--[[

HTTP server implementation for LuCI - luci handler
(c) 2008 Steven Barth <steven@midlink.org>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

$Id$

]]--

module("luci.httpd.handler.file", package.seeall)

require("luci.httpd.module")
require("luci.http.protocol.date")
require("luci.http.protocol.mime")
require("luci.http.protocol.conditionals")
require("luci.fs")
require("ltn12")

Simple = luci.util.class(luci.httpd.module.Handler)
Response = luci.httpd.module.Response

function Simple.__init__(self, docroot, dirlist)
	luci.httpd.module.Handler.__init__(self)
	self.docroot = docroot
	self.dirlist = dirlist and true or false
	self.mime    = luci.http.protocol.mime
	self.date    = luci.http.protocol.date
	self.cond    = luci.http.protocol.conditionals
end

function Simple.getfile(self, uri)
	local file = self.docroot .. uri:gsub("%.%./+", "")
	local stat = luci.fs.stat(file)

	return file, stat
end

function Simple.handle_get(self, request, sourcein, sinkerr)
	local file, stat = self:getfile(request.env.PATH_INFO)

	if stat then
		if stat.type == "regular" then

			-- Generate Entity Tag
			local etag = self.cond.mk_etag( stat )

			-- Check conditionals
			local ok, code, hdrs

			ok, code, hdrs = self.cond.if_modified_since( request, stat )
			if ok then
				ok, code, hdrs = self.cond.if_match( request, stat )
				if ok then
					ok, code, hdrs = self.cond.if_unmodified_since( request, stat )
					if ok then
						ok, code, hdrs = self.cond.if_none_match( request, stat )
						if ok then
							-- Send Response
							return Response(
								200, {
									["Date"]           = self.date.to_http( os.time() );
									["Last-Modified"]  = self.date.to_http( stat.mtime );
									["Content-Type"]   = self.mime.to_mime( file );
									["Content-Length"] = stat.size;
									["ETag"]           = etag;
								}
							), ltn12.source.file(io.open(file))
						else
							return Response( code, hdrs or { } ),
								ltn12.source.empty()
						end
					else
						return Response( code, hdrs or { } ),
							ltn12.source.empty()
					end
				else
					return Response( code, hdrs or { } ),
						ltn12.source.empty()
				end
			else
				return Response( code, hdrs or { } ),
					ltn12.source.empty()
			end
		else
			return self:failure(403, "Unable to transmit " .. stat.type .. " " .. file)
		end
	else
		return self:failure(404, "No such file: " .. file)
	end
end

function Simple.handle_head(self, ...)
	local response, sourceout = self:handle_get(...)
	return response
end