From 23e84c263d0b60e5ba022572c19289c0cc06efe4 Mon Sep 17 00:00:00 2001
From: Mason Payne <mason@masonitestudios.com>
Date: Mon, 1 Sep 2025 11:09:49 -0600
Subject: [PATCH] WIP: start the proto interpreter

---
 interpreter/proto_interpreter.go | 65 ++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 interpreter/proto_interpreter.go

diff --git a/interpreter/proto_interpreter.go b/interpreter/proto_interpreter.go
new file mode 100644
index 0000000..c2c414b
--- /dev/null
+++ b/interpreter/proto_interpreter.go
@@ -0,0 +1,65 @@
+package interpreter
+
+import (
+	"fmt"
+	"masonry/lang"
+	"strings"
+)
+
+type ProtoInterpreter struct {
+	entities  map[string]*lang.Entity
+	endpoints map[string]*lang.Endpoint
+	server    *lang.Server
+}
+
+func NewProtoInterpreter() *ProtoInterpreter {
+	return &ProtoInterpreter{
+		entities:  make(map[string]*lang.Entity),
+		endpoints: make(map[string]*lang.Endpoint),
+	}
+}
+
+func (pi *ProtoInterpreter) Interpret(ast lang.AST) error {
+
+	for _, def := range ast.Definitions {
+		if def.Server != nil {
+			pi.server = def.Server
+		} else if def.Entity != nil {
+			pi.entities[def.Entity.Name] = def.Entity
+		} else if def.Endpoint != nil {
+			key := fmt.Sprintf("%s_%s", def.Endpoint.Method, strings.ReplaceAll(def.Endpoint.Path, "/", "_"))
+			pi.endpoints[key] = def.Endpoint
+		}
+	}
+
+	// Validate references
+	for _, endpoint := range pi.endpoints {
+		if endpoint.Entity != nil {
+			if _, exists := pi.entities[*endpoint.Entity]; !exists {
+				return fmt.Errorf("undefined entity referenced in endpoint request: %s", *endpoint.Entity)
+			}
+		}
+		if endpoint.Response != nil {
+			entity, exists := pi.entities[*endpoint.Entity]
+			if !exists {
+				return fmt.Errorf("undefined entity referenced in endpoint response: %s", *endpoint.Entity)
+			}
+			// validate the fields of the response
+			for _, field := range endpoint.Response.Fields {
+				// check for a field with the same name in the entity
+				found := false
+				for _, entityField := range entity.Fields {
+					if entityField.Name == field {
+						found = true
+						break
+					}
+				}
+				if !found {
+					return fmt.Errorf("undefined field referenced in endpoint response: %s", field)
+				}
+			}
+		}
+	}
+
+	return nil
+}