/**
 * Maven helper utilities
 * Path conversion, XML generation, checksum calculation
 */

import * as plugins from '../plugins.js';
import type {
  IMavenCoordinate,
  IMavenMetadata,
  IChecksums,
  IMavenPom,
} from './interfaces.maven.js';

/**
 * Convert Maven GAV coordinates to storage path
 * Example: com.example:my-lib:1.0.0 → com/example/my-lib/1.0.0
 */
export function gavToPath(
  groupId: string,
  artifactId: string,
  version?: string
): string {
  const groupPath = groupId.replace(/\./g, '/');
  if (version) {
    return `${groupPath}/${artifactId}/${version}`;
  }
  return `${groupPath}/${artifactId}`;
}

/**
 * Parse Maven path to GAV coordinates
 * Example: com/example/my-lib/1.0.0/my-lib-1.0.0.jar → {groupId, artifactId, version, ...}
 */
export function pathToGAV(path: string): IMavenCoordinate | null {
  // Remove leading slash if present
  const cleanPath = path.startsWith('/') ? path.substring(1) : path;

  // Split path into parts
  const parts = cleanPath.split('/');
  if (parts.length < 4) {
    return null; // Not a valid artifact path
  }

  // Last part is filename
  const filename = parts[parts.length - 1];
  const version = parts[parts.length - 2];
  const artifactId = parts[parts.length - 3];
  const groupId = parts.slice(0, -3).join('.');

  // Parse filename to extract classifier and extension
  const parsed = parseFilename(filename, artifactId, version);
  if (!parsed) {
    return null;
  }

  return {
    groupId,
    artifactId,
    version,
    classifier: parsed.classifier,
    extension: parsed.extension,
  };
}

/**
 * Parse Maven artifact filename
 * Example: my-lib-1.0.0-sources.jar → {classifier: 'sources', extension: 'jar'}
 * Example: my-lib-1.0.0.jar.md5 → {extension: 'md5'}
 */
export function parseFilename(
  filename: string,
  artifactId: string,
  version: string
): { classifier?: string; extension: string } | null {
  // Expected format: {artifactId}-{version}[-{classifier}].{extension}[.checksum]
  const prefix = `${artifactId}-${version}`;

  if (!filename.startsWith(prefix)) {
    return null;
  }

  let remainder = filename.substring(prefix.length);

  // Check if this is a checksum file (double extension like .jar.md5)
  const checksumExtensions = ['md5', 'sha1', 'sha256', 'sha512'];
  const lastDotIndex = remainder.lastIndexOf('.');
  if (lastDotIndex !== -1) {
    const possibleChecksum = remainder.substring(lastDotIndex + 1);
    if (checksumExtensions.includes(possibleChecksum)) {
      // This is a checksum file - just return the checksum extension
      // The base artifact extension doesn't matter for checksum retrieval
      return { extension: possibleChecksum };
    }
  }

  // Regular artifact file parsing
  const dotIndex = remainder.lastIndexOf('.');
  if (dotIndex === -1) {
    return null; // No extension
  }

  const extension = remainder.substring(dotIndex + 1);
  const classifierPart = remainder.substring(0, dotIndex);

  if (classifierPart.length === 0) {
    // No classifier
    return { extension };
  }

  if (classifierPart.startsWith('-')) {
    // Has classifier
    const classifier = classifierPart.substring(1);
    return { classifier, extension };
  }

  return null; // Invalid format
}

/**
 * Build Maven artifact filename
 * Example: {artifactId: 'my-lib', version: '1.0.0', classifier: 'sources', extension: 'jar'}
 *          → 'my-lib-1.0.0-sources.jar'
 */
export function buildFilename(coordinate: IMavenCoordinate): string {
  const { artifactId, version, classifier, extension } = coordinate;

  let filename = `${artifactId}-${version}`;
  if (classifier) {
    filename += `-${classifier}`;
  }
  filename += `.${extension}`;

  return filename;
}

/**
 * Calculate checksums for Maven artifact
 * Returns MD5, SHA-1, SHA-256, SHA-512
 */
export async function calculateChecksums(data: Buffer): Promise<IChecksums> {
  const crypto = await import('crypto');

  return {
    md5: crypto.createHash('md5').update(data).digest('hex'),
    sha1: crypto.createHash('sha1').update(data).digest('hex'),
    sha256: crypto.createHash('sha256').update(data).digest('hex'),
    sha512: crypto.createHash('sha512').update(data).digest('hex'),
  };
}

/**
 * Generate maven-metadata.xml from metadata object
 */
export function generateMetadataXml(metadata: IMavenMetadata): string {
  const { groupId, artifactId, versioning } = metadata;
  const { latest, release, versions, lastUpdated, snapshot, snapshotVersions } = versioning;

  let xml = '<?xml version="1.0" encoding="UTF-8"?>\n';
  xml += '<metadata>\n';
  xml += `  <groupId>${escapeXml(groupId)}</groupId>\n`;
  xml += `  <artifactId>${escapeXml(artifactId)}</artifactId>\n`;

  // Add version if SNAPSHOT
  if (snapshot) {
    const snapshotVersion = versions[versions.length - 1]; // Assume last version is the SNAPSHOT
    xml += `  <version>${escapeXml(snapshotVersion)}</version>\n`;
  }

  xml += '  <versioning>\n';

  if (latest) {
    xml += `    <latest>${escapeXml(latest)}</latest>\n`;
  }

  if (release) {
    xml += `    <release>${escapeXml(release)}</release>\n`;
  }

  xml += '    <versions>\n';
  for (const version of versions) {
    xml += `      <version>${escapeXml(version)}</version>\n`;
  }
  xml += '    </versions>\n';

  xml += `    <lastUpdated>${lastUpdated}</lastUpdated>\n`;

