'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 { productAccessFilter } from '@/lib/product-access'
import { requireProductWriter } from '@/lib/auth'

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

const taskSchema = z.object({
  title: z.string().min(1, 'Titel is verplicht').max(200),
  description: z.string().max(1000).optional(),
  priority: z.coerce.number().int().min(1).max(4),
})

export async function createTaskAction(_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 storyId = formData.get('storyId') as string
  const sprintId = formData.get('sprintId') as string

  const parsed = taskSchema.safeParse({
    title: formData.get('title'),
    description: formData.get('description') || undefined,
    priority: formData.get('priority') ?? 2,
  })
  if (!parsed.success) return { error: parsed.error.flatten().fieldErrors }

  const story = await prisma.story.findFirst({
    where: { id: storyId, product: productAccessFilter(session.userId) },
  })
  if (!story) return { error: 'Story niet gevonden' }

  const last = await prisma.task.findFirst({
    where: { story_id: storyId },
    orderBy: { sort_order: 'desc' },
  })

  const task = await prisma.task.create({
    data: {
      story_id: storyId,
      sprint_id: sprintId || null,
      title: parsed.data.title,
      description: parsed.data.description ?? null,
      priority: parsed.data.priority,
      sort_order: (last?.sort_order ?? 0) + 1.0,
      status: 'TO_DO',
    },
  })

  revalidatePath(`/products/${story.product_id}/sprint/planning`)
  return { success: true, task }
}

export async function updateTaskAction(_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 id = formData.get('id') as string
  const parsed = taskSchema.safeParse({
    title: formData.get('title'),
    description: formData.get('description') || undefined,
    priority: formData.get('priority'),
  })
  if (!parsed.success) return { error: parsed.error.flatten().fieldErrors }

  const task = await prisma.task.findFirst({
    where: { id, story: { product: productAccessFilter(session.userId) } },
    include: { story: true },
  })
  if (!task) return { error: 'Taak niet gevonden' }

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

  revalidatePath(`/products/${task.story.product_id}/sprint/planning`)
  return { success: true }
}

export async function updateTaskStatusAction(id: string, status: 'TO_DO' | 'IN_PROGRESS' | 'DONE') {
  const session = await getSession()
  if (!session.userId) return { error: 'Niet ingelogd' }
  if (session.isDemo) return { error: 'Niet beschikbaar in demo-modus' }

  const task = await prisma.task.findFirst({
    where: { id, story: { product: productAccessFilter(session.userId) } },
    include: { story: true },
  })
  if (!task) return { error: 'Taak niet gevonden' }

  await prisma.task.update({ where: { id }, data: { status } })

  revalidatePath(`/products/${task.story.product_id}/sprint/planning`)
  revalidatePath(`/products/${task.story.product_id}/solo`)
  return { success: true }
}

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

  const task = await prisma.task.findFirst({
    where: { id, story: { product: productAccessFilter(session.userId) } },
    include: { story: true },
  })
  if (!task) return { error: 'Taak niet gevonden' }

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

  revalidatePath(`/products/${task.story.product_id}/sprint/planning`)
  return { success: true }
}

const updateTaskPlanSchema = z.object({
  taskId: z.string().min(1),
  productId: z.string().min(1),
  implementationPlan: z.string().max(10000),
})

export async function updateTaskPlanAction(taskId: string, productId: string, implementationPlan: string) {
  try {
    await requireProductWriter(productId)
  } catch (e) {
    return { error: e instanceof Error ? e.message : 'Niet geautoriseerd' }
  }

  const parsed = updateTaskPlanSchema.safeParse({ taskId, productId, implementationPlan })
  if (!parsed.success) return { error: 'Ongeldige invoer' }

  const task = await prisma.task.findFirst({
    where: { id: taskId, story: { product_id: productId } },
    include: { story: true },
  })
  if (!task) return { error: 'Taak niet gevonden' }

  await prisma.task.update({
    where: { id: taskId },
    data: { implementation_plan: implementationPlan || null },
  })

  revalidatePath(`/products/${productId}/solo`)
  revalidatePath(`/products/${productId}/sprint/planning`)
  return { success: true }
}

export async function reorderTasksAction(storyId: string, orderedIds: string[]) {
  const session = await getSession()
  if (!session.userId) return { error: 'Niet ingelogd' }
  if (session.isDemo) return { error: 'Niet beschikbaar in demo-modus' }

  const story = await prisma.story.findFirst({
    where: { id: storyId, product: productAccessFilter(session.userId) },
  })
  if (!story) return { error: 'Story niet gevonden' }

  await prisma.$transaction(
    orderedIds.map((id, i) =>
      prisma.task.update({ where: { id }, data: { sort_order: i + 1.0 } })
    )
  )

  revalidatePath(`/products/${story.product_id}/sprint/planning`)
  return { success: true }
}