/**
 * WebDAV XML generation utilities
 */

import type { IWebDAVResource, IWebDAVProperty, IWebDAVLock } from './webdav.types.js';
import { DAV_NAMESPACE } from './webdav.types.js';

/**
 * Escape XML special characters
 */
function escapeXml(str: string): string {
  return str
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&apos;');
}

/**
 * Format date for WebDAV (RFC 1123)
 */
function formatDate(date: Date): string {
  return date.toUTCString();
}

/**
 * Format date for creationdate (ISO 8601)
 */
function formatCreationDate(date: Date): string {
  return date.toISOString();
}

/**
 * Generate multistatus response for PROPFIND
 */
export function generateMultistatus(resources: IWebDAVResource[]): string {
  const responses = resources.map(resource => generateResponse(resource)).join('\n');

  return `<?xml version="1.0" encoding="utf-8"?>
<D:multistatus xmlns:D="${DAV_NAMESPACE}">
${responses}
</D:multistatus>`;
}

/**
 * Generate single response element
 */
function generateResponse(resource: IWebDAVResource): string {
  const props: string[] = [];

  // Resource type
  if (resource.isCollection) {
    props.push('<D:resourcetype><D:collection/></D:resourcetype>');
  } else {
    props.push('<D:resourcetype/>');
  }

  // Display name
  if (resource.displayName) {
    props.push(`<D:displayname>${escapeXml(resource.displayName)}</D:displayname>`);
  }

  // Content type
  if (resource.contentType) {
    props.push(`<D:getcontenttype>${escapeXml(resource.contentType)}</D:getcontenttype>`);
  }

  // Content length
  if (resource.contentLength !== undefined) {
    props.push(`<D:getcontentlength>${resource.contentLength}</D:getcontentlength>`);
  }

  // Last modified
  if (resource.lastModified) {
    props.push(`<D:getlastmodified>${formatDate(resource.lastModified)}</D:getlastmodified>`);
  }

  // Creation date
  if (resource.creationDate) {
    props.push(`<D:creationdate>${formatCreationDate(resource.creationDate)}</D:creationdate>`);
  }

  // ETag
  if (resource.etag) {
    props.push(`<D:getetag>"${escapeXml(resource.etag)}"</D:getetag>`);
  }

  // Supported lock
  props.push(`<D:supportedlock>
    <D:lockentry>
      <D:lockscope><D:exclusive/></D:lockscope>
      <D:locktype><D:write/></D:locktype>
    </D:lockentry>
  </D:supportedlock>`);

  // Custom properties
  for (const prop of resource.properties) {
    if (prop.value) {
      props.push(`<${prop.name} xmlns="${prop.namespace}">${escapeXml(prop.value)}</${prop.name}>`);
    } else {
      props.push(`<${prop.name} xmlns="${prop.namespace}"/>`);
    }
  }

  return `  <D:response>
    <D:href>${escapeXml(resource.href)}</D:href>
    <D:propstat>
      <D:prop>
        ${props.join('\n        ')}
      </D:prop>
      <D:status>HTTP/1.1 200 OK</D:status>
    </D:propstat>
  </D:response>`;
}

/**
 * Generate lock discovery response
 */
export function generateLockDiscovery(locks: IWebDAVLock[]): string {
  if (locks.length === 0) {
    return '<D:lockdiscovery/>';
  }

  const lockEntries = locks.map(lock => `
    <D:activelock>
      <D:locktype><D:write/></D:locktype>
      <D:lockscope><D:${lock.scope}/></D:lockscope>
      <D:depth>${lock.depth}</D:depth>
      <D:owner>${escapeXml(lock.owner)}</D:owner>
      <D:timeout>Second-${lock.timeout}</D:timeout>
      <D:locktoken><D:href>${escapeXml(lock.token)}</D:href></D:locktoken>
    </D:activelock>`).join('');

  return `<D:lockdiscovery>${lockEntries}
  </D:lockdiscovery>`;
}

/**
 * Generate lock response
 */
export function generateLockResponse(lock: IWebDAVLock): string {
  return `<?xml version="1.0" encoding="utf-8"?>
<D:prop xmlns:D="${DAV_NAMESPACE}">
  ${generateLockDiscovery([lock])}
</D:prop>`;
}

/**
 * Generate error response
 */
export function generateError(status: number, message: string): string {
  return `<?xml version="1.0" encoding="utf-8"?>
<D:error xmlns:D="${DAV_NAMESPACE}">
  <D:${message.toLowerCase().replace(/\s+/g, '-')}/>
</D:error>`;
}

/**
 * Parse PROPFIND request body to extract requested properties
 */
export function parsePropfindRequest(body: string): { allprop: boolean; propnames: string[] } {
  // Simple XML parsing for PROPFIND
  if (!body || body.includes('<allprop') || body.includes('<D:allprop')) {
    return { allprop: true, propnames: [] };
  }

  if (body.includes('<propname') || body.includes('<D:propname')) {
    return { allprop: false, propnames: [] };
  }

  // Extract property names
  const propnames: string[] = [];
  const propMatch = body.match(/<(?:D:)?prop[^>]*>([\s\S]*?)<\/(?:D:)?prop>/i);
  if (propMatch) {
    const propContent = propMatch[1];
    const tagMatches = propContent.matchAll(/<(?:D:)?(\w+)[^>]*\/?>/gi);
    for (const match of tagMatches) {
      propnames.push(match[1]);
    }
  }

  return { allprop: propnames.length === 0, propnames };
}