// lldap-to-ldap migrates LLDAP directory data to standard LDAP (LDIF format).
// Part of the NetKingdom IAM migration contract.
package main

import (
	"flag"
	"fmt"
	"os"

	"github.com/rs/zerolog"
	"gopkg.in/yaml.v3"

	"keycape/internal/migration/lldapexport"
	"keycape/internal/migration/toldap"
	"keycape/internal/server/telemetry"
)

func main() {
	inputFile := flag.String("input", "", "Path to canonical-export.yaml (required)")
	outputFile := flag.String("output", "export.ldif", "Path to write LDIF output")
	baseDN := flag.String("basedn", "dc=netkingdom,dc=local", "LDAP base DN")
	targetStr := flag.String("target", "openldap", "LDAP target: openldap | 389ds | ad")
	flag.Parse()

	if *inputFile == "" {
		fmt.Fprintln(os.Stderr, "lldap-to-ldap: -input is required")
		flag.Usage()
		os.Exit(1)
	}

	target, err := parseTarget(*targetStr)
	if err != nil {
		fmt.Fprintf(os.Stderr, "lldap-to-ldap: %v\n", err)
		os.Exit(1)
	}

	data, err := os.ReadFile(*inputFile)
	if err != nil {
		fmt.Fprintf(os.Stderr, "lldap-to-ldap: read %q: %v\n", *inputFile, err)
		os.Exit(1)
	}

	var export lldapexport.ExportResult
	if err := yaml.Unmarshal(data, &export); err != nil {
		fmt.Fprintf(os.Stderr, "lldap-to-ldap: parse YAML: %v\n", err)
		os.Exit(1)
	}

	log := zerolog.New(os.Stderr).With().Timestamp().Logger()
	em := telemetry.NewLogEmitter(log)
	gen := toldap.New(toldap.Config{
		BaseDN: *baseDN,
		Target: target,
	}, em)

	ldif, err := gen.Generate(&export)
	if err != nil {
		fmt.Fprintf(os.Stderr, "lldap-to-ldap: generate: %v\n", err)
		os.Exit(1)
	}

	if err := os.WriteFile(*outputFile, []byte(ldif), 0o600); err != nil {
		fmt.Fprintf(os.Stderr, "lldap-to-ldap: write %q: %v\n", *outputFile, err)
		os.Exit(1)
	}

	fmt.Printf("lldap-to-ldap: wrote %s (%d bytes)\n", *outputFile, len(ldif))
}

func parseTarget(s string) (toldap.Target, error) {
	switch s {
	case "openldap":
		return toldap.TargetOpenLDAP, nil
	case "389ds":
		return toldap.Target389DS, nil
	case "ad":
		return toldap.TargetAD, nil
	default:
		return "", fmt.Errorf("unknown target %q: must be one of openldap, 389ds, ad", s)
	}
}