feat: complete production-quality Model Router AI traffic control platform

backend/app/router/rules_engine.py

@@ -0,0 +1,73 @@
+from typing import List, Optional, Tuple
+from app.storage.models import RoutingRuleRecord
+from app.models.schemas import RequestAnalysis
+
+
+def evaluate_routing_rules(
+    rules: List[RoutingRuleRecord],
+    analysis: RequestAnalysis,
+    current_budget_percent: float = 0.0,
+) -> Tuple[Optional[str], Optional[str], Optional[str]]:
+    """
+    Evaluates enabled routing rules in order of priority (highest priority number first).
+    Returns: (action_type, action_target, matched_rule_name) or (None, None, None)
+    """
+    sorted_rules = sorted([r for r in rules if r.is_enabled], key=lambda x: x.priority, reverse=True)
+
+    for rule in sorted_rules:
+        field = rule.condition_field.lower()
+        op = rule.condition_operator
+        target_val = rule.condition_value
+
+        matched = False
+
+        if field == "task_type":
+            val = analysis.task_type.value
+            if op == "==":
+                matched = (val == target_val)
+            elif op == "!=":
+                matched = (val != target_val)
+            elif op == "contains":
+                matched = (target_val in val)
+
+        elif field == "complexity":
+            val = analysis.complexity
+            try:
+                target_num = float(target_val)
+                if op == ">=":
+                    matched = (val >= target_num)
+                elif op == ">":
+                    matched = (val > target_num)
+                elif op == "<=":
+                    matched = (val <= target_num)
+                elif op == "<":
+                    matched = (val < target_num)
+                elif op == "==":
+                    matched = (abs(val - target_num) < 0.01)
+            except ValueError:
+                pass
+
+        elif field in ("budget_percent", "monthly_budget_percent"):
+            try:
+                target_num = float(target_val)
+                if op == ">=":
+                    matched = (current_budget_percent >= target_num)
+                elif op == ">":
+                    matched = (current_budget_percent > target_num)
+            except ValueError:
+                pass
+
+        elif field == "context_size":
+            try:
+                target_num = int(target_val)
+                if op == ">=":
+                    matched = (analysis.context_size >= target_num)
+                elif op == ">":
+                    matched = (analysis.context_size > target_num)
+            except ValueError:
+                pass
+
+        if matched:
+            return rule.action_type, rule.action_target, rule.name
+
+    return None, None, None