package settings

import (
	"errors"
	"fmt"
	"log/slog"
	"os"
	"path/filepath"
	"vctp/internal/utils"

	"gopkg.in/yaml.v2"
)

type Settings struct {
	SettingsPath string
	Logger       *slog.Logger
	Values       *SettingsYML
}

// SettingsYML struct holds various runtime data that is too cumbersome to specify via command line, eg replacement properties
type SettingsYML struct {
	Settings struct {
		LogLevel                         string   `yaml:"log_level"`
		LogOutput                        string   `yaml:"log_output"`
		DatabaseDriver                   string   `yaml:"database_driver"`
		DatabaseURL                      string   `yaml:"database_url"`
		BindIP                           string   `yaml:"bind_ip"`
		BindPort                         int      `yaml:"bind_port"`
		BindDisableTLS                   bool     `yaml:"bind_disable_tls"`
		TLSCertFilename                  string   `yaml:"tls_cert_filename"`
		TLSKeyFilename                   string   `yaml:"tls_key_filename"`
		VcenterUsername                  string   `yaml:"vcenter_username"`
		VcenterPassword                  string   `yaml:"vcenter_password"`
		VcenterInsecure                  bool     `yaml:"vcenter_insecure"`
		VcenterEventPollingSeconds       int      `yaml:"vcenter_event_polling_seconds"`
		VcenterInventoryPollingSeconds   int      `yaml:"vcenter_inventory_polling_seconds"`
		VcenterInventorySnapshotSeconds  int      `yaml:"vcenter_inventory_snapshot_seconds"`
		VcenterInventoryAggregateSeconds int      `yaml:"vcenter_inventory_aggregate_seconds"`
		HourlySnapshotMaxAgeDays         int      `yaml:"hourly_snapshot_max_age_days"`
		DailySnapshotMaxAgeMonths        int      `yaml:"daily_snapshot_max_age_months"`
		SnapshotCleanupCron              string   `yaml:"snapshot_cleanup_cron"`
		TenantsToFilter                  []string `yaml:"tenants_to_filter"`
		NodeChargeClusters               []string `yaml:"node_charge_clusters"`
		SrmActiveActiveVms               []string `yaml:"srm_activeactive_vms"`
		VcenterAddresses                 []string `yaml:"vcenter_addresses"`
	} `yaml:"settings"`
}

func New(logger *slog.Logger, settingsPath string) *Settings {
	return &Settings{
		SettingsPath: utils.GetFilePath(settingsPath),
		Logger:       logger,
	}
}

func (s *Settings) ReadYMLSettings() error {
	// Create config structure
	var settings SettingsYML

	// Check for empty filename
	if len(s.SettingsPath) == 0 {
		return errors.New("settings file path not specified")
	}

	//path := utils.GetFilePath(settingsPath)

	// Open config file
	file, err := os.Open(s.SettingsPath)
	if err != nil {
		return fmt.Errorf("unable to open settings file : '%s'", err)
	}
	s.Logger.Debug("Opened settings yaml file", "file_path", s.SettingsPath)
	defer file.Close()

	// Init new YAML decode
	d := yaml.NewDecoder(file)

	// Start YAML decoding from file
	if err := d.Decode(&settings); err != nil {
		return fmt.Errorf("unable to decode settings file : '%s'", err)
	}

	s.Logger.Debug("Updating settings", "settings", settings)
	s.Values = &settings

	return nil
}

func (s *Settings) WriteYMLSettings() error {
	if s.Values == nil {
		return errors.New("settings are not loaded")
	}
	if len(s.SettingsPath) == 0 {
		return errors.New("settings file path not specified")
	}

	data, err := yaml.Marshal(s.Values)
	if err != nil {
		return fmt.Errorf("unable to encode settings file: %w", err)
	}

	mode := os.FileMode(0o644)
	if info, err := os.Stat(s.SettingsPath); err == nil {
		mode = info.Mode().Perm()
	}

	dir := filepath.Dir(s.SettingsPath)
	tmp, err := os.CreateTemp(dir, "vctp-settings-*.yml")
	if err != nil {
		return fmt.Errorf("unable to create temp settings file: %w", err)
	}
	tmpName := tmp.Name()
	defer func() {
		_ = os.Remove(tmpName)
	}()

	if _, err := tmp.Write(data); err != nil {
		_ = tmp.Close()
		return fmt.Errorf("unable to write temp settings file: %w", err)
	}
	if err := tmp.Chmod(mode); err != nil {
		_ = tmp.Close()
		return fmt.Errorf("unable to set temp settings permissions: %w", err)
	}
	if err := tmp.Close(); err != nil {
		return fmt.Errorf("unable to close temp settings file: %w", err)
	}
	if err := os.Rename(tmpName, s.SettingsPath); err != nil {
		return fmt.Errorf("unable to replace settings file: %w", err)
	}

	return nil
}