#!/usr/bin/env node

import { spawn } from "node:child_process";
import fs from "node:fs";
import { copyFile, readFile, rm } from "node:fs/promises";
import os from "node:os";
import path from "node:path";

import {
  DEFAULT_CODEX_CONFIG_PATH,
  DEFAULT_HEALTH_PATH,
  DEFAULT_LISTEN_HOST,
  DEFAULT_LISTEN_PORT,
  DEFAULT_REASONING_EQUALS,
  DEFAULT_REASONING_MATCH_MODE,
  DEFAULT_STATE_ROOT,
  ensureDirectory,
  expandEscapedLineBreaks,
  getCodexProviderContext,
  getGatewayBaseUrl,
  getGatewayStatePaths,
  normalizeIntArray,
  normalizePhraseArray,
  normalizeReasoningMatchMode,
  normalizeStringArray,
  parseOptions,
  readJsonFile,
  setCodexProviderBaseUrl,
  waitGatewayHealth,
  writeJsonFile,
  writeUtf8File,
} from "./admin-lib.mjs";

const DEFAULT_PROFILES_DIR = path.join(os.homedir(), ".config", "codex-retry-gateway", "profiles");
const DEFAULT_REQUEST_BODY_LIMIT_BYTES = 1024 * 1024 * 1024;
const LEGACY_DEFAULT_REQUEST_BODY_LIMIT_BYTES = 10 * 1024 * 1024;

function parseEnvFile(content) {
  const parsed = {};
  for (const rawLine of content.split(/\r?\n/)) {
    const line = rawLine.trim();
    if (!line || line.startsWith("#")) {
      continue;
    }
    const separatorIndex = line.indexOf("=");
    if (separatorIndex <= 0) {
      continue;
    }
    const key = line.slice(0, separatorIndex).trim();
    let value = line.slice(separatorIndex + 1).trim();
    if (value.startsWith('"') && value.endsWith('"')) {
      try {
        value = JSON.parse(value);
      } catch {
        value = value.slice(1, -1);
      }
    } else if (value.startsWith("'") && value.endsWith("'")) {
      value = value.slice(1, -1);
    }
    parsed[key] = typeof value === "string" ? expandEscapedLineBreaks(value) : value;
  }
  return parsed;
}

function getProfileName(options) {
  const positional = options._?.[0];
  return `${options.profile || positional || process.env.CODEX_RETRY_GATEWAY_PROFILE || ""}`.trim();
}

function resolveDefaultRequestedProfileName(existingState) {
  const stateProfileName = `${existingState?.profile_name || ""}`.trim();
  if (stateProfileName) {
    return stateProfileName;
  }
  return process.env.CODEX_RETRY_GATEWAY_DEFAULT_PROFILE || "default";
}

function resolvePreferredProfileName({ requestedProfileName, existingState, preferStateProfile, profilesDir }) {
  if (!preferStateProfile) {
    return requestedProfileName;
  }

  const stateProfileName = `${existingState?.profile_name || ""}`.trim();
  if (!stateProfileName) {
    return requestedProfileName;
  }

  const stateProfilePath = path.join(profilesDir, `${stateProfileName}.env`);
  if (!fs.existsSync(stateProfilePath)) {
    return requestedProfileName;
  }

  return stateProfileName;
}

function boolFromEnv(value, fallback = false) {
  if (value === undefined || value === null || value === "") {
    return fallback;
  }
  return ["1", "true", "yes", "on"].includes(`${value}`.trim().toLowerCase());
}

function normalizeRequestBodyLimitBytes(value) {
  const parsed = Number.parseInt(`${value ?? ""}`, 10);
  if (!Number.isFinite(parsed) || parsed <= 0) {
    return DEFAULT_REQUEST_BODY_LIMIT_BYTES;
  }
  if (parsed === LEGACY_DEFAULT_REQUEST_BODY_LIMIT_BYTES) {
    return DEFAULT_REQUEST_BODY_LIMIT_BYTES;
  }
  return parsed;
}

function normalizeAuthMode(value) {
  const mode = `${value || "passthrough"}`.trim().toLowerCase();
  if (["passthrough", "fixed_bearer", "manual_bearer", "auth_json"].includes(mode)) {
    return mode;
  }
  return "passthrough";
}

