'use server'

import { revalidatePath } from 'next/cache'
import { cookies } from 'next/headers'
import { getIronSession } from 'iron-session'
import { z } from 'zod'
import { prisma } from '@/lib/prisma'
import { SessionData, sessionOptions } from '@/lib/session'
import { getAccessibleProduct } from '@/lib/product-access'
import { isValidCode, MAX_CODE_LENGTH, normalizeCode } from '@/lib/code'
import { createWithCodeRetry, generateNextPbiCode } from '@/lib/code-server'
import { pbiStatusFromApi } from '@/lib/task-status'

async function getSession() {
  return getIronSession<SessionData>(await cookies(), sessionOptions)
}

const codeField = z.string().max(MAX_CODE_LENGTH).optional()

const statusField = z.enum(['ready', 'blocked', 'done']).optional()

const createPbiSchema = z.object({
  productId: z.string(),
  code: codeField,
  title: z.string().min(1, 'Titel is verplicht').max(200),
  description: z.string().max(2000).optional(),
  priority: z.coerce.number().int().min(1).max(4),
  status: statusField,
})

const updatePbiSchema = z.object({
  id: z.string(),
  code: codeField,
  title: z.string().min(1, 'Titel is verplicht').max(200),
  description: z.string().max(2000).optional(),
  priority: z.coerce.number().int().min(1).max(4),
  status: statusField,
})

export async function createPbiAction(_prevState: unknown, formData: FormData) {
  const session = await getSession()
  if (!session.userId) return { error: 'Niet ingelogd' }
  if (session.isDemo) return { error: 'Niet beschikbaar in demo-modus' }

  const parsed = createPbiSchema.safeParse({
    productId: formData.get('productId'),
    code: (formData.get('code') as string) || undefined,
    title: formData.get('title'),
    description: formData.get('description') || undefined,
    priority: formData.get('priority'),
    status: (formData.get('status') as string) || undefined,
  })
  if (!parsed.success) return { error: parsed.error.flatten().fieldErrors }

  const product = await getAccessibleProduct(parsed.data.productId, session.userId)
  if (!product) return { error: 'Product niet gevonden' }

  const manualCode = normalizeCode(parsed.data.code)
  if (manualCode !== null && !isValidCode(manualCode)) {
    return { error: { code: ['Code mag alleen letters, cijfers, punten, koppeltekens of underscores bevatten'] } }
  }
  if (manualCode) {
    const dup = await prisma.pbi.findFirst({ where: { product_id: parsed.data.productId, code: manualCode } })
    if (dup) return { error: { code: ['Deze code is al in gebruik binnen dit product'] } }
  }

  const last = await prisma.pbi.findFirst({
    where: { product_id: parsed.data.productId, priority: parsed.data.priority },
    orderBy: { sort_order: 'desc' },
  })
  const sort_order = (last?.sort_order ?? 0) + 1.0

  const status = parsed.data.status ? pbiStatusFromApi(parsed.data.status) ?? undefined : undefined

  const insert = (code: string | null) =>
    prisma.pbi.create({
      data: {
        product_id: parsed.data.productId,
        code,
        title: parsed.data.title,
        description: parsed.data.description ?? null,
        priority: parsed.data.priority,
        sort_order,
        ...(status ? { status } : {}),
      },
    })

  let pbi
  try {
    pbi = manualCode
      ? await insert(manualCode)
      : await createWithCodeRetry(
          () => generateNextPbiCode(parsed.data.productId),
          (code) => insert(code),
        )
  } catch {
    return { error: { code: ['Kon geen unieke code genereren — probeer opnieuw'] } }
  }

  revalidatePath(`/products/${parsed.data.productId}`)
  return { success: true, pbi }
}

export async function updatePbiAction(_prevState: unknown, formData: FormData) {
  const session = await getSession()
  if (!session.userId) return { error: 'Niet ingelogd' }
  if (session.isDemo) return { error: 'Niet beschikbaar in demo-modus' }

  const parsed = updatePbiSchema.safeParse({
    id: formData.get('id'),
    code: (formData.get('code') as string) || undefined,
    title: formData.get('title'),
    description: formData.get('description') || undefined,
    priority: formData.get('priority'),
    status: (formData.get('status') as string) || undefined,
  })
  if (!parsed.success) return { error: parsed.error.flatten().fieldErrors }

  const pbi = await prisma.pbi.findFirst({
    where: { id: parsed.data.id },
    include: { product: true },
  })
  if (!pbi) return { error: 'PBI niet gevonden' }
  const accessible = await getAccessibleProduct(pbi.product_id, session.userId)
  if (!accessible) return { error: 'PBI niet gevonden' }

  const code = normalizeCode(parsed.data.code)
  if (code !== null && !isValidCode(code)) {
    return { error: { code: ['Code mag alleen letters, cijfers, punten, koppeltekens of underscores bevatten'] } }
  }
  if (code) {
    const dup = await prisma.pbi.findFirst({
      where: { product_id: pbi.product_id, code, NOT: { id: parsed.data.id } },
    })
    if (dup) return { error: { code: ['Deze code is al in gebruik binnen dit product'] } }
  }

  const status = parsed.data.status ? pbiStatusFromApi(parsed.data.status) ?? undefined : undefined

  await prisma.pbi.update({
    where: { id: parsed.data.id },
    data: {
      code,
      title: parsed.data.title,
      description: parsed.data.description ?? null,
      priority: parsed.data.priority,
      ...(status ? { status } : {}),
    },
  })

  revalidatePath(`/products/${pbi.product_id}`)
  return { success: true }
}

export async function deletePbiAction(id: string) {
  const session = await getSession()
  if (!session.userId) return { error: 'Niet ingelogd' }
  if (session.isDemo) return { error: 'Niet beschikbaar in demo-modus' }

  const pbi = await prisma.pbi.findFirst({
    where: { id },
    include: { product: true },
  })
  if (!pbi) return { error: 'PBI niet gevonden' }
  const accessible = await getAccessibleProduct(pbi.product_id, session.userId)
  if (!accessible) return { error: 'PBI niet gevonden' }

  await prisma.pbi.delete({ where: { id } })

  revalidatePath(`/products/${pbi.product_id}`)
  return { success: true }
}
