From 2dde9d75ed743837c5314555da5e212766d825f4 Mon Sep 17 00:00:00 2001
From: Emery Hemingway <ehmry@posteo.net>
Date: Fri, 25 Aug 2023 20:12:49 +0100
Subject: [PATCH] Initial commit

---
 .envrc                       |  2 ++
 Tuprules.tup                 |  2 ++
 icalendar_actor.nimble       |  5 +++
 icalendar_components.prs     | 10 ++++++
 shell.nix                    |  5 +++
 src/Tupfile                  |  4 +++
 src/icalendar_actor.nim      | 60 ++++++++++++++++++++++++++++++++++++
 src/icalendar_components.nim | 26 ++++++++++++++++
 8 files changed, 114 insertions(+)
 create mode 100644 .envrc
 create mode 100644 Tuprules.tup
 create mode 100644 icalendar_actor.nimble
 create mode 100644 icalendar_components.prs
 create mode 100644 shell.nix
 create mode 100644 src/Tupfile
 create mode 100644 src/icalendar_actor.nim
 create mode 100644 src/icalendar_components.nim

diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..d324c24
--- /dev/null
+++ b/.envrc
@@ -0,0 +1,2 @@
+source_env ..
+use nix
diff --git a/Tuprules.tup b/Tuprules.tup
new file mode 100644
index 0000000..f902ead
--- /dev/null
+++ b/Tuprules.tup
@@ -0,0 +1,2 @@
+include ../syndicate-nim/depends.tup
+NIM_FLAGS += --path:$(TUP_CWD)/../syndicate-nim/src
diff --git a/icalendar_actor.nimble b/icalendar_actor.nimble
new file mode 100644
index 0000000..12ebe15
--- /dev/null
+++ b/icalendar_actor.nimble
@@ -0,0 +1,5 @@
+bin = @["icalendar_actor"]
+license = "Unlicense"
+requires: "nim", "syndicate"
+srcDir = "src"
+version = "20230825"
diff --git a/icalendar_components.prs b/icalendar_components.prs
new file mode 100644
index 0000000..7e6c7cc
--- /dev/null
+++ b/icalendar_components.prs
@@ -0,0 +1,10 @@
+version 1.
+embeddedType EntityRef.Cap .
+
+Component = [@label string @properties [Property ...] @components [Component ...]].
+
+Property = [@label string @parameters Parameters @type string @values any ...].
+
+Parameters = {symbol: string ...:...}.
+
+CalendarDataspace = <calendar @url string @dataspace #!any>.
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..745dd0e
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,5 @@
+let
+  syndicate = builtins.getFlake "syndicate";
+  pkgs =
+    import <nixpkgs> { overlays = (builtins.attrValues syndicate.overlays); };
+in pkgs.nim2Packages.syndicate_utils
diff --git a/src/Tupfile b/src/Tupfile
new file mode 100644
index 0000000..6c4abe9
--- /dev/null
+++ b/src/Tupfile
@@ -0,0 +1,4 @@
+include_rules
+: foreach ../*.prs |> !preserves_schema_nim |> {schema}
+: icalendar_actor.nim | $(SYNDICATE_PROTOCOL) {schema} |> !nim_bin |> {bin}
+: {bin} |> !assert_built |>
diff --git a/src/icalendar_actor.nim b/src/icalendar_actor.nim
new file mode 100644
index 0000000..007e7b6
--- /dev/null
+++ b/src/icalendar_actor.nim
@@ -0,0 +1,60 @@
+# SPDX-FileCopyrightText: ☭ Emery Hemingway
+# SPDX-License-Identifier: Unlicense
+
+import std/[json, sequtils, tables, uri]
+import preserves, preserves/jsonhooks, syndicate
+from syndicate/protocols/dataspace import Observe
+
+import ./icalendar_components
+
+type Observe = dataspace.Observe[Cap]
+
+type BootArgs {.preservesDictionary.} = object
+  dataspace: Cap
+
+proc importCalendar(location: string): Component =
+  let uri = parseUri(location)
+  if uri.scheme != "file":
+    raiseAssert """only supported calendar schema is "file" ignoring """ & location
+  else:
+    var
+      js = parseFile(uri.path)
+      pr = jsonhooks.toPreserveHook(js, void)
+    if not result.fromPreserve(pr):
+      # TODO: convert directly from JsonNode
+      raise newException(ValueError, "Preserves was not a valid iCalendar component")
+    if result.label != "vcalendar":
+      raise newException(ValueError, "Preserves was not a valid vcalendar @component")
+
+proc toPreserveHook(prop: Property; E: typedesc): Preserve[E] =
+  initRecord(prop.label,
+      prop.parameters.toPreserve(E),
+      prop.`type`.toPreserve(E),
+      prop.values.toPreserve(E),
+    )
+
+proc toPreserveHook(comp: Component; E: typedesc): Preserve[E] =
+  initRecord(comp.label,
+      comp.properties.toPreserve(E),
+      comp.components.toPreserve(E),
+    )
+
+proc serve(turn: var Turn; url: string): Cap =
+  let ds = newDataspace(turn)
+  let calendar = importCalendar(url)
+  run(turn.facet) do (turn: var Turn):
+    for prop in calendar.properties:
+      discard publish(turn, ds, prop)
+    for comp in calendar.components:
+      discard publish(turn, ds, comp)
+  ds
+
+runActor("icalendar_actor") do (root: Cap; turn: var Turn):
+  connectStdio(root, turn)
+  stderr.writeLine "connected stdio to ", root
+  during(turn, root, ?BootArgs) do (ds: Cap):
+    stderr.writeLine "got dataspace at ", ds
+    during(turn, ds, ?Observe(pattern: !CalendarDataspace) ?? {0: grabLit()}) do (url: string):
+      let cap = serve(turn, url)
+      stderr.writeLine "serving ", url, " at ", cap
+      discard publish(turn, ds, initRecord("calendar", url.toPreserve(Cap), cap.toPreserve(Cap)))
diff --git a/src/icalendar_components.nim b/src/icalendar_components.nim
new file mode 100644
index 0000000..542c260
--- /dev/null
+++ b/src/icalendar_components.nim
@@ -0,0 +1,26 @@
+
+import
+  preserves, std/tables
+
+type
+  CalendarDataspace* {.preservesRecord: "calendar".} = object
+    `url`*: string
+    `dataspace`* {.preservesEmbedded.}: Preserve[void]
+
+  Property* {.preservesTuple.} = object
+    `label`*: string
+    `parameters`*: Parameters
+    `type`*: string
+    `values`* {.preservesTupleTail.}: seq[Preserve[void]]
+
+  Parameters* = Table[Symbol, string]
+  Component* {.acyclic, preservesTuple.} = ref object
+    `label`*: string
+    `properties`*: seq[Property]
+    `components`*: seq[Component]
+
+proc `$`*(x: CalendarDataspace | Property | Parameters | Component): string =
+  `$`(toPreserve(x))
+
+proc encode*(x: CalendarDataspace | Property | Parameters | Component): seq[byte] =
+  encode(toPreserve(x))