--[[ Copyright (c) 2012-2014 Kaarle Ritvanen See LICENSE file for license details --]] local M = {} local raise = require('aconf.error').raise local object = require('aconf.object') local class = object.class local isinstance = object.isinstance local super = object.super local pth = require('aconf.path') local util = require('aconf.util') local copy = util.copy local setdefaults = util.setdefaults local update = util.update function M.null_addr(path, name) return '/null'..pth.join(path, name) end M.BoundMember = class() function M.BoundMember:init(parent, name, field) local pmt = getmetatable(parent) local mt = {} function mt.__index(t, k) local member = field[k] if type(member) ~= 'function' then return member end local addr = field.addr or pth.escape(name) if type(addr) == 'function' then addr = addr(pmt.path, name) end return function(self, ...) return member( field, { txn=pmt.txn, privileged=pmt.privileged, parent=parent, path=pth.join(pmt.path, name), addr=pth.to_absolute(addr, pmt.addr) }, ... ) end end setmetatable(self, mt) end M.TreeNode = class() local function equal_tns(tn1, tn2) return getmetatable(tn1).path == getmetatable(tn2).path end function M.TreeNode:init(context, params) local mt = getmetatable(self) update(mt, context) mt.name = pth.name(mt.path) mt.__eq = equal_tns if not (mt.txn and mt.txn.user) then mt.privileged = true end mt.escalate = mt.privileged and self or mt.class( setdefaults({privileged=true}, context), params ) function mt.get(k, options) return mt.load(k, options) end function mt._fetch(path, create) if #path == 0 then return self end local name = path[1] table.remove(path, 1) if name == pth.up then if not mt.parent then raise(mt.path, 'Root object does not have parent') end return getmetatable(mt.parent)._fetch(path, create) end if not mt.member(name) then raise(mt.path, 'Member does not exist: '..name) end local options = {} if create then options.create = true if #path == 0 then options.dereference = false end end local next = mt.get(name, options) if next == nil and (not create or #path > 0) then raise(mt.path, 'Subordinate does not exist: '..name) end if #path == 0 then return next end if type(next) ~= 'table' then raise(pth.join(mt.path, name), 'Is a primitive value') end return getmetatable(next)._fetch(path, create) end local cache = {} function mt.fetch(path, create) local res = cache[path] if res then return res end if pth.is_absolute(path) and mt.path > '/' then assert(not create) res = mt.txn:fetch(path, mt.privileged) else res = mt._fetch(pth.split(path), create) end if isinstance(res, M.TreeNode) then cache[path] = res end return res end local permissions = {} function mt._has_permission(permission) end -- TODO audit trail function mt.has_permission(permission) if mt.privileged then return true end local name = permission..mt.path local res = permissions[name] if res ~= nil then return res end local user = mt.txn.user res = user.superuser or mt._has_permission(permission) if res == nil then if getmetatable(mt.escalate).fetch('/auth/permissions')[name] then res = user:check_permission(name) else if ({create=true, delete=true})[permission] then permission = 'modify' end res = getmetatable(mt.parent).has_permission(permission) end end permissions[name] = res return res end function mt.check_permission(permission) if not mt.has_permission(permission) then raise('forbidden', permission..mt.path) end end function mt.removable() end function mt.value_removable(v) if isinstance(v, M.TreeNode) then return getmetatable(v).removable() end end local function key_removable(k) if not mt.removing_permitted() then return false end local res = mt.value_removable(mt.load(k, {dereference=false})) if res == nil then return params.editable end return res end function mt.check_removable(k) if not (mt.privileged or key_removable(k)) then raise(pth.join(mt.path, k), 'Cannot be deleted') end end function mt.meta() if not mt._meta then mt._meta = {type=params.dtype} if mt.txn then if mt.parent then mt._meta['ui-name'] = getmetatable(mt.parent).mmeta(mt.name)['ui-name'] end mt.init_meta(mt._meta) end end local res = copy(mt._meta) res.removable = {} for _, key in ipairs(mt.members()) do if key_removable(key) then table.insert(res.removable, key) end end return res end if not mt.txn then return end function mt.save(k, v) rawset(self, k, v) end function mt.__index(t, k) return mt.get(k, {private=true}) end function mt.