// ─── remote.ts — Matches original rust/crates/runtime/src/remote.rs ──────────
// Upstream proxy, WebSocket bridge, subprocess environment, remote session context

import * as fs from "fs";
import * as path from "path";

// ─── Types ───────────────────────────────────────────────────────────────────

export interface RemoteSessionContext {
  enabled: boolean;
  sessionId: string | undefined;
  baseUrl: string;
}

export interface UpstreamProxyBootstrap {
  enabled: boolean;
  token: string | undefined;
  sessionId: string | undefined;
  baseUrl: string;
  caBundlePath: string | undefined;
  wsUrl: () => string;
  shouldEnable: () => boolean;
  stateForPort: (port: number) => UpstreamProxyState;
}

export interface UpstreamProxyState {
  enabled: boolean;
  proxyUrl: string | undefined;
  caBundlePath: string | undefined;
  token: string | undefined;
  subprocessEnv: () => Record<string, string>;
}

// ─── Remote session context (from env) ───────────────────────────────────────

export function remoteSessionContextFromEnv(): RemoteSessionContext {
  return remoteSessionContextFromEnvMap(process.env as Record<string, string>);
}

export function remoteSessionContextFromEnvMap(
  env: Record<string, string>
): RemoteSessionContext {
  const remoteFlag = env["CLAW_CODE_REMOTE"];
  const enabled =
    remoteFlag === "true" || remoteFlag === "1" || remoteFlag === "yes";

  return {
    enabled,
    sessionId: env["CLAW_CODE_REMOTE_SESSION_ID"],
    baseUrl: env["ANTHROPIC_BASE_URL"] || "https://api.anthropic.com",
  };
}

// ─── Token reader ────────────────────────────────────────────────────────────

export function readToken(tokenPath: string): string | undefined {
  try {
    const content = fs.readFileSync(tokenPath, "utf-8");
    const trimmed = content.trim();
    return trimmed.length > 0 ? trimmed : undefined;
  } catch {
    return undefined;
  }
}

// ─── Upstream proxy URL ──────────────────────────────────────────────────────

export function upstreamProxyWsUrl(baseUrl: string): string {
  // Convert http(s) to ws(s)
  let wsUrl = baseUrl.replace(/\/$/, "");
  if (wsUrl.startsWith("https://")) {
    wsUrl = "wss://" + wsUrl.slice(8);
  } else if (wsUrl.startsWith("http://")) {
    wsUrl = "ws://" + wsUrl.slice(7);
  }
  return `${wsUrl}/v1/code/upstreamproxy/ws`;
}

// ─── No-proxy list ───────────────────────────────────────────────────────────

export function noProxyList(): string {
  return [
    "localhost",
    "127.0.0.1",
    "::1",
    "anthropic.com",
    "api.anthropic.com",
    "github.com",
    "api.github.com",
    "*.github.com",
    "*.githubusercontent.com",
  ].join(",");
}

// ─── Inherited upstream proxy env (matches original remote.rs EXACTLY) ──────

// All 8 env keys from original Rust UPSTREAM_PROXY_ENV_KEYS
const UPSTREAM_PROXY_ENV_KEYS = [
  "HTTPS_PROXY",
  "https_proxy",
  "NO_PROXY",
  "no_proxy",
  "SSL_CERT_FILE",
  "NODE_EXTRA_CA_CERTS",
  "REQUESTS_CA_BUNDLE",
  "CURL_CA_BUNDLE",
];

export function inheritedUpstreamProxyEnv(
  env: Record<string, string>
): Record<string, string> {
  // Both HTTPS_PROXY and SSL_CERT_FILE must be present (matches original guard)
  if (!env["HTTPS_PROXY"] || !env["SSL_CERT_FILE"]) {
    return {};
  }

  const result: Record<string, string> = {};
  for (const key of UPSTREAM_PROXY_ENV_KEYS) {
    if (env[key]) {
      result[key] = env[key];
    }
  }
  return result;
}

