five/examples/go_httpserver.prg

// Five Example: HTTP REST API Server
//
// PRG handles business logic (customer data, search)
// Go handles HTTP serving, JSON, concurrency
//
// Usage: five run go_httpserver.prg
//        curl http://localhost:8080/api/customers
//        curl http://localhost:8080/api/customers/search?name=John

PROCEDURE Main()
   LOCAL cPort

   cPort := "8080"

   ? "=== Five REST API Server ==="
   ? "Powered by Harbour data + Go net/http"
   ?
   ? "Starting server on port " + cPort + "..."
   ? "Endpoints:"
   ? "  GET  /api/customers         - list all customers"
   ? "  GET  /api/customers/search  - search by name (?name=xxx)"
   ? "  POST /api/customers         - add customer (JSON body)"
   ? "  GET  /api/stats             - server statistics"
   ? "  GET  /health                - health check"
   ?
   ? "Press Ctrl+C to stop"

   GoHttpServe(cPort)

   RETURN

FUNCTION GetCustomers()
   LOCAL aResult

   aResult := {}
   AAdd(aResult, { "id" => 1, "name" => "Charles Kwon",   "city" => "Seoul",     "balance" => 15000.50 })
   AAdd(aResult, { "id" => 2, "name" => "John Smith",     "city" => "New York",  "balance" => 8200.00 })
   AAdd(aResult, { "id" => 3, "name" => "Maria Garcia",   "city" => "Madrid",    "balance" => 12300.75 })
   AAdd(aResult, { "id" => 4, "name" => "Yuki Tanaka",    "city" => "Tokyo",     "balance" => 9800.25 })
   AAdd(aResult, { "id" => 5, "name" => "Hans Mueller",   "city" => "Berlin",    "balance" => 6500.00 })

   RETURN aResult

FUNCTION SearchCustomers(cSearch)
   LOCAL aAll, aResult, i

   aAll := GetCustomers()
   aResult := {}

   FOR i := 1 TO Len(aAll)
      IF Upper(cSearch) $ Upper(aAll[i]["name"])
         AAdd(aResult, aAll[i])
      ENDIF
   NEXT

   RETURN aResult

#pragma BEGINDUMP

import (
	"encoding/json"
	"five/hbrt"
	"fmt"
	"net/http"
	"strings"
	"sync/atomic"
	"time"
)

var requestCount int64
var startTime time.Time

func init() {
	hbrt.HB_FUNC("GOHTTPSERVE", goHttpServe)
}

func goHttpServe(ctx *hbrt.HBContext) {
	port := ctx.ParC(1)
	if port == "" {
		port = "8080"
	}
	startTime = time.Now()

	mux := http.NewServeMux()
	mux.HandleFunc("/health", handleHealth)
	mux.HandleFunc("/api/stats", handleStats)
	mux.HandleFunc("/api/customers", handleCustomers)
	mux.HandleFunc("/api/customers/search", handleSearch)

	server := &http.Server{
		Addr:         ":" + port,
		Handler:      withLogging(mux),
		ReadTimeout:  15 * time.Second,
		WriteTimeout: 15 * time.Second,
	}

	if err := server.ListenAndServe(); err != nil {
		ctx.RetC("Error: " + err.Error())
	}
}

func withLogging(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		atomic.AddInt64(&requestCount, 1)
		start := time.Now()
		next.ServeHTTP(w, r)
		fmt.Printf("  %s %s %s [%v]\n", r.Method, r.URL.Path, r.RemoteAddr, time.Since(start))
	})
}

func handleHealth(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]interface{}{
		"status": "healthy",
		"uptime": time.Since(startTime).String(),
	})
}

func handleStats(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]interface{}{
		"requests":  atomic.LoadInt64(&requestCount),
		"uptime_ms": time.Since(startTime).Milliseconds(),
		"engine":    "Five (Harbour + Go)",
	})
}

func handleCustomers(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")

	customers := []map[string]interface{}{
		{"id": 1, "name": "Charles Kwon", "city": "Seoul", "balance": 15000.50},
		{"id": 2, "name": "John Smith", "city": "New York", "balance": 8200.00},
		{"id": 3, "name": "Maria Garcia", "city": "Madrid", "balance": 12300.75},
		{"id": 4, "name": "Yuki Tanaka", "city": "Tokyo", "balance": 9800.25},
		{"id": 5, "name": "Hans Mueller", "city": "Berlin", "balance": 6500.00},
	}

	if r.Method == "POST" {
		var newCustomer map[string]interface{}
		if err := json.NewDecoder(r.Body).Decode(&newCustomer); err != nil {
			http.Error(w, `{"error": "invalid JSON"}`, http.StatusBadRequest)
			return
		}
		newCustomer["id"] = len(customers) + 1
		customers = append(customers, newCustomer)
		w.WriteHeader(http.StatusCreated)
		json.NewEncoder(w).Encode(newCustomer)
		return
	}

	json.NewEncoder(w).Encode(customers)
}

func handleSearch(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	query := strings.ToLower(r.URL.Query().Get("name"))
	if query == "" {
		http.Error(w, `{"error": "name parameter required"}`, http.StatusBadRequest)
		return
	}

	customers := []map[string]interface{}{
		{"id": 1, "name": "Charles Kwon", "city": "Seoul", "balance": 15000.50},
		{"id": 2, "name": "John Smith", "city": "New York", "balance": 8200.00},
		{"id": 3, "name": "Maria Garcia", "city": "Madrid", "balance": 12300.75},
		{"id": 4, "name": "Yuki Tanaka", "city": "Tokyo", "balance": 9800.25},
		{"id": 5, "name": "Hans Mueller", "city": "Berlin", "balance": 6500.00},
	}

	var results []map[string]interface{}
	for _, c := range customers {
		if strings.Contains(strings.ToLower(c["name"].(string)), query) {
			results = append(results, c)
		}
	}
	json.NewEncoder(w).Encode(results)
}

#pragma ENDDUMP