function inferProfileAuthMode(profileEnv) {
  if (profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_MODE) {
    return normalizeAuthMode(profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_MODE);
  }
  if (
    profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_JSON_PATH ||
    profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_JSON_KEY
  ) {
    return "auth_json";
  }
  if (
    profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_FILE ||
    profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_ENV
  ) {
    return "fixed_bearer";
  }
  return "passthrough";
}

function buildProfileAuthConfig(profileEnv) {
  const authMode = inferProfileAuthMode(profileEnv);
  const authConfig = {
    upstream_auth_mode: authMode,
    upstream_auth_env: "",
    upstream_auth_file: "",
    upstream_auth_json_path: "",
    upstream_auth_json_key: "",
  };

  if (authMode === "fixed_bearer") {
    authConfig.upstream_auth_env =
      profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_ENV ||
      "CODEX_RETRY_GATEWAY_UPSTREAM_API_KEY";
    authConfig.upstream_auth_file = profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_FILE || "";
  } else if (authMode === "manual_bearer") {
    authConfig.upstream_auth_file = profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_FILE || "";
  } else if (authMode === "auth_json") {
    authConfig.upstream_auth_json_path = profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_JSON_PATH || "";
    authConfig.upstream_auth_json_key =
      profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_AUTH_JSON_KEY ||
      "OPENAI_API_KEY";
  }

  return authConfig;
}

async function loadProfileEnv(profileName, profilesDir) {
  const profilePath = path.join(profilesDir, `${profileName}.env`);
  if (!fs.existsSync(profilePath)) {
    throw new Error(`Profile env file was not found: ${profilePath}`);
  }
  const content = await readFile(profilePath, "utf8");
  return {
    profilePath,
    env: parseEnvFile(content),
  };
}

function buildProfileConfig({ profileName, profileEnv, existingGatewayConfig, providerContext, localGatewayBaseUrl }) {
  const upstreamBaseUrl =
    profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_BASE_URL ||
    existingGatewayConfig?.upstream_base_url ||
    (providerContext.currentBaseUrl === localGatewayBaseUrl
      ? null
      : providerContext.currentBaseUrl);

  if (!upstreamBaseUrl) {
    throw new Error("A real upstream base_url could not be determined for this profile.");
  }

  const profileAuthConfig = buildProfileAuthConfig(profileEnv);
  const reasoningMatchMode = normalizeReasoningMatchMode(
    profileEnv.CODEX_RETRY_GATEWAY_REASONING_MATCH_MODE ||
      existingGatewayConfig?.reasoning_match_mode ||
      DEFAULT_REASONING_MATCH_MODE,
  );

