package bind

import (
	"context"
	"fmt"
	"strings"
)

// ZoneFilePath returns the on-pod path of a zone database file.
func ZoneFilePath(zone string) string {
	return fmt.Sprintf("%s/zones/db.%s", DataDir, strings.TrimSuffix(zone, "."))
}

// CatalogFilePath returns the on-pod path of a catalog zone database file.
func CatalogFilePath(zone string) string {
	return fmt.Sprintf("%s/catalog/db.%s", DataDir, strings.TrimSuffix(zone, "."))
}

// ZoneExists reports whether a zone is currently loaded on the pod.
func (e *Executor) ZoneExists(ctx context.Context, namespace, pod, zone, view string) bool {
	args := []string{"zonestatus", zone}
	if view != "" {
		args = append(args, "in", view)
	}
	_, err := e.Rndc(ctx, namespace, pod, args...)
	return err == nil
}

// renderSeedZone renders a minimal loadable zone (SOA + apex NS + glue). The
// apex NS is the in-zone name ns1, and a glue A record pointing at primaryIP is
// included so BIND's check-integrity accepts the zone (an in-zone NS without an
// address record is a load error).
func renderSeedZone(zone, primaryIP string, serial int64) string {
	origin := dot(zone)
	ns := "ns1." + origin
	// Short refresh/retry so a secondary that misses a NOTIFY (e.g. its pod IP
	// changed and the primary's also-notify was briefly stale) still converges
	// in minutes, not the hour a 3600s refresh would impose. minimum is the
	// negative-cache TTL: keep it low so a stale-secondary NXDOMAIN does not
	// stick in downstream resolvers for long. NOTIFY (also-notify on the
	// primary) remains the fast path; these are the fallback.
	return fmt.Sprintf(`$TTL 3600
@ IN SOA %s hostmaster.%s (
    %d ; serial
    300        ; refresh
    60         ; retry
    1209600    ; expire
    60 )       ; minimum
@ IN NS %s
ns1 IN A %s
`, ns, origin, serial, ns, primaryIP)
}

// EnsureSeedZone makes path loadable without discarding live data: it probes
// the zone file and journal, moves aside whatever cannot load, and writes a
// skeleton only when there is nothing to preserve. Every caller that needs a
// zone database file on disk goes through here, never WriteSeedZone directly.
func (e *Executor) EnsureSeedZone(ctx context.Context, namespace, pod, zone, path, primaryIP string) error {
	state, err := e.ZoneDiskState(ctx, namespace, pod, path)
	if err != nil {
		return err
	}
	plan := PlanSeed(state)
	if plan.Blocked != "" {
		return fmt.Errorf("seed zone %s: %s", zone, plan.Blocked)
	}
	if err := e.Quarantine(ctx, namespace, pod, path, plan); err != nil {
		return err
	}
	if !plan.WriteSeed {
		return nil
	}
	return e.WriteSeedZone(ctx, namespace, pod, zone, path, primaryIP, plan.Serial)
}

// WriteSeedZone writes a seed zone file to path, creating parent directories.
// It overwrites any existing file unconditionally: use EnsureSeedZone unless
// the caller has already run PlanSeed and acted on it.
func (e *Executor) WriteSeedZone(ctx context.Context, namespace, pod, zone, path, primaryIP string, serial int64) error {
	content := renderSeedZone(zone, primaryIP, serial)
	q := shellQuote(path)
	cmd := []string{"sh", "-c", fmt.Sprintf("mkdir -p \"$(dirname %s)\" && cat > %s", q, q)}
	if out, err := e.Exec(ctx, namespace, pod, cmd, content); err != nil {
		return fmt.Errorf("seed zone %s: %w (out: %s)", zone, err, out)
	}
	return nil
}

// AddCatalogMember registers a member zone in a catalog zone by adding the
// catalog PTR record, so secondaries auto-provision it.
func (e *Executor) AddCatalogMember(ctx context.Context, namespace, pod, catalogZone, memberZone string, creds TSIGCreds) error {
	hash := catalogHash(memberZone)
	owner := fmt.Sprintf("%s.zones.%s", hash, dot(catalogZone))
	updates := []RecordUpdate{{
		FQDN:   owner,
		Type:   "PTR",
		TTL:    3600,
		Values: []string{dot(memberZone)},
	}}
	return e.NSUpdate(ctx, namespace, pod, catalogZone, creds, updates)
}

// RemoveCatalogMember deregisters a member zone from a catalog zone.
func (e *Executor) RemoveCatalogMember(ctx context.Context, namespace, pod, catalogZone, memberZone string, creds TSIGCreds) error {
	hash := catalogHash(memberZone)
	owner := fmt.Sprintf("%s.zones.%s", hash, dot(catalogZone))
	updates := []RecordUpdate{{FQDN: owner, Type: "PTR", Delete: true}}
	return e.NSUpdate(ctx, namespace, pod, catalogZone, creds, updates)
}