package controller

import (
	"context"
	"fmt"
	"strings"

	"sigs.k8s.io/controller-runtime/pkg/client"

	bindv1alpha1 "git.unkin.net/unkin/bind-operator/api/v1alpha1"
	"git.unkin.net/unkin/bind-operator/internal/bind"
)

func isPrimaryType(t bindv1alpha1.ZoneType) bool {
	return t == bindv1alpha1.ZonePrimary || t == ""
}

// catalogEnabled reports whether a primary zone should be registered in the
// cluster catalog zone.
func catalogEnabled(zone *bindv1alpha1.BindZone) bool {
	if !isPrimaryType(zone.Spec.Type) {
		return false
	}
	if zone.Spec.Catalog == nil {
		return true
	}
	return *zone.Spec.Catalog
}

// fqdn resolves a record owner name relative to a zone origin.
func fqdn(name, zone string) string {
	zone = strings.TrimSuffix(zone, ".") + "."
	if name == "" || name == "@" {
		return zone
	}
	if strings.HasSuffix(name, ".") {
		return name
	}
	return name + "." + zone
}

func recordsToUpdates(zone string, records []bindv1alpha1.Record, defaultTTL int32) []bind.RecordUpdate {
	updates := make([]bind.RecordUpdate, 0, len(records))
	for _, rec := range records {
		ttl := defaultTTL
		if rec.TTL != nil {
			ttl = *rec.TTL
		}
		updates = append(updates, bind.RecordUpdate{
			FQDN:   fqdn(rec.Name, zone),
			Type:   rec.Type,
			TTL:    ttl,
			Values: rec.Values,
		})
	}
	return updates
}

// updateKeyName returns the TSIG key name (as used in named.conf) for a zone's
// update key, falling back to the object name.
func updateKeyName(ctx context.Context, c client.Client, zone *bindv1alpha1.BindZone) string {
	return tsigKeyName(ctx, c, zone.Namespace, zone.Spec.UpdateKeyRef)
}

// tsigKeyName resolves a BindTSIGKey object reference to the TSIG key name used
// in named.conf (the KeyName override when set, otherwise the object name).
// Returns "" for an empty ref, and falls back to the ref if the object cannot be
// read.
func tsigKeyName(ctx context.Context, c client.Client, namespace, ref string) string {
	if ref == "" {
		return ""
	}
	var key bindv1alpha1.BindTSIGKey
	if err := c.Get(ctx, client.ObjectKey{Namespace: namespace, Name: ref}, &key); err != nil {
		return ref
	}
	if key.Spec.KeyName != "" {
		return key.Spec.KeyName
	}
	return ref
}

// matchListInline renders address-match-list entries on one line.
func matchListInline(entries []string) string { return terminateInline(entries) }

func terminateInline(entries []string) string {
	var parts []string
	for _, e := range entries {
		e = strings.TrimSpace(strings.TrimRight(e, ";"))
		if e == "" {
			continue
		}
		parts = append(parts, e+";")
	}
	return strings.Join(parts, " ")
}

// alsoNotifyList renders also-notify entries, each optionally annotated with a
// TSIG key so the primary signs its NOTIFYs and secondaries can accept them by
// key (`allow-notify { key ... }`) rather than by pod IP. An entry that already
// carries a `key` clause is left untouched.
func alsoNotifyList(addrs []string, key string) string {
	key = strings.TrimSpace(key)
	var parts []string
	for _, a := range addrs {
		a = strings.TrimSpace(strings.TrimRight(a, ";"))
		if a == "" {
			continue
		}
		if key != "" && !strings.Contains(a, " key ") {
			a = fmt.Sprintf("%s key \"%s\"", a, key)
		}
		parts = append(parts, a+";")
	}
	return strings.Join(parts, " ")
}