Move client and launcher to its own files

client.go

@@ -0,0 +1,37 @@
+package asynq
+
+import (
+	"time"
+
+	"github.com/go-redis/redis/v7"
+)
+
+// Client is an interface for scheduling tasks.
+type Client struct {
+	rdb *rdb
+}
+
+// NewClient creates and returns a new client.
+func NewClient(opt *RedisOpt) *Client {
+	client := redis.NewClient(&redis.Options{Addr: opt.Addr, Password: opt.Password})
+	return &Client{rdb: newRDB(client)}
+}
+
+// Process enqueues the task to be performed at a given time.
+func (c *Client) Process(task *Task, executeAt time.Time) error {
+	msg := &taskMessage{
+		Type:    task.Type,
+		Payload: task.Payload,
+		Queue:   "default",
+		Retry:   defaultMaxRetry,
+	}
+	return c.enqueue(msg, executeAt)
+}
+
+// enqueue pushes a given task to the specified queue.
+func (c *Client) enqueue(msg *taskMessage, executeAt time.Time) error {
+	if time.Now().After(executeAt) {
+		return c.rdb.push(msg)
+	}
+	return c.rdb.zadd(scheduled, float64(executeAt.Unix()), msg)
+}