#!/usr/bin/lua5.3

local http_request = require("http.request")
local cjson        = require("cjson")
local socket       = require('socket')

local redmine_api_key = ""
local gitlab_api_key  = ""
local redmine_uri     = "https://bugs.alpinelinux.org"
local gitlab_uri      = "http://192.168.2.163"
local allowed_chars   = "[%a%d_-%.]"

local function tfind(t,i)
	for _,v in pairs(t) do
		if v == i then return true end
	end
	return false
end

local function string_allowed(str, allowed_chars)
    local r = ""
    str:gsub(".", function(c)
		r = c:find(allowed_chars) and r..c or r.."-"
	end)
    return r
end

local function add_headers(request, headers)
	local private = { "x-redmine-api-key", "private-token" }
	for k,v in pairs(headers) do
		request.headers:upsert(k, v, tfind(private, k))
	end
end

local function get_http_body(uri, headers, method, data)
	local request = assert(http_request.new_from_uri(uri))
	local status_ok = "200"
	add_headers(request, headers)
	if data then
		request.headers:upsert(":method", method)
		request:set_body(data)
	end
	if method == "POST" then status_ok = "201" end
	local headers, stream = request:go()
	local body = assert(stream:get_body_as_string())
	local status = headers:get(":status")
	if status ~= status_ok then
		print(("Status: %s\nMessage: %s"):format(status, cjson.decode(body).message))
	end
	return body
end

-- add user to gitlab
-- user: table with user data
local function gitlab_add_user(data)
	local uri = ("%s/api/v4/users"):format(gitlab_uri)
	local headers = {
		["private-token"] = gitlab_api_key,
		["content-type"] = "application/json"
	}
	return get_http_body(uri, headers, "POST", cjson.encode(data))
end

local function gitlab_update_user(id, data)
	local uri = ("%s/api/v4/users/%s"):format(gitlab_uri, id)
	local headers = {
		["private-token"] = gitlab_api_key,
		["content-type"] = "application/json"
	}
	return get_http_body(uri, headers, "PUT", cjson.encode(data))
end


-- get list of redmine users
-- offset of the user list
local function redmine_get_users(offset, limit)
	local uri = ("%s/users.json?offset=%s&limit=%s"):format(redmine_uri, offset, limit)
	local headers = {
		["x-redmine-api-key"] = redmine_api_key
	}
	return get_http_body(uri, headers)
end

local function redmine_get_user(uid)
	local uri = ("%s/users/%s.json"):format(redmine_uri, uid)
	local headers = {
		["x-redmine-api-key"] = redmine_api_key
	}
    return get_http_body(uri, headers)
end


local function genpass(length)
	local charset = {}
	for c = 48, 57  do table.insert(charset, string.char(c)) end
	for c = 65, 90  do table.insert(charset, string.char(c)) end
	for c = 97, 122 do table.insert(charset, string.char(c)) end
	if not length or length <= 0 then return '' end
	math.randomseed(socket.gettime() * 1000000)
	return genpass(length - 1) .. charset[math.random(1, #charset)]
end


local function add_users_legacy()
	local limit = 25
	local offset = 0
	local total = 0
	while total >= offset do
		local resp = redmine_get_users(offset, limit)
		local json = cjson.decode(resp)
		for _,v in ipairs(json.users) do
			if v.last_login_on == cjson.null or v.mail:match(".*@mail%.ru") then
				print(("Skipping user: %s %s (%s) with email: %s"):format(
					v.firstname, v.lastname, v.login, v.mail))
			else
				print(("Adding user: %s %s (%s) with email: %s"):format(
					v.firstname, v.lastname, v.login, v.mail))
				gitlab_add_user({
					username = string_allowed(v.login, allowed_chars),
					name = ("%s %s"):format(v.firstname, v.lastname),
					email = v.mail,
					skip_confirmation = true,
					reset_password = false,
					password = "Mit5EmhGup1q"
				})
			end
		end
		total = json.total_count
		offset = offset + limit
	end
end

local function add_users()
	for uid in io.lines(arg[1]) do
		local json = redmine_get_user(uid)
		local user = cjson.decode(json)
		local pass = genpass(16)
		user = user.user
		if user.mail == cjson.null then
			print(("Skipping user: %s %s (%s) with email: %s"):format(
				user.firstname, user.lastname, user.login, user.mail))
		else
			print(("Adding user: %s %s (%s) with email: %s and password: %s"):format(
				user.firstname, user.lastname, user.login, user.mail, pass))
			gitlab_add_user({
				username = string_allowed(user.login, allowed_chars),
				name = ("%s %s"):format(user.firstname, user.lastname),
				email = user.mail,
				skip_confirmation = true,
				reset_password = false,
				password = pass,
				admin = true
			})
		end
	end
end

add_users()