import { useMemo } from 'react'
import { createLogger } from '@sim/logger'
import { useSession } from '@/lib/auth/auth-client'
import type { WorkspacePermissions } from '@/hooks/queries/workspace'

export type PermissionType = 'admin' | 'write' | 'read'

const logger = createLogger('useUserPermissions')

export interface WorkspaceUserPermissions {
  // Core permission checks
  canRead: boolean
  canEdit: boolean
  canAdmin: boolean

  // Utility properties
  userPermissions: PermissionType
  isLoading: boolean
  error: string | null
}

/**
 * Custom hook to check current user's permissions within a workspace
 * This version accepts workspace permissions to avoid duplicate API calls
 *
 * @param workspacePermissions - The workspace permissions data
 * @param permissionsLoading - Whether permissions are currently loading
 * @param permissionsError - Any error from fetching permissions
 * @returns Object containing permission flags and utility properties
 */
export function useUserPermissions(
  workspacePermissions: WorkspacePermissions | null,
  permissionsLoading = false,
  permissionsError: string | null = null
): WorkspaceUserPermissions {
  const { data: session, isPending: sessionLoading } = useSession()

  const userPermissions = useMemo((): WorkspaceUserPermissions => {
    const sessionEmail = session?.user?.email
    if (permissionsLoading || sessionLoading || !sessionEmail) {
      return {
        canRead: false,
        canEdit: false,
        canAdmin: false,
        userPermissions: 'read',
        isLoading: permissionsLoading || sessionLoading,
        error: permissionsError,
      }
    }

    /**
     * Prefer the server-resolved `viewer.permissionType` — it already accounts for workspace
     * owners and organization owners/admins who have no explicit `permissions` row but are
     * effectively admins. Falls back to scanning `users` only if the server response predates
     * the viewer field (rolling deploy).
     */
    const viewerPerms = workspacePermissions?.viewer?.permissionType
    if (viewerPerms) {
      return {
        canRead: true,
        canEdit: viewerPerms === 'write' || viewerPerms === 'admin',
        canAdmin: viewerPerms === 'admin',
        userPermissions: viewerPerms,
        isLoading: false,
        error: permissionsError,
      }
    }

    const currentUser = workspacePermissions?.users?.find(
      (user) => user.email.toLowerCase() === sessionEmail.toLowerCase()
    )

    if (!currentUser) {
      logger.warn('User not found in workspace permissions', {
        userEmail: sessionEmail,
        hasPermissions: !!workspacePermissions,
        userCount: workspacePermissions?.users?.length || 0,
      })

      return {
        canRead: false,
        canEdit: false,
        canAdmin: false,
        userPermissions: 'read',
        isLoading: false,
        error: permissionsError || 'User not found in workspace',
      }
    }

    const userPerms = currentUser.permissionType || 'read'
    const canAdmin = userPerms === 'admin'
    const canEdit = userPerms === 'write' || userPerms === 'admin'

    return {
      canRead: true,
      canEdit,
      canAdmin,
      userPermissions: userPerms,
      isLoading: false,
      error: permissionsError,
    }
  }, [session, sessionLoading, workspacePermissions, permissionsLoading, permissionsError])

  return userPermissions
}