const path = require('path');
const jsBuilder = require('./JSBuilder');
const mdBuilder = require('./MDBuilder');
const Documentation = require('./Documentation');
const Browser = require('../../lib/Browser');

const PROJECT_DIR = path.join(__dirname, '..', '..');

let EXCLUDE_CLASSES = new Set([
  'Connection',
  'FrameManager',
  'Helper',
  'Navigator',
  'NetworkManager',
  'ProxyStream'
]);

let EXCLUDE_METHODS = new Set([
  'Body.constructor',
  'Dialog.constructor',
  'Frame.constructor',
  'Headers.constructor',
  'Headers.fromPayload',
  'InterceptedRequest.constructor',
  'Page.constructor',
  'Page.create',
  'Request.constructor',
  'Response.constructor',
]);

/**
 * @param {!Page} page
 * @param {string} docsFolderPath
 * @param {string} jsFolderPath
 * @return {!Promise<!Array<string>>}
 */
async function lint(page, docsFolderPath, jsFolderPath) {
  let mdResult = await mdBuilder(page, docsFolderPath);
  let jsResult = await jsBuilder(jsFolderPath);
  let jsDocumentation = filterJSDocumentation(jsResult);
  let mdDocumentation = mdResult.documentation;

  let jsErrors = [];
  let mdErrors = Documentation.diff(mdDocumentation, jsDocumentation);
  // Report all markdown parse errors.
  mdErrors.push(...mdResult.errors);

  jsErrors.push(...Documentation.validate(jsDocumentation));
  mdErrors.push(...Documentation.validate(mdDocumentation));
  mdErrors.push(...lintMarkdown(mdDocumentation));

  // Push all errors with proper prefixes
  let errors = jsErrors.map(error => '[JavaScript] ' + error);
  errors.push(...mdErrors.map(error => '[MarkDown] ' + error));
  return errors;
}

/**
 * @param {!Documentation} doc
 * @return {!Array<string>}
 */
function lintMarkdown(doc) {
  const errors = [];
  for (let cls of doc.classesArray) {
    let members = cls.membersArray;

    // Events should go first.
    let eventIndex = 0;
    for (; eventIndex < members.length && members[eventIndex].type === 'event'; ++eventIndex);
    for (; eventIndex < members.length && members[eventIndex].type !== 'event'; ++eventIndex);
    if (eventIndex < members.length)
      errors.push(`Events should go first. Event '${members[eventIndex].name}' in class ${cls.name} breaks order`);

    // Constructor should be right after events and before all other members.
    let constructorIndex = members.findIndex(member => member.type === 'method' && member.name === 'constructor');
    if (constructorIndex > 0 && members[constructorIndex - 1].type !== 'event')
      errors.push(`Constructor of ${cls.name} should go before other methods`);

    // Events should be sorted alphabetically.
    for (let i = 0; i < members.length - 1; ++i) {
      let member1 = cls.membersArray[i];
      let member2 = cls.membersArray[i + 1];
      if (member1.type !== 'event' || member2.type !== 'event')
        continue;
      if (member1.name > member2.name)
        errors.push(`Event '${member1.name}' in class ${cls.name} breaks alphabetic ordering of events`);
    }

    // All other members should be sorted alphabetically.
    for (let i = 0; i < members.length - 1; ++i) {
      let member1 = cls.membersArray[i];
      let member2 = cls.membersArray[i + 1];
      if (member1.type === 'event' || member2.type === 'event')
        continue;
      if (member1.type === 'method' && member1.name === 'constructor')
        continue;
      if (member1.name > member2.name) {
        let memberName = `${cls.name}.${member1.name}`;
        if (member1.type === 'method')
          memberName += '()';
        errors.push(`${memberName} breaks alphabetic ordering of class members.`);
      }
    }
  }
  return errors;
}

/**
 * @param {!Documentation} jsDocumentation
 * @return {!Documentation}
 */
function filterJSDocumentation(jsDocumentation) {
  // Filter classes and methods.
  let classes = [];
  for (let cls of jsDocumentation.classesArray) {
    if (EXCLUDE_CLASSES.has(cls.name))
      continue;
    let members = cls.membersArray.filter(member => {
      if (member.name.startsWith('_'))
        return false;
      return !EXCLUDE_METHODS.has(`${cls.name}.${member.name}`);
    });
    classes.push(new Documentation.Class(cls.name, members));
  }
  return new Documentation(classes);
}

module.exports = lint;

const RED_COLOR = '\x1b[31m';
const RESET_COLOR = '\x1b[0m';

// Handle CLI invocation.
if (!module.parent) {
  const startTime = Date.now();
  const browser = new Browser({args: ['--no-sandbox']});
  browser.newPage().then(async page => {
    const errors = await lint(page, path.join(PROJECT_DIR, 'docs'), path.join(PROJECT_DIR, 'lib'));
    await browser.close();
    if (errors.length) {
      console.log('Documentation Failures:');
      for (let i = 0; i < errors.length; ++i) {
        let error = errors[i];
        error = error.split('\n').join('\n    ');
        console.log(`${i + 1}) ${RED_COLOR}${error}${RESET_COLOR}`);
      }
    }
    console.log(`${errors.length} failures`);
    const runningTime = Date.now() - startTime;
    console.log(`Finished in ${runningTime / 1000} seconds`);
    process.exit(errors.length > 0 ? 1 : 0);
  });
}