Add initial parsing

Signed-off-by: Marcel Müller <neikos@neikos.email>

src/lib.rs

@@ -1,14 +1,99 @@
-pub fn add(left: u64, right: u64) -> u64 {
-    left + right
+use std::collections::BTreeMap;
+use std::collections::HashMap;
+
+use displaydoc::Display;
+use serde::Serialize;
+use thiserror::Error;
+
+pub mod parser;
+
+#[derive(Debug, Error, Display)]
+pub enum TempleError {
+    /// Could not parse the given template
+    ParseError {},
+}
+
+pub struct Temple {
+    templates: HashMap<String, Template>,
+}
+
+impl Default for Temple {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Temple {
+    pub fn new() -> Temple {
+        Temple {
+            templates: HashMap::new(),
+        }
+    }
+
+    pub fn add_template(
+        &mut self,
+        name: impl Into<String>,
+        value: impl AsRef<str>,
+    ) -> Result<(), TempleError> {
+        Ok(())
+    }
+
+    fn render(&self, arg: &str, ctx: &Context) -> Result<String, TempleError> {
+        Ok(String::new())
+    }
+}
+
+struct Template {}
+
+pub struct Context {
+    values: BTreeMap<String, serde_json::Value>,
+}
+
+impl Default for Context {
+    fn default() -> Self {
+        Context::new()
+    }
+}
+
+impl Context {
+    pub fn new() -> Context {
+        Context {
+            values: BTreeMap::new(),
+        }
+    }
+
+    pub fn try_insert(
+        &mut self,
+        key: impl Into<String>,
+        value: impl Serialize,
+    ) -> Result<(), serde_json::Error> {
+        self.values.insert(key.into(), serde_json::to_value(value)?);
+
+        Ok(())
+    }
+
+    pub fn insert(&mut self, key: impl Into<String>, value: impl Serialize) {
+        self.try_insert(key, value)
+            .expect("inserted value should serialize without error");
+    }
 }
 
 #[cfg(test)]
 mod tests {
-    use super::*;
+    use crate::Context;
+    use crate::Temple;
 
     #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
+    fn check_simple_template() {
+        let mut temp = Temple::new();
+
+        temp.add_template("base", "Hello {{= name }}").unwrap();
+
+        let mut ctx = Context::new();
+        ctx.insert("name", "World");
+
+        let rendered = temp.render("base", &ctx).unwrap();
+
+        insta::assert_snapshot!(rendered, @"")
     }
 }