assign random planet on game start

db.go

@@ -2,13 +2,21 @@ package main
 
 import (
 	"database/sql"
+	"fmt"
 	_ "github.com/mattn/go-sqlite3"
 	"math"
+	"math/rand"
 	"os"
 )
 
+var planetIndex map[int]exoSystem
+
+func dbconnect() (*sql.DB, error) {
+	return sql.Open("sqlite3", "./exo.db")
+}
+
 func setupDb() {
-	db, err := sql.Open("sqlite3", "./exo.db")
+	db, err := dbconnect()
 	if err != nil {
 		bail(E_No_DB, "unable to open database: %v", err)
 	}
@@ -29,7 +37,6 @@ func setupDb() {
 	}
 
 	n, err := countPlanets(db)
-	log_info("num planets: %v error: %v", n, err)
 	if n == 0 {
 		fi, err := os.Open(dataPath)
 		if err != nil {
@@ -42,9 +49,9 @@ func setupDb() {
 		}
 	}
 
-	idx := indexPlanets(db)
-	log_info("%v", idx)
-	fillEdges(db, idx)
+	indexPlanets(db)
+	// log_info("%v", idx)
+	// fillEdges(db, idx)
 
 	stmnt = `create table if not exists edges (
         id_1 integer,
@@ -57,6 +64,16 @@ func setupDb() {
 		return
 	}
 
+	stmnt = `create table if not exists players (
+        id integer not null primary key autoincrement,
+        name text
+    );`
+	_, err = db.Exec(stmnt)
+	if err != nil {
+		log_error("couldn't create player table: %v", err)
+		return
+	}
+
 }
 
 func sq(x float64) float64 {
@@ -78,7 +95,7 @@ func indexPlanets(db *sql.DB) map[int]exoSystem {
 		return nil
 	}
 	defer rows.Close()
-	planets := make(map[int]exoSystem, 551)
+	planetIndex = make(map[int]exoSystem, 551)
 	for rows.Next() {
 		var id int
 		p := exoSystem{}
@@ -86,9 +103,9 @@ func indexPlanets(db *sql.DB) map[int]exoSystem {
 			log_info("unable to scan planet row: %v", err)
 			continue
 		}
-		planets[id] = p
+		planetIndex[id] = p
 	}
-	return planets
+	return planetIndex
 }
 
 func fillEdges(db *sql.DB, planets map[int]exoSystem) {
@@ -98,3 +115,14 @@ func fillEdges(db *sql.DB, planets map[int]exoSystem) {
 		}
 	}
 }
+
+func randomPlanet() (*exoSystem, error) {
+	n := len(planetIndex)
+	if n == 0 {
+		return nil, fmt.Errorf("no planets are known to exist")
+	}
+
+	pick := rand.Intn(n)
+    planet := planetIndex[pick]
+    return &planet, nil
+}

errors.go

@@ -8,6 +8,7 @@ const (
 	E_Ok int = iota
 	E_No_Data
 	E_No_DB
+    E_No_Port
 )
 
 type errorGroup []error

interactions.go

@@ -0,0 +1,6 @@
+package main
+
+import (
+)
+
+

main.go

@@ -1,8 +1,12 @@
 package main
 
 import (
+	"bufio"
 	"fmt"
+	"net"
 	"os"
+	"regexp"
+	"strings"
 )
 
 var dataPath = "/projects/exo/expl.speck"
@@ -26,6 +30,41 @@ func bail(status int, template string, args ...interface{}) {
 	os.Exit(status)
 }
 
+func handleConnection(conn net.Conn) {
+    namePattern := regexp.MustCompile(`^[[:alpha:]][[:alnum:]-_]{0,19}$`)
+	r := bufio.NewReader(conn)
+	fmt.Fprintf(conn, "what is your name, adventurer?\n")
+	name, err := r.ReadString('\n')
+	if err == nil {
+		name = strings.TrimSpace(name)
+		log_info("player connected: %v", name)
+	} else {
+		log_error("player failed to connect: %v", err)
+	}
+    if !namePattern.MatchString(name) {
+        fmt.Fprintf(conn, "that name is illegal.\n")
+    }
+
+    planet, err := randomPlanet()
+    if err != nil {
+        log_error("player %s failed to get random planet: %v", name, err)
+        return
+    }
+    fmt.Fprintf(conn, "you are on the planet %s\n", planet.name)
+}
+
 func main() {
 	setupDb()
+	listener, err := net.Listen("tcp", ":9220")
+	if err != nil {
+		bail(E_No_Port, "unable to start server: %v", err)
+	}
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			log_error("error accepting connection: %v", err)
+			continue
+		}
+		go handleConnection(conn)
+	}
 }