/**
 * @file codex-config.js
 * @description HTTP surface for inspecting and (carefully) mutating Codex
 * CLI configuration: skills, agents, rules, memory (AGENTS.md),
 * config.toml, MCP servers, plugins, and marketplaces. Powers the Codex
 * Config panel — the Codex counterpart of cc-config.js.
 *
 * Read paths (skills/agents/rules/memory/config) come from codex-discovery.js
 * (pure file reads). MCP servers, plugins, and marketplaces have no on-disk
 * reader — codex-discovery.js deliberately leaves them to the `codex` CLI —
 * so those three GET routes, plus every mutation, shell out through
 * codex-cli.js. A non-zero CLI exit is reported as 422 with stdout/stderr
 * preserved, never a 500.
 *
 * Write paths (skills/agents/rules/memory/config) go through codex-mutate.js:
 * every write/delete is preceded by a timestamped backup, and every mutation
 * error code is mapped explicitly below so an unmapped one can never fall
 * through to a bare 500.
 *
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const fs = require("node:fs");
const path = require("node:path");
const { Router } = require("express");
const codexDiscovery = require("../lib/codex-discovery");
const codexMutate = require("../lib/codex-mutate");
const codexCli = require("../lib/codex-cli");
const { getCodexHome, getProjectCodexDir, getProjectRoot } = require("../lib/codex-home");
const { isUnder, MAX_FILE_BYTES } = require("../lib/cc-discovery");
const { broadcast } = require("../websocket");

const router = Router();

function emitChanged(payload) {
  try {
    broadcast("codex_config_changed", { source: "dashboard", ...payload });
  } catch {
    /* websocket may not be initialised in unit tests */
  }
}

function scopeOf(req) {
  const s = String(req.query.scope || "all");
  return s === "user" || s === "project" ? s : "all";
}

function cwdOf(req) {
  // Mirrors cc-config's cwdOf: the server's own cwd is the natural
  // "project", but ?cwd= lets the caller inspect another working dir.
  const c = typeof req.query.cwd === "string" && req.query.cwd ? req.query.cwd : null;
  return c || process.cwd();
}

// ── Mutation errors (codex-mutate.js) → HTTP status ────────────────────
// Anything unmapped is a 500 — this map must cover every code codex-mutate
// can throw.
const ERR_TO_STATUS = {
  EBADTYPE: 400,
  EBADSCOPE: 400,
  EBADNAME: 400,
  EBADCONTENT: 400,
  EOUTOFROOT: 400,
  ETOOLARGE: 413,
  ENOTFOUND: 404,
};

function mutateError(res, err) {
  const status = ERR_TO_STATUS[err.code] || 500;
  return res
    .status(status)
    .json({ error: { code: err.code || "EINTERNAL", message: err.message } });
}

// ── Discovery reads ─────────────────────────────────────────────────────

router.get("/overview", (req, res) => {
  res.json(codexDiscovery.readOverview({ cwd: cwdOf(req) }));
});

router.get("/skills", (req, res) => {
  res.json({ skills: codexDiscovery.readSkills({ scope: scopeOf(req), cwd: cwdOf(req) }) });
});

router.get("/agents", (req, res) => {
  res.json({ agents: codexDiscovery.readAgents({ scope: scopeOf(req), cwd: cwdOf(req) }) });
});

router.get("/rules", (req, res) => {
  res.json({ rules: codexDiscovery.readRules({ scope: scopeOf(req), cwd: cwdOf(req) }) });
});

router.get("/memory", (req, res) => {
  res.json({ memory: codexDiscovery.readMemory({ cwd: cwdOf(req) }) });
});

router.get("/config", (req, res) => {
  res.json({ config: codexDiscovery.readConfig({ cwd: cwdOf(req) }) });
});