// ─── Upstream proxy bootstrap ────────────────────────────────────────────────

export function upstreamProxyBootstrapFromEnv(): UpstreamProxyBootstrap {
  return upstreamProxyBootstrapFromEnvMap(
    process.env as Record<string, string>
  );
}

export function upstreamProxyBootstrapFromEnvMap(
  env: Record<string, string>
): UpstreamProxyBootstrap {
  const remoteFlag = env["CLAW_CODE_REMOTE"];
  const proxyEnabled = env["CCR_UPSTREAM_PROXY_ENABLED"];
  const sessionId = env["CLAW_CODE_REMOTE_SESSION_ID"];
  const baseUrl = env["ANTHROPIC_BASE_URL"] || "https://api.anthropic.com";
  const tokenPath = env["CCR_SESSION_TOKEN_PATH"];
  const caBundlePath = env["CCR_CA_BUNDLE_PATH"];

  const isRemote =
    remoteFlag === "true" || remoteFlag === "1" || remoteFlag === "yes";
  const isProxyEnabled =
    proxyEnabled === "true" || proxyEnabled === "1" || proxyEnabled === "yes";

  // Read token from file
  const token = tokenPath ? readToken(tokenPath) : undefined;

  const bootstrap: UpstreamProxyBootstrap = {
    enabled: isRemote && isProxyEnabled,
    token,
    sessionId,
    baseUrl,
    caBundlePath,

    wsUrl(): string {
      return upstreamProxyWsUrl(baseUrl);
    },

    shouldEnable(): boolean {
      return isRemote && isProxyEnabled && !!token && !!sessionId;
    },

    stateForPort(port: number): UpstreamProxyState {
      if (!bootstrap.shouldEnable()) {
        return {
          enabled: false,
          proxyUrl: undefined,
          caBundlePath: undefined,
          token: undefined,
          subprocessEnv: () => ({}),
        };
      }

      const proxyUrl = `http://127.0.0.1:${port}`;
      const capturedToken = token;
      const capturedCaBundle = caBundlePath;

      return {
        enabled: true,
        proxyUrl,
        caBundlePath: capturedCaBundle,
        token: capturedToken,

        subprocessEnv(): Record<string, string> {
          const noProxy = noProxyList();
          const result: Record<string, string> = {
            HTTPS_PROXY: proxyUrl,
            https_proxy: proxyUrl,
            HTTP_PROXY: proxyUrl,
            http_proxy: proxyUrl,
            NO_PROXY: noProxy,
            no_proxy: noProxy,
          };

          if (capturedCaBundle) {
            result["SSL_CERT_FILE"] = capturedCaBundle;
            result["NODE_EXTRA_CA_CERTS"] = capturedCaBundle;
            result["REQUESTS_CA_BUNDLE"] = capturedCaBundle;
            result["CURL_CA_BUNDLE"] = capturedCaBundle;
          }

          return result;
        },
      };
    },
  };

  return bootstrap;
}

// ─── Remote session management ───────────────────────────────────────────────

export interface RemoteSession {
  id: string;
  baseUrl: string;
  token: string | undefined;
  proxyState: UpstreamProxyState;
  isActive: boolean;
}

export function createRemoteSession(
  context: RemoteSessionContext,
  proxyState: UpstreamProxyState
): RemoteSession {
  return {
    id: context.sessionId || `remote-${Date.now()}`,
    baseUrl: context.baseUrl,
    token: proxyState.token,
    proxyState,
    isActive: context.enabled,
  };
}

// ─── Heartbeat config ────────────────────────────────────────────────────────

export interface HeartbeatConfig {
  intervalMs: number;
  timeoutMs: number;
  maxRetries: number;
}

export function defaultHeartbeatConfig(): HeartbeatConfig {
  return {
    intervalMs: 30_000,
    timeoutMs: 10_000,
    maxRetries: 3,
  };
}