streamdeck-go/internal/config/config.go

package config

import (
	"fmt"
	"os"
	"path/filepath"

	"gopkg.in/yaml.v3"
)

// PollConfig defines how to poll for the current state of a toggle key.
type PollConfig struct {
	Command  string `yaml:"command"`  // shell command whose output is checked
	Interval string `yaml:"interval"` // how often to poll, e.g. "2s" (default: "2s")
	Match    string `yaml:"match"`    // substring to find in output → "on" state; omit to use exit code 0

	// Module-based alternative to Command: resolved to a shell string at startup.
	Module   string            `yaml:"module"`
	Function string            `yaml:"function"`
	Params   map[string]string `yaml:"params"`
}

// KeyConfig defines what a single Stream Deck key does.
type KeyConfig struct {
	Icon      string `yaml:"icon"`       // filename relative to icons_dir (regular keys)
	Text      string `yaml:"text"`       // text overlay on the key (auto-sized, supports newlines)
	TextColor string `yaml:"text_color"` // text color: "white" (default), "black", "red", "blue", or hex "#RRGGBB"
	Command   string `yaml:"command"`    // shell command to run on press

	// Dynamic text: periodically run TextCommand and render its stdout as the
	// key's text overlay. Refresh is the interval (default 1s, floor 250ms).
	// Text (above) is the static fallback / initial value.
	TextCommand string `yaml:"text_command"` // shell command whose stdout becomes the overlay text
	Refresh     string `yaml:"refresh"`      // how often to re-run text_command, e.g. "1s" (default: "1s")

	// Toggle/status keys: show different icons based on polled state.
	IconTrue  string      `yaml:"icon_true"`  // icon when poll match is true
	IconFalse string      `yaml:"icon_false"` // icon when poll match is false
	Poll      *PollConfig `yaml:"poll"`

	// Module-based alternative to Command: resolved to a shell string at startup.
	Module   string            `yaml:"module"`
	Function string            `yaml:"function"`
	Params   map[string]string `yaml:"params"`

	// Folder key: pressing it swaps the deck to the named folder's keys
	// (defined under the top-level `folders:` block). Folders nest — a folder's
	// key may itself have a folder — and every folder shows a back key.
	Folder string `yaml:"folder"`
}

// BackConfig customises the back key every folder shows. All fields are
// optional: the default is key 0 drawn with a built-in arrow and "Back" label.
type BackConfig struct {
	Key       *int   `yaml:"key"`        // slot index for the back key (default 0)
	Icon      string `yaml:"icon"`       // icon filename relative to icons_dir (default: built-in arrow)
	Text      string `yaml:"text"`       // label (default "Back")
	TextColor string `yaml:"text_color"` // same values as KeyConfig.TextColor
}

// FolderConfig is a sub-page of keys shown while a folder is open.
type FolderConfig struct {
	Back BackConfig        `yaml:"back"`
	Keys map[int]KeyConfig `yaml:"keys"`
}

// BackKey returns the slot index the folder's back key occupies.
func (f FolderConfig) BackKey() int {
	if f.Back.Key != nil {
		return *f.Back.Key
	}
	return 0
}

// DefaultConfigPath returns the default config file path, respecting XDG_CONFIG_HOME.
func DefaultConfigPath() string {
	base := os.Getenv("XDG_CONFIG_HOME")
	if base == "" {
		home, _ := os.UserHomeDir()
		base = filepath.Join(home, ".config")
	}
	return filepath.Join(base, "streamdeck-go", "config.yaml")
}

// ModulesPath returns the path to the modules.yaml file next to the given config file.
func ModulesPath(cfgPath string) string {
	return filepath.Join(filepath.Dir(cfgPath), "modules.yaml")
}

// Config is the top-level structure of the YAML config file.
type Config struct {
	IconsDir   string            `yaml:"icons_dir"`
	Brightness int               `yaml:"brightness"`
	Device     DeviceConfig      `yaml:"device"`
	Keys       map[int]KeyConfig `yaml:"keys"`
	// Folders are sub-pages opened by keys with a `folder:` field. The root
	// page is Keys; a folder's keys replace it until its back key is pressed.
	Folders map[string]FolderConfig `yaml:"folders"`
}

// DeviceConfig allows overriding USB IDs (defaults work for Stream Deck XL v2).
type DeviceConfig struct {
	VendorID  uint16 `yaml:"vendor_id"`
	ProductID uint16 `yaml:"product_id"`
}

// Load reads and parses a YAML config file, applying sane defaults.
// icons_dir defaults to an "icons" folder next to the config file.
func Load(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("read config %q: %w", path, err)
	}

	cfg := &Config{
		IconsDir:   filepath.Join(filepath.Dir(path), "icons"),
		Brightness: 70,
		Device: DeviceConfig{
			VendorID:  0x0fd9,
			ProductID: 0x00ba, // Stream Deck XL v2
		},
	}

	if err := yaml.Unmarshal(data, cfg); err != nil {
		return nil, fmt.Errorf("parse config: %w", err)
	}

	// Resolve relative icons_dir against the config file's directory so the
	// binary works regardless of the working directory (e.g. as a systemd service).
	if !filepath.IsAbs(cfg.IconsDir) {
		cfg.IconsDir = filepath.Join(filepath.Dir(path), cfg.IconsDir)
	}

	return cfg, nil
}