/**
 * FileConsentCard utilities for MS Teams large file uploads (>4MB) in personal chats.
 *
 * Teams requires user consent before the bot can upload large files. This module provides
 * utilities for:
 * - Building FileConsentCard attachments (to request upload permission)
 * - Building FileInfoCard attachments (to confirm upload completion)
 * - Parsing fileConsent/invoke activities
 */

import { lookup } from "node:dns/promises";
import { normalizeLowercaseStringOrEmpty } from "openclaw/plugin-sdk/text-runtime";
import { buildUserAgent } from "./user-agent.js";

/**
 * Allowlist of domains that are valid targets for file consent uploads.
 * These are the Microsoft/SharePoint domains that Teams legitimately provides
 * as upload destinations in the FileConsentCard flow.
 */
export const CONSENT_UPLOAD_HOST_ALLOWLIST = [
  "sharepoint.com",
  "sharepoint.us",
  "sharepoint.de",
  "sharepoint.cn",
  "sharepoint-df.com",
  "storage.live.com",
  "onedrive.com",
  "1drv.ms",
  "graph.microsoft.com",
  "graph.microsoft.us",
  "graph.microsoft.de",
  "graph.microsoft.cn",
] as const;

/**
 * Returns true if the given IPv4 or IPv6 address is in a private, loopback,
 * or link-local range that must never be reached via consent uploads.
 */
export function isPrivateOrReservedIP(ip: string): boolean {
  // Handle IPv4-mapped IPv6 first (e.g., ::ffff:127.0.0.1, ::ffff:10.0.0.1)
  const ipv4MappedMatch = /^::ffff:(\d+\.\d+\.\d+\.\d+)$/i.exec(ip);
  if (ipv4MappedMatch) {
    return isPrivateOrReservedIP(ipv4MappedMatch[1]);
  }

  // IPv4 checks
  const v4Parts = ip.split(".");
  if (v4Parts.length === 4) {
    const octets = v4Parts.map(Number);
    // Validate all octets are integers in 0-255
    if (octets.some((n) => !Number.isInteger(n) || n < 0 || n > 255)) {
      return false;
    }
    const [a, b] = octets;
    // 10.0.0.0/8
    if (a === 10) {
      return true;
    }
    // 172.16.0.0/12
    if (a === 172 && b >= 16 && b <= 31) {
      return true;
    }
    // 192.168.0.0/16
    if (a === 192 && b === 168) {
      return true;
    }
    // 127.0.0.0/8 (loopback)
    if (a === 127) {
      return true;
    }
    // 169.254.0.0/16 (link-local)
    if (a === 169 && b === 254) {
      return true;
    }
    // 0.0.0.0/8
    if (a === 0) {
      return true;
    }
  }

  // IPv6 checks
  const normalized = normalizeLowercaseStringOrEmpty(ip);
  // ::1 loopback
  if (normalized === "::1") {
    return true;
  }
  // fe80::/10 link-local
  if (normalized.startsWith("fe80:") || normalized.startsWith("fe80")) {
    return true;
  }
  // fc00::/7 unique-local (fc00:: and fd00::)
  if (normalized.startsWith("fc") || normalized.startsWith("fd")) {
    return true;
  }
  // :: unspecified
  if (normalized === "::") {
    return true;
  }

  return false;
}

/**
 * Validate that a consent upload URL is safe to PUT to.
 * Checks:
 * 1. Protocol is HTTPS
 * 2. Hostname matches the consent upload allowlist
 * 3. Resolved IP is not in a private/reserved range (anti-SSRF)
 *
 * @throws Error if the URL fails validation
 */
export async function validateConsentUploadUrl(
  url: string,
  opts?: {
    allowlist?: readonly string[];
    resolveFn?: (hostname: string) => Promise<{ address: string } | { address: string }[]>;
  },
): Promise<void> {
  let parsed: URL;
  try {
    parsed = new URL(url);
  } catch {
    throw new Error("Consent upload URL is not a valid URL");
  }

  // 1. Protocol check
  if (parsed.protocol !== "https:") {
    throw new Error(`Consent upload URL must use HTTPS, got ${parsed.protocol}`);
  }

  // 2. Hostname allowlist check
  const hostname = normalizeLowercaseStringOrEmpty(parsed.hostname);
  const allowlist = opts?.allowlist ?? CONSENT_UPLOAD_HOST_ALLOWLIST;
  const hostAllowed = allowlist.some(
    (entry) => hostname === entry || hostname.endsWith(`.${entry}`),
  );
  if (!hostAllowed) {
    throw new Error(`Consent upload URL hostname "${hostname}" is not in the allowed domains`);
  }

