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

/**
 * Proof of Concept: Git Storage (Notes & Orphan Branches)
 *
 * This module demonstrates how we can use Deno's `Deno.Command` API to interact
 * with Git Notes and Orphan Branches to store agent state and metadata without
 * polluting the main working tree.
 */

async function runGitCmd(args: string[]): Promise<string> {
  const cmd = new Deno.Command("git", {
    args,
    stdout: "piped",
    stderr: "piped",
  });
  const output = await cmd.output();
  const stdout = new TextDecoder().decode(output.stdout).trim();
  const stderr = new TextDecoder().decode(output.stderr).trim();

  if (!output.success) {
    throw new Error(`Git command failed: git ${args.join(" ")}\n${stderr}`);
  }
  return stdout;
}

export async function addGitNote(ref: string, message: string, targetRef: string = "HEAD") {
  // First, check if a note already exists to avoid overwriting blindly
  // For this PoC, we will append or overwrite
  await runGitCmd(["notes", "--ref", ref, "add", "-f", "-m", message, targetRef]);
}

export async function readGitNote(ref: string, targetRef: string = "HEAD"): Promise<string> {
  try {
    return await runGitCmd(["notes", "--ref", ref, "show", targetRef]);
  } catch (error: any) {
    if (error.message.includes("No note found")) {
      return "";
    }
    throw error;
  }
}

// In a real scenario, tests would be separated. For this PoC, we will run the tests here.
if (import.meta.main) {
  console.log("Running Git Storage PoC tests...");

  // 1. Test Git Notes
  const customRef = "forum/test-reasoning";
  const testMessage = JSON.stringify({
    agent: "poc-agent",
    risk: "low",
    thought: "This is a hidden thought stored in a git note."
  });

  try {
    console.log(`Adding note to current HEAD under ref ${customRef}...`);
    await addGitNote(customRef, testMessage);

    console.log(`Reading note back...`);
    const readMessage = await readGitNote(customRef);

    assertEquals(readMessage, testMessage);
    console.log("✅ Git Notes PoC successful: Read/Write worked as expected.");

    // Clean up
    await runGitCmd(["notes", "--ref", customRef, "remove", "HEAD"]);
  } catch (err) {
    console.error("❌ Git Notes PoC failed:", err);
  }
}