package main

import (
	"bytes"
	"fmt"
	"strings"
	"time"
)

// discoverWindow is how long to read integration responses per device.
const discoverWindow = 3 * time.Second

// runDiscovery connects to each configured device, asks for its integration IDs,
// prints the responses, and returns. It is a config aid, not part of normal
// operation.
func runDiscovery(devices []*DeviceConfig) {
	for _, dc := range devices {
		discoverDevice(dc)
	}
}

// discoverDevice queries one device for its integration IDs and prints what it
// reports.
func discoverDevice(dc *DeviceConfig) {
	fmt.Printf("== %s (%s, integration_id %d) ==\n", dc.Name, dc.Transport, dc.IntegrationID)
	conn, err := openTransport(dc)
	if err != nil {
		fmt.Printf("  connect failed: %s\n", err)
		return
	}

	// Print integration responses until the connection is closed.
	done := make(chan struct{})
	go func() {
		defer close(done)
		buf := make([]byte, 0, 256)
		tmp := make([]byte, 256)
		for {
			n, err := conn.Read(tmp)
			if err != nil {
				return
			}
			buf = append(buf, tmp[:n]...)
			for {
				i := bytes.IndexByte(buf, '\n')
				if i < 0 {
					break
				}
				line := strings.TrimSpace(strings.ReplaceAll(string(buf[:i]), "QSE>", ""))
				buf = buf[i+1:]
				if line != "" {
					fmt.Printf("  %s\n", line)
				}
			}
		}
	}()

	// "?INTEGRATIONID,3" with no ID prints info for all integration IDs.
	if _, err := conn.Write([]byte("?INTEGRATIONID,3" + qseTerminator)); err != nil {
		fmt.Printf("  query failed: %s\n", err)
	}
	time.Sleep(discoverWindow)
	conn.Close()
	<-done
}