import * as core from '@actions/core';
import * as github from '@actions/github';
import {Minimatch} from 'minimatch';

export interface ChangedFilesMatchConfig {
  changedFiles?: {
    all?: string[];
    any?: string[];
  };
}

type ClientType = ReturnType<typeof github.getOctokit>;

export async function getChangedFiles(
  client: ClientType,
  prNumber: number
): Promise<string[]> {
  const listFilesOptions = client.rest.pulls.listFiles.endpoint.merge({
    owner: github.context.repo.owner,
    repo: github.context.repo.repo,
    pull_number: prNumber
  });

  const listFilesResponse = await client.paginate(listFilesOptions);
  const changedFiles = listFilesResponse.map((f: any) => f.filename);

  core.debug('found changed files:');
  for (const file of changedFiles) {
    core.debug('  ' + file);
  }

  return changedFiles;
}

export function toChangedFilesMatchConfig(
  config: any
): ChangedFilesMatchConfig {
  if (!config['changed-files']) {
    return {};
  }
  const changedFilesConfig = config['changed-files'];

  // If the value provided is a string or an array of strings then default to `any` matching
  if (typeof changedFilesConfig === 'string') {
    return {
      changedFiles: {
        any: [changedFilesConfig]
      }
    };
  }

  const changedFilesMatchConfig = {
    changedFiles: {}
  };

  if (Array.isArray(changedFilesConfig)) {
    if (changedFilesConfig.every(entry => typeof entry === 'string')) {
      changedFilesMatchConfig.changedFiles = {
        any: changedFilesConfig
      };
    } else {
      // If it is not an array of strings then it should be array of further config options
      // so assign them to our `changedFilesMatchConfig`
      Object.assign(
        changedFilesMatchConfig.changedFiles,
        ...changedFilesConfig
      );
      Object.keys(changedFilesMatchConfig.changedFiles).forEach(key => {
        const value = changedFilesMatchConfig.changedFiles[key];
        changedFilesMatchConfig.changedFiles[key] = Array.isArray(value)
          ? value
          : [value];
      });
    }
  }

  return changedFilesMatchConfig;
}

function printPattern(matcher: Minimatch): string {
  return (matcher.negate ? '!' : '') + matcher.pattern;
}

function isMatch(changedFile: string, matchers: Minimatch[]): boolean {
  core.debug(`    matching patterns against file ${changedFile}`);
  for (const matcher of matchers) {
    core.debug(`   - ${printPattern(matcher)}`);
    if (!matcher.match(changedFile)) {
      core.debug(`   ${printPattern(matcher)} did not match`);
      return false;
    }
  }

  core.debug(`   all patterns matched`);
  return true;
}

// equivalent to "Array.some()" but expanded for debugging and clarity
export function checkAny(changedFiles: string[], globs: string[]): boolean {
  const matchers = globs.map(g => new Minimatch(g));
  core.debug(`  checking "any" patterns`);
  for (const changedFile of changedFiles) {
    if (isMatch(changedFile, matchers)) {
      core.debug(`  "any" patterns matched against ${changedFile}`);
      return true;
    }
  }

  core.debug(`  "any" patterns did not match any files`);
  return false;
}

// equivalent to "Array.every()" but expanded for debugging and clarity
export function checkAll(changedFiles: string[], globs: string[]): boolean {
  const matchers = globs.map(g => new Minimatch(g));
  core.debug(` checking "all" patterns`);
  for (const changedFile of changedFiles) {
    if (!isMatch(changedFile, matchers)) {
      core.debug(`  "all" patterns did not match against ${changedFile}`);
      return false;
    }
  }

  core.debug(`  "all" patterns matched all files`);
  return true;
}