adding revenue handlers and shell

internal/handlers/main.go

@@ -6,47 +6,104 @@ import (
 	"database/sql"
 	"encoding/json"
 	"net/http"
+	"runtime"
+	"time"
 
 	_ "github.com/mattn/go-sqlite3"
 )
 
+var startTime = time.Now()
+
 func HealthHandler(db *sql.DB) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "application/json")
 
-		dbStatus := "ok"
-		if err := db.Ping(); err != nil {
-			dbStatus = "error: " + err.Error()
+		health := checkHealth(db)
+
+		if health["status"] != "ok" {
 			w.WriteHeader(http.StatusServiceUnavailable)
 		}
 
-		json.NewEncoder(w).Encode(map[string]string{
-			"status":   "ok",
-			"database": dbStatus,
-		})
+		json.NewEncoder(w).Encode(health)
 	}
 }
 
+func checkHealth(db *sql.DB) map[string]any {
+	// database
+	dbStatus := "ok"
+	dbLatency := ""
+	t := time.Now()
+	if err := db.Ping(); err != nil {
+		dbStatus = "error: " + err.Error()
+	} else {
+		dbLatency = time.Since(t).String()
+	}
+
+	// db pool stats
+	stats := db.Stats()
+
+	// overall status
+	status := "ok"
+	if dbStatus != "ok" {
+		status = "degraded"
+	}
+
+	var mem runtime.MemStats
+	runtime.ReadMemStats(&mem)
+
+	return map[string]any{
+		"status": status,
+		"uptime": time.Since(startTime).String(),
+		"database": map[string]any{
+			"status":           dbStatus,
+			"latency":          dbLatency,
+			"open_connections": stats.OpenConnections,
+			"in_use":           stats.InUse,
+			"idle":             stats.Idle,
+		},
+		"memory": map[string]any{
+			"alloc_mb": bToMb(mem.Alloc),
+			"sys_mb":   bToMb(mem.Sys),
+			"num_gc":   mem.NumGC,
+		},
+		"go_version": runtime.Version(),
+		"goroutines": runtime.NumGoroutine(),
+	}
+}
+
+func bToMb(b uint64) float64 {
+	return float64(b) / 1024 / 1024
+}
+
 func AddCompanyHandler(db *sql.DB) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		if r.Method != http.MethodPost {
-			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
-			return
-		}
-
 		var input model.CompanyInput
 		if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
 			http.Error(w, "invalid json", http.StatusBadRequest)
 			return
 		}
 
-		if err := service.AddCompany(input, db); err != nil {
+		id, err := service.InsertCompany(db, input)
+		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
 
 		w.Header().Set("Content-Type", "application/json")
 		w.WriteHeader(http.StatusCreated)
-		json.NewEncoder(w).Encode(map[string]string{"status": "created"})
+		json.NewEncoder(w).Encode(map[string]any{"status": "created", "id": id})
+	}
+}
+
+func GetCompaniesHandler(db *sql.DB) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		companies, err := service.GetAllCompanies(db)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(companies)
 	}
 }