import { createServerFn, createServerOnlyFn } from '@tanstack/react-start'
import { eq } from 'drizzle-orm'
import { z } from 'zod'

import { db } from '#/db'
import { restaurantSettings } from '#/db/schema'
import { requireStaffSession } from '#/lib/auth'
import { zodValidator } from '#/lib/server-validator'
import { dataUrlImageSchema } from '#/lib/table-image'

// Reads never require a session — the public booking form needs the interval and
// lead time to generate its own time-slot grid, just like getTables(). Exported
// (rather than only reachable through the server fn below) so reservations.ts can
// read the current settings directly while validating a booking. This module is
// imported by client-reachable route files for the createServerFns below, so —
// same issue as `#/lib/auth` — a plain, unwrapped export using `db` directly would
// drag the Postgres driver into the browser bundle; `createServerOnlyFn` keeps it
// server-side only.
export const loadReservationSettings = createServerOnlyFn(async function loadReservationSettings() {
  const [existing] = await db.select().from(restaurantSettings).limit(1)
  if (existing) return existing

  const [created] = await db.insert(restaurantSettings).values({}).returning()
  return created
})

export const getReservationSettings = createServerFn({ method: 'GET' }).handler(async () => {
  return loadReservationSettings()
})

const updateReservationSettingsSchema = z.object({
  reservationIntervalMinutes: z.number().int().min(5).max(120),
  reservationDurationMinutes: z.number().int().min(15).max(480),
  minLeadTimeMinutes: z.number().int().min(0).max(10080),
  maxLeadTimeDays: z.number().int().min(1).max(365),
  tableDisplayMode: z.enum(['individual', 'overview']),
  tableOverviewImageUrl: dataUrlImageSchema,
})

export const updateReservationSettings = createServerFn({ method: 'POST' })
  .validator(zodValidator(updateReservationSettingsSchema))
  .handler(async ({ data }) => {
    console.log('[settings] updateReservationSettings called with', data)

    const session = await requireStaffSession()
    console.log('[settings] session role:', session.user.role)

    if (session.user.role !== 'admin') {
      throw new Error('Nur Admins dürfen die Einstellungen ändern')
    }

    const existing = await loadReservationSettings()
    console.log('[settings] existing row before update:', existing)

    const [updated] = await db
      .update(restaurantSettings)
      .set(data)
      .where(eq(restaurantSettings.id, existing.id))
      .returning()

    console.log('[settings] row after update:', updated)

    return updated
  })