#!/usr/bin/env bun
/**
 * port-to-omp.mjs — regenerate the omp port of pygenium from this repo.
 *
 * The omp port is "base + patch layer"; this script IS the patch layer. This
 * repo is the single source of truth; ~/.omp/agent/extensions/pygenium (or
 * --out) is a generated artifact. Every op asserts its target and fails
 * loudly on base drift — never silently producing a stale port.
 *
 * Usage:
 *   bun port-to-omp.mjs                # write ~/.omp/agent/extensions/pygenium
 *   bun port-to-omp.mjs --out <dir>    # write elsewhere (CI: the omp repo clone)
 *
 * CI: .gitea/workflows/port-to-omp.yml clones the omp-pygenium repo and
 * runs this script into it, then commits + pushes when the port changed.
 */

import {
  cpSync,
  existsSync,
  mkdirSync,
  readdirSync,
  readFileSync,
  rmSync,
  writeFileSync,
} from "node:fs";
import { join } from "node:path";
import { execSync } from "node:child_process";
import { homedir } from "node:os";

const HOME = homedir();
const PI = join(HOME, ".pi", "agent", "extensions");
const OMP = join(HOME, ".omp", "agent", "extensions");

const SKIP = new Set([
  "port-to-omp.mjs",
  ".gitea",
  ".github",
  "node_modules",
  ".git",
  ".DS_Store",
  ".pi-lens",
  "bun.lock",
  "package-lock.json",
  "dist",
]);

const OMP_SDK = "17.2.12";

// ─── helpers ────────────────────────────────────────────────────────────────

function assertEdit(src, from, to, file, label = "") {
  const idx = src.indexOf(from);
  if (idx === -1) {
    throw new Error(
      `[${file}] target not found${label ? ` (${label})` : ""}:\n${from.slice(0, 300)}`,
    );
  }
  return src.slice(0, idx) + to + src.slice(idx + from.length);
}

function replaceAll(src, from, to, file, label) {
  const parts = src.split(from);
  if (parts.length === 1) {
    throw new Error(`[${file}] target not found${label ? ` (${label})` : ""}:\n${from.slice(0, 300)}`);
  }
  return parts.join(to);
}

function reEdit(src, re, to, file, label) {
  const out = src.replace(re, to);
  if (out === src) {
    throw new Error(`[${file}] regex matched nothing (${label}): ${re}`);
  }
  return out;
}

function reAll(src, re, to, file, label) {
  let count = 0;
  const out = src.replace(re, (...args) => {
    count++;
    return typeof to === "function" ? to(...args) : to;
  });
  if (count === 0) {
    throw new Error(`[${file}] regex matched nothing (${label}): ${re}`);
  }
  return out;
}

/** Run a list of ops over a file's text. op = {from,to} | {re,to,label}. */
function applyOps(src, ops, file) {
  for (const op of ops) {
    if ("from" in op) {
      src = op.all ? replaceAll(src, op.from, op.to, file, op.label) : assertEdit(src, op.from, op.to, file, op.label);
    } else {
      src = op.all ? reAll(src, op.re, op.to, file, op.label) : reEdit(src, op.re, op.to, file, op.label);
    }
  }
  return src;
}

function mirrorTree(srcDir, dstDir) {
  mkdirSync(dstDir, { recursive: true });
  cpSync(srcDir, dstDir, {
    recursive: true,
    force: true,
    filter: (p) => !SKIP.has(p.split("/").pop()),
  });
  // drop stale files in dst that no longer exist in src; keep .git* intact
  for (const rel of walk(dstDir)) {
    if (rel.startsWith(".git")) continue;
    if (!existsSync(join(srcDir, rel))) rmSync(join(dstDir, rel), { force: true, recursive: true });
  }
}

function walk(dir) {
  const out = [];
  for (const entry of readdirSync(dir, { withFileTypes: true })) {
    if (SKIP.has(entry.name)) continue;
    const p = join(dir, entry.name);
    if (entry.isDirectory()) out.push(...walk(p).map((r) => join(entry.name, r)));
    else out.push(entry.name);
  }
  return out;
}

const SPECIFIERS = [
  ["@earendil-works/pi-coding-agent", "@oh-my-pi/pi-coding-agent"],
  ["@earendil-works/pi-tui", "@oh-my-pi/pi-tui"],
  ["@earendil-works/pi-ai", "@oh-my-pi/pi-ai"],
  ["@earendil-works/pi-agent-core", "@oh-my-pi/pi-agent-core"],
];

function rewriteSpecifiers(src) {
  for (const [from, to] of SPECIFIERS) src = src.split(from).join(to);
  return src;
}