  // Add SNAPSHOT info if present
  if (snapshot) {
    xml += '    <snapshot>\n';
    xml += `      <timestamp>${escapeXml(snapshot.timestamp)}</timestamp>\n`;
    xml += `      <buildNumber>${snapshot.buildNumber}</buildNumber>\n`;
    xml += '    </snapshot>\n';
  }

  // Add SNAPSHOT versions if present
  if (snapshotVersions && snapshotVersions.length > 0) {
    xml += '    <snapshotVersions>\n';
    for (const sv of snapshotVersions) {
      xml += '      <snapshotVersion>\n';
      if (sv.classifier) {
        xml += `        <classifier>${escapeXml(sv.classifier)}</classifier>\n`;
      }
      xml += `        <extension>${escapeXml(sv.extension)}</extension>\n`;
      xml += `        <value>${escapeXml(sv.value)}</value>\n`;
      xml += `        <updated>${sv.updated}</updated>\n`;
      xml += '      </snapshotVersion>\n';
    }
    xml += '    </snapshotVersions>\n';
  }

  xml += '  </versioning>\n';
  xml += '</metadata>\n';

  return xml;
}

/**
 * Parse maven-metadata.xml to metadata object
 * Basic XML parsing for Maven metadata
 */
export function parseMetadataXml(xml: string): IMavenMetadata | null {
  try {
    // Simple regex-based parsing (for basic metadata)
    // In production, use a proper XML parser

    const groupIdMatch = xml.match(/<groupId>([^<]+)<\/groupId>/);
    const artifactIdMatch = xml.match(/<artifactId>([^<]+)<\/artifactId>/);
    const latestMatch = xml.match(/<latest>([^<]+)<\/latest>/);
    const releaseMatch = xml.match(/<release>([^<]+)<\/release>/);
    const lastUpdatedMatch = xml.match(/<lastUpdated>([^<]+)<\/lastUpdated>/);

    if (!groupIdMatch || !artifactIdMatch) {
      return null;
    }

    // Parse versions
    const versionsMatch = xml.match(/<versions>([\s\S]*?)<\/versions>/);
    const versions: string[] = [];
    if (versionsMatch) {
      const versionMatches = versionsMatch[1].matchAll(/<version>([^<]+)<\/version>/g);
      for (const match of versionMatches) {
        versions.push(match[1]);
      }
    }

    return {
      groupId: groupIdMatch[1],
      artifactId: artifactIdMatch[1],
      versioning: {
        latest: latestMatch ? latestMatch[1] : undefined,
        release: releaseMatch ? releaseMatch[1] : undefined,
        versions,
        lastUpdated: lastUpdatedMatch ? lastUpdatedMatch[1] : formatMavenTimestamp(new Date()),
      },
    };
  } catch (error) {
    return null;
  }
}

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

/**
 * Format timestamp in Maven format: yyyyMMddHHmmss
 */
export function formatMavenTimestamp(date: Date): string {
  const year = date.getUTCFullYear();
  const month = String(date.getUTCMonth() + 1).padStart(2, '0');
  const day = String(date.getUTCDate()).padStart(2, '0');
  const hours = String(date.getUTCHours()).padStart(2, '0');
  const minutes = String(date.getUTCMinutes()).padStart(2, '0');
  const seconds = String(date.getUTCSeconds()).padStart(2, '0');

  return `${year}${month}${day}${hours}${minutes}${seconds}`;
}

/**
 * Format SNAPSHOT timestamp: yyyyMMdd.HHmmss
 */
export function formatSnapshotTimestamp(date: Date): string {
  const year = date.getUTCFullYear();
  const month = String(date.getUTCMonth() + 1).padStart(2, '0');
  const day = String(date.getUTCDate()).padStart(2, '0');
  const hours = String(date.getUTCHours()).padStart(2, '0');
  const minutes = String(date.getUTCMinutes()).padStart(2, '0');
  const seconds = String(date.getUTCSeconds()).padStart(2, '0');

  return `${year}${month}${day}.${hours}${minutes}${seconds}`;
}

/**
 * Check if version is a SNAPSHOT
 */
export function isSnapshot(version: string): boolean {
  return version.endsWith('-SNAPSHOT');
}

/**
 * Validate POM basic structure
 */
export function validatePom(pomXml: string): boolean {
  try {
    // Basic validation - check for required fields
    return (
      pomXml.includes('<groupId>') &&
      pomXml.includes('<artifactId>') &&
      pomXml.includes('<version>') &&
      pomXml.includes('<modelVersion>')
    );
  } catch (error) {
    return false;
  }
}

/**
 * Extract GAV from POM XML
 */
export function extractGAVFromPom(pomXml: string): { groupId: string; artifactId: string; version: string } | null {
  try {
    const groupIdMatch = pomXml.match(/<groupId>([^<]+)<\/groupId>/);
    const artifactIdMatch = pomXml.match(/<artifactId>([^<]+)<\/artifactId>/);
    const versionMatch = pomXml.match(/<version>([^<]+)<\/version>/);

    if (groupIdMatch && artifactIdMatch && versionMatch) {
      return {
        groupId: groupIdMatch[1],
        artifactId: artifactIdMatch[1],
        version: versionMatch[1],
      };
    }

    return null;
  } catch (error) {
    return null;
  }
}