// keycape-to-keycloak migrates a KeyCape canonical snapshot to a Keycloak
// realm export format. Part of the NetKingdom IAM migration contract.
package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"os"

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

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

func main() {
	inputFile := flag.String("input", "", "Path to canonical-export.yaml (required)")
	outputFile := flag.String("output", "keycloak-realm.json", "Path to write Keycloak realm import JSON")
	realmName := flag.String("realm", "netkingdom", "Keycloak realm name")
	issuer := flag.String("issuer", "", "OIDC issuer URL")
	flag.Parse()

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

	data, err := os.ReadFile(*inputFile)
	if err != nil {
		fmt.Fprintf(os.Stderr, "keycape-to-keycloak: 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, "keycape-to-keycloak: parse YAML: %v\n", err)
		os.Exit(1)
	}

	log := zerolog.New(os.Stderr).With().Timestamp().Logger()
	em := telemetry.NewLogEmitter(log)
	tr := tokeycloak.New(tokeycloak.Config{
		RealmName: *realmName,
		Issuer:    *issuer,
	}, em)

	realm, err := tr.Transform(&export)
	if err != nil {
		fmt.Fprintf(os.Stderr, "keycape-to-keycloak: transform: %v\n", err)
		os.Exit(1)
	}

	// Print validation report to stderr.
	report := tr.ValidationReport(&export, realm)
	for _, issue := range report {
		fmt.Fprintf(os.Stderr, "WARNING: %s\n", issue)
	}

	out, err := json.MarshalIndent(realm, "", "  ")
	if err != nil {
		fmt.Fprintf(os.Stderr, "keycape-to-keycloak: marshal JSON: %v\n", err)
		os.Exit(1)
	}

	if err := os.WriteFile(*outputFile, out, 0o644); err != nil {
		fmt.Fprintf(os.Stderr, "keycape-to-keycloak: write %q: %v\n", *outputFile, err)
		os.Exit(1)
	}

	fmt.Printf("keycape-to-keycloak: wrote %s (%d bytes)\n", *outputFile, len(out))
}