'use server'

import { revalidatePath } from 'next/cache'
import { cookies } from 'next/headers'
import { getIronSession } from 'iron-session'
import { prisma } from '@/lib/prisma'
import { SessionData, sessionOptions } from '@/lib/session'
import { getAccessibleProduct, productAccessFilter } from '@/lib/product-access'
import { requireProductWriter } from '@/lib/auth'
import { isValidCode, normalizeCode } from '@/lib/code'
import { createWithCodeRetry, generateNextStoryCode } from '@/lib/code-server'
import { createStorySchema, updateStorySchema } from '@/lib/schemas/story'

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

type StoryFieldErrors = Record<string, string[]>

async function verifyStoryAccess(storyId: string, userId: string) {
  return prisma.story.findFirst({
    where: { id: storyId, product: productAccessFilter(userId) },
    include: { product: true },
  })
}

function hasDuplicateIds(ids: string[]) {
  return new Set(ids).size !== ids.length
}

export async function createStoryAction(_prevState: unknown, formData: FormData) {
  const session = await getSession()
  if (!session.userId) return { error: 'Niet ingelogd', code: 403 }
  if (session.isDemo) return { error: 'Niet beschikbaar in demo-modus', code: 403 }

  const parsed = createStorySchema.safeParse({
    pbiId: formData.get('pbiId'),
    productId: formData.get('productId'),
    code: (formData.get('code') as string) || undefined,
    title: formData.get('title'),
    description: formData.get('description') || undefined,
    acceptance_criteria: formData.get('acceptance_criteria') || undefined,
    priority: formData.get('priority') ?? 2,
  })
  if (!parsed.success) {
    return {
      error: 'Validatie mislukt',
      code: 422,
      fieldErrors: parsed.error.flatten().fieldErrors as StoryFieldErrors,
    }
  }

  const pbi = await prisma.pbi.findFirst({
    where: { id: parsed.data.pbiId, product: productAccessFilter(session.userId) },
  })
  if (!pbi) return { error: 'PBI niet gevonden', code: 403 }

  const manualCode = normalizeCode(parsed.data.code)
  if (manualCode !== null && !isValidCode(manualCode)) {
    return {
      error: 'Validatie mislukt',
      code: 422,
      fieldErrors: { code: ['Alleen letters, cijfers, punten, koppeltekens of underscores'] } as StoryFieldErrors,
    }
  }
  if (manualCode) {
    const dup = await prisma.story.findFirst({ where: { product_id: pbi.product_id, code: manualCode } })
    if (dup) {
      return {
        error: 'Validatie mislukt',
        code: 422,
        fieldErrors: { code: ['Deze code is al in gebruik binnen dit product'] } as StoryFieldErrors,
      }
    }
  }

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

  const insert = (code: string) =>
    prisma.story.create({
      data: {
        pbi_id: parsed.data.pbiId,
        product_id: pbi.product_id,
        code,
        title: parsed.data.title,
        description: parsed.data.description ?? null,
        acceptance_criteria: parsed.data.acceptance_criteria ?? null,
        priority: parsed.data.priority,
        sort_order,
        status: 'OPEN',
      },
    })

  let story
  try {
    story = manualCode
      ? await insert(manualCode)
      : await createWithCodeRetry(
          () => generateNextStoryCode(pbi.product_id),
          (code) => insert(code),
        )
  } catch {
    return {
      error: 'Validatie mislukt',
      code: 422,
      fieldErrors: { code: ['Kon geen unieke code genereren — probeer opnieuw'] } as StoryFieldErrors,
    }
  }

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

export async function updateStoryAction(_prevState: unknown, formData: FormData) {
  const session = await getSession()
  if (!session.userId) return { error: 'Niet ingelogd', code: 403 }
  if (session.isDemo) return { error: 'Niet beschikbaar in demo-modus', code: 403 }

  const parsed = updateStorySchema.safeParse({
    id: formData.get('id'),
    code: (formData.get('code') as string) || undefined,
    title: formData.get('title'),
    description: formData.get('description') || undefined,
    acceptance_criteria: formData.get('acceptance_criteria') || undefined,
    priority: formData.get('priority'),
  })
  if (!parsed.success) {
    return {
      error: 'Validatie mislukt',
      code: 422,
      fieldErrors: parsed.error.flatten().fieldErrors as StoryFieldErrors,
    }
  }

  const story = await verifyStoryAccess(parsed.data.id, session.userId)
  if (!story) return { error: 'Story niet gevonden', code: 403 }

  const code = normalizeCode(parsed.data.code)
  if (code !== null && !isValidCode(code)) {
    return {
      error: 'Validatie mislukt',
      code: 422,
      fieldErrors: { code: ['Alleen letters, cijfers, punten, koppeltekens of underscores'] } as StoryFieldErrors,
    }
  }
  if (code) {
    const dup = await prisma.story.findFirst({
      where: { product_id: story.product_id, code, NOT: { id: parsed.data.id } },
    })
    if (dup) {
      return {
        error: 'Validatie mislukt',
        code: 422,
        fieldErrors: { code: ['Deze code is al in gebruik binnen dit product'] } as StoryFieldErrors,
      }
    }
  }