// GET /api/codex-config/file?path=/abs/path — return body of a single file.
// Path must resolve under CODEX_HOME, the project .codex dir, or (only for a
// file literally named AGENTS.md) the project root. No dedicated reader for
// this exists in codex-discovery.js (it only reads whole surfaces), so this
// mirrors cc-discovery's readFileSafe against the Codex roots instead.
function readCodexFileSafe(absPath, opts = {}) {
  const codexHome = getCodexHome();
  const projectCodexDir = getProjectCodexDir(opts.cwd);
  const projectRoot = getProjectRoot(opts.cwd);
  const resolved = path.resolve(absPath);
  const inside = [codexHome, projectCodexDir, projectRoot].some((root) => isUnder(root, resolved));
  if (!inside) return { error: "path is outside allowed roots" };
  if (
    isUnder(projectRoot, resolved) &&
    !isUnder(projectCodexDir, resolved) &&
    path.basename(resolved) !== "AGENTS.md"
  ) {
    return { error: "only AGENTS.md is readable from project root" };
  }
  let stat;
  try {
    stat = fs.statSync(resolved);
  } catch {
    return { error: "file not readable" };
  }
  if (!stat.isFile()) return { error: "file not readable" };
  let text;
  try {
    text = fs.readFileSync(resolved, "utf8");
  } catch {
    return { error: "file not readable" };
  }
  const truncated = stat.size > MAX_FILE_BYTES;
  return {
    ok: true,
    file: resolved,
    size: stat.size,
    mtime: stat.mtimeMs,
    truncated,
    text: truncated ? text.slice(0, MAX_FILE_BYTES) : text,
  };
}

router.get("/file", (req, res) => {
  const p = req.query.path;
  if (typeof p !== "string" || !p) {
    return res.status(400).json({ error: { code: "BAD_PATH", message: "path is required" } });
  }
  const result = readCodexFileSafe(p, { cwd: cwdOf(req) });
  if (result.error)
    return res.status(400).json({ error: { code: "READ_DENIED", message: result.error } });
  res.json(result);
});

// ── Mutation endpoints (codex-mutate.js) ────────────────────────────────
//
// PUT  /api/codex-config/file   — create or overwrite. Body: { scope, type, name?, content }
// DELETE /api/codex-config/file — delete. Body: { scope, type, name? }
// GET  /api/codex-config/backups[?scope=&type=] — list backups

router.put("/file", (req, res) => {
  const { scope, type, name, content } = req.body || {};
  if (typeof scope !== "string" || typeof type !== "string") {
    return res
      .status(400)
      .json({ error: { code: "EBADREQ", message: "scope and type are required" } });
  }
  try {
    const result = codexMutate.writeArtifact({ scope, type, name, content, cwd: cwdOf(req) });
    emitChanged({ action: "write", scope, type, name: name || null });
    res.json(result);
  } catch (err) {
    return mutateError(res, err);
  }
});

router.delete("/file", (req, res) => {
  const { scope, type, name } = req.body || {};
  if (typeof scope !== "string" || typeof type !== "string") {
    return res
      .status(400)
      .json({ error: { code: "EBADREQ", message: "scope and type are required" } });
  }
  try {
    const result = codexMutate.deleteArtifact({ scope, type, name, cwd: cwdOf(req) });
    emitChanged({ action: "delete", scope, type, name: name || null });
    res.json(result);
  } catch (err) {
    return mutateError(res, err);
  }
});

router.get("/backups", (req, res) => {
  const scope =
    req.query.scope === "user" || req.query.scope === "project" ? req.query.scope : undefined;
  const type = typeof req.query.type === "string" ? req.query.type : undefined;
  try {
    res.json({ items: codexMutate.listBackups({ scope, type, cwd: cwdOf(req) }) });
  } catch (err) {
    return mutateError(res, err);
  }
});

// ── MCP servers / plugins / marketplaces (via the `codex` CLI) ─────────
//
// Same reasoning as cc-config.js's plugin/marketplace routes: these shell
// out to `codex …` with an argv array — never a shell string — because the
// CLI owns config.toml's schema. Identifiers travel in the body, not the
// URL, for the same reason DELETE /file does.

const CLI_ERR_TO_STATUS = {
  EBADARG: 400,
  ECLINOTFOUND: 503,
  ETIMEOUT: 504,
};

function cliError(res, err) {
  const status = CLI_ERR_TO_STATUS[err.code] || 500;
  return res
    .status(status)
    .json({ error: { code: err.code || "EINTERNAL", message: err.message } });
}