// ─── package.json transforms ────────────────────────────────────────────────

function pkgName(piName) {
  if (piName.startsWith("@mikefreno/")) return piName.replace(/^@mikefreno\//, "@mikefreno/omp-");
  return `@mikefreno/omp-${piName}`;
}

function reorder(obj, keys) {
  const out = {};
  for (const k of keys) if (k in obj) out[k] = obj[k];
  for (const k of Object.keys(obj)) if (!(k in out)) out[k] = obj[k];
  return out;
}


const PKG_RULES = {
    order: ["name", "version", "description", "keywords", "license", "type", "engines", "omp", "devDependencies", "scripts"],
    transform(p) {
      p.name = pkgName(p.name);
      p.description = p.description.replace("for pi —", "for omp (port of the pi extension) —");
      p.keywords = ["omp", "omp-extension", ...p.keywords.slice(2)];
      p.engines.bun = ">=1.3.14";
      p.omp = p.pi;
      delete p.pi;
      delete p.peerDependencies;
      delete p.peerDependenciesMeta;
      p.devDependencies = {
        "@oh-my-pi/pi-coding-agent": OMP_SDK,
        "@oh-my-pi/pi-tui": OMP_SDK,
        ...p.devDependencies,
      };
    },
  };
function transformPkg() {
  const raw = JSON.parse(readFileSync(join(import.meta.dir, "package.json"), "utf8"));
  if (!raw.pi) throw new Error('expected "pi" manifest key in package.json');
  const rule = PKG_RULES;
  rule.transform(raw);
  const ordered = reorder(raw, rule.order);
  return JSON.stringify(ordered, null, 2) + "\n";
}
const FILE_RULES = {
    "src/index.ts": [
      { from: " * Read the pygienium chat style from pi's settings.json.", to: " * Read the pygienium chat style from omp's settings.json." },
      { from: " * Looks for `pygienium.chatStyle` under `~/.pi/agent/settings.json`.", to: " * Looks for `pygienium.chatStyle` under `~/.omp/agent/settings.json`." },
      { from: '\t\t\tjoin(homedir(), ".pi", "agent", "settings.json"),', to: '\t\t\tjoin(homedir(), ".omp", "agent", "settings.json"),' },
      {
        from:
          "\t\t\t\tconst pygieniumCtx: PygieniumCtx = {\n\t\t\t\t\tcwd: ctx.cwd,\n\t\t\t\t\tmode: ctx.mode,\n\t\t\t\t\thasUI: ctx.hasUI,",
        to:
          "\t\t\t\tconst pygieniumCtx: PygieniumCtx = {\n\t\t\t\t\tcwd: ctx.cwd,\n\t\t\t\t\thasUI: ctx.hasUI,",
        label: "ctx.mode removal",
      },
    ],
    "src/commands.ts": [
      { from: " * names. Each handler accepts the narrow context slice it needs (`cwd`, `mode`,", to: " * names. Each handler accepts the narrow context slice it needs (`cwd`," },
      { from: '\t"cwd" | "mode" | "hasUI" | "ui"', to: '\t"cwd" | "hasUI" | "ui"', label: "PygieniumCtx Pick" },
      {
        from: "\t// In TUI mode, also surface the first line as a notification.\n\tif (ctx.mode === \"tui\" && ctx.ui?.notify) {",
        to: "\t// With a dialog-capable UI, also surface the first line as a notification.\n\tif (ctx.hasUI && ctx.ui?.notify) {",
        label: "print notify",
      },
    ],
    "src/agent-runner.ts": [
      {
        from:
          "\t// Lazily import the SDK so the rest of the module graph (and tests using the\n\t// fake runner) never resolve the heavy pi-coding-agent package.\n\tconst {\n\t\tcreateAgentSession,\n\t\tDefaultResourceLoader,\n\t\tgetAgentDir,\n\t\tSessionManager,\n\t} = await import(\"@oh-my-pi/pi-coding-agent\");\n\tconst loader = new DefaultResourceLoader({\n\t\tcwd: opts.cwd,\n\t\tagentDir: getAgentDir(),\n\t\tsystemPromptOverride: () => agent.systemPrompt,\n\t\t// Keep the sub-agent isolated: no nested extensions/skills/themes/etc.\n\t\tnoExtensions: true,\n\t\tnoSkills: true,\n\t\tnoThemes: true,\n\t\tnoPromptTemplates: true,\n\t});\n\tawait loader.reload();",
        to:
          "\t// Lazily import the SDK so the rest of the module graph (and tests using the\n\t// fake runner) never resolve the heavy pi-coding-agent package. The specifier\n\t// is static by intent (dynamic-import exception: module is intentionally\n\t// excluded from the import-time graph to keep fake-runner tests SDK-free).\n\tconst { createAgentSession, AgentRegistry, SessionManager } = await import(\n\t\t\"@oh-my-pi/pi-coding-agent\"\n\t);",
        label: "SDK import + loader removal",
      },
      { from: '\t\tagent.allowedTools ?? ["read", "bash", "grep", "find"];', to: '\t\tagent.allowedTools ?? ["read", "bash", "grep", "glob"];', label: "default tools" },
      {
        from:
          "\tconst { session } = await createAgentSession({\n\t\tcwd: opts.cwd,\n\t\ttools,\n\t\tsessionManager: SessionManager.inMemory(opts.cwd),\n\t\tresourceLoader: loader,\n\t});",
        to:
          "\tconst { session } = await createAgentSession({\n\t\tcwd: opts.cwd,\n\t\ttoolNames: tools,\n\t\t// `tools` is an allowlist, not a request list.\n\t\trestrictToolNames: true,\n\t\tsessionManager: SessionManager.inMemory(opts.cwd),\n\t\t// Replace the fully rendered default prompt with the agent body.\n\t\tsystemPrompt: agent.systemPrompt,\n\t\t// Keep the sub-agent isolated: no nested extensions/skills/prompts/etc.\n\t\tdisableExtensionDiscovery: true,\n\t\tskills: [],\n\t\tpromptTemplates: [],\n\t\trules: [],\n\t\tcontextFiles: [],\n\t\tenableMCP: false,\n\t\tenableLsp: false,\n\t\t// Private registry: the host session owns the process-global \"Main\"\n\t\t// identity, so a per-run registry keeps these in-process workers\n\t\t// disjoint from the main agent.\n\t\tagentRegistry: new AgentRegistry(),\n\t});",
        label: "createAgentSession",
      },
    ],
    "src/agents.ts": [{ from: "     - find", to: "     - glob", label: "frontmatter example" }],
    "README.md": [
      { from: "[pi](https://github.com/earendil-works/pi-coding-agent)", to: "[omp](https://github.com/oh-my-pi)" },
      { from: "local pi extension under `~/.pi/agent/extensions/pygienium/`.", to: "local omp extension under `~/.omp/agent/extensions/pygienium/`." },
      { from: "Pi loads it via `pi.extensions`", to: "Omp loads it via `omp.extensions`" },
      { from: "Pi auto-discovers the extension from this location via the `pi.extensions` entry", to: "Omp auto-discovers the extension from this location via the `omp.extensions` entry" },
      { from: "pi's `settings.json` (`~/.pi/agent/settings.json`)", to: "omp's `settings.json` (`~/.omp/agent/settings.json`)" },
      { from: "Reload pi (or `/reload`)", to: "Reload omp (or `/reload`)" },
    ],
  };
const AGENT_MD_GLOB = { re: /`find`(?! \.)/g, to: "`glob`", label: "find token", all: true };
const AGENT_MD_FRONTMATTER = { from: "  - find", to: "  - glob", label: "frontmatter tools", all: true };

