import type { Kysely } from 'kysely'
import type { DB } from '../types/db.types.js'

/**
 * Ensures a login-capable client user exists for a client org, idempotently.
 *
 * Finds or creates a `user` row (role `client`) keyed by lower-cased email,
 * then ensures a `client_member` row links that user to the client as `organiser`.
 *
 * Reuse-by-email is intentional: one person who organises for several clients
 * gets one login with multiple `client_member` rows.
 * Returns the resolved `userId`.
 */
export async function provisionClientLogin(
  kysely: Kysely<DB>,
  { clientId, email, name }: { clientId: string; email: string; name: string | null },
): Promise<string> {
  const normalisedEmail = email.toLowerCase()

  const existing = await kysely
    .selectFrom('user')
    .where('email', '=', normalisedEmail)
    .select('id')
    .executeTakeFirst()

  const id = existing?.id ?? crypto.randomUUID()
  if (!existing) {
    const now = new Date().toISOString()
    await kysely
      .insertInto('user')
      .values({
        id,
        email: normalisedEmail,
        name: name ?? normalisedEmail,
        emailVerified: 0,
        createdAt: now,
        updatedAt: now,
        role: 'client',
        locale: 'de',
      } as any)
      .execute()
  }

  await kysely
    .insertInto('clientMember')
    .values({ clientId, userId: id, role: 'organiser' })
    .onConflict((oc) => oc.columns(['clientId', 'userId']).doNothing())
    .execute()

  return id
}