-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

--

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

-- luacheck: ignore 113/CFG_PLUGINDIR

local dir_sep, path_sep = package.config:match("^(%S+)%s(%S+)");

local lua_version = _VERSION:match(" (.+)$");

local plugin_dir = {};

for path in (CFG_PLUGINDIR or "./plugins/"):gsub("[/\\]", dir_sep):gmatch("[^"..path_sep.."]+") do

	path = path..dir_sep; -- add path separator to path end

	path = path:gsub(dir_sep..dir_sep.."+", dir_sep); -- coalesce multiple separators

	plugin_dir[#plugin_dir + 1] = path;

end

local io_open = io.open;

local envload = require "util.envload".envload;

local pluginloader_methods = {};

local pluginloader_mt = { __index = pluginloader_methods };

function pluginloader_methods:load_file(names)

	local file, err, path;

	local load_filter_cb = self._options.load_filter_cb;

	for i=1,#plugin_dir do

		for j=1,#names do

			path = plugin_dir[i]..names[j];

			file, err = io_open(path);

			if file then

				local content = file:read("*a");

				file:close();

				local metadata;

				if load_filter_cb then

					path, content, metadata = load_filter_cb(path, content);

				end

				if content and path then

					return content, path, metadata;

				end

			end

		end

	end

	return file, err;

end

function pluginloader_methods:load_resource(plugin, resource)

	resource = resource or "mod_"..plugin..".lua";

	local names = {

		"mod_"..plugin..dir_sep..plugin..dir_sep..resource; -- mod_hello/hello/mod_hello.lua

		"mod_"..plugin..dir_sep..resource;                  -- mod_hello/mod_hello.lua

		plugin..dir_sep..resource;                          -- hello/mod_hello.lua

		resource;                                           -- mod_hello.lua

		"share"..dir_sep.."lua"..dir_sep..lua_version..dir_sep..resource;

		"share"..dir_sep.."lua"..dir_sep..lua_version..dir_sep.."mod_"..plugin..dir_sep..resource;

	};

	return self:load_file(names);

end

function pluginloader_methods:load_code(plugin, resource, env)

	local content, err, metadata = self:load_resource(plugin, resource);

	if not content then return content, err; end

	local path = err;

	local f, err = envload(content, "@"..path, env);

	if not f then return f, err; end

	return f, path, metadata;

end

function pluginloader_methods:load_code_ext(plugin, resource, extension, env)

	local content, err, metadata = self:load_resource(plugin, resource.."."..extension);

	if not content and extension == "lib.lua" then

		content, err, metadata = self:load_resource(plugin, resource..".lua");

	end

	if not content then

		content, err, metadata = self:load_resource(resource, resource.."."..extension);

		if not content then

			return content, err;

		end

	end

	local path = err;

	local f, err = envload(content, "@"..path, env);

	if not f then return f, err; end

	return f, path, metadata;

end

local function init(options)

	return setmetatable({

		_options = options or {};

	}, pluginloader_mt);

end

local function bind(self, method)

	return function (...)

		return method(self, ...);

	end;

end

local default_loader = init();

return {

	load_file = bind(default_loader, default_loader.load_file);

	load_resource = bind(default_loader, default_loader.load_resource);

	load_code = bind(default_loader, default_loader.load_code);

	load_code_ext = bind(default_loader, default_loader.load_code_ext);

	init = init;

};