import { randomUUID } from "node:crypto";
import type { IncomingMessage, ServerResponse } from "node:http";
import { resolveDefaultAgentId } from "../agents/agent-scope.js";
import {
  buildAllowedModelSet,
  modelKey,
  parseModelRef,
  resolveDefaultModelForAgent,
} from "../agents/model-selection.js";
import { loadConfig } from "../config/config.js";
import { buildAgentMainSessionKey, normalizeAgentId } from "../routing/session-key.js";
import {
  normalizeLowercaseStringOrEmpty,
  normalizeOptionalString,
} from "../shared/string-coerce.js";
import { normalizeMessageChannel } from "../utils/message-channel.js";
import type { AuthRateLimiter } from "./auth-rate-limit.js";
import {
  authorizeHttpGatewayConnect,
  type GatewayAuthResult,
  type ResolvedGatewayAuth,
} from "./auth.js";
import { sendGatewayAuthFailure } from "./http-common.js";
import { ADMIN_SCOPE, CLI_DEFAULT_OPERATOR_SCOPES } from "./method-scopes.js";
import { loadGatewayModelCatalog } from "./server-model-catalog.js";

export const OPENCLAW_MODEL_ID = "openclaw";
export const OPENCLAW_DEFAULT_MODEL_ID = "openclaw/default";

export function getHeader(req: IncomingMessage, name: string): string | undefined {
  const raw = req.headers[normalizeLowercaseStringOrEmpty(name)];
  if (typeof raw === "string") {
    return raw;
  }
  if (Array.isArray(raw)) {
    return raw[0];
  }
  return undefined;
}

export function getBearerToken(req: IncomingMessage): string | undefined {
  const raw = normalizeOptionalString(getHeader(req, "authorization")) ?? "";
  if (!normalizeLowercaseStringOrEmpty(raw).startsWith("bearer ")) {
    return undefined;
  }
  return normalizeOptionalString(raw.slice(7));
}

type SharedSecretGatewayAuth = Pick<ResolvedGatewayAuth, "mode">;
export type AuthorizedGatewayHttpRequest = {
  authMethod?: GatewayAuthResult["method"];
  trustDeclaredOperatorScopes: boolean;
};

export function resolveHttpBrowserOriginPolicy(
  req: IncomingMessage,
  cfg = loadConfig(),
): NonNullable<Parameters<typeof authorizeHttpGatewayConnect>[0]["browserOriginPolicy"]> {
  return {
    requestHost: getHeader(req, "host"),
    origin: getHeader(req, "origin"),
    allowedOrigins: cfg.gateway?.controlUi?.allowedOrigins,
    allowHostHeaderOriginFallback:
      cfg.gateway?.controlUi?.dangerouslyAllowHostHeaderOriginFallback === true,
  };
}

function usesSharedSecretHttpAuth(auth: SharedSecretGatewayAuth | undefined): boolean {
  return auth?.mode === "token" || auth?.mode === "password";
}

function usesSharedSecretGatewayMethod(method: GatewayAuthResult["method"] | undefined): boolean {
  return method === "token" || method === "password";
}

function shouldTrustDeclaredHttpOperatorScopes(
  req: IncomingMessage,
  authOrRequest:
    | SharedSecretGatewayAuth
    | Pick<AuthorizedGatewayHttpRequest, "trustDeclaredOperatorScopes">
    | undefined,
): boolean {
  if (authOrRequest && "trustDeclaredOperatorScopes" in authOrRequest) {
    return authOrRequest.trustDeclaredOperatorScopes;
  }
  return !isGatewayBearerHttpRequest(req, authOrRequest);
}

