add: markdown emoji parsing

crates/core/src/model/uploads.rs

@@ -48,6 +48,8 @@ pub struct CustomEmoji {
     pub name: String,
 }
 
+pub type EmojiParserResult = Vec<(String, usize, String)>;
+
 impl CustomEmoji {
     /// Create a new [`CustomEmoji`].
     pub fn new(owner: usize, community: usize, upload_id: usize, name: String) -> Self {
@@ -63,4 +65,105 @@ impl CustomEmoji {
             name,
         }
     }
+
+    /// Replace emojis in the given input string.
+    pub fn replace(input: &str) -> String {
+        let res = Self::parse(input);
+        let mut out = input.to_string();
+
+        for emoji in res {
+            if emoji.1 == 0 {
+                out = out.replace(
+                    &emoji.0,
+                    match emojis::get_by_shortcode(&emoji.2) {
+                        Some(e) => e.as_str(),
+                        None => &emoji.0,
+                    },
+                );
+            } else {
+                out = out.replace(
+                    &emoji.0,
+                    &format!(
+                        "<img class=\"emoji\" src=\"/api/v1/communities/{}/emoji/{}\" />",
+                        emoji.1, emoji.2
+                    ),
+                );
+            }
+        }
+
+        out
+    }
+
+    /// Parse text for emojis.
+    ///
+    /// Another "great" parser, just like the mentions parser.
+    ///
+    /// # Returns
+    /// `(capture, community id, emoji name)`
+    pub fn parse(input: &str) -> EmojiParserResult {
+        let mut out = Vec::new();
+        let mut buffer: String = String::new();
+
+        let mut escape: bool = false;
+        let mut in_emoji: bool = false;
+
+        let mut chars = input.chars();
+        while let Some(char) = chars.next() {
+            if escape == true {
+                buffer.push(char);
+                continue;
+            }
+
+            if char == '\\' && escape == false {
+                escape = true;
+                continue;
+            } else if char == ':' {
+                let mut community_id: String = String::new();
+                let mut accepting_community_id_chars: bool = true;
+                let mut emoji_name: String = String::new();
+
+                let mut char_count: u32 = 0; // if we're past the first 4 characters and we haven't hit a digit, stop accepting community id
+                while let Some(char) = chars.next() {
+                    if (char == ':') | (char == ' ') {
+                        in_emoji = false;
+                        break;
+                    }
+
+                    if char.is_digit(10) && accepting_community_id_chars {
+                        community_id.push(char);
+                    } else if char == '.' {
+                        // the period closes the community id
+                        accepting_community_id_chars = false;
+                    } else {
+                        emoji_name.push(char);
+                    }
+
+                    if char_count >= 4 && community_id.is_empty() {
+                        accepting_community_id_chars = false;
+                    }
+
+                    char_count += 1;
+                }
+
+                out.push((
+                    format!(
+                        ":{}{emoji_name}:",
+                        if !community_id.is_empty() {
+                            format!("{community_id}.")
+                        } else {
+                            String::new()
+                        }
+                    ),
+                    community_id.parse::<usize>().unwrap_or(0),
+                    emoji_name,
+                ));
+
+                continue;
+            } else if in_emoji {
+                buffer.push(char);
+            }
+        }
+
+        out
+    }
 }