/*
 * Copyright (C) 2015 Square, Inc.
 *
 * 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.
 */
package okhttp3;

import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.annotation.Nullable;
import okhttp3.internal.Util;
import okhttp3.internal.http.HttpDate;
import okhttp3.internal.publicsuffix.PublicSuffixDatabase;

import static okhttp3.internal.Util.UTC;
import static okhttp3.internal.Util.canonicalizeHost;
import static okhttp3.internal.Util.delimiterOffset;
import static okhttp3.internal.Util.indexOfControlOrNonAscii;
import static okhttp3.internal.Util.trimSubstring;