  // 3. DNS resolution — reject private/reserved IPs.
  // Check all resolved addresses to avoid SSRF bypass via mixed public/private answers.
  const resolveFn = opts?.resolveFn ?? ((name: string) => lookup(name, { all: true }));
  let resolved: { address: string }[];
  try {
    const result = await resolveFn(hostname);
    resolved = Array.isArray(result) ? result : [result];
  } catch {
    throw new Error(`Failed to resolve consent upload URL hostname "${hostname}"`);
  }

  for (const entry of resolved) {
    if (isPrivateOrReservedIP(entry.address)) {
      throw new Error(`Consent upload URL resolves to a private/reserved IP (${entry.address})`);
    }
  }
}

export interface FileConsentCardParams {
  filename: string;
  description?: string;
  sizeInBytes: number;
  /** Custom context data to include in the card (passed back in the invoke) */
  context?: Record<string, unknown>;
}

export interface FileInfoCardParams {
  filename: string;
  contentUrl: string;
  uniqueId: string;
  fileType: string;
}

/**
 * Build a FileConsentCard attachment for requesting upload permission.
 * Use this for files >= 4MB in personal (1:1) chats.
 */
export function buildFileConsentCard(params: FileConsentCardParams) {
  return {
    contentType: "application/vnd.microsoft.teams.card.file.consent",
    name: params.filename,
    content: {
      description: params.description ?? `File: ${params.filename}`,
      sizeInBytes: params.sizeInBytes,
      acceptContext: { filename: params.filename, ...params.context },
      declineContext: { filename: params.filename, ...params.context },
    },
  };
}

/**
 * Build a FileInfoCard attachment for confirming upload completion.
 * Send this after successfully uploading the file to the consent URL.
 */
export function buildFileInfoCard(params: FileInfoCardParams) {
  return {
    contentType: "application/vnd.microsoft.teams.card.file.info",
    contentUrl: params.contentUrl,
    name: params.filename,
    content: {
      uniqueId: params.uniqueId,
      fileType: params.fileType,
    },
  };
}

export interface FileConsentUploadInfo {
  name: string;
  uploadUrl: string;
  contentUrl: string;
  uniqueId: string;
  fileType: string;
}

export interface FileConsentResponse {
  action: "accept" | "decline";
  uploadInfo?: FileConsentUploadInfo;
  context?: Record<string, unknown>;
}

/**
 * Parse a fileConsent/invoke activity.
 * Returns null if the activity is not a file consent invoke.
 */
export function parseFileConsentInvoke(activity: {
  name?: string;
  value?: unknown;
}): FileConsentResponse | null {
  if (activity.name !== "fileConsent/invoke") {
    return null;
  }

  const value = activity.value as {
    type?: string;
    action?: string;
    uploadInfo?: FileConsentUploadInfo;
    context?: Record<string, unknown>;
  };

  if (value?.type !== "fileUpload") {
    return null;
  }

  return {
    action: value.action === "accept" ? "accept" : "decline",
    uploadInfo: value.uploadInfo,
    context: value.context,
  };
}

/**
 * Upload a file to the consent URL provided by Teams.
 * The URL is provided in the fileConsent/invoke response after user accepts.
 *
 * @throws Error if the URL fails SSRF validation (non-HTTPS, disallowed host, private IP)
 */
export async function uploadToConsentUrl(params: {
  url: string;
  buffer: Buffer;
  contentType?: string;
  fetchFn?: typeof fetch;
  /** Override for testing — custom allowlist and DNS resolver */
  validationOpts?: {
    allowlist?: readonly string[];
    resolveFn?: (hostname: string) => Promise<{ address: string } | { address: string }[]>;
  };
}): Promise<void> {
  await validateConsentUploadUrl(params.url, params.validationOpts);

  const fetchFn = params.fetchFn ?? fetch;
  const res = await fetchFn(params.url, {
    method: "PUT",
    headers: {
      "User-Agent": buildUserAgent(),
      "Content-Type": params.contentType ?? "application/octet-stream",
      "Content-Range": `bytes 0-${params.buffer.length - 1}/${params.buffer.length}`,
    },
    body: new Uint8Array(params.buffer),
  });

  if (!res.ok) {
    throw new Error(`File upload to consent URL failed: ${res.status} ${res.statusText}`);
  }
}