// Package config holds the small set of deployment-specific settings the
// tool needs: how this box is reached from the outside, and where its state
// lives on disk.
package config

import (
	"fmt"
	"os"

	"gopkg.in/yaml.v3"
)

// Config is the tool's deployment configuration, normally loaded from
// /etc/ssh-access-tui/config.yaml (see scripts/install.sh).
type Config struct {
	// JumpHost is the address end users' ssh clients connect to — usually
	// this box's public hostname/IP, used only to render client configs.
	JumpHost string `yaml:"jump_host"`
	JumpPort int    `yaml:"jump_port"`

	StateDir   string `yaml:"state_dir"`   // git-backed YAML state (groups/users)
	ExportDir  string `yaml:"export_dir"`  // where finished .7z archives are written
	ScratchDir string `yaml:"scratch_dir"` // ephemeral working dir, wiped after each export
	AuditLog   string `yaml:"audit_log"`   // append-only JSONL connect/disconnect log
}

// Default returns sane defaults for an install following scripts/install.sh.
func Default() Config {
	return Config{
		JumpPort:   22,
		StateDir:   "/var/lib/ssh-access-tui/state",
		ExportDir:  "/var/lib/ssh-access-tui/exports",
		ScratchDir: "/var/lib/ssh-access-tui/scratch",
		AuditLog:   "/var/lib/ssh-access-tui/audit/audit.jsonl",
	}
}

// Load reads path if it exists, overlaying it on Default(); missing fields
// keep their default. A missing file is not an error (first run).
func Load(path string) (Config, error) {
	cfg := Default()
	data, err := os.ReadFile(path)
	if os.IsNotExist(err) {
		return cfg, nil
	}
	if err != nil {
		return cfg, fmt.Errorf("read config %s: %w", path, err)
	}
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return cfg, fmt.Errorf("parse config %s: %w", path, err)
	}
	return cfg, nil
}

// Save writes cfg to path as YAML, creating parent directories as needed.
func Save(path string, cfg Config) error {
	data, err := yaml.Marshal(cfg)
	if err != nil {
		return err
	}
	return os.WriteFile(path, data, 0o644)
}