// Package testutil has helpers shared by tests, chiefly locating BIND's
// tools so integration tests can run against the real named-checkconf,
// named-checkzone, named and rndc.
//
// Set JARL_BIND_ROOT to a directory containing an extracted BIND
// installation (usr/sbin/named, usr/bin/named-checkconf, ... and the
// libraries under usr/lib/x86_64-linux-gnu) to use binaries that are not
// installed system-wide. See docs/development.md.
package testutil

import (
	"os"
	"os/exec"
	"path/filepath"
	"testing"

	"jarl/internal/bind"
)

// BindBinaries holds paths to the BIND binaries.
type BindBinaries struct {
	Named, CheckConf, CheckZone, RNDC, TSIGKeygen, Dig string
	Env                                                []string
}

// FindBind locates the BIND binaries, or returns nil if they are missing.
func FindBind() *BindBinaries {
	b := &BindBinaries{}
	if root := os.Getenv("JARL_BIND_ROOT"); root != "" {
		b.Named = filepath.Join(root, "usr/sbin/named")
		b.RNDC = filepath.Join(root, "usr/sbin/rndc")
		b.TSIGKeygen = filepath.Join(root, "usr/sbin/tsig-keygen")
		b.CheckConf = filepath.Join(root, "usr/bin/named-checkconf")
		b.CheckZone = filepath.Join(root, "usr/bin/named-checkzone")
		b.Dig = filepath.Join(root, "usr/bin/dig")
		libs, _ := filepath.Glob(filepath.Join(root, "usr/lib/*-linux-gnu"))
		if len(libs) > 0 {
			b.Env = []string{"LD_LIBRARY_PATH=" + libs[0]}
		}
		if _, err := os.Stat(b.CheckConf); err != nil {
			return nil
		}
		return b
	}
	look := func(name string) string {
		if p, err := exec.LookPath(name); err == nil {
			return p
		}
		for _, dir := range []string{"/usr/sbin", "/usr/bin", "/sbin"} {
			p := filepath.Join(dir, name)
			if _, err := os.Stat(p); err == nil {
				return p
			}
		}
		return ""
	}
	b.CheckConf = look("named-checkconf")
	b.CheckZone = look("named-checkzone")
	b.Named = look("named")
	b.RNDC = look("rndc")
	b.TSIGKeygen = look("tsig-keygen")
	b.Dig = look("dig")
	if b.CheckConf == "" || b.CheckZone == "" {
		return nil
	}
	return b
}

// BindTools returns bind.Tools using the located binaries, skipping the
// test when they are not available.
func BindTools(t testing.TB) *bind.Tools {
	t.Helper()
	b := FindBind()
	if b == nil {
		t.Skip("BIND tools not found (install bind9-utils or set JARL_BIND_ROOT)")
	}
	return &bind.Tools{NamedCheckConf: b.CheckConf, NamedCheckZone: b.CheckZone, RNDC: b.RNDC, Env: b.Env}
}