--[[
FFLuCI - Configuration Bind Interface

Description:
Offers an interface for binding confiugration values to certain
data types. Supports value and range validation and basic dependencies.

FileId:
$Id$

License:
Copyright 2008 Steven Barth <steven@midlink.org>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at 

	http://www.apache.org/licenses/LICENSE-2.0 

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

]]--
module("ffluci.cbi", package.seeall)

require("ffluci.template")
require("ffluci.util")
require("ffluci.http")
require("ffluci.model.uci")

local Template   = ffluci.template.Template
local class      = ffluci.util.class
local instanceof = ffluci.util.instanceof


function load(cbimap)
	require("ffluci.fs")
	require("ffluci.i18n")
	
	local cbidir = ffluci.fs.dirname(ffluci.util.__file__()) .. "model/cbi/"
	local func, err = loadfile(cbidir..cbimap..".lua")
	
	if not func then
		error(err)
		return nil
	end
	
	ffluci.util.resfenv(func)
	ffluci.util.updfenv(func, ffluci.cbi)
	ffluci.util.extfenv(func, "translate", ffluci.i18n.translate)
	
	local map = func()
	
	if not instanceof(map, Map) then
		error("CBI map returns no valid map object!")
		return nil
	end
	
	return map
end

-- Node pseudo abstract class
Node = class()

function Node.__init__(self, title, description)
	self.children = {}
	self.title = title or ""
	self.description = description or ""
	self.template = "cbi/node"
end

function Node.append(self, obj)
	table.insert(self.children, obj)
end

function Node.parse(self)
	for k, child in ipairs(self.children) do
		child:parse()
	end
end

function Node.render(self)
	ffluci.template.render(self.template, {self=self})
end

function Node.render_children(self)
	for k, node in ipairs(self.children) do
		node:render()
	end
end


--[[
Map - A map describing a configuration file 
]]--
Map = class(Node)

function Map.__init__(self, config, ...)
	Node.__init__(self, ...)
	self.config = config
	self.template = "cbi/map"
	self.uci = ffluci.model.uci.Session()
end

function Map.parse(self)
	self.ucidata = self.uci:show(self.config)
	if not self.ucidata then
		error("Unable to read UCI data: " .. self.config)
	else
		self.ucidata = self.ucidata[self.config]
	end
	Node.parse(self)
end

function Map.render(self)
	self.ucidata = self.uci:show(self.config)
	if not self.ucidata then
		error("Unable to read UCI data: " .. self.config)
	else
		self.ucidata = self.ucidata[self.config]
	end
	Node.render(self)	
end

function Map.section(self, class, ...)
	if instanceof(class, AbstractSection) then
		local obj  = class(...)
		obj.map    = self
		obj.config = self.config
		self:append(obj)
		return obj
	else
		error("class must be a descendent of AbstractSection")
	end
end

function Map.set(self, section, option, value)
	return self.uci:set(self.config, section, option, value)
end

--[[
AbstractSection
]]--
AbstractSection = class(Node)

function AbstractSection.__init__(self, sectiontype, ...)
	Node.__init__(self, ...)
	self.sectiontype = sectiontype
end

function AbstractSection.option(self, class, ...)
	if instanceof(class, AbstractValue) then
		local obj  = class(...)
		obj.map    = self.map
		obj.config = self.config
		self:append(obj)
		return obj
	else
		error("class must be a descendent of AbstractValue")
	end	
end
	


--[[
NamedSection - A fixed configuration section defined by its name
]]--
NamedSection = class(AbstractSection)

function NamedSection.__init__(self, section, ...)
	AbstractSection.__init__(self, ...)
	self.template = "cbi/nsection"
	
	self.section = section
end

function NamedSection.option(self, ...)
	local obj = AbstractSection.option(self, ...)
	obj.section = self.section
	return obj
end


--[[
TypedSection - A (set of) configuration section(s) defined by the type
	addremove: 	Defines whether the user can add/remove sections of this type
	anonymous:  Allow creating anonymous sections
	valid: 		a table with valid names or a function returning nil if invalid
]]--
TypedSection = class(AbstractSection)

function TypedSection.__init__(self, ...)
	AbstractSection.__init__(self, ...)
	self.template  = "cbi/tsection"
	
	self.addremove = true
	self.anonymous = false
	self.valid     = nil
end

function TypedSection.parse(self)
	for k, v in pairs(self:ucisections()) do
		for i, node in ipairs(self.children) do
			node.section = k
			node:parse()
		end 
	end
end

function TypedSection.render_children(self, section)
	for k, node in ipairs(self.children) do
		node.section = section
		node:render()
	end
end

function TypedSection.ucisections(self)
	local sections = {}
	for k, v in pairs(self.map.ucidata) do
		if v[".type"] == self.sectiontype then
			sections[k] = v
		end
	end
	return sections	
end


--[[
AbstractValue - An abstract Value Type
	null:		Value can be empty
	valid:		A function returning the value if it is valid otherwise nil 
	depends:	A table of option => value pairs of which one must be true
	default:	The default value
]]--
AbstractValue = class(Node)

function AbstractValue.__init__(self, option, ...)
	Node.__init__(self, ...)
	self.option  = option
	
	self.valid   = nil
	self.depends = nil
	self.default = nil
end

function AbstractValue.formvalue(self)
	local key = "cbid."..self.map.config.."."..self.section.."."..self.option
	return ffluci.http.formvalue(key)
end

function AbstractValue.parse(self)
	local fvalue = self:validate(self:formvalue())
	if fvalue and not (fvalue == self:ucivalue()) then
		self:write(fvalue)
	end 
end

function AbstractValue.ucivalue(self)
	return self.map.ucidata[self.section][self.option]
end

function AbstractValue.validate(self, value)
	return ffluci.util.validate(value, nil, nil, self.valid)
end

function AbstractValue.write(self, value)
	return self.map:set(self.section, self.option, value)
end


--[[
Value - A one-line value
	maxlength:	The maximum length
	isnumber:	The value must be a valid (floating point) number
	isinteger:  The value must be a valid integer
]]--
Value = class(AbstractValue)

function Value.__init__(self, ...)
	AbstractValue.__init__(self, ...)
	self.template  = "cbi/value"
	
	self.maxlength = nil
	self.isnumber  = false
	self.isinteger = false
end


--[[
ListValue - A one-line value predefined in a list
]]--
ListValue = class(AbstractValue)

function ListValue.__init__(self, ...)
	AbstractValue.__init__(self, ...)
	self.template  = "cbi/lvalue"
	
	self.list = {}
end

function ListValue.add_value(self, key, val)
	val = val or key
	self.list[key] = val
end