Move the builders to the utils

The builders aren't a large enough portion of the library to deserve
their own root-level module, so move them to the `utils` module.

Additionally, split them into separate files, as the library will be
receiving more builders and the single-file pattern was getting rather
large.

1 files changed, 55 insertions, 0 deletions

diff --git a/src/utils/builder/execute_webhook.rs b/src/utils/builder/execute_webhook.rs
new file mode 100644
index 0000000..d2a14aa
--- /dev/null
+++ b/src/utils/builder/execute_webhook.rs
@@ -0,0 +1,55 @@
+use serde_json::builder::ObjectBuilder;
+use serde_json::Value;
+use std::default::Default;
+
+/// A builder to create the inner content of a [`Webhook`]'s execution.
+///
+/// This is a structured way of cleanly creating the inner execution payload,
+/// to reduce potential argument counts.
+///
+/// Refer to the documentation for [`execute_webhook`] on restrictions with
+/// execution payloads and its fields.
+///
+/// [`Webhook`]: ../model/struct.Webhook.html
+/// [`execute_webhook`]: ../client/http/fn.execute_webhook.html
+pub struct ExecuteWebhook(pub ObjectBuilder);
+
+impl ExecuteWebhook {
+    /// Override the default avatar of the webhook with an image URL.
+    pub fn avatar_url(self, avatar_url: &str) -> Self {
+        ExecuteWebhook(self.0.insert("avatar_url", avatar_url))
+    }
+
+    /// Set the content of the message.
+    pub fn content(self, content: &str) -> Self {
+        ExecuteWebhook(self.0.insert("content", content))
+    }
+
+    // Set the embeds associated with the message.
+    pub fn embeds(self, embeds: Vec<Value>) -> Self {
+        ExecuteWebhook(self.0.insert("embeds", embeds))
+    }
+
+    /// Whether the message is a text-to-speech message.
+    ///
+    /// Think carefully before setting this to `true`.
+    pub fn tts(self, tts: bool) -> Self {
+        ExecuteWebhook(self.0.insert("tts", tts))
+    }
+
+    /// Override the default username of the webhook.
+    pub fn username(self, username: &str) -> Self {
+        ExecuteWebhook(self.0.insert("username", username))
+    }
+}
+
+impl Default for ExecuteWebhook {
+    /// Returns a default set of values for a [`Webhook`] execution.
+    ///
+    /// The only default value is `tts` being set to `true`. In the event that
+    /// there is a bug that Discord defaults `tts` to `true`, at least
+    /// serenity.rs won't be a part of it.
+    fn default() -> ExecuteWebhook {
+        ExecuteWebhook(ObjectBuilder::new().insert("tts", false))
+    }
+}