const PYGENIUM_TSCONFIG = `{
  "compilerOptions": {
    "target": "ES2022",
    "module": "ES2022",
    "moduleResolution": "bundler",
    "lib": ["ES2022"],
    "types": ["node"],
    "noEmit": true,
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "resolveJsonModule": true
  },
  "include": ["src/**/*.ts"],
  "exclude": ["node_modules", "dist"]
}
`;



// ─── main ───────────────────────────────────────────────────────────────────

const OUT_DEFAULT = join(homedir(), ".omp", "agent", "extensions", "pygenium");

function portExtension() {
  const srcDir = import.meta.dir;
  const dstDir = process.argv.includes("--out")
    ? process.argv[process.argv.indexOf("--out") + 1]
    : OUT_DEFAULT;
  if (!dstDir) throw new Error("--out requires a directory argument");
  if (!existsSync(srcDir)) throw new Error(`no base extension at ${srcDir}`);

  console.log(`== ${srcDir} -> ${dstDir}`);
  mirrorTree(srcDir, dstDir);

  for (const rel of walk(dstDir)) {
    const p = join(dstDir, rel);
    if (!existsSync(p)) continue;
    if (rel.endsWith(".ts")) {
      let text = readFileSync(p, "utf8");
      text = rewriteSpecifiers(text);
      if (FILE_RULES[rel]) text = applyOps(text, FILE_RULES[rel], rel);
      writeFileSync(p, text);
    } else if (rel === "package.json") {
      writeFileSync(p, transformPkg());
    } else if (rel.endsWith(".md")) {
      let text = readFileSync(p, "utf8");
      if (FILE_RULES[rel]) text = applyOps(text, FILE_RULES[rel], rel);
      if (rel.startsWith("agents/")) {
        text = applyOps(text, [AGENT_MD_FRONTMATTER, AGENT_MD_GLOB], rel);
      }
      writeFileSync(p, text);
    }
  }
  writeFileSync(join(dstDir, "tsconfig.json"), PYGENIUM_TSCONFIG);
  console.log("== bun install (regenerates bun.lock + node_modules)");
  execSync("bun install", { cwd: dstDir, stdio: "inherit" });
  console.log("== done");
}

portExtension();