// Command seed-platform-admin upserts the first (or additional) platform admin
// for greenfield / production deploys where no legacy admin_users cutover ran
// and seed-demo must not be used.
//
// Usage:
//
//	cd apps/api
//	go run ./cmd/seed-platform-admin \
//	  -postgres "$env:DATABASE_URL" \
//	  -email you@example.com \
//	  -password 'choose-a-strong-password' \
//	  -confirm
//
// Env aliases: PLATFORM_ADMIN_EMAIL, PLATFORM_ADMIN_PASSWORD, DATABASE_URL.
//
// -promote-only grants admin on an existing user without changing the password
// (-password is ignored). Always requires -confirm.
package main

import (
	"context"
	"errors"
	"flag"
	"fmt"
	"log"
	"os"
	"strings"
	"time"

	"github.com/descrybe/descrybe-v2/apps/api/internal/auth"
	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"
)

func main() {
	postgresURL := flag.String("postgres", os.Getenv("DATABASE_URL"), "Postgres URL")
	email := flag.String("email", os.Getenv("PLATFORM_ADMIN_EMAIL"), "Platform admin email")
	password := flag.String("password", os.Getenv("PLATFORM_ADMIN_PASSWORD"), "Password (min 8; ignored with -promote-only)")
	name := flag.String("name", "", "Display name (defaults to email local-part)")
	promoteOnly := flag.Bool("promote-only", false, "Grant platform admin on an existing user; do not set password")
	confirm := flag.Bool("confirm", false, "Required: acknowledge this writes is_platform_admin + staff_role=admin")
	flag.Parse()

	opts, err := parseOptions(*postgresURL, *email, *password, *name, *promoteOnly, *confirm, os.Getenv("APP_ENV"))
	if err != nil {
		log.Fatal(err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
	defer cancel()

	pg, err := pgxpool.New(ctx, opts.PostgresURL)
	if err != nil {
		log.Fatalf("postgres: %v", err)
	}
	defer pg.Close()

	userID, created, err := upsertPlatformAdmin(ctx, pg, opts)
	if err != nil {
		log.Fatal(err)
	}

	action := "updated"
	if created {
		action = "created"
	}
	fmt.Printf("platform admin %s\n", action)
	fmt.Printf("  id:                 %s\n", userID)
	fmt.Printf("  email:              %s\n", opts.Email)
	fmt.Printf("  is_platform_admin:  true\n")
	fmt.Printf("  staff_role:         %s\n", auth.StaffRoleAdmin)
	if opts.PromoteOnly {
		fmt.Println("  password:           unchanged (-promote-only)")
	} else {
		fmt.Println("  password:           set (argon2id)")
	}
	fmt.Println()
	fmt.Println("Sign in on the web app, then open /admin.")
}

type options struct {
	PostgresURL string
	Email       string
	Password    string
	Name        string
	PromoteOnly bool
}

func parseOptions(postgresURL, email, password, name string, promoteOnly, confirm bool, appEnv string) (options, error) {
	if !confirm {
		return options{}, fmt.Errorf("-confirm is required (refuses silent privilege grants)")
	}
	pg := strings.TrimSpace(postgresURL)
	if pg == "" {
		return options{}, fmt.Errorf("-postgres / DATABASE_URL is required")
	}
	emailNorm := strings.ToLower(strings.TrimSpace(email))
	if emailNorm == "" || !strings.Contains(emailNorm, "@") {
		return options{}, fmt.Errorf("-email / PLATFORM_ADMIN_EMAIL is required")
	}
	if err := rejectLocalDemoAccount(emailNorm, appEnv); err != nil {
		return options{}, err
	}

	display := strings.TrimSpace(name)
	if display == "" {
		display = emailNorm
		if i := strings.IndexByte(display, '@'); i > 0 {
			display = display[:i]
		}
	}

	opts := options{
		PostgresURL: pg,
		Email:       emailNorm,
		Name:        display,
		PromoteOnly: promoteOnly,
	}
	if promoteOnly {
		return opts, nil
	}
	pass := password // keep as provided (do not trim interior spaces)
	if len(pass) < 8 {
		return options{}, fmt.Errorf("-password / PLATFORM_ADMIN_PASSWORD must be at least 8 characters")
	}
	if err := rejectDemoPassword(pass, appEnv); err != nil {
		return options{}, err
	}
	opts.Password = pass
	return opts, nil
}

func rejectLocalDemoAccount(email, appEnv string) error {
	if !isProductionEnv(appEnv) {
		return nil
	}
	if strings.HasSuffix(email, ".local") || strings.HasSuffix(email, "@descrybe.test") {
		return fmt.Errorf("refusing demo/local emails in production APP_ENV=%q", strings.TrimSpace(appEnv))
	}
	return nil
}

func rejectDemoPassword(password, appEnv string) error {
	if !isProductionEnv(appEnv) {
		return nil
	}
	if password == "DemoPass123!" {
		return fmt.Errorf("refusing seed-demo password in production")
	}
	return nil
}

func isProductionEnv(appEnv string) bool {
	switch strings.ToLower(strings.TrimSpace(appEnv)) {
	case "production", "prod":
		return true
	default:
		return false
	}
}

func upsertPlatformAdmin(ctx context.Context, pg *pgxpool.Pool, opts options) (uuid.UUID, bool, error) {
	if opts.PromoteOnly {
		var userID uuid.UUID
		err := pg.QueryRow(ctx, `
			UPDATE users
			SET is_platform_admin = true,
			    staff_role = $2,
			    is_active = true,
			    updated_at = now()
			WHERE email = $1
			RETURNING id`, opts.Email, auth.StaffRoleAdmin).Scan(&userID)
		if err != nil {
			if errors.Is(err, pgx.ErrNoRows) {
				return uuid.Nil, false, fmt.Errorf("user %q not found (-promote-only requires an existing account)", opts.Email)
			}
			return uuid.Nil, false, fmt.Errorf("promote: %w", err)
		}
		return userID, false, nil
	}

	hash, err := auth.HashPassword(opts.Password)
	if err != nil {
		return uuid.Nil, false, fmt.Errorf("hash password: %w", err)
	}

	tx, err := pg.Begin(ctx)
	if err != nil {
		return uuid.Nil, false, fmt.Errorf("begin: %w", err)
	}
	defer tx.Rollback(ctx)

	var existed bool
	err = tx.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM users WHERE email = $1)`, opts.Email).Scan(&existed)
	if err != nil {
		return uuid.Nil, false, fmt.Errorf("lookup: %w", err)
	}

	var userID uuid.UUID
	err = tx.QueryRow(ctx, `
		INSERT INTO users (
			email, name, password_hash, must_set_password,
			is_platform_admin, staff_role, is_active, updated_at
		) VALUES ($1, $2, $3, false, true, $4, true, now())
		ON CONFLICT (email) DO UPDATE SET
			name = EXCLUDED.name,
			password_hash = EXCLUDED.password_hash,
			must_set_password = false,
			is_platform_admin = true,
			staff_role = EXCLUDED.staff_role,
			is_active = true,
			updated_at = now()
		RETURNING id`, opts.Email, opts.Name, hash, auth.StaffRoleAdmin).Scan(&userID)
	if err != nil {
		return uuid.Nil, false, fmt.Errorf("upsert user: %w", err)
	}
	if err := tx.Commit(ctx); err != nil {
		return uuid.Nil, false, fmt.Errorf("commit: %w", err)
	}
	return userID, !existed, nil
}