export async function authorizeGatewayHttpRequestOrReply(params: {
  req: IncomingMessage;
  res: ServerResponse;
  auth: ResolvedGatewayAuth;
  trustedProxies?: string[];
  allowRealIpFallback?: boolean;
  rateLimiter?: AuthRateLimiter;
}): Promise<AuthorizedGatewayHttpRequest | null> {
  const token = getBearerToken(params.req);
  const browserOriginPolicy = resolveHttpBrowserOriginPolicy(params.req);
  const authResult = await authorizeHttpGatewayConnect({
    auth: params.auth,
    connectAuth: token ? { token, password: token } : null,
    req: params.req,
    trustedProxies: params.trustedProxies,
    allowRealIpFallback: params.allowRealIpFallback,
    rateLimiter: params.rateLimiter,
    browserOriginPolicy,
  });
  if (!authResult.ok) {
    sendGatewayAuthFailure(params.res, authResult);
    return null;
  }
  return {
    authMethod: authResult.method,
    // Shared-secret bearer auth proves possession of the gateway secret, but it
    // does not prove a narrower per-request operator identity. HTTP endpoints
    // must opt in explicitly if they want to treat that shared-secret path as a
    // full trusted-operator surface.
    trustDeclaredOperatorScopes: !usesSharedSecretGatewayMethod(authResult.method),
  };
}

export function isGatewayBearerHttpRequest(
  req: IncomingMessage,
  auth?: SharedSecretGatewayAuth,
): boolean {
  return usesSharedSecretHttpAuth(auth) && Boolean(getBearerToken(req));
}

export function resolveTrustedHttpOperatorScopes(
  req: IncomingMessage,
  authOrRequest?:
    | SharedSecretGatewayAuth
    | Pick<AuthorizedGatewayHttpRequest, "trustDeclaredOperatorScopes">,
): string[] {
  if (!shouldTrustDeclaredHttpOperatorScopes(req, authOrRequest)) {
    // Gateway bearer auth only proves possession of the shared secret. Do not
    // let HTTP clients self-assert operator scopes through request headers.
    return [];
  }

  const headerValue = getHeader(req, "x-openclaw-scopes");
  if (headerValue === undefined) {
    // No scope header present — trusted clients without an explicit header
    // get the default operator scopes (matching pre-#57783 behavior).
    return [...CLI_DEFAULT_OPERATOR_SCOPES];
  }
  const raw = headerValue.trim();
  if (!raw) {
    return [];
  }
  return raw
    .split(",")
    .map((scope) => scope.trim())
    .filter((scope) => scope.length > 0);
}

export function resolveOpenAiCompatibleHttpOperatorScopes(
  req: IncomingMessage,
  requestAuth: AuthorizedGatewayHttpRequest,
): string[] {
  if (usesSharedSecretGatewayMethod(requestAuth.authMethod)) {
    // Shared-secret HTTP bearer auth is a documented trusted-operator surface
    // for the compat APIs and direct /tools/invoke. This is designed-as-is:
    // token/password auth proves possession of the gateway operator secret, not
    // a narrower per-request scope identity, so restore the normal defaults.
    return [...CLI_DEFAULT_OPERATOR_SCOPES];
  }
  return resolveTrustedHttpOperatorScopes(req, requestAuth);
}

export function resolveHttpSenderIsOwner(
  req: IncomingMessage,
  authOrRequest?:
    | SharedSecretGatewayAuth
    | Pick<AuthorizedGatewayHttpRequest, "trustDeclaredOperatorScopes">,
): boolean {
  return resolveTrustedHttpOperatorScopes(req, authOrRequest).includes(ADMIN_SCOPE);
}

export function resolveOpenAiCompatibleHttpSenderIsOwner(
  req: IncomingMessage,
  requestAuth: AuthorizedGatewayHttpRequest,
): boolean {
  if (usesSharedSecretGatewayMethod(requestAuth.authMethod)) {
    // Shared-secret HTTP bearer auth also carries owner semantics on the compat
    // APIs and direct /tools/invoke. This is intentional: there is no separate
    // per-request owner primitive on that shared-secret path, so owner-only
    // tool policy follows the documented trusted-operator contract.
    return true;
  }
  return resolveHttpSenderIsOwner(req, requestAuth);
}

export function resolveAgentIdFromHeader(req: IncomingMessage): string | undefined {
  const raw =
    normalizeOptionalString(getHeader(req, "x-openclaw-agent-id")) ||
    normalizeOptionalString(getHeader(req, "x-openclaw-agent")) ||
    "";
  if (!raw) {
    return undefined;
  }
  return normalizeAgentId(raw);
}

