// Package puppet holds the small pieces of PuppetDB/Puppetboard plumbing shared
// by the node-lookup companion tools (pburl, pblastreport): config loading,
// PuppetDB "nodes" queries, Puppetboard URL construction, and reading hostnames
// from piped node-lookup output.
//
// It intentionally reads the SAME config file, env vars, and defaults as the
// node-lookup CLI so a single `~/.config/node-lookup/config.yaml` configures
// every tool in the family.
package puppet

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

	"gopkg.in/yaml.v3"
)

const (
	// DefaultPuppetDBURL is the PuppetDB v4 facts endpoint (shared with node-lookup).
	DefaultPuppetDBURL = "http://puppetdbapi.service.consul:8080/pdb/query/v4/facts"
	// DefaultRoleFact is the role fact node-lookup queries with -R.
	DefaultRoleFact = "enc_role"
	// DefaultPuppetboardURL is the base URL of the Puppetboard web UI.
	DefaultPuppetboardURL = "https://puppetboard.k8s.syd1.au.unkin.net"

	appName        = "node-lookup"
	configFileName = "config.yaml"
)

// Config mirrors node-lookup's config plus the puppetboard_url key used by the
// companion tools. Fields map 1:1 to config file keys and env vars.
type Config struct {
	PuppetDBURL    string `yaml:"puppetdb_url"`
	RoleFact       string `yaml:"role_fact"`
	PuppetboardURL string `yaml:"puppetboard_url"`
}

// DefaultConfig returns the built-in defaults.
func DefaultConfig() Config {
	return Config{
		PuppetDBURL:    DefaultPuppetDBURL,
		RoleFact:       DefaultRoleFact,
		PuppetboardURL: DefaultPuppetboardURL,
	}
}

// ConfigDir returns the XDG_CONFIG_HOME/node-lookup directory.
func ConfigDir() string {
	base := os.Getenv("XDG_CONFIG_HOME")
	if base == "" {
		home, _ := os.UserHomeDir()
		base = filepath.Join(home, ".config")
	}
	return filepath.Join(base, appName)
}

// ConfigPath returns the full path to the shared config file.
func ConfigPath() string {
	return filepath.Join(ConfigDir(), configFileName)
}

// Load reads the config file (if present), then applies env var overrides.
// Precedence (lowest → highest): defaults < config file < env vars.
func Load() (Config, error) {
	cfg := DefaultConfig()

	path := ConfigPath()
	data, err := os.ReadFile(path)
	if err != nil && !os.IsNotExist(err) {
		return cfg, fmt.Errorf("reading config %s: %w", path, err)
	}
	if err == nil {
		if err := yaml.Unmarshal(data, &cfg); err != nil {
			return cfg, fmt.Errorf("parsing config %s: %w", path, err)
		}
	}

	if v := os.Getenv("NODE_LOOKUP_URL"); v != "" {
		cfg.PuppetDBURL = v
	}
	if v := os.Getenv("NODE_LOOKUP_ROLE_FACT"); v != "" {
		cfg.RoleFact = v
	}
	if v := os.Getenv("NODE_LOOKUP_PUPPETBOARD_URL"); v != "" {
		cfg.PuppetboardURL = v
	}

	return cfg, nil
}