From 5f4e240af00c4a6ed7b99fb6a7983ae9f4696a27 Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Thu, 13 Jul 2023 19:09:44 -0400
Subject: [PATCH] Add an initial implementation of PlainLink.

---
 .../plain_link/all_default_links.org          | 26 +++++++++
 src/parser/object.rs                          |  3 +-
 src/parser/object_parser.rs                   |  1 +
 src/parser/plain_link.rs                      | 57 ++++++++++++++++++-
 4 files changed, 83 insertions(+), 4 deletions(-)
 create mode 100644 org_mode_samples/plain_link/all_default_links.org

diff --git a/org_mode_samples/plain_link/all_default_links.org b/org_mode_samples/plain_link/all_default_links.org
new file mode 100644
index 0000000..8ceca6f
--- /dev/null
+++ b/org_mode_samples/plain_link/all_default_links.org
@@ -0,0 +1,26 @@
+non-link text
+id://foo
+eww://foo
+rmail://foo
+mhe://foo
+irc://foo
+info://foo
+gnus://foo
+docview://foo
+bibtex://foo
+bbdb://foo
+w3m://foo
+doi://foo
+file+sys://foo
+file+emacs://foo
+shell://foo
+news://foo
+mailto://foo
+https://foo
+http://foo
+ftp://foo
+help://foo
+file://foo
+elisp://foo
+randomfakeprotocl://foo
+non-link text
diff --git a/src/parser/object.rs b/src/parser/object.rs
index 5ff013e..cef816c 100644
--- a/src/parser/object.rs
+++ b/src/parser/object.rs
@@ -76,7 +76,8 @@ pub struct RadioLink<'s> {
 #[derive(Debug, PartialEq)]
 pub struct PlainLink<'s> {
     pub source: &'s str,
-    pub children: Vec<Object<'s>>,
+    pub link_type: &'s str,
+    pub path: &'s str,
 }
 
 impl<'s> Source<'s> for Object<'s> {
diff --git a/src/parser/object_parser.rs b/src/parser/object_parser.rs
index 086f648..3b29a6c 100644
--- a/src/parser/object_parser.rs
+++ b/src/parser/object_parser.rs
@@ -68,6 +68,7 @@ pub fn any_object_except_plain_text<'r, 's>(
             parser_with_context!(regular_link)(context),
             Object::RegularLink,
         ),
+        map(parser_with_context!(plain_link)(context), Object::PlainLink),
     ))(input)
 }
 
diff --git a/src/parser/plain_link.rs b/src/parser/plain_link.rs
index c95bb9c..c102ea6 100644
--- a/src/parser/plain_link.rs
+++ b/src/parser/plain_link.rs
@@ -1,6 +1,10 @@
 use nom::branch::alt;
+use nom::bytes::complete::tag;
+use nom::bytes::complete::tag_no_case;
+use nom::bytes::complete::take_while;
 use nom::character::complete::none_of;
 use nom::combinator::eof;
+use nom::combinator::peek;
 use nom::combinator::recognize;
 
 use super::Context;
@@ -8,14 +12,20 @@ use crate::error::CustomError;
 use crate::error::MyError;
 use crate::error::Res;
 use crate::parser::object::PlainLink;
+use crate::parser::parser_with_context::parser_with_context;
+use crate::parser::util::get_consumed;
 use crate::parser::util::get_one_before;
-use crate::parser::util::not_yet_implemented;
 use crate::parser::util::WORD_CONSTITUENT_CHARACTERS;
 
 #[tracing::instrument(ret, level = "debug")]
 pub fn plain_link<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, PlainLink<'s>> {
-    not_yet_implemented()?;
-    todo!();
+    let (remaining, _) = pre(context, input)?;
+    let (remaining, proto) = protocol(context, remaining)?;
+    let (remaining, _separator) = tag(":")(remaining)?;
+    let (remaining, path) = path_plain(context, remaining)?;
+    peek(parser_with_context!(post)(context))(remaining)?;
+    let source = get_consumed(input, remaining);
+    Ok((remaining, PlainLink { source, link_type: proto, path }))
 }
 
 #[tracing::instrument(ret, level = "debug")]
@@ -43,3 +53,44 @@ pub fn post<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, ()
     let (remaining, _) = alt((eof, recognize(none_of(WORD_CONSTITUENT_CHARACTERS))))(input)?;
     Ok((remaining, ()))
 }
+
+#[tracing::instrument(ret, level = "debug")]
+pub fn protocol<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
+    let (remaining, proto) = alt((
+        alt((
+            tag_no_case("id"),
+            tag_no_case("eww"),
+            tag_no_case("rmail"),
+            tag_no_case("mhe"),
+            tag_no_case("irc"),
+            tag_no_case("info"),
+            tag_no_case("gnus"),
+            tag_no_case("docview"),
+            tag_no_case("bibtex"),
+            tag_no_case("bbdb"),
+            tag_no_case("w3m"),
+        )),
+        alt((
+            tag_no_case("doi"),
+            tag_no_case("file+sys"),
+            tag_no_case("file+emacs"),
+            tag_no_case("shell"),
+            tag_no_case("news"),
+            tag_no_case("mailto"),
+            tag_no_case("https"),
+            tag_no_case("http"),
+            tag_no_case("ftp"),
+            tag_no_case("help"),
+            tag_no_case("file"),
+            tag_no_case("elisp"),
+        )),
+    ))(input)?;
+    Ok((remaining, proto))
+}
+
+#[tracing::instrument(ret, level = "debug")]
+pub fn path_plain<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
+    // TODO: "optionally containing parenthesis-wrapped non-whitespace non-bracket substrings up to a depth of two. The string must end with either a non-punctation non-whitespace character, a forwards slash, or a parenthesis-wrapped substring"
+    take_while(|c| !" \t\r\n()[]<>".contains(c))(input)
+    // recognize(many1(none_of(" \t\r\n()[]<>")))(input)
+}