import { Prisma } from '@prisma/client'
import { prisma } from './prisma'
import {
  findNearestGroupMemberships,
  lastOrganizationPathSegment,
  LEGACY_DEPARTMENT_ALIASES,
  normalizeOrganizationPath,
  isUnderOrganizationPath,
  organizationPathChain,
  unionPermissionPacks,
  type PermissionPackMap,
} from './organization-material-permissions'
import { packItemsToMap } from './user-permission-inherit'

function isMissingGroupTable(error: unknown) {
  return error instanceof Prisma.PrismaClientKnownRequestError && error.code === 'P2021'
}

const PACK_ITEM_SELECT = {
  materialType: true,
  canView: true,
  canDownload: true,
  canDownloadSource: true,
  canShare: true,
  canEditAssets: true,
} as const

function packTargetDepartment(slug: string): string | null {
  if (slug === 'operations') return '运营中心'
  if (slug === 'visual') return '视觉中心'
  return null
}

function unitMatchesPack(unitName: string, target: string): boolean {
  return unitName === target || LEGACY_DEPARTMENT_ALIASES[unitName] === target
}

function pickCanonicalGroupDepartments(paths: string[]): string[] {
  const unique = Array.from(new Set(paths.map(normalizeOrganizationPath).filter(Boolean)))
  return unique.filter(
    (path) => !unique.some((other) => other !== path && isUnderOrganizationPath(path, other)),
  )
}

export async function seedDefaultGroupDepartments() {
  try {
    const packs = await prisma.materialPermissionPack.findMany({
      where: { slug: { in: ['operations', 'visual'] } },
      select: {
        id: true,
        slug: true,
        _count: { select: { departments: true } },
      },
    })
    const needsSeed = packs.filter((pack) => pack._count.departments === 0)
    if (needsSeed.length === 0) return

    const [units, occupiedRows] = await Promise.all([
      prisma.organizationUnit.findMany({
        where: { isActive: true },
        select: { path: true, name: true },
      }),
      prisma.materialPermissionPackDepartment.findMany({
        select: { departmentPath: true },
      }),
    ])
    const occupied = new Set(occupiedRows.map((row) => row.departmentPath))

    for (const pack of needsSeed) {
      const target = packTargetDepartment(pack.slug)
      if (!target) continue
      const matched = units
        .filter((unit) => unitMatchesPack(lastOrganizationPathSegment(unit.path) || unit.name, target))
        .map((unit) => unit.path)
      const canonical = pickCanonicalGroupDepartments(matched).filter((path) => !occupied.has(path))
      if (canonical.length === 0) continue
      await prisma.materialPermissionPackDepartment.createMany({
        data: canonical.map((departmentPath) => ({
          packId: pack.id,
          departmentPath,
        })),
        skipDuplicates: true,
      })
      for (const path of canonical) occupied.add(path)
    }
  } catch (error) {
    if (isMissingGroupTable(error)) return
    throw error
  }
}

export async function loadDepartmentGroupPack(path: string): Promise<PermissionPackMap | null> {
  const packs = await loadDepartmentGroupPacks([path])
  return packs.get(normalizeOrganizationPath(path)) ?? null
}

export async function loadDepartmentGroupPacks(paths: string[]): Promise<Map<string, PermissionPackMap>> {
  const normalizedPaths = Array.from(new Set(paths.map(normalizeOrganizationPath).filter(Boolean)))
  const chains = new Map(normalizedPaths.map((path) => [path, organizationPathChain(path)]))
  const candidatePaths = Array.from(new Set(Array.from(chains.values()).flat()))
  const result = new Map<string, PermissionPackMap>()
  if (candidatePaths.length === 0) return result

  try {
    const memberships = await prisma.materialPermissionPackDepartment.findMany({
      where: { departmentPath: { in: candidatePaths } },
      select: {
        departmentPath: true,
        pack: {
          select: {
            items: { select: PACK_ITEM_SELECT },
          },
        },
      },
    })
    for (const path of normalizedPaths) {
      const nearest = findNearestGroupMemberships(path, memberships)
      if (!nearest) continue
      result.set(path, unionPermissionPacks(...nearest.items.map((row) => packItemsToMap(row.pack.items))))
    }
    return result
  } catch (error) {
    if (isMissingGroupTable(error)) return result
    throw error
  }
}

export async function findConflictingDepartmentGroup(path: string, packId: string) {
  const existing = await prisma.materialPermissionPackDepartment.findFirst({
    where: { departmentPath: path, NOT: { packId } },
    select: { pack: { select: { slug: true, name: true } } },
  })
  return existing?.pack ?? null
}

export function makePermissionGroupSlug(name: string): string {
  const ascii = name
    .trim()
    .toLowerCase()
    .replace(/[^a-z0-9]+/g, '-')
    .replace(/^-+|-+$/g, '')
  const suffix = Date.now().toString(36)
  return ascii ? `${ascii}-${suffix}` : `group-${suffix}`
}