restructured all the reminder creation stuff into builders

src/models/reminder/content.rs

@@ -0,0 +1,74 @@
+use serenity::model::{channel::Message, guild::Guild, misc::Mentionable};
+
+use regex::Captures;
+
+use crate::{consts::REGEX_CONTENT_SUBSTITUTION, models::reminder::errors::ContentError};
+
+pub struct Content {
+    pub content: String,
+    pub tts: bool,
+    pub attachment: Option<Vec<u8>>,
+    pub attachment_name: Option<String>,
+}
+
+impl Content {
+    pub fn new() -> Self {
+        Self {
+            content: "".to_string(),
+            tts: false,
+            attachment: None,
+            attachment_name: None,
+        }
+    }
+
+    pub async fn build<S: ToString>(content: S, message: &Message) -> Result<Self, ContentError> {
+        if message.attachments.len() > 1 {
+            Err(ContentError::TooManyAttachments)
+        } else if let Some(attachment) = message.attachments.get(0) {
+            if attachment.size > 8_000_000 {
+                Err(ContentError::AttachmentTooLarge)
+            } else if let Ok(attachment_bytes) = attachment.download().await {
+                Ok(Self {
+                    content: content.to_string(),
+                    tts: false,
+                    attachment: Some(attachment_bytes),
+                    attachment_name: Some(attachment.filename.clone()),
+                })
+            } else {
+                Err(ContentError::AttachmentDownloadFailed)
+            }
+        } else {
+            Ok(Self {
+                content: content.to_string(),
+                tts: false,
+                attachment: None,
+                attachment_name: None,
+            })
+        }
+    }
+
+    pub fn substitute(&mut self, guild: Guild) {
+        if self.content.starts_with("/tts ") {
+            self.tts = true;
+            self.content = self.content.split_off(5);
+        }
+
+        self.content = REGEX_CONTENT_SUBSTITUTION
+            .replace(&self.content, |caps: &Captures| {
+                if let Some(user) = caps.name("user") {
+                    format!("<@{}>", user.as_str())
+                } else if let Some(role_name) = caps.name("role") {
+                    if let Some(role) = guild.role_by_name(role_name.as_str()) {
+                        role.mention().to_string()
+                    } else {
+                        format!("<<{}>>", role_name.as_str().to_string())
+                    }
+                } else {
+                    String::new()
+                }
+            })
+            .to_string()
+            .replace("<<everyone>>", "@everyone")
+            .replace("<<here>>", "@here");
+    }
+}