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END DESC
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LIMIT 1
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`, currentID).Scan(&site.ID, &site.Name, &site.URL, &site.Favicon)
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if err != nil {
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return nil, err
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}
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return &site, nil
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}
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func getSiteData(db *sql.DB, id string) (*models.SiteData, error) {
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var data models.SiteData
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err := db.QueryRow(`
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WITH ring AS (
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SELECT id, name, url, favicon, is_up,
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LAG(id) OVER (ORDER BY id) AS prev_id,
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LAG(name) OVER (ORDER BY id) AS prev_name,
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LAG(url) OVER (ORDER BY id) AS prev_url,
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LAG(favicon) OVER (ORDER BY id) AS prev_favicon,
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LEAD(id) OVER (ORDER BY id) AS next_id,
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LEAD(name) OVER (ORDER BY id) AS next_name,
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LEAD(url) OVER (ORDER BY id) AS next_url,
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LEAD(favicon) OVER (ORDER BY id) AS next_favicon
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FROM sites
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WHERE is_up = true
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),
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wrapped AS (
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SELECT *,
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FIRST_VALUE(id) OVER (ORDER BY id) AS first_id,
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FIRST_VALUE(name) OVER (ORDER BY id) AS first_name,
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FIRST_VALUE(url) OVER (ORDER BY id) AS first_url,
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FIRST_VALUE(favicon) OVER (ORDER BY id) AS first_favicon,
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LAST_VALUE(id) OVER (ORDER BY id RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS last_id,
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LAST_VALUE(name) OVER (ORDER BY id RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS last_name,
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LAST_VALUE(url) OVER (ORDER BY id RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS last_url,
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LAST_VALUE(favicon) OVER (ORDER BY id RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS last_favicon
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FROM ring
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)
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SELECT
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COALESCE(prev_id, last_id) AS prev_id,
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COALESCE(prev_name, last_name) AS prev_name,
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COALESCE(prev_url, last_url) AS prev_url,
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COALESCE(prev_favicon, last_favicon) AS prev_favicon,
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id AS curr_id,
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name AS curr_name,
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url AS curr_url,
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favicon AS curr_favicon,
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COALESCE(next_id, first_id) AS next_id,
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COALESCE(next_name, first_name) AS next_name,
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COALESCE(next_url, first_url) AS next_url,
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COALESCE(next_favicon, first_favicon) AS next_favicon
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FROM wrapped
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WHERE id = $1
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`, id).Scan(
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&data.Prev.ID, &data.Prev.Name, &data.Prev.URL, &data.Prev.Favicon,
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&data.Curr.ID, &data.Curr.Name, &data.Curr.URL, &data.Curr.Favicon,
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&data.Next.ID, &data.Next.Name, &data.Next.URL, &data.Next.Favicon,
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)
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if err != nil {
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return nil, err
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}
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return &data, nil
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}
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func getRandomSite(db *sql.DB, currentID string) (*models.PublicSite, error) {
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var site models.PublicSite
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err := db.QueryRow(`
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SELECT id, name, url, favicon
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FROM sites
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WHERE is_up = true AND id != $1
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ORDER BY RANDOM()
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LIMIT 1
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`, currentID).Scan(&site.ID, &site.Name, &site.URL, &site.Favicon)
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if err != nil {
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if errors.Is(err, sql.ErrNoRows) {
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return nil, fmt.Errorf("no available sites found")
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}
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return nil, fmt.Errorf("database error: %v", err)
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}
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return &site, nil
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}
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