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

/**
 * Proof of Concept: The Constitution (Gen 2)
 *
 * Demonstrates a mechanism to parse an actual markdown file with YAML frontmatter
 * and Markdown AST or structured regex to programmatically restrict an agent's
 * proposed actions. Here we read from real filesystem I/O instead of a string mock.
 */

export async function parseConstitution(filePath: string) {
  const content = await Deno.readTextFile(filePath);

  const allowedSection = content.match(
    /## Allowed Tech Stack\n([\s\S]*?)(?=##|$)/,
  );
  const deniedSection = content.match(
    /## Denied Libraries\n([\s\S]*?)(?=##|$)/,
  );

  const allowed = allowedSection
    ? allowedSection[1].split("\n").map((l) => l.replace(/^- /, "").trim())
      .filter(Boolean)
    : [];
  const denied = deniedSection
    ? deniedSection[1].split("\n").map((l) => l.replace(/^- /, "").trim())
      .filter(Boolean)
    : [];

  return { allowed, denied };
}

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 (Gen 2) tests...");

  try {
    const tempFile = await Deno.makeTempFile({ suffix: ".md" });
    await Deno.writeTextFile(
      tempFile,
      `
# System Constitution

## Allowed Tech Stack
- Deno
- TypeScript
- PostgreSQL

## Denied Libraries
- React
- MongoDB
    `,
    );

    const { allowed, denied } = await parseConstitution(tempFile);
    await Deno.remove(tempFile);

    const safeProposal = ["Deno", "TypeScript"];
    const safeResult = evaluateAgentProposal(safeProposal, allowed, denied);
    assert(safeResult.valid, "Expected safe proposal to be valid");

    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(
      "✅ The Constitution PoC (Gen 2) successful: Real File I/O constraints parsed and enforced.",
    );
  } catch (err) {
    console.error("❌ The Constitution PoC (Gen 2) failed:", err);
    Deno.exit(1);
  }
}