  return {
    profile_name: profileName,
    listen_host: profileEnv.CODEX_RETRY_GATEWAY_LISTEN_HOST || DEFAULT_LISTEN_HOST,
    listen_port: profileEnv.CODEX_RETRY_GATEWAY_LISTEN_PORT
      ? Number.parseInt(`${profileEnv.CODEX_RETRY_GATEWAY_LISTEN_PORT}`, 10)
      : DEFAULT_LISTEN_PORT,
    upstream_base_url: upstreamBaseUrl,
    ...profileAuthConfig,
    request_body_limit_bytes: profileEnv.CODEX_RETRY_GATEWAY_REQUEST_BODY_LIMIT_BYTES
      ? normalizeRequestBodyLimitBytes(profileEnv.CODEX_RETRY_GATEWAY_REQUEST_BODY_LIMIT_BYTES)
      : normalizeRequestBodyLimitBytes(existingGatewayConfig?.request_body_limit_bytes),
    request_history_limit: profileEnv.CODEX_RETRY_GATEWAY_REQUEST_HISTORY_LIMIT
      ? Number.parseInt(`${profileEnv.CODEX_RETRY_GATEWAY_REQUEST_HISTORY_LIMIT}`, 10)
      : Number.parseInt(`${existingGatewayConfig?.request_history_limit || 200}`, 10),
    model_remap: profileEnv.CODEX_RETRY_GATEWAY_MODEL_REMAP || existingGatewayConfig?.model_remap || "",
    endpoints: normalizeStringArray(
      profileEnv.CODEX_RETRY_GATEWAY_ENDPOINTS || existingGatewayConfig?.endpoints,
      ["/responses", "/chat/completions", "/v1/responses", "/v1/chat/completions"],
    ),
    reasoning_match_mode: reasoningMatchMode,
    reasoning_equals: normalizeIntArray(
      profileEnv.CODEX_RETRY_GATEWAY_REASONING_EQUALS || existingGatewayConfig?.reasoning_equals,
      DEFAULT_REASONING_EQUALS,
    ),
    retryable_status_codes: normalizeIntArray(
      profileEnv.CODEX_RETRY_GATEWAY_RETRYABLE_STATUS_CODES || existingGatewayConfig?.retryable_status_codes,
      [429, 503],
    ),
    retryable_error_messages: normalizePhraseArray(
      profileEnv.CODEX_RETRY_GATEWAY_RETRYABLE_ERROR_MESSAGES || existingGatewayConfig?.retryable_error_messages,
      [
        "Selected model is at capacity. Please try a different model.",
        "stream disconnected before completion: Concurrency limit exceeded for account, please retry later",
      ],
    ),
    management_access_key:
      profileEnv.CODEX_RETRY_GATEWAY_MANAGEMENT_ACCESS_KEY ||
      existingGatewayConfig?.management_access_key ||
      "",
    upstream_fetch_retry_attempts: profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_FETCH_RETRY_ATTEMPTS
      ? Number.parseInt(`${profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_FETCH_RETRY_ATTEMPTS}`, 10)
      : Number.parseInt(`${existingGatewayConfig?.upstream_fetch_retry_attempts || 5}`, 10),
    upstream_fetch_retry_backoff_ms: profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_FETCH_RETRY_BACKOFF_MS
      ? Number.parseInt(`${profileEnv.CODEX_RETRY_GATEWAY_UPSTREAM_FETCH_RETRY_BACKOFF_MS}`, 10)
      : Number.parseInt(`${existingGatewayConfig?.upstream_fetch_retry_backoff_ms || 350}`, 10),
    non_stream_status_code: profileEnv.CODEX_RETRY_GATEWAY_NON_STREAM_STATUS_CODE
      ? Number.parseInt(`${profileEnv.CODEX_RETRY_GATEWAY_NON_STREAM_STATUS_CODE}`, 10)
      : Number.parseInt(`${existingGatewayConfig?.non_stream_status_code || 502}`, 10),
    stream_action: profileEnv.CODEX_RETRY_GATEWAY_STREAM_ACTION || existingGatewayConfig?.stream_action || "strict_502",
    log_match: profileEnv.CODEX_RETRY_GATEWAY_LOG_MATCH === undefined
      ? existingGatewayConfig?.log_match !== false
      : boolFromEnv(profileEnv.CODEX_RETRY_GATEWAY_LOG_MATCH, true),
    health_path: profileEnv.CODEX_RETRY_GATEWAY_HEALTH_PATH || existingGatewayConfig?.health_path || DEFAULT_HEALTH_PATH,
  };
}

async function ensureCodexPointsToGateway({ paths, codexConfigPath, providerContext, localGatewayBaseUrl }) {
  await ensureDirectory(paths.backupDir);
  const existingState = await readJsonFile(paths.statePath);

  let originalBaseUrl = providerContext.currentBaseUrl;
  if (providerContext.currentBaseUrl === localGatewayBaseUrl) {
    originalBaseUrl = existingState?.original_base_url || null;
  }
  if (!originalBaseUrl || originalBaseUrl === localGatewayBaseUrl) {
    throw new Error("A restorable original Codex base_url could not be determined.");
  }

  const backupPath =
    existingState?.latest_backup_path ||
    path.join(
      paths.backupDir,
      `config-${new Date().toISOString().replace(/[:.]/g, "").replace("T", "-").slice(0, 15)}.toml`,
    );
  if (!existingState?.latest_backup_path) {
    await copyFile(codexConfigPath, backupPath);
  }

  if (providerContext.currentBaseUrl !== localGatewayBaseUrl) {
    await setCodexProviderBaseUrl({
      codexConfigPath,
      providerName: providerContext.providerName,
      newBaseUrl: localGatewayBaseUrl,
    });
  }

  return { existingState, originalBaseUrl, backupPath };
}

async function main() {
  const options = parseOptions(process.argv, { booleanFlags: ["no-codex-config-update", "prefer-state-profile"] });
  const profilesDir = options.profilesDir || DEFAULT_PROFILES_DIR;
  const stateRoot = options.stateRoot || process.env.CODEX_RETRY_GATEWAY_STATE_ROOT || DEFAULT_STATE_ROOT;
  const codexConfigPath =
    options.codexConfigPath ||
    process.env.CODEX_RETRY_GATEWAY_CODEX_CONFIG_PATH ||
    DEFAULT_CODEX_CONFIG_PATH;
  const paths = getGatewayStatePaths(stateRoot);