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

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

export async function deleteStoryAction(id: 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 verifyStoryAccess(id, session.userId)
  if (!story) return { error: 'Story niet gevonden' }

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

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

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

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

  const pbis = await prisma.pbi.findMany({
    where: { id: { in: orderedIds }, product_id: productId },
    select: { id: true },
  })
  if (pbis.length !== orderedIds.length) return { error: 'Ongeldige PBI-volgorde' }

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

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

export async function updatePbiPriorityAction(pbiId: string, priority: number, _productId: 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: pbiId, product: productAccessFilter(session.userId) },
  })
  if (!pbi) return { error: 'PBI niet gevonden' }
  if (!Number.isInteger(priority) || priority < 1 || priority > 4) return { error: 'Ongeldige prioriteit' }

  const last = await prisma.pbi.findFirst({
    where: { product_id: pbi.product_id, priority },
    orderBy: { sort_order: 'desc' },
  })

  await prisma.pbi.update({
    where: { id: pbiId },
    data: { priority, sort_order: (last?.sort_order ?? 0) + 1.0 },
  })

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

export async function getStoryLogsAction(storyId: string) {
  const session = await getSession()
  if (!session.userId) return { error: 'Niet ingelogd' }

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

  const logs = await prisma.storyLog.findMany({
    where: { story_id: storyId },
    orderBy: { created_at: 'asc' },
  })

  return {
    success: true,
    logs: logs.map((l: (typeof logs)[number]) => ({
      id: l.id,
      type: l.type,
      content: l.content,
      status: l.status,
      commit_hash: l.commit_hash,
      commit_message: l.commit_message,
      created_at: l.created_at.toISOString(),
    })),
    repoUrl: story.product.repo_url,
  }
}

export async function claimStoryAction(storyId: string, productId: string) {
  try {
    await requireProductWriter(productId)
  } catch (e: unknown) {
    return { error: e instanceof Error ? e.message : 'Geen toegang' }
  }

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

  await prisma.story.update({ where: { id: storyId }, data: { assignee_id: session.userId } })

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

export async function unclaimStoryAction(storyId: string, productId: string) {
  try {
    await requireProductWriter(productId)
  } catch (e: unknown) {
    return { error: e instanceof Error ? e.message : 'Geen toegang' }
  }

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

  await prisma.story.update({ where: { id: storyId }, data: { assignee_id: null } })

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

export async function reassignStoryAction(storyId: string, productId: string, targetUserId: string) {
  try {
    await requireProductWriter(productId)
  } catch (e: unknown) {
    return { error: e instanceof Error ? e.message : 'Geen toegang' }
  }

  // Validate target user is owner or member of the product
  const product = await prisma.product.findFirst({
    where: {
      id: productId,
      OR: [
        { user_id: targetUserId },
        { members: { some: { user_id: targetUserId } } },
      ],
    },
  })
  if (!product) return { error: 'Gebruiker is geen lid van dit product' }

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

  await prisma.story.update({ where: { id: storyId }, data: { assignee_id: targetUserId } })

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

export async function claimAllUnassignedInActiveSprintAction(productId: string) {
  try {
    await requireProductWriter(productId)
  } catch (e: unknown) {
    return { error: e instanceof Error ? e.message : 'Geen toegang' }
  }

  const session = await getSession()
  const userId = session.userId

  const sprint = await prisma.sprint.findFirst({
    where: { product_id: productId, status: 'ACTIVE' },
  })
  if (!sprint) return { error: 'Geen actieve sprint gevonden' }

  const result = await prisma.story.updateMany({
    where: { sprint_id: sprint.id, product_id: productId, assignee_id: null },
    data: { assignee_id: userId },
  })

  revalidatePath(`/products/${productId}/sprint`)
  revalidatePath('/solo')
  return { success: true, count: result.count }
}

export async function reorderStoriesAction(
  pbiId: string,
  productId: string,
  orderedIds: string[],
  newPriority?: number
) {
  const session = await getSession()
  if (!session.userId) return { error: 'Niet ingelogd' }
  if (session.isDemo) return { error: 'Niet beschikbaar in demo-modus' }
  if (hasDuplicateIds(orderedIds)) return { error: 'Ongeldige story-volgorde' }
  if (newPriority !== undefined && (!Number.isInteger(newPriority) || newPriority < 1 || newPriority > 4)) {
    return { error: 'Ongeldige prioriteit' }
  }

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

  const stories = await prisma.story.findMany({
    where: { id: { in: orderedIds }, pbi_id: pbiId, product_id: pbi.product_id },
    select: { id: true },
  })
  if (stories.length !== orderedIds.length) return { error: 'Ongeldige story-volgorde' }

  await prisma.$transaction(
    orderedIds.map((id, i) =>
      prisma.story.update({
        where: { id },
        data: {
          sort_order: i + 1.0,
          ...(newPriority !== undefined ? { priority: newPriority } : {}),
        },
      })
    )
  )

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