import { z } from "zod";

// Schema for pod remediation actions
export const RemediationActionSchema = z.object({
  clusterId: z.string(),
  namespace: z.string().min(1),
  targetResource: z.string(),
  actionType: z.enum([
    "RESTART_POD",
    "SCALE_DEPLOYMENT_REPLICAS",
    "PATCH_CONTAINER_MEMORY",
    "DRAIN_NODE",
  ]),
  parameters: z.record(z.unknown()),
  estimatedRisk: z.enum(["LOW", "MEDIUM", "HIGH", "CRITICAL"]),
});

export type RemediationAction = z.infer<typeof RemediationActionSchema>;

export interface ExecutionVerdict {
  isAllowed: boolean;
  requiresHumanApproval: boolean;
  reason: string;
}

export class DevOpsPolicyEngine {
  private allowedNamespaces = new Set(["staging", "production-workers"]);
  private maxMemoryScaleMB = 4096;

  public evaluateAction(action: RemediationAction): ExecutionVerdict {
    // Rule 1: Enforce namespace boundary
    if (!this.allowedNamespaces.has(action.namespace)) {
      return {
        isAllowed: false,
        requiresHumanApproval: false,
        reason: `Namespace '${action.namespace}' is outside autonomous agent execution boundary.`,
      };
    }

    // Rule 2: Escalation gate for node drainage or critical mutations
    if (action.actionType === "DRAIN_NODE" || action.estimatedRisk === "CRITICAL") {
      return {
        isAllowed: false,
        requiresHumanApproval: true,
        reason: `High-risk operation (${action.actionType}) requires explicit on-call SRE approval.`,
      };
    }

    // Rule 3: Resource ceiling validation
    if (action.actionType === "PATCH_CONTAINER_MEMORY") {
      const requestedMB = Number(action.parameters.memoryMB || 0);
      if (requestedMB > this.maxMemoryScaleMB) {
        return {
          isAllowed: false,
          requiresHumanApproval: true,
          reason: `Requested memory limit (${requestedMB}MB) exceeds safe ceiling of ${this.maxMemoryScaleMB}MB.`,
        };
      }
    }

    return {
      isAllowed: true,
      requiresHumanApproval: false,
      reason: "Action passed all deterministic policy criteria.",
    };
  }
}