local restserver = {}

local request = require("wsapi.request")

local response = require("wsapi.response")

local json = require("dkjson")

local unpack = unpack or table.unpack

local function add_resource(self, name, entries, authfunc)

for _, entry in ipairs(entries) do

local path = ("^/" .. name .. "/" .. entry.path):gsub("([^{]+)(%b{})", function (literal,pattern) return literal:gsub("%-", "%%-")..pattern end):gsub("/+", "/"):gsub("/$", "") .. "$"

entry.rest_path = path

entry.match_path = path:gsub("{[^:]*:([^}]*)}", "(%1)"):gsub("{[^}]*}", "([^/]+)")

-- set up auth (if not already present) for all entries of this resource

if not entry.auth and authfunc then entry.auth = authfunc end

path = path:gsub("{[^:]*:([^}]*)}", "%1"):gsub("{[^}]*}", "[^/]+")

local methods = self.config.paths[path]

if not methods then

methods = {}

self.config.paths[path] = methods

table.insert(self.config.path_list, path)

end

if methods[entry.method] then

local ui_path = "/" .. name .. "/" .. entry.path

error("A handler for method "..entry.method.." in path "..ui_path.." is already defined.")

end

methods[entry.method] = entry

end

end

local function set_error_handler(self, entry)

self.error_handler = function(_, code, msg)

return {

response = entry.handler(code, msg),

headers = { ["Content-Type"] = entry.produces or "text/plain" }

}

end

self.error_schema = entry.output_schema

end

local function type_check(tbl, schema)

for k, s in pairs(schema) do

if not tbl[k] then

if not s.optional then

return nil, "missing field '"..k.."'"

end

elseif type(tbl[k]) ~= s.type then

return nil, "in field '"..k.."', expected type "..s.type..", got "..type(tbl[k])

elseif s.array and next(tbl[k]) and not tbl[k][1] then

return nil, "in field '"..k.."', expected an array"

end

end

return true

end

local function decode(data, mimetype, schema)

if mimetype == "application/json" then

local tbl = json.decode(data)

if schema then

local ok, err = type_check(tbl, schema)

if not ok then

return nil, err

end

end

return tbl

elseif mimetype == "text/plain" then

return data or ""

elseif not mimetype or mimetype == "*/*" then

return data or ""

else

error("Mimetype "..mimetype.." not supported.")

end

end

local function encode(data, mimetype, schema)

if mimetype == "application/json" then

if schema then

local ok, err = type_check(data, schema)

if not ok then

return nil, err

end

end

return json.encode(data)

elseif mimetype == "text/plain" then

return data or ""

elseif not mimetype then

return data or ""

else

error("Mimetype "..mimetype.." not supported.")

end

end

local function get_error_response(self, code, msg, wreq)

local res = self.error_handler(wreq, code, msg)

res.headers = res.headers or { ["Content-Type"] = "text/plain" }

local output, err = encode(res.response, res.headers["Content-Type"], self.error_schema)

if not output then

return nil, err

end

res.content = output

return res

end

local function fail(self, wreq, code, msg)

local res, err = get_error_response(self, code, msg, wreq)

local wres = response.new(code, res.headers)

local output

if err then

wres = response.new(500, { ["Content-Type"] = "text/plain" })

output = "Internal Server Error - Server built a response that fails schema validation: "..err

else

output = res.content

end

wres:write(output)

return wres:finish()

end

local function match_path(self, path_info)

for _, path in ipairs(self.config.path_list) do

if path_info:match(path) then

return self.config.paths[path]

end

end

end

local function wsapi_handler_with_self(self, wsapi_env, rs_api)

local wreq = request.new(wsapi_env)

local input_path = wsapi_env.PATH_INFO:gsub("/$", "")

local methods = self.config.paths["^" .. input_path .. "$"] or match_path(self, wsapi_env.PATH_INFO)

local entry = methods and methods[wreq.method]

if not entry then

return fail(self, wreq, 405, "Method Not Allowed")

end

local input, err

if wreq.method == "POST" then

input, err = decode(wreq.POST.post_data, entry.consumes, entry.input_schema)

elseif wreq.method == "GET" then

input = wreq.GET

elseif wreq.method == "DELETE" then

input = ""

else

error("Other methods not implemented yet.")

end

if not input then

return fail(self, wreq, 400, "Bad Request - Your request fails schema validation: "..("" or err) )

end

local placeholder_matches = (entry.rest_path ~= entry.match_path) and { input_path:match(entry.match_path) } or {}

local ok, res

local handler

local pass_wreq = false

if rs_api == "0.3" then

handler = entry.handler

pass_wreq = true

elseif entry.handle_req then

handler = entry.handle_req

pass_wreq = true

else

handler = entry.handler

pass_wreq = false

end

local auth_result = entry.auth and entry.auth(wsapi_env) -- return { errorcode = 401|403, user = 'alice' } or nil

if auth_result and auth_result.errorcode then

return fail(self, wreq, auth_result.errorcode, "Authentication error: "..(auth_result.message or ""))

end

if pass_wreq then

if auth_result then

ok, res = pcall(handler, wreq, input, auth_result.user, unpack(placeholder_matches))

else

ok, res = pcall(handler, wreq, input, unpack(placeholder_matches))

end

else

if auth_result then

ok, res = pcall(handler, input, auth_result.user, unpack(placeholder_matches))

else

ok, res = pcall(handler, input, unpack(placeholder_matches))

end

end

if not ok then

return fail(self, wreq, 500, "Application error: "..res)

end

if not res then

return fail(self, wreq, 500, "Server failed to produce a response.")

end

local output, err = encode(res.config.entity, entry.produces, entry.output_schema)

if not output then

return fail(self, wreq, 500, "Server built a response that fails schema validation: "..err)

end

local headers = { ["Content-Type"] = entry.produces or "text/plain" }

if res.config.headers then

for k,v in pairs(res.config.headers) do

headers[k] = v

end

end

local wres = response.new(res.config.status,headers)

wres:write(output)

return wres:finish()

end

local function add_setter(self, var)

self[var] = function (self, val)

self.config[var] = val

return self

end

end

function restserver.new(rs_api)

local server = {

config = {

paths = {},

path_list = {},

},

enable = function(self, plugin_name)

local mod = require(plugin_name)

mod.extend(self)

return self

end,

add_resource = add_resource,

set_error_handler = set_error_handler,

get_error_response = get_error_response, -- To be used by server plugins

}

add_setter(server, "host")

add_setter(server, "port")

server.wsapi_handler = function(wsapi_env)

return wsapi_handler_with_self(server, wsapi_env, rs_api)

end

server.error_handler = function(wreq, code, msg)

return { response = tostring(code).." "..msg }

end

return server

end

function restserver.response()

local res = {

config = {},

}

add_setter(res, "status")

add_setter(res, "entity")

add_setter(res, "headers")

return res

end

return restserver