#!/usr/bin/env lua

CFG_SOURCEDIR=os.getenv("PROSODY_SRCDIR");

CFG_CONFIGDIR=os.getenv("PROSODY_CFGDIR");

local default_config = (CFG_CONFIGDIR or ".").."/migrator.cfg.lua";

-- Command-line parsing

local options = {};

local handled_opts = 0;

for i = 1, #arg do

	if arg[i]:sub(1,2) == "--" then

		local opt, val = arg[i]:match("([%w-]+)=?(.*)");

		if opt then

			options[(opt:sub(3):gsub("%-", "_"))] = #val > 0 and val or true;

		end

		handled_opts = i;

	else

		break;

	end

end

table.remove(arg, handled_opts);

-- Load config file

local function loadfilein(file, env)

	if loadin then

		return loadin(env, io.open(file):read("*a"));

	else

		local chunk, err = loadfile(file);

		if chunk then

			setfenv(chunk, env);

		end

		return chunk, err;

	end

end

local config_file = options.config or default_config;

local from_store = arg[1] or "input";

local to_store = arg[2] or "output";

config = {};

local config_env = setmetatable({}, { __index = function(t, k) return function(tbl) config[k] = tbl; end; end });

local config_chunk, err = loadfilein(config_file, config_env);

if not config_chunk then

	print("There was an error loading the config file, check the file exists");

	print("and that the syntax is correct:");

	print("", err);

	os.exit(1);

end

config_chunk();

if CFG_SOURCEDIR then

	package.path = CFG_SOURCEDIR.."/?.lua;"..package.path;

	package.cpath = CFG_SOURCEDIR.."/?.so;"..package.cpath;

elseif not package.loaded["util.json"] then

	package.path = "../../?.lua;"..package.path

	package.cpath = "../../?.so;"..package.cpath

end

local have_err;

if #arg > 0 and #arg ~= 2 then

	have_err = true;

	print("Error: Incorrect number of parameters supplied.");

end

if not config[from_store] then

	have_err = true;

	print("Error: Input store '"..from_store.."' not found in the config file.");

end

if not config[to_store] then

	have_err = true;

	print("Error: Output store '"..to_store.."' not found in the config file.");

end

function load_store_handler(name)

	local store_type = config[name].type;

	if not store_type then

		print("Error: "..name.." store type not specified in the config file");

		return false;

	else

		local ok, err = pcall(require, "migrator."..store_type);

		if not ok then

			if package.loaded["migrator."..store_type] then

				print(("Error: Failed to initialize '%s' store:\n\t%s")

					:format(name, err));

			else

				print(("Error: Unrecognised store type for '%s': %s")

					:format(from_store, store_type));

			end

			return false;

		end

	end

	return true;

end

have_err = have_err or not(load_store_handler(from_store, "input") and load_store_handler(to_store, "output"));

if have_err then

	print("");

	print("Usage: "..arg[0].." FROM_STORE TO_STORE");

	print("If no stores are specified, 'input' and 'output' are used.");

	print("");

	print("The available stores in your migrator config are:");

	print("");

	for store in pairs(config) do

		print("", store);

	end

	print("");

	os.exit(1);

end

local itype = config[from_store].type;

local otype = config[to_store].type;

local reader = require("migrator."..itype).reader(config[from_store]);

local writer = require("migrator."..otype).writer(config[to_store]);

local json = require "util.json";

for x in reader do

	--print(json.encode(x))

	writer(x);

end

writer(nil); -- close