Add statusbar config

cmd/statusbar/config/config.go

@@ -0,0 +1,159 @@
+package config
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/cpu"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/datetime"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/disk"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/eth"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/light"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/memory"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/mic"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/mlight"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/power"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/temp"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/volume"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/wlan"
+	"code.chimeric.al/dwrz/statusbar/internal/statusbar/wwan"
+)
+
+// Config corresponds to the top-level JSON object.
+type Config struct {
+	Separator string        `json:"separator"`
+	Timezone  string        `json:"timezone"`
+	Blocks    []BlockConfig `json:"blocks"`
+}
+
+// BlockConfig holds the configuration for a single block.
+type BlockConfig struct {
+	Datetime *datetime.Config `json:"datetime,omitempty"`
+	Disk     *disk.Config     `json:"disk,omitempty"`
+	Eth      *eth.Config      `json:"eth,omitempty"`
+	Name     string           `json:"name,omitempty"`
+	Power    *power.Config    `json:"power,omitempty"`
+	Temp     *temp.Config     `json:"temp,omitempty"`
+	WLAN     *wlan.Config     `json:"wlan,omitempty"`
+	WWAN     *wwan.Config     `json:"wwan,omitempty"`
+}
+
+// Load reads the config file and returns the Config and an instantiated slice
+// of Blocks.
+func Load() (*Config, []statusbar.Block, error) {
+	cfgDir, err := os.UserConfigDir()
+	if err != nil {
+		return nil, nil, fmt.Errorf(
+			"failed to get user config dir: %w", err,
+		)
+	}
+	cfgPath := filepath.Join(cfgDir, "statusbar", "config.json")
+	cfgBytes, err := os.ReadFile(cfgPath)
+	if err != nil {
+		return nil, nil, fmt.Errorf(
+			"failed to read config file %s: %w", cfgPath, err,
+		)
+	}
+
+	var cfg Config
+	if err := json.Unmarshal(cfgBytes, &cfg); err != nil {
+		return nil, nil, fmt.Errorf(
+			"failed to parse config json: %w", err,
+		)
+	}
+
+	var blocks = make([]statusbar.Block, 0, len(cfg.Blocks))
+	for _, bconf := range cfg.Blocks {
+		block, err := CreateBlock(bconf, &cfg)
+		if err != nil {
+			return nil, nil, fmt.Errorf(
+				"failed to instantiate block '%s': %w",
+				bconf.Name, err,
+			)
+		}
+		if block != nil {
+			blocks = append(blocks, block)
+		}
+	}
+
+	return &cfg, blocks, nil
+}
+
+// CreateBlock creates a single block based on its configuration.
+func CreateBlock(bconf BlockConfig, cfg *Config) (statusbar.Block, error) {
+	switch bconf.Name {
+	case "cpu":
+		return cpu.New(), nil
+	case "datetime":
+		var conf datetime.Config
+		if bconf.Datetime != nil {
+			conf = *bconf.Datetime
+		}
+
+		if conf.Timezone == "" {
+			conf.Timezone = cfg.Timezone
+		}
+
+		if conf.Format == "" {
+			now := time.Now()
+			yearEnd := time.Date(
+				now.Year()+1, 1, 1, 0, 0, 0, 0, time.UTC,
+			).AddDate(0, 0, -1)
+			conf.Format = fmt.Sprintf(
+				"+%%Y-%%m-%%d %%u/7 %%W/52 %%j/%d %%H:%%M %%Z",
+				yearEnd.YearDay(),
+			)
+		}
+		return datetime.New(conf), nil
+	case "disk":
+		if bconf.Disk == nil || len(bconf.Disk.Mounts) == 0 {
+			return nil, fmt.Errorf("missing disk mounts")
+		}
+		return disk.New(bconf.Disk.Mounts...), nil
+	case "eth":
+		if bconf.Eth == nil || bconf.Eth.Iface == "" {
+			return nil, fmt.Errorf("missing eth interface")
+		}
+		return eth.New(bconf.Eth.Iface), nil
+	case "light":
+		return light.New(), nil
+	case "mlight":
+		return mlight.New(), nil
+	case "memory":
+		return memory.New(), nil
+	case "mic":
+		return mic.New(), nil
+	case "power":
+		var path = power.Path
+		if bconf.Power != nil && bconf.Power.Path != "" {
+			path = bconf.Power.Path
+		}
+		return power.New(path), nil
+	case "temp":
+		var tconf temp.Config
+		if bconf.Temp != nil {
+			tconf = *bconf.Temp
+		}
+		return temp.New(tconf), nil
+	case "volume":
+		return volume.New(), nil
+	case "wlan":
+		var iface = "wlan0"
+		if bconf.WLAN != nil && bconf.WLAN.Iface != "" {
+			iface = bconf.WLAN.Iface
+		}
+		return wlan.New(iface), nil
+	case "wwan":
+		if bconf.WWAN == nil || bconf.WWAN.Iface == "" {
+			return nil, fmt.Errorf("missing wwan interface")
+		}
+		return wwan.New(bconf.WWAN.Iface), nil
+
+	default:
+		return nil, fmt.Errorf("unknown block type")
+	}
+}