1 files changed, 30 insertions, 8 deletions

diff --git a/src/modelica_ast.rs b/src/modelica_ast.rs
index 2958025..f6d32b8 100644
--- a/src/modelica_ast.rs
+++ b/src/modelica_ast.rs
@@ -116,12 +116,6 @@ impl ModelicaModel {
     // TODO: allow passing in Q
     pub fn solve_for(&self, indep_vars: Vec<String>, dep_vars: Vec<String>) -> Result<ModelicaModel,String> {
         let constants = self.get_constant_vars();
-        let param_objs = self.components.iter().filter(|v| match v.prefix {
-                Some(ComponentPrefix::Constant) | Some(ComponentPrefix::Parameter) => false,
-                _ => true,
-            });
-        let params: Vec<String> = param_objs.map(|c| c.name.clone()).collect();
-
         let mut all_vars: HashSet<String> = HashSet::new();
         for eqn in &self.equations {
             all_vars.extend(eqn.identifiers());
@@ -138,7 +132,11 @@ impl ModelicaModel {
 
         // check that  V = Q + P + M
         if all_vars.len() != (constants.len() + indep_vars.len() + dep_vars.len()) {
-            return Err("Variable counts don't add up".to_string());
+            return Err(format!("Variable counts don't add up (V={} Q={} P={} M={})",
+                all_vars.len(),
+                constants.len(),
+                indep_vars.len(),
+                dep_vars.len()));
         }
 
         // check that all constants are bound and simple
@@ -165,8 +163,32 @@ impl ModelicaModel {
         println!("Soliving for {:?} in terms of params {:?} and constants {:?}, with {} equations",
             dep_vars, indep_vars, constants, self.equations.len());
 
-        Ok((*self).clone()) // XXX
+        let mut unsolved_eqns = self.equations.clone();
+        let mut solved: Vec<SimpleEquation> = vec![];
+        let mut unsolved_vars = dep_vars.clone();
+        while unsolved_eqns.len() > 0 {
+            let next_i = unsolved_eqns
+                .iter()
+                .position(|ref x| intersect_strings(&unsolved_vars, &x.identifiers()).len() == 1);
+            let eqn = match next_i {
+                None => { return Err("NaiveImplementation (or poor equation selection?)".to_string()); },
+                Some(i) => unsolved_eqns.remove(i),
+            };
+            let ref var = intersect_strings(&unsolved_vars, &eqn.identifiers())[0];
+            let eqn = eqn.rebalance_for(var.to_string()).expect("rebalance for success");
+            solved.push(eqn);
+            let var_i = unsolved_vars.iter().position(|ref x| x == &var).unwrap();
+            unsolved_vars.remove(var_i);
+        };
+
         // TODO: sort output equations by LHS
+        Ok(ModelicaModel{
+            name: self.name.clone(),
+            components: self.components.clone(),
+            connections: vec![],
+            equations: solved,
+            extends: vec![],
+        })
     }
 }