__newindex(t, k, v) mt.save(k, v) end mt.txn.validable[mt.path] = mt.addr end function M.TreeNode:search_refs(path) if type(path) == 'string' then path = pth.split(path) end if #path == 0 then return {} end local mt = getmetatable(getmetatable(self).escalate) local name = path[1] table.remove(path, 1) local function collect(name) local next = mt.load(name, {dereference=false}) if not next then return {} end local member = mt.member(name) if member.deleted then return {member} end return isinstance(next, M.TreeNode) and M.TreeNode.search_refs( next, path ) or {} end if name == pth.wildcard then local res = {} for _, member in ipairs(mt.members()) do util.extend(res, collect(member)) end return res end return collect(name) end M.Collection = class(M.TreeNode) function M.Collection:init(context, params) super(self, M.Collection):init( context, setdefaults(params, {dtype='collection'}) ) self.init = nil self.search_refs = nil local mt = getmetatable(self) local field = M.BoundMember(self, pth.wildcard, params.field) function mt.topology() return field:topology() end function mt.member(name) return M.BoundMember(self, name, params.field) end function mt.load(k, options) return mt.member(k):load(options) end function mt.removing_permitted() return mt.has_permission('delete') end if not mt.txn then return end function mt.init_meta(meta) update( meta, { editable=params.editable and mt.has_permission('create'), members=field:meta(), required=params.required, ['ui-member']=params.ui_member or meta['ui-name']:gsub('s$', ''), widget=params.layout } ) end function mt.mmeta(name) local meta = mt.meta() local res = copy(meta.members) if name ~= pth.wildcard then res['ui-name'] = meta['ui-member']..' '..name end return res end function mt.members() return mt.txn:get(mt.addr) or {} end function mt.__len() return #mt.members() end function mt.validate() if #mt.members() > 0 then return end if params.required then raise(mt.path, 'Collection cannot be empty') end if params.destroy then mt.txn:set(mt.addr) validate(mt.parent) end end function mt.save(k, v) if not mt.privileged then local delete = v == nil local old = mt.load(k, {dereference=false}) if old == nil then if delete then return end if not params.editable then raise(mt.path, 'Collection is not editable') end mt.check_permission('create') elseif delete then mt.check_removable(k) elseif type(old) == 'table' then mt.check_removable(k) mt.check_permission('create') else mt.check_permission('modify') end end if params.key then local kf = M.BoundMember(self, k, params.key) if kf:normalize(k) ~= k then raise(mt.path, 'Invalid member name: '..k) end kf:validate(k) end mt.member(k):save(v) end end M.List = class(M.Collection) function M.List:init(context, params) super(self, M.List):init(context, setdefaults(params, {dtype='list'})) local mt = getmetatable(self) local tmt = getmetatable(mt.escalate) mt._save = mt.save function mt.save(k, v) assert(type(k) == 'number') if v == nil then mt.check_removable(k) local len = #mt.members() while k < len do tmt._save(k, tmt.load(k + 1, {dereference=false})) k = k + 1 end tmt._save(len) else mt._save(k, v) end end function mt.insert(v, i) assert(v ~= nil) mt.check_permission('create') local len = #mt.members() if not i then i = len + 1 end for j = len,i,-1 do tmt._save(j + 1, tmt.load(j, {dereference=false})) end tmt._save(i, v) end end -- experimental M.Mixed = class(M.Collection) function M.Mixed:init(context, params) super(self, M.Mixed):init(context, params) -- TODO dynamic meta: list non-leaf children local mt = getmetatable(self) mt.meta = {type='mixed', ['ui-name']=mt.path} function mt.mmeta(name) return {type='mixed', ['ui-name']=pth.join(mt.path, name)} end end local function meta_func(attr) return function(node, ...) local res = getmetatable(node)[attr] if type(res) == 'function' then return res(...) end return res end end for _, mf in ipairs{ 'addr', 'check_permission', 'contains', 'escalate', 'fetch', 'has_permission', 'insert', 'meta', 'mmeta', 'name', 'parent', 'path', 'save', 'topology' } do M[mf] = meta_func(mf) end function M.pairs(tbl, dereference) if not isinstance(tbl, M.TreeNode) then return pairs(tbl) end local mt = getmetatable(tbl) local res = {} for _, member in ipairs(mt.members()) do res[member] = mt.load(member, {dereference=dereference}) end return pairs(res) end local function _ipairs(mt, i) i = i + 1 local v = mt.load(i, {create=false}) if v == nil then return end return i, v end function M.ipairs(tbl) if not isinstance(tbl, M.TreeNode) then return ipairs(tbl) end return _ipairs, getmetatable(tbl), 0 end return M