export function resolveAgentIdFromModel(
  model: string | undefined,
  cfg = loadConfig(),
): string | undefined {
  const raw = model?.trim();
  if (!raw) {
    return undefined;
  }
  const lowered = normalizeLowercaseStringOrEmpty(raw);
  if (lowered === OPENCLAW_MODEL_ID || lowered === OPENCLAW_DEFAULT_MODEL_ID) {
    return resolveDefaultAgentId(cfg);
  }

  const m =
    raw.match(/^openclaw[:/](?<agentId>[a-z0-9][a-z0-9_-]{0,63})$/i) ??
    raw.match(/^agent:(?<agentId>[a-z0-9][a-z0-9_-]{0,63})$/i);
  const agentId = m?.groups?.agentId;
  if (!agentId) {
    return undefined;
  }
  return normalizeAgentId(agentId);
}

export async function resolveOpenAiCompatModelOverride(params: {
  req: IncomingMessage;
  agentId: string;
  model: string | undefined;
}): Promise<{ modelOverride?: string; errorMessage?: string }> {
  const requestModel = params.model?.trim();
  if (requestModel && !resolveAgentIdFromModel(requestModel)) {
    return {
      errorMessage: "Invalid `model`. Use `openclaw` or `openclaw/<agentId>`.",
    };
  }

  const raw = getHeader(params.req, "x-openclaw-model")?.trim();
  if (!raw) {
    return {};
  }

  const cfg = loadConfig();
  const defaultModelRef = resolveDefaultModelForAgent({ cfg, agentId: params.agentId });
  const defaultProvider = defaultModelRef.provider;
  const parsed = parseModelRef(raw, defaultProvider);
  if (!parsed) {
    return { errorMessage: "Invalid `x-openclaw-model`." };
  }

  const catalog = await loadGatewayModelCatalog();
  const allowed = buildAllowedModelSet({
    cfg,
    catalog,
    defaultProvider,
    agentId: params.agentId,
  });
  const normalized = modelKey(parsed.provider, parsed.model);
  if (!allowed.allowAny && !allowed.allowedKeys.has(normalized)) {
    return {
      errorMessage: `Model '${normalized}' is not allowed for agent '${params.agentId}'.`,
    };
  }

  return { modelOverride: raw };
}

export function resolveAgentIdForRequest(params: {
  req: IncomingMessage;
  model: string | undefined;
}): string {
  const cfg = loadConfig();
  const fromHeader = resolveAgentIdFromHeader(params.req);
  if (fromHeader) {
    return fromHeader;
  }

  const fromModel = resolveAgentIdFromModel(params.model, cfg);
  return fromModel ?? resolveDefaultAgentId(cfg);
}

export function resolveSessionKey(params: {
  req: IncomingMessage;
  agentId: string;
  user?: string | undefined;
  prefix: string;
}): string {
  const explicit = getHeader(params.req, "x-openclaw-session-key")?.trim();
  if (explicit) {
    return explicit;
  }

  const user = params.user?.trim();
  const mainKey = user ? `${params.prefix}-user:${user}` : `${params.prefix}:${randomUUID()}`;
  return buildAgentMainSessionKey({ agentId: params.agentId, mainKey });
}

export function resolveGatewayRequestContext(params: {
  req: IncomingMessage;
  model: string | undefined;
  user?: string | undefined;
  sessionPrefix: string;
  defaultMessageChannel: string;
  useMessageChannelHeader?: boolean;
}): { agentId: string; sessionKey: string; messageChannel: string } {
  const agentId = resolveAgentIdForRequest({ req: params.req, model: params.model });
  const sessionKey = resolveSessionKey({
    req: params.req,
    agentId,
    user: params.user,
    prefix: params.sessionPrefix,
  });

  const messageChannel = params.useMessageChannelHeader
    ? (normalizeMessageChannel(getHeader(params.req, "x-openclaw-message-channel")) ??
      params.defaultMessageChannel)
    : params.defaultMessageChannel;

  return { agentId, sessionKey, messageChannel };
}