/**
 * Copyright (c) Microsoft Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import type * as channels from '@protocol/channels';

class Cookie {
  private _raw: channels.NetworkCookie;
  constructor(data: channels.NetworkCookie) {
    this._raw = data;
  }

  name(): string {
    return this._raw.name;
  }

  // https://datatracker.ietf.org/doc/html/rfc6265#section-5.4
  matches(url: URL): boolean {
    if (this._raw.secure && (url.protocol !== 'https:' && url.hostname !== 'localhost'))
      return false;
    if (!domainMatches(url.hostname, this._raw.domain))
      return false;
    if (!pathMatches(url.pathname, this._raw.path))
      return false;
    return true;
  }

  equals(other: Cookie) {
    return this._raw.name === other._raw.name &&
      this._raw.domain === other._raw.domain &&
      this._raw.path === other._raw.path;
  }

  networkCookie(): channels.NetworkCookie {
    return this._raw;
  }

  updateExpiresFrom(other: Cookie) {
    this._raw.expires = other._raw.expires;
  }

  expired() {
    if (this._raw.expires === -1)
      return false;
    return this._raw.expires * 1000 < Date.now();
  }
}

export class CookieStore {
  private readonly _nameToCookies: Map<string, Set<Cookie>> = new Map();

  addCookies(cookies: channels.NetworkCookie[]) {
    for (const cookie of cookies)
      this._addCookie(new Cookie(cookie));
  }

  cookies(url: URL): channels.NetworkCookie[] {
    const result = [];
    for (const cookie of this._cookiesIterator()) {
      if (cookie.matches(url))
        result.push(cookie.networkCookie());
    }
    return result;
  }

  allCookies(): channels.NetworkCookie[] {
    const result = [];
    for (const cookie of this._cookiesIterator())
      result.push(cookie.networkCookie());
    return result;
  }

  private _addCookie(cookie: Cookie) {
    let set = this._nameToCookies.get(cookie.name());
    if (!set) {
      set = new Set();
      this._nameToCookies.set(cookie.name(), set);
    }
    // https://datatracker.ietf.org/doc/html/rfc6265#section-5.3
    for (const other of set) {
      if (other.equals(cookie))
        set.delete(other);
    }
    set.add(cookie);
    CookieStore.pruneExpired(set);
  }

  private *_cookiesIterator(): IterableIterator<Cookie> {
    for (const [name, cookies] of this._nameToCookies) {
      CookieStore.pruneExpired(cookies);
      for (const cookie of cookies)
        yield cookie;
      if (cookies.size === 0)
        this._nameToCookies.delete(name);
    }
  }

  private static pruneExpired(cookies: Set<Cookie>) {
    for (const cookie of cookies) {
      if (cookie.expired())
        cookies.delete(cookie);
    }
  }
}

export function domainMatches(value: string, domain: string): boolean {
  if (value === domain)
    return true;
  // Only strict match is allowed if domain doesn't start with '.' (host-only-flag is true in the spec)
  if (!domain.startsWith('.'))
    return false;
  value = '.' + value;
  return value.endsWith(domain);
}

function pathMatches(value: string, path: string): boolean {
  if (value === path)
    return true;
  if (!value.endsWith('/'))
    value = value + '/';
  if (!path.endsWith('/'))
    path = path + '/';
  return value.startsWith(path);
}