import { isCI } from 'ci-info';
import type { Span } from '../../trace';
import { calculateContentHash } from '../content-hash';
import { compareAndWriteFile, writeFileLines } from '../create-file';

/**
 * The class is not about holding rule data, instead it determines how the
 * date is written to a file.
 */
export abstract class BaseWriteStrategy {
  public abstract readonly name: string;

  /**
   * Sometimes a ruleset will create extra files (e.g. reject-url-regex w/ mitm.sgmodule),
   * and doesn't share the same filename and id. This property is used to overwrite the filename.
   */
  public overwriteFilename: string | null = null;
  public withFilename(filename: string) {
    this.overwriteFilename = filename;
    return this;
  }

  public abstract readonly type: 'domainset' | 'non_ip' | 'ip' | (string & {});

  abstract readonly fileExtension: 'conf' | 'txt' | 'json' | 'sgmodule'; /* | (string & {}) */

  constructor(public readonly outputDir: string) {}

  protected abstract result: string[] | null;

  /**
   * Whether the output has no volatile metadata (e.g. "Last Updated") to preserve,
   * so on CI the previous file can simply be overwritten without comparison (the
   * comparison would only serve to reduce SSD wear, which CI doesn't care about).
   * Only enable this when withPadding emits neither a banner nor any date.
   */
  protected readonly skipCompareOnCI: boolean = false;

  abstract writeDomain(domain: string): void;
  abstract writeDomainSuffix(domain: string): void;
  abstract writeDomainKeywords(keyword: Set<string>): void;
  abstract writeDomainWildcard(wildcard: string): void;
  abstract writeUserAgents(userAgent: Set<string>): void;
  abstract writeProcessNames(processName: Set<string>): void;
  abstract writeProcessPaths(processPath: Set<string>): void;
  abstract writeUrlRegexes(urlRegex: Set<string>): void;
  abstract writeIpCidrs(ipCidr: string[], noResolve: boolean): void;
  abstract writeIpCidr6s(ipCidr6: string[], noResolve: boolean): void;
  abstract writeGeoip(geoip: Set<string>, noResolve: boolean): void;
  abstract writeIpAsns(asns: Set<string>, noResolve: boolean): void;
  abstract writeSourceIpCidrs(sourceIpCidr: string[]): void;
  abstract writeSourcePorts(port: Set<string>): void;
  abstract writeDestinationPorts(port: Set<string>): void;
  abstract writeProtocols(protocol: Set<string>): void;
  abstract writeOtherRules(rule: string[]): void;

  protected abstract withPadding(title: string, description: string[] | readonly string[], date: Date, content: string[], contentHash: string | null): string[];

  public output(
    span: Span,
    title: string,
    description: string[] | readonly string[],
    date: Date,
    filePath: string
  ): void | Promise<void> {
    const result = this.result;
    if (!result) {
      return;
    }

    // Without volatile metadata to preserve, the compare-before-write only serves
    // to reduce SSD wear -- irrelevant on CI, so skip hashing and comparison alike.
    if (isCI && this.skipCompareOnCI) {
      return writeFileLines(
        span,
        this.withPadding(title, description, date, result, null),
        filePath
      );
    }

    // The hash covers the real content (title, description and rules) but not the
    // volatile date, so compareAndWriteFile can bail out by only reading the head
    // of the previous output. Strategies whose withPadding doesn't embed the marker
    // (e.g. JSON output) simply fall back to the full comparison.
    const contentHash = calculateContentHash(title, description, result);

    return compareAndWriteFile(
      span,
      this.withPadding(
        title,
        description,
        date,
        result,
        contentHash
      ),
      filePath,
      contentHash
    );
  };

  public get content() {
    return this.result;
  }
}