add guff-stuff static files handler

1 files changed, 77 insertions, 0 deletions

diff --git a/src/guff/handlers/guff-stuff.cr b/src/guff/handlers/guff-stuff.cr
new file mode 100644
index 0000000..cc3ac6c
--- /dev/null
+++ b/src/guff/handlers/guff-stuff.cr
@@ -0,0 +1,77 @@
+require "uri"
+require "../handler"
+require "../mime-type"
+require "../views/html/page"
+
+class Guff::Handlers::GuffStuffHandler < Guff::Handler
+  def initialize(models)
+    super(models)
+    @digests = {} of String => String
+  end
+
+  def call(context : HTTP::Server::Context)
+    path = context.request.path.not_nil!
+
+    if matching_request?(context.request.method, path)
+      reply(context)
+    else
+      call_next(context)
+    end
+  end
+
+  private def reply(context : HTTP::Server::Context)
+    # get expanded path to file
+    if path = expand_path(context.request.path.not_nil!)
+      # get file digest
+      file_digest = digest(path)
+
+      # check for cache header
+      if context.request.headers["if-none-match"]? == file_digest
+        # cached, send 304 not modified
+        context.response.status_code = 304
+      else
+        # not cached, set code and send headers
+        context.response.status_code = 200
+        context.response.content_type = Guff::MimeType.mime_type(path)
+        context.response.content_length = File.size(path)
+        context.response.headers["etag"] = file_digest
+
+        if context.request.method == "GET"
+          # send body
+          File.open(path) do |fh|
+            IO.copy(fh, context.response)
+          end
+        end
+      end
+    else
+      # file not found
+      context.response.status_code = 404
+    end
+  end
+
+  VALID_METHODS = %w{GET HEAD}
+  PATH_RE = %r{^/guff-stuff/}
+
+  private def matching_request?(method, path)
+    VALID_METHODS.includes?(method) && PATH_RE.match(path)
+  end
+
+  private def expand_path(req_path : String) : String?
+    # unescape path, check for nil byte
+    path = URI.unescape(req_path)
+    return nil if path.includes?('\0')
+
+    # build absolute path
+    r = File.join(
+      @models.config["stuff"],
+      File.expand_path(path.gsub(PATH_RE, ""), "/")
+    )
+
+    # return path if file exists, or nil otherwise
+    File.file?(r) ? r : nil
+  end
+
+  private def digest(path : String) : String
+    @digests[path] ||= OpenSSL::Digest.new("SHA1").file(path).hexdigest
+  end
+end