package notify

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
)

// Config is ~/.config/notifyr/config.json, created with homelab
// defaults on first run. NOTIFYR_CONFIG overrides the path.
type Config struct {
	Server       string            `json:"server"`
	Token        string            `json:"token"`
	DefaultTopic string            `json:"default_topic"`
	Topics       map[string]string `json:"topics"` // known topics -> what they carry (informational)
}

func DefaultConfig() *Config {
	return &Config{
		Server:       "https://ntfy.brasse-pc.eu",
		Token:        "",
		DefaultTopic: "claude",
		Topics: map[string]string{
			"claude":           "agents' direct notes to Björn",
			"agent-helm":       "agent-helm events (question waiting, session died)",
			"Info":             "*arr system events",
			"media-hamtningar": "media grabbed for download",
			"media-nytt":       "new media landed in Jellyfin",
			"pi5-server":       "server maintenance (reboots, watchtower)",
			"pi5-server-fel":   "server problems: failed units, disk space",
			"ci-fel":           "failed Gitea Actions builds",
			"monitoring":       "Uptime Kuma up/down alerts",
		},
	}
}

func ConfigPath() string {
	if p := os.Getenv("NOTIFYR_CONFIG"); p != "" {
		return p
	}
	dir, err := os.UserConfigDir()
	if err != nil {
		dir = "."
	}
	return filepath.Join(dir, "notifyr", "config.json")
}

// LoadConfig reads the config, creating it with defaults on first run.
func LoadConfig(path string) (*Config, error) {
	cfg := DefaultConfig()
	data, err := os.ReadFile(path)
	if os.IsNotExist(err) {
		if err := SaveConfig(path, cfg); err != nil {
			return nil, err
		}
		fmt.Fprintf(os.Stderr, "notifyr: created %s\n", path)
		return cfg, nil
	}
	if err != nil {
		return nil, err
	}
	if err := json.Unmarshal(data, cfg); err != nil {
		return nil, fmt.Errorf("%s: %w", path, err)
	}
	return cfg, nil
}

func SaveConfig(path string, cfg *Config) error {
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		return err
	}
	data, err := json.MarshalIndent(cfg, "", "  ")
	if err != nil {
		return err
	}
	return os.WriteFile(path, append(data, '\n'), 0o600)
}