Restructure modules

Modules are now separated into a fashion where the library can be used
for most use cases, without needing to compile the rest.

The core of serenity, with no features enabled, contains only the
struct (model) definitions, constants, and prelude. Models do not have
most functions compiled in, as that is separated into the `model`
feature.

The `client` module has been split into 3 modules: `client`, `gateway`,
and `http`.

`http` contains functions to interact with the REST API. `gateway`
contains the Shard to interact with the gateway, requiring `http` for
retrieving the gateway URL. `client` requires both of the other features
and acts as an abstracted interface over both the gateway and REST APIs,
handling the event loop.

The `builder` module has been separated from `utils`, and can now be
optionally compiled in. It and the `http` feature are required by the
`model` feature due to a large number of methods requiring access to
them.

`utils` now contains a number of utilities, such as the Colour struct, the
`MessageBuilder`, and mention parsing functions.

Each of the original `ext` modules are still featured, with `cache` not
requiring any feature to be enabled, `framework` requiring the `client`,
`model`, and `utils`, and `voice` requiring `gateway`.

In total the features and their requirements are:

- `builder`: none
- `cache`: none
- `client`: `gateway`, `http`
- `framework`: `client`, `model`, `utils`
- `gateway`: `http`
- `http`: none
- `model`: `builder`, `http`
- `utils`: none
- `voice`: `gateway`

The default features are `builder`, `cache`, `client`, `framework`,
`gateway`, `model`, `http`, and `utils`.

To help with forwards compatibility, modules have been re-exported from
their original locations.

1 files changed, 164 insertions, 0 deletions

diff --git a/src/framework/command.rs b/src/framework/command.rs
new file mode 100644
index 0000000..5f43284
--- /dev/null
+++ b/src/framework/command.rs
@@ -0,0 +1,164 @@
+use std::sync::Arc;
+use super::Configuration;
+use ::client::Context;
+use ::model::Message;
+use ::model::Permissions;
+use std::collections::HashMap;
+
+pub type Check = Fn(&mut Context, &Message) -> bool + Send + Sync + 'static;
+pub type Exec = Fn(&mut Context, &Message, Vec<String>) -> Result<(), String> + Send + Sync + 'static;
+pub type Help = Fn(&mut Context, &Message, HashMap<String, Arc<CommandGroup>>, &[String]) -> Result<(), String> + Send + Sync + 'static;
+pub type BeforeHook = Fn(&mut Context, &Message, &String) -> bool + Send + Sync + 'static;
+pub type AfterHook = Fn(&mut Context, &Message, &String, Result<(), String>) + Send + Sync + 'static;
+#[doc(hidden)]
+pub type InternalCommand = Arc<Command>;
+pub type PrefixCheck = Fn(&mut Context) -> Option<String> + Send + Sync + 'static;
+
+#[doc(hidden)]
+pub enum CommandOrAlias {
+    Alias(String),
+    Command(InternalCommand),
+}
+
+/// Command function type. Allows to access internal framework things inside
+/// your commands.
+pub enum CommandType {
+    StringResponse(String),
+    Basic(Box<Exec>),
+    WithCommands(Box<Help>),
+}
+
+#[derive(Default)]
+pub struct CommandGroup {
+    pub prefix: Option<String>,
+    pub commands: HashMap<String, CommandOrAlias>,
+}
+
+/// Command struct used to store commands internally.
+pub struct Command {
+    /// A set of checks to be called prior to executing the command. The checks
+    /// will short-circuit on the first check that returns `false`.
+    pub checks: Vec<Box<Check>>,
+    /// Function called when the command is called.
+    pub exec: CommandType,
+    /// Ratelimit bucket.
+    pub bucket: Option<String>,
+    /// Command description, used by other commands.
+    pub desc: Option<String>,
+    /// Example arguments, used by other commands.
+    pub example: Option<String>,
+    /// Command usage schema, used by other commands.
+    pub usage: Option<String>,
+    /// Whether arguments should be parsed using quote parser or not.
+    pub use_quotes: bool,
+    /// Minumum amount of arguments that should be passed.
+    pub min_args: Option<i32>,
+    /// Maximum amount of arguments that can be passed.
+    pub max_args: Option<i32>,
+    /// Permissions required to use this command.
+    pub required_permissions: Permissions,
+    /// Whether command should be displayed in help list or not, used by other commands.
+    pub help_available: bool,
+    /// Whether command can be used only privately or not.
+    pub dm_only: bool,
+    /// Whether command can be used only in guilds or not.
+    pub guild_only: bool,
+    /// Whether command can only be used by owners or not.
+    pub owners_only: bool,
+    #[doc(hidden)]
+    pub aliases: Vec<String>,
+}
+
+impl Command {
+    pub fn new<F>(f: F) -> Self
+        where F: Fn(&mut Context, &Message, Vec<String>) -> Result<(), String> + Send + Sync + 'static {
+        Command {
+            aliases: Vec::new(),
+            checks: Vec::default(),
+            exec: CommandType::Basic(Box::new(f)),
+            desc: None,
+            usage: None,
+            example: None,
+            use_quotes: false,
+            dm_only: false,
+            bucket: None,
+            guild_only: false,
+            help_available: true,
+            min_args: None,
+            max_args: None,
+            owners_only: false,
+            required_permissions: Permissions::empty(),
+        }
+    }
+}
+
+pub fn positions(ctx: &mut Context, content: &str, conf: &Configuration) -> Option<Vec<usize>> {
+    if !conf.prefixes.is_empty() || conf.dynamic_prefix.is_some() {
+        // Find out if they were mentioned. If not, determine if the prefix
+        // was used. If not, return None.
+        let mut positions: Vec<usize> = vec![];
+
+        if let Some(mention_end) = find_mention_end(content, conf) {
+            positions.push(mention_end);
+        } else if let Some(ref func) = conf.dynamic_prefix {
+            if let Some(x) = func(ctx) {
+                if content.starts_with(&x) {
+                    positions.push(x.len());
+                }
+            } else {
+                for n in conf.prefixes.clone() {
+                    if content.starts_with(&n) {
+                        positions.push(n.len());
+                    }
+                }
+            }
+        } else {
+            for n in conf.prefixes.clone() {
+                if content.starts_with(&n) {
+                    positions.push(n.len());
+                }
+            }
+        };
+
+        if positions.is_empty() {
+            return None;
+        }
+
+        if conf.allow_whitespace {
+            let pos = *unsafe { positions.get_unchecked(0) };
+
+            positions.insert(0, pos + 1);
+        }
+
+        Some(positions)
+    } else if conf.on_mention.is_some() {
+        match find_mention_end(content, conf) {
+            Some(mention_end) => {
+                let mut positions = vec![mention_end];
+
+                if conf.allow_whitespace {
+                    positions.insert(0, mention_end + 1);
+                }
+
+                Some(positions)
+            },
+            None => None,
+        }
+    } else {
+        None
+    }
+}
+
+fn find_mention_end(content: &str, conf: &Configuration) -> Option<usize> {
+    if let Some(ref mentions) = conf.on_mention {
+        for mention in mentions {
+            if !content.starts_with(&mention[..]) {
+                continue;
+            }
+
+            return Some(mention.len());
+        }
+    }
+
+    None
+}