// src/installer.ts
import { copy } from "jsr:@std/fs/copy";
import { ensureDir } from "jsr:@std/fs/ensure-dir";
import { join, resolve } from "jsr:@std/path";

async function runCmd(
  cmd: string,
  args: string[],
  cwd: string,
): Promise<string> {
  const command = new Deno.Command(cmd, {
    args,
    cwd,
    stdout: "piped",
    stderr: "piped",
  });
  const output = await command.output();
  if (output.code !== 0) {
    const errText = new TextDecoder().decode(output.stderr).trim();
    throw new Error(
      `Command '${cmd} ${args.join(" ")}' failed in ${cwd}: ${errText}`,
    );
  }
  return new TextDecoder().decode(output.stdout).trim();
}

export async function main(args: string[] = Deno.args) {
  const rawTarget = args[0] ?? Deno.cwd();
  const targetDir = resolve(rawTarget);
  const engineRoot = resolve(new URL(".", import.meta.url).pathname, "..");

  console.log(`-> Installing Agent Forum from ${engineRoot} to ${targetDir}`);

  // 1. Verify target is a git repository
  await runCmd("git", ["rev-parse", "--show-toplevel"], targetDir);

  // 2. Scaffolding directories
  const targetForum = join(targetDir, ".forum");
  await ensureDir(join(targetForum, "src"));
  await ensureDir(join(targetForum, "hooks"));
  await ensureDir(join(targetForum, "config"));

  // 3. Copy engine source and hooks
  await copy(join(engineRoot, "src"), join(targetForum, "src"), {
    overwrite: true,
  });
  await copy(join(engineRoot, "src", "hooks"), join(targetForum, "hooks"), {
    overwrite: true,
  });

  // 4. Configure git hooks path
  await runCmd("git", ["config", "core.hooksPath", ".forum/hooks"], targetDir);

  // 5. Append managed block to target .gitignore
  const gitignorePath = join(targetDir, ".gitignore");
  let gitignoreContent = "";
  try {
    gitignoreContent = await Deno.readTextFile(gitignorePath);
  } catch {
    // File does not exist yet
  }

  const managedHeader = "# === AGENT-FORUM MANAGED BLOCK ===";
  const managedFooter = "# === END AGENT-FORUM MANAGED BLOCK ===";
  const block = [
    managedHeader,
    ".forum/ast/",
    ".forum/security/",
    ".forum/reports/",
    ".forum/worktree_meta/",
    managedFooter,
  ].join("\n");

  if (!gitignoreContent.includes(managedHeader)) {
    const updated = gitignoreContent
      ? `${gitignoreContent.trimEnd()}\n\n${block}\n`
      : `${block}\n`;
    await Deno.writeTextFile(gitignorePath, updated);
  }

  // 5.5 Create agent-forum configuration in the target root if it does not exist
  const configPath = join(targetDir, "agent-forum.json");
  try {
    await Deno.stat(configPath);
    console.log(
      "-> Existing agent-forum.json found in repository root. Preserving it.",
    );
  } catch {
    console.log("-> Creating default agent-forum.json configuration...");
    const defaultConfig = {
      "stryker": {
        "ignoreTests": ["test/integration/"],
        "showProgress": true,
      },
    };
    await Deno.writeTextFile(
      configPath,
      JSON.stringify(defaultConfig, null, 2),
    );
  }

  // Cleanup old config if it exists in .forum/
  const oldConfigPath = join(targetForum, "agent-forum.json");
  try {
    await Deno.stat(oldConfigPath);
    await Deno.remove(oldConfigPath);
    console.log("-> Cleaned up old agent-forum.json from .forum/ directory.");
  } catch {
    // Old config does not exist, nothing to clean up
  }

  // 6. Bootstrap meta-state branch
  await runCmd(
    "deno",
    ["run", "-A", join(targetForum, "src", "cli.ts"), "bootstrap"],
    targetDir,
  );

  // 7. Sync Vector Database
  console.log("-> Synchronizing Vector Databases...");
  await runCmd(
    "deno",
    [
      "run",
      "-A",
      join(targetForum, "src", "cli.ts"),
      "replay",
      "--sync",
    ],
    targetDir,
  );

  console.log("✅ Agent Forum installed successfully.");
}

if (import.meta.main) {
  await main(Deno.args);
}