local JSON = require('util/JSON')
local settings = require('util.settings')
local defaults = require('conf_defaults')

local M = {}
M.__index = M

local REQUEST_ID_ARGUMENT = 'rq_id'

M.httpStatusCode, M.httpStatusText, M.contentType = nil, nil, nil
M.binaryData, M.binarySavename = nil, nil

local function printHeaderLine(headerType, headerValue)
	io.write(headerType .. ": " .. headerValue .. "\r\n")
end


setmetatable(M, {
	__call = function(cls, ...)
		return cls.new(...)
	end
})

--requestObject should always be passed (except on init failure, when it is not yet available)
function M.new(requestObject)
	local self = setmetatable({}, M)
	self.body = { status = nil, data = {} }
	self:setHttpStatus(200, 'OK')
	self:setContentType('text/plain;charset=UTF-8')
	--self:setContentType('application/json;charset=UTF-8')

  -- a queue for functions to be executed when the response has bin given
  -- needed for api calls like network/associate, which requires a restart of the webserver
  self.postResponseQueue = {}

	if requestObject ~= nil then
		local rqId = requestObject:get(REQUEST_ID_ARGUMENT)
		if rqId ~= nil then self.body[REQUEST_ID_ARGUMENT] = rqId end

		if settings.API_INCLUDE_ENDPOINT_INFO == true then
			self.body['module'] = requestObject:getRequestedApiModule()
			self.body['function'] = requestObject:getRealApiFunctionName() or ''
		end
	end

	return self
end

function M:setHttpStatus(code, text)
	if code ~= nil then self.httpStatusCode = code end
	if text ~= nil then self.httpStatusText = text end
end

function M:setContentType(contentType)
	if contentType ~= nil then self.contentType = contentType end
end

function M:setSuccess(msg)
	self.body.status = 'success'
	if msg ~= '' then self.body.msg = msg end
end

function M:setFail(msg)
	self.body.status = 'fail'
	if msg ~= '' then self.body.msg = msg end
end

function M:setError(msg)
	self.body.status = 'error'
	if msg ~= '' then self.body.msg = msg end

	self:addData('more_info', 'http://' .. defaults.API_BASE_URL_PATH .. '/wiki/wiki/communication-api')
end

--NOTE: with this method, to add nested data, it is necessary to precreate the table and add it with its root key
--(e.g.: response:addData('data', {f1=3, f2='x'}))
function M:addData(k, v)
	self.body.data[k] = v
	self.binaryData = nil
end

function M:addPostResponseFunction(fn)
  table.insert(self.postResponseQueue, fn)
end

function M:executePostResponseQueue()
  --local utils = require('util.utils')
  --local log = require('util.logger')
  --log:info("Response:executePostResponseQueue: " .. utils.dump(self.postResponseQueue))

  for i,fn in ipairs(self.postResponseQueue) do fn() end
end

function M:apiURL(mod, func)
	if not mod then return nil end
	if func then func = '/' .. func else func = "" end
	return 'http://' .. defaults.API_BASE_URL_PATH .. '/cgi-bin/d3dapi/' .. mod .. func
end

function M:serializeAsJson()
	return JSON:encode(self.body)
end

function M:send()
	printHeaderLine("Status", self.httpStatusCode .. " " .. self.httpStatusText)
	printHeaderLine("Content-Type", self.contentType)
	printHeaderLine("Access-Control-Allow-Origin", "*")

	if self.binaryData == nil then
		io.write("\r\n")
		print(self:serializeAsJson())
	else
		printHeaderLine("Content-Disposition", "attachment; filename=" .. self.binarySavename)
		io.write("\r\n")
		io.write(self.binaryData)
	end
end

function M:setBinaryFileData(rFile, saveName, contentType)
	if type(rFile) ~= 'string' or rFile:len() == 0 then return false end

	local f,msg = io.open(rFile, "rb")

	if not f then return nil,msg end

	self.binaryData = f:read("*all")
	f:close()

	self.binarySavename = saveName
	self:setContentType(contentType)

	return true
end

return M