import {
  assert,
  assertEquals,
} from "https://deno.land/std@0.224.0/testing/asserts.ts";

/**
 * Proof of Concept: The Constitution (AGENTS.md)
 *
 * Demonstrates a mechanism to parse an AGENTS.md rule file and use it to
 * programmatically restrict an agent's proposed actions (e.g. stack validation).
 */

const mockAgentsMd = `
# System Constitution

## Allowed Tech Stack
- Deno
- TypeScript
- Vue.js
- Tailwind CSS
- PostgreSQL

## Denied Libraries
- React
- Express
- MongoDB
`;

function extractAllowedStack(markdown: string): string[] {
  const allowedSection = markdown.match(
    /## Allowed Tech Stack\n([\s\S]*?)(?=##|$)/,
  );
  if (!allowedSection) return [];

  return allowedSection[1]
    .split("\n")
    .map((line) => line.replace(/^- /, "").trim())
    .filter((line) => line.length > 0);
}

function extractDeniedStack(markdown: string): string[] {
  const deniedSection = markdown.match(
    /## Denied Libraries\n([\s\S]*?)(?=##|$)/,
  );
  if (!deniedSection) return [];

  return deniedSection[1]
    .split("\n")
    .map((line) => line.replace(/^- /, "").trim())
    .filter((line) => line.length > 0);
}

function evaluateAgentProposal(
  proposal: string[],
  allowed: string[],
  denied: string[],
): { valid: boolean; violations: string[] } {
  const violations = [];

  for (const tech of proposal) {
    if (denied.includes(tech)) {
      violations.push(`${tech} is explicitly forbidden.`);
    } else if (!allowed.includes(tech)) {
      violations.push(`${tech} is not in the approved tech stack.`);
    }
  }

  return { valid: violations.length === 0, violations };
}

if (import.meta.main) {
  console.log("Running The Constitution PoC tests...");

  try {
    const allowed = extractAllowedStack(mockAgentsMd);
    const denied = extractDeniedStack(mockAgentsMd);

    // Scenario 1: Agent proposes an allowed stack update
    const safeProposal = ["Deno", "TypeScript"];
    const safeResult = evaluateAgentProposal(safeProposal, allowed, denied);
    assert(safeResult.valid, "Expected safe proposal to be valid");
    console.log("✅ Safe proposal accepted.");

    // Scenario 2: Agent hallucinates a React/Mongo app
    const unsafeProposal = ["Deno", "React", "MongoDB"];
    const unsafeResult = evaluateAgentProposal(unsafeProposal, allowed, denied);
    assert(!unsafeResult.valid, "Expected unsafe proposal to be invalid");
    assertEquals(unsafeResult.violations.length, 2);
    console.log(
      "✅ Unsafe proposal correctly rejected based on AGENTS.md rules:",
    );
    unsafeResult.violations.forEach((v) => console.log(`   - ${v}`));

    console.log("✅ The Constitution PoC successful.");
  } catch (err) {
    console.error("❌ The Constitution PoC failed:", err);
    Deno.exit(1);
  }
}