1 files changed, 263 insertions, 0 deletions
diff --git a/internal/config/config.go b/internal/config/config.go
new file mode 100644
index 0000000..7551a10
--- /dev/null
+++ b/internal/config/config.go
@@ -0,0 +1,263 @@
+package config
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/loadbars/loadbars/internal/constants"
+)
+
+// Config holds all loadbars configuration (file + CLI).
+// Defaults match the Perl Shared.pm %C.
+type Config struct {
+	Hosts      []string // Each entry is "host" or "host:user"
+	Title      string
+	BarWidth   int
+	CPUAverage int
+	Extended   bool
+	HasAgent   bool
+	Height     int
+	MaxWidth   int
+	NetAverage int
+	NetInt     string
+	NetLink    string
+	ShowCores  bool
+	ShowMem    bool
+	ShowNet    bool
+	SSHOpts    string
+	Cluster    string
+}
+
+// Default returns a Config with default values.
+func Default() Config {
+	return Config{
+		BarWidth:   20,
+		CPUAverage: 10,
+		Extended:   false,
+		HasAgent:   false,
+		Height:    150,
+		MaxWidth:  1900,
+		NetAverage: 15,
+		NetLink:   "gbit",
+		ShowCores: false,
+		ShowMem:   false,
+		ShowNet:   false,
+	}
+}
+
+// ConfFilePath returns the full path to the config file (~/.loadbarsrc).
+func ConfFilePath() (string, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("home dir: %w", err)
+	}
+	return filepath.Join(home, constants.ConfFile), nil
+}
+
+// Load reads config from the config file and merges into c. Unknown keys are ignored.
+func (c *Config) Load() error {
+	path, err := ConfFilePath()
+	if err != nil {
+		return err
+	}
+	f, err := os.Open(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return fmt.Errorf("open config: %w", err)
+	}
+	defer f.Close()
+	return c.parseReader(f)
+}
+
+func (c *Config) parseReader(f *os.File) error {
+	validKeys := map[string]bool{
+		"title": true, "barwidth": true, "cpuaverage": true, "extended": true,
+		"hasagent": true, "height": true, "maxwidth": true, "netaverage": true,
+		"netint": true, "netlink": true, "showcores": true, "showmem": true,
+		"shownet": true, "sshopts": true, "cluster": true,
+	}
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if idx := strings.Index(line, "#"); idx >= 0 {
+			line = strings.TrimSpace(line[:idx])
+		}
+		if line == "" {
+			continue
+		}
+		parts := strings.SplitN(line, "=", 2)
+		if len(parts) != 2 {
+			continue
+		}
+		key := strings.TrimSpace(parts[0])
+		val := strings.TrimSpace(parts[1])
+		if !validKeys[key] {
+			continue
+		}
+		c.set(key, val)
+	}
+	return scanner.Err()
+}
+
+func (c *Config) set(key, val string) {
+	switch key {
+	case "title":
+		c.Title = val
+	case "barwidth":
+		if n, err := strconv.Atoi(val); err == nil {
+			c.BarWidth = n
+		}
+	case "cpuaverage":
+		if n, err := strconv.Atoi(val); err == nil {
+			c.CPUAverage = n
+		}
+	case "extended":
+		c.Extended = parseBool(val)
+	case "hasagent":
+		c.HasAgent = parseBool(val)
+	case "height":
+		if n, err := strconv.Atoi(val); err == nil {
+			c.Height = n
+		}
+	case "maxwidth":
+		if n, err := strconv.Atoi(val); err == nil {
+			c.MaxWidth = n
+		}
+	case "netaverage":
+		if n, err := strconv.Atoi(val); err == nil {
+			c.NetAverage = n
+		}
+	case "netint":
+		c.NetInt = val
+	case "netlink":
+		c.NetLink = val
+	case "showcores":
+		c.ShowCores = parseBool(val)
+	case "showmem":
+		c.ShowMem = parseBool(val)
+	case "shownet":
+		c.ShowNet = parseBool(val)
+	case "sshopts":
+		c.SSHOpts = val
+	case "cluster":
+		c.Cluster = val
+	}
+}
+
+func parseBool(s string) bool {
+	s = strings.TrimSpace(strings.ToLower(s))
+	return s == "1" || s == "true" || s == "yes"
+}
+
+// Write saves the current config to the config file (excluding title).
+func (c *Config) Write() error {
+	path, err := ConfFilePath()
+	if err != nil {
+		return err
+	}
+	f, err := os.Create(path)
+	if err != nil {
+		return fmt.Errorf("create config: %w", err)
+	}
+	defer f.Close()
+	return c.writeTo(f)
+}
+
+func (c *Config) writeTo(f *os.File) error {
+	w := bufio.NewWriter(f)
+	writeInt := func(key string, v int) { fmt.Fprintf(w, "%s=%d\n", key, v) }
+	writeStr := func(key, v string) { fmt.Fprintf(w, "%s=%s\n", key, v) }
+	writeBool := func(key string, v bool) {
+		val := "0"
+		if v {
+			val = "1"
+		}
+		fmt.Fprintf(w, "%s=%s\n", key, val)
+	}
+	writeInt("barwidth", c.BarWidth)
+	writeInt("cpuaverage", c.CPUAverage)
+	writeBool("extended", c.Extended)
+	writeBool("hasagent", c.HasAgent)
+	writeInt("height", c.Height)
+	writeInt("maxwidth", c.MaxWidth)
+	writeInt("netaverage", c.NetAverage)
+	writeStr("netint", c.NetInt)
+	writeStr("netlink", c.NetLink)
+	writeBool("showcores", c.ShowCores)
+	writeBool("showmem", c.ShowMem)
+	writeBool("shownet", c.ShowNet)
+	writeStr("sshopts", c.SSHOpts)
+	writeStr("cluster", c.Cluster)
+	return w.Flush()
+}
+
+// GetClusterHosts resolves a cluster name from /etc/clusters into a list of hosts.
+func GetClusterHosts(cluster string) ([]string, error) {
+	return GetClusterHostsFromFile(cluster, constants.CSSHConfFile)
+}
+
+// GetClusterHostsFromFile resolves a cluster from a clusters file (for testing or custom path).
+// Supports recursive cluster references with cycle detection.
+func GetClusterHostsFromFile(cluster, path string) ([]string, error) {
+	return getClusterHostsRec(cluster, path, 1, nil)
+}
+
+func getClusterHostsRec(cluster, path string, depth int, seen map[string]bool) ([]string, error) {
+	if depth > constants.CSSHMaxRecursion {
+		return nil, fmt.Errorf("cluster recursion limit reached in %s (possible cycle)", path)
+	}
+	if seen == nil {
+		seen = make(map[string]bool)
+	}
+	if seen[cluster] {
+		return nil, fmt.Errorf("cluster cycle detected: %s", cluster)
+	}
+
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("open %s: %w", path, err)
+	}
+	defer f.Close()
+
+	var line string
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		ln := strings.TrimSpace(scanner.Text())
+		if ln == "" || strings.HasPrefix(ln, "#") {
+			continue
+		}
+		fields := strings.Fields(ln)
+		if len(fields) >= 1 && fields[0] == cluster {
+			if len(fields) > 1 {
+				line = strings.Join(fields[1:], " ")
+			}
+			break
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	if line == "" {
+		return []string{cluster}, nil
+	}
+
+	seen[cluster] = true
+	defer delete(seen, cluster)
+
+	var out []string
+	for _, part := range strings.Fields(line) {
+		hosts, err := getClusterHostsRec(part, path, depth+1, seen)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, hosts...)
+	}
+	return out, nil
+}