// lldap-export exports the LLDAP directory as a canonical YAML snapshot
// for use with the validator and migration tools.
package main

import (
	"context"
	"flag"
	"fmt"
	"os"
	"strings"

	"keycape/internal/adapters/lldap"
	"keycape/internal/migration/lldapexport"
	"keycape/internal/server/telemetry"
	"keycape/internal/validator"

	"github.com/rs/zerolog"
)

func main() {
	// Flags.
	url := flag.String("url", "ldap://localhost:389", "LLDAP server URL (ldap:// or ldaps://)")
	bindDN := flag.String("bind-dn", "", "Service account bind DN (required)")
	bindPW := flag.String("bind-pw", "", "Service account password (DEPRECATED: visible to any local user via ps; prefer KEYCAPE_LLDAP_BIND_PW or --bind-pw-file)")
	bindPWFile := flag.String("bind-pw-file", "", "File containing the service account password")
	baseDN := flag.String("base-dn", "", "LDAP search base DN (required)")
	output := flag.String("output", "canonical-export.yaml", "Output file path")
	tlsSkip := flag.Bool("tls-skip-verify", false, "Skip TLS certificate verification (dev only)")
	flag.Parse()

	if *bindDN == "" || *baseDN == "" {
		fmt.Fprintln(os.Stderr, "lldap-export: --bind-dn and --base-dn are required")
		flag.Usage()
		os.Exit(1)
	}

	password, err := resolveBindPassword(*bindPW, *bindPWFile)
	if err != nil {
		fmt.Fprintf(os.Stderr, "lldap-export: %v\n", err)
		os.Exit(1)
	}

	log := zerolog.New(os.Stderr).With().Timestamp().Logger()
	emitter := telemetry.NewLogEmitter(log)

	cfg := lldap.Config{
		URL:           *url,
		BindDN:        *bindDN,
		BindPW:        password,
		BaseDN:        *baseDN,
		TLSSkipVerify: *tlsSkip,
	}

	repo := lldap.New(cfg)
	exp := lldapexport.New(repo, validator.ModeProvisioning, emitter)

	result, exportErr := exp.Export(context.Background(), *output)
	if exportErr != nil {
		fmt.Fprintf(os.Stderr, "lldap-export: export failed: %v\n", exportErr)
		os.Exit(1)
	}

	fmt.Fprintf(os.Stdout, "Exported %d users, %d groups to %s (group enumeration: %s)\n",
		len(result.Users), len(result.Groups), *output, result.GroupEnumeration)

	if result.GroupEnumeration != lldapexport.EnumerationDirectory {
		fmt.Fprintln(os.Stderr,
			"lldap-export: groups were derived from user memberships; groups with no members are absent")
	}

	if len(result.IncompatibilityReport) > 0 {
		fmt.Fprintln(os.Stderr, "Incompatibility report:")
		for _, item := range result.IncompatibilityReport {
			fmt.Fprintln(os.Stderr, "  -", item)
		}
		os.Exit(2) // partial success: exported with warnings
	}
}

// bindPasswordEnv is the preferred way to supply the service account password.
const bindPasswordEnv = "KEYCAPE_LLDAP_BIND_PW"

// resolveBindPassword takes the password from the environment, a file, or the
// deprecated flag, in that order.
//
// A password on argv is readable by any local user through ps and is captured by
// shell history and process accounting, which is why the flag is deprecated
// rather than merely discouraged (KEY-WP-0026). It still works, because the
// migration scripts and existing runbooks use it, but it warns.
func resolveBindPassword(flagValue, filePath string) (string, error) {
	if env := os.Getenv(bindPasswordEnv); env != "" {
		if flagValue != "" || filePath != "" {
			return "", fmt.Errorf("%s is set as well as a password flag; supply exactly one", bindPasswordEnv)
		}
		return env, nil
	}
	if filePath != "" {
		if flagValue != "" {
			return "", fmt.Errorf("--bind-pw and --bind-pw-file are mutually exclusive")
		}
		contents, err := os.ReadFile(filePath)
		if err != nil {
			return "", fmt.Errorf("read --bind-pw-file: %w", err)
		}
		// A password file almost always ends in a newline from the editor or
		// heredoc that wrote it; binding with it would fail confusingly.
		return strings.TrimRight(string(contents), "\r\n"), nil
	}
	if flagValue != "" {
		fmt.Fprintf(os.Stderr,
			"lldap-export: warning: --bind-pw exposes the password to any local user via ps; prefer %s or --bind-pw-file\n",
			bindPasswordEnv)
		return flagValue, nil
	}
	return "", fmt.Errorf("no password supplied: set %s, or pass --bind-pw-file", bindPasswordEnv)
}