1 files changed, 108 insertions, 0 deletions
diff --git a/stockton-levels/src/q3/entities.rs b/stockton-levels/src/q3/entities.rs
new file mode 100644
index 0000000..1614f26
--- /dev/null
+++ b/stockton-levels/src/q3/entities.rs
@@ -0,0 +1,108 @@
+// Copyright (C) 2019 Oscar Shrimpton
+//
+// This file is part of stockton-bsp.
+//
+// stockton-bsp is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// stockton-bsp is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with stockton-bsp.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::str;
+use std::collections::HashMap;
+
+use crate::types::{Result, ParseError};
+use crate::traits::entities::*;
+use super::Q3BSPFile;
+
+const QUOTE: u8 = b'"';
+const END_BRACKET: u8 = b'}';
+const START_BRACKET: u8 = b'{';
+
+/// Internal enum to parse through the entities string.
+#[derive(PartialEq, Eq)]
+enum ParseState {
+    InKey,
+    InValue,
+    AfterKey,
+    InsideEntity,
+    OutsideEntity,
+}
+
+/// Parse the given data as an Entities lump
+pub fn from_data(data: &[u8]) -> Result<Box<[Entity]>> {
+    use self::ParseState::*;
+
+    let string = str::from_utf8(data).unwrap();
+
+    let mut attrs = HashMap::new();
+    let mut entities = Vec::new();
+
+    let mut state = ParseState::OutsideEntity;
+
+    let mut key_start = 0;
+    let mut key_end = 0;
+    let mut val_start = 0;
+    let mut val_end;
+
+    for (i, chr) in string.bytes().enumerate() {
+        match chr {
+            QUOTE => match state {
+                InsideEntity => {
+                    state = ParseState::InKey;
+                    key_start = i + 1;
+                }
+                InKey => {
+                    state = ParseState::AfterKey;
+                    key_end = i;
+                }
+                AfterKey => {
+                    state = ParseState::InValue;
+                    val_start = i + 1;
+                }
+                InValue => {
+                    state = ParseState::InsideEntity;
+                    val_end = i;
+
+                    attrs.insert(string[key_start..key_end].to_owned(), string[val_start..val_end].to_owned());
+                }
+                _ => {
+                    return Err(ParseError::Invalid);
+                }
+            },
+            END_BRACKET => {
+                if state != InsideEntity {
+                    return Err(ParseError::Invalid);
+                }
+
+                state = OutsideEntity;
+
+                entities.push(Entity { attributes: attrs });
+                attrs = HashMap::new();
+            }
+            START_BRACKET => {
+                if state != OutsideEntity {
+                    return Err(ParseError::Invalid);
+                }
+                state = InsideEntity;
+            }
+            _ => {}
+        }
+    }
+    Ok(entities.into_boxed_slice())
+}
+
+impl<'a> HasEntities<'a> for Q3BSPFile {
+    type EntitiesIter = std::slice::Iter<'a, Entity>;
+
+    fn entities_iter(&'a self) -> Self::EntitiesIter {
+        self.entities.iter()
+    }
+}