package config

import (
	"fmt"
	"os"
	"time"
)

type Config struct {
	DataDir        string
	QuadletDir     string
	EnrollmentFile string
	HTTPAddr       string
	SocketPath     string
	PodmanSocket   string
	SystemdBus     string
	ThemeCSSFile   string
	PollInterval   time.Duration
	StopTimeout    time.Duration
}

// DefaultSocketPath is the local administration transport, authenticated by filesystem permission.
const DefaultSocketPath = "/run/toad/toad.sock"

func Load() (Config, error) {
	var cfg Config
	var missing []string
	required := func(name string) string {
		value := os.Getenv(name)
		if value == "" {
			missing = append(missing, name)
		}
		return value
	}
	optional := func(name, fallback string) string {
		if value := os.Getenv(name); value != "" {
			return value
		}
		return fallback
	}

	cfg.DataDir = required("TOAD_DATA_DIR")
	cfg.QuadletDir = required("TOAD_QUADLET_DIR")
	cfg.EnrollmentFile = required("TOAD_ENROLLMENT_FILE")
	cfg.HTTPAddr = optional("TOAD_HTTP_ADDR", "127.0.0.1:8090")
	cfg.SocketPath = optional("TOAD_SOCKET", DefaultSocketPath)
	cfg.PodmanSocket = optional("TOAD_PODMAN_SOCKET", "/run/podman/podman.sock")
	cfg.SystemdBus = optional("TOAD_SYSTEMD_BUS", "unix:path=/run/toad/user-bus")
	cfg.ThemeCSSFile = os.Getenv("TOAD_THEME_CSS")
	if len(missing) > 0 {
		return Config{}, fmt.Errorf("missing configuration: %v", missing)
	}

	var err error
	if cfg.PollInterval, err = duration("TOAD_POLL_INTERVAL", "2s"); err != nil {
		return Config{}, err
	}
	if cfg.StopTimeout, err = duration("TOAD_STOP_TIMEOUT", "90s"); err != nil {
		return Config{}, err
	}
	return cfg, nil
}

func duration(name, fallback string) (time.Duration, error) {
	text := os.Getenv(name)
	if text == "" {
		text = fallback
	}
	value, err := time.ParseDuration(text)
	if err != nil || value <= 0 {
		return 0, fmt.Errorf("invalid %s %q", name, text)
	}
	return value, nil
}