extract the state to save

1 files changed, 40 insertions, 0 deletions

diff --git a/src/savestate.rs b/src/savestate.rs
new file mode 100644
index 0000000..8afbbf1
--- /dev/null
+++ b/src/savestate.rs
@@ -0,0 +1,40 @@
+
+use std::collections::HashMap;
+use serde_json::{json, Value};
+use crate::Pos;
+use crate::template::Template;
+
+pub struct SaveState {
+	pub changes: HashMap<Pos, Vec<Template>>
+}
+
+impl SaveState {
+	
+	pub fn new() -> Self {
+		Self {
+			changes: HashMap::new()
+		}
+	}
+	
+	pub fn to_json(&self) -> Value {
+		json!({
+			"changes": self.changes.iter().map(
+					|(pos, templates)|
+					(pos, templates.iter().map(|t| t.to_json()).collect())
+				).collect::<Vec<(&Pos, Vec<Value>)>>()
+		})
+	}
+	
+	pub fn from_json(val: &Value) -> Option<Self> {
+		let mut changes = HashMap::new();
+		for v in val.get("changes")?.as_array()? {
+			let pos = Pos::from_json(v.get(0)?)?;
+			let mut templates = Vec::new();
+			for t in v.get(1)?.as_array()? {
+				templates.push(Template::from_json(t)?);
+			}
+			changes.insert(pos, templates);
+		}
+		Some(Self {changes})
+	}
+}