require "json"
require "uuid"
require "uuid/json"
require "baguette-crystal-base"

require "dodb"

class DNSManager::Storage
	getter user_data         : DODB::CachedDataBase(UserData)
	getter user_data_by_uid  : DODB::Index(UserData)

	getter zones             : DODB::CachedDataBase(Zone)
	getter zones_by_domain   : DODB::Index(Zone)

	def initialize(@root : String, reindex : Bool = false)
		@user_data         = DODB::CachedDataBase(UserData).new "#{@root}/user-data"
		@user_data_by_uid  = @user_data.new_index "uid", &.uid.to_s
		@zones             = DODB::CachedDataBase(Zone).new "#{@root}/zones"
		@zones_by_domain   = @zones.new_index "domain", &.domain

		Baguette::Log.info "storage initialized"

		if reindex
			Baguette::Log.debug "Reindexing user data..."
			@user_data.reindex_everything!
			Baguette::Log.debug "Reindexing zones..."
			@zones.reindex_everything!
			Baguette::Log.debug "Reindexed!"
		end
	end

	def get_user_data(uid : Int32)
		user_data_by_uid.get uid.to_s
	rescue e : DODB::MissingEntry
		entry = UserData.new uid
		entry
	end

	def get_user_data(user : ::AuthD::User::Public)
		get_user_data user.uid
	end

	def update_user_data(user_data : UserData)
		user_data_by_uid.update_or_create user_data.uid.to_s, user_data
	end

	def ensure_user_data(user_id : Int32)
		user_data = user_data_by_uid.get? user_id.to_s
		unless user_data
			Baguette::Log.info "New user #{user_id}"
			@user_data << Storage::UserData.new user_id
		end

		Response::Success.new
	end

	def add_or_update_zone(user_id : Int32, zone : Zone) : IPC::JSON
		# Test zone validity.
		if errors = zone.get_errors?
			Baguette::Log.warning "zone #{zone.domain} update with errors: #{errors}"
			return DNSManager::Response::InvalidZone.new errors
		end

		# User must exist.
		user_data = user_data_by_uid.get? user_id.to_s
		unless user_data
			Baguette::Log.warning "unknown user #{user_id} tries to add -or update- zone #{zone.domain}"
			return Response::UnknownUser.new
		end

		# Does the zone already exist?
		if z = zones_by_domain.get? zone.domain
			# User must own the zone.
			unless user_data.domains.includes? zone.domain
				Baguette::Log.warning "user #{user_id} doesn't own domain #{zone.domain}"
				return Response::NoOwnership.new
			end
		else
			# Add the domain to the user's domain.
			user_data.domains << zone.domain

			# Actually write data on-disk.
			update_user_data user_data
		end

		# Add -or replace- the zone.
		zones_by_domain.update_or_create zone.domain, zone

		Response::Success.new
	rescue e
		Baguette::Log.error "trying to add -or update- zone #{zone.domain}: #{e}"
		Response::Error.new "error while updating the domain #{zone.domain}"
	end

	def delete_domain(user_id : Int32, domain : String) : IPC::JSON
		# User must exist.
		user_data = user_data_by_uid.get? user_id.to_s
		unless user_data
			Baguette::Log.warning "unknown user #{user_id} tries to delete domain #{domain}"
			return Response::UnknownUser.new
		end

		# User must own the domain.
		unless user_data.domains.includes? domain
			Baguette::Log.warning "user #{user_id} tries to delete domain #{domain} but doesn't own it"
			return Response::NoOwnership.new
		end

		# Remove this domain from the list of user's domains.
		user_data.domains.delete domain

		# Update on-disk user data.
		update_user_data user_data

		# Remove the related zone.
		zones_by_domain.delete domain

		Response::Success.new
	rescue e
		Baguette::Log.error "trying to delete a domain #{domain}: #{e}"
		Response::Error.new "error while deleting the domain #{domain}"
	end

end

require "./storage/*"