  await ensureDirectory(paths.stateRoot);
  await ensureDirectory(paths.configDir);
  await ensureDirectory(paths.logDir);
  await ensureDirectory(paths.backupDir);

  const existingState = await readJsonFile(paths.statePath);
  const requestedProfileName = getProfileName(options) || resolveDefaultRequestedProfileName(existingState);
  const profileName = resolvePreferredProfileName({
    requestedProfileName,
    existingState,
    preferStateProfile: Boolean(options.preferStateProfile),
    profilesDir,
  });
  if (profileName !== requestedProfileName) {
    process.stdout.write(
      `[run-profile] prefer-state-profile requested=${requestedProfileName} effective=${profileName}\n`,
    );
  }

  const { profilePath, env: profileEnv } = await loadProfileEnv(profileName, profilesDir);
  for (const [key, value] of Object.entries(profileEnv)) {
    process.env[key] = value;
  }

  const providerContext = await getCodexProviderContext(codexConfigPath);
  const listenHost = profileEnv.CODEX_RETRY_GATEWAY_LISTEN_HOST || DEFAULT_LISTEN_HOST;
  const listenPort = profileEnv.CODEX_RETRY_GATEWAY_LISTEN_PORT
    ? Number.parseInt(`${profileEnv.CODEX_RETRY_GATEWAY_LISTEN_PORT}`, 10)
    : DEFAULT_LISTEN_PORT;
  const localGatewayBaseUrl = getGatewayBaseUrl(listenHost, listenPort);
  const existingGatewayConfig = await readJsonFile(paths.configPath);

  const gatewayConfig = buildProfileConfig({
    profileName,
    profileEnv,
    existingGatewayConfig,
    providerContext,
    localGatewayBaseUrl,
  });

  const installState = options.noCodexConfigUpdate
    ? {
        existingState,
        originalBaseUrl: providerContext.currentBaseUrl,
        backupPath: null,
      }
    : await ensureCodexPointsToGateway({
        paths,
        codexConfigPath,
        providerContext,
        localGatewayBaseUrl,
      });

  await writeJsonFile(paths.configPath, gatewayConfig);
  await writeJsonFile(paths.statePath, {
    ...(installState.existingState || {}),
    installed_at: installState.existingState?.installed_at || new Date().toISOString(),
    last_started_at: new Date().toISOString(),
    profile_name: profileName,
    profile_env_path: profilePath,
    codex_config_path: codexConfigPath,
    provider_name: providerContext.providerName,
    original_base_url: installState.originalBaseUrl,
    gateway_base_url: localGatewayBaseUrl,
    gateway_config_path: paths.configPath,
    gateway_log_path: paths.logPath,
    gateway_pid_path: paths.pidPath,
    latest_backup_path: installState.backupPath || installState.existingState?.latest_backup_path || null,
    state_root: paths.stateRoot,
  });

  await writeUtf8File(paths.pidPath, `${process.pid}\n`);

  const gatewayEntry = path.resolve(import.meta.dirname, "..", "gateway.mjs");
  const child = spawn(process.execPath, [gatewayEntry, "--config", paths.configPath, "--log", paths.logPath], {
    cwd: path.resolve(import.meta.dirname, ".."),
    stdio: "inherit",
    windowsHide: true,
  });

  let stoppingBySignal = false;
  const forwardSignal = (signal) => {
    stoppingBySignal = true;
    if (!child.killed) {
      child.kill(signal);
    }
  };
  process.on("SIGTERM", () => forwardSignal("SIGTERM"));
  process.on("SIGINT", () => forwardSignal("SIGINT"));

  child.on("exit", async (code, signal) => {
    await rm(paths.pidPath, { force: true }).catch(() => {});
    if (stoppingBySignal) {
      process.exit(0);
    }
    process.exit(code ?? (signal ? 0 : 1));
  });

  try {
    await waitGatewayHealth({
      listenHost: gatewayConfig.listen_host,
      listenPort: gatewayConfig.listen_port,
      healthPath: gatewayConfig.health_path,
    });
  } catch (error) {
    if (!child.killed) {
      child.kill("SIGTERM");
    }
    throw error;
  }
}

main().catch((error) => {
  process.stderr.write(`${error?.stack || error}\n`);
  process.exit(1);
});