package dns

import (
	"errors"
	"strings"
	"sync"

	"darvaza.org/core"
	"darvaza.org/slog"
	"git.jpi.io/amery/jpictl/pkg/cluster"
	"golang.org/x/net/publicsuffix"
)

// Manager is a DNS Manager instance
type Manager struct {
	mu sync.Mutex

	domain  string
	suffix  string
	zones   map[string]*Zone
	regions map[string][]string

	p Provider
	l slog.Logger
}

// ManagerOption configures a Manager
type ManagerOption func(*Manager) error

func newErrorManagerOption(err error, hint string) ManagerOption {
	return func(*Manager) error {
		if hint != "" {
			err = core.Wrap(err, hint)
		}
		return err
	}
}

// WithProvider attaches a libdns Provider to the Manager
func WithProvider(p Provider) ManagerOption {
	var err error

	if p == nil {
		p, err = DefaultDNSProvider()
	}

	if err != nil {
		return newErrorManagerOption(err, "WithProvider")
	}

	return func(mgr *Manager) error {
		mgr.p = p
		return nil
	}
}

// WithLogger attaches a logger to the Manager
func WithLogger(log slog.Logger) ManagerOption {
	if log == nil {
		log = cluster.DefaultLogger()
	}

	return func(mgr *Manager) error {
		mgr.l = log
		return nil
	}
}

func (mgr *Manager) setDefaults() error {
	var opts []ManagerOption

	if mgr.l == nil {
		opts = append(opts, WithLogger(nil))
	}

	if mgr.domain == "" || mgr.suffix == "" {
		return errors.New("domain not specified")
	}

	mgr.zones = make(map[string]*Zone)
	mgr.regions = make(map[string][]string)

	for _, opt := range opts {
		if err := opt(mgr); err != nil {
			return err
		}
	}
	return nil
}

// WithDomain specifies where the manager operates
func WithDomain(domain string) ManagerOption {
	base, err := publicsuffix.EffectiveTLDPlusOne(domain)
	if err != nil {
		return newErrorManagerOption(err, "publicsuffix")
	}

	suffix := strings.TrimSuffix(domain, base)
	if suffix != "" {
		suffix = "." + suffix[:len(suffix)-1]
	}

	return func(mgr *Manager) error {
		mgr.domain = base
		mgr.suffix = suffix
		return nil
	}
}

// NewManager creates a DNS manager with the
func NewManager(opts ...ManagerOption) (*Manager, error) {
	mgr := new(Manager)

	for _, opt := range opts {
		if err := opt(mgr); err != nil {
			return nil, err
		}
	}

	if err := mgr.setDefaults(); err != nil {
		return nil, err
	}
	return mgr, nil
}