/**
 * Best-effort human message from a failed run. codex-cli.js does not export
 * one (unlike cc-plugin-cli's cliMessage), so this route-local helper does
 * the same "last non-empty line, prefer a marked one" heuristic.
 */
function cliMessage(result) {
  const text = `${result.stderr || ""}\n${result.stdout || ""}`;
  const lines = text
    .split("\n")
    .map((l) => l.trim())
    .filter(Boolean);
  const marked = lines.find((l) => l.includes("✘") || l.toLowerCase().includes("error"));
  const picked = marked || lines[lines.length - 1] || "";
  return picked.replace(/^✘\s*/, "").slice(0, 1000);
}

/** A non-zero CLI exit is a 422, not a 500 — the caller can inspect stderr. */
function cliFailure(res, result) {
  return res.status(422).json({
    error: {
      code: "ECLIEXIT",
      message: cliMessage(result) || `codex exited with code ${result.code}`,
    },
    code: result.code,
    stdout: result.stdout,
    stderr: result.stderr,
  });
}

/** Read-through result for a GET route backed by the CLI. */
function cliRead(res, result, key) {
  if (!result.ok) return cliFailure(res, result);
  res.json({ [key]: result.data !== undefined ? result.data : result.stdout });
}

/** Result for a mutating route: broadcast on success, 422 on CLI failure. */
function cliResult(res, result, changed) {
  if (!result.ok) return cliFailure(res, result);
  emitChanged(changed);
  res.json({ ok: true, stdout: result.stdout, stderr: result.stderr });
}

router.get("/mcp", async (_req, res) => {
  try {
    return cliRead(res, await codexCli.mcpList(), "mcp");
  } catch (err) {
    return cliError(res, err);
  }
});

router.get("/plugins", async (_req, res) => {
  try {
    return cliRead(res, await codexCli.pluginList(), "plugins");
  } catch (err) {
    return cliError(res, err);
  }
});

router.get("/marketplaces", async (_req, res) => {
  try {
    return cliRead(res, await codexCli.marketplaceList(), "marketplaces");
  } catch (err) {
    return cliError(res, err);
  }
});

router.post("/mcp/add", async (req, res) => {
  try {
    const result = await codexCli.mcpAdd(req.body || {});
    return cliResult(res, result, { action: "add", type: "mcp", name: (req.body || {}).name });
  } catch (err) {
    return cliError(res, err);
  }
});

router.post("/mcp/remove", async (req, res) => {
  const { name } = req.body || {};
  try {
    const result = await codexCli.mcpRemove(name);
    return cliResult(res, result, { action: "remove", type: "mcp", name });
  } catch (err) {
    return cliError(res, err);
  }
});

const PLUGIN_ACTIONS = {
  add: codexCli.pluginAdd,
  remove: codexCli.pluginRemove,
};

router.post("/plugins/action", async (req, res) => {
  const { spec, action } = req.body || {};
  const run = PLUGIN_ACTIONS[action];
  if (!run) {
    return res.status(400).json({
      error: {
        code: "EBADACTION",
        message: `action must be one of ${Object.keys(PLUGIN_ACTIONS).join(", ")}`,
      },
    });
  }
  try {
    const result = await run(spec);
    return cliResult(res, result, { action, type: "plugin", name: spec });
  } catch (err) {
    return cliError(res, err);
  }
});

router.post("/marketplaces/add", async (req, res) => {
  const { url } = req.body || {};
  try {
    const result = await codexCli.marketplaceAdd(url);
    return cliResult(res, result, { action: "add", type: "marketplace", name: url });
  } catch (err) {
    return cliError(res, err);
  }
});

const MARKETPLACE_ACTIONS = {
  remove: codexCli.marketplaceRemove,
};

router.post("/marketplaces/action", async (req, res) => {
  const { name, action } = req.body || {};
  const run = MARKETPLACE_ACTIONS[action];
  if (!run) {
    return res.status(400).json({
      error: {
        code: "EBADACTION",
        message: `action must be one of ${Object.keys(MARKETPLACE_ACTIONS).join(", ")}`,
      },
    });
  }
  try {
    const result = await run(name);
    return cliResult(res, result, { action, type: "marketplace", name });
  } catch (err) {
    return cliError(res, err);
  }
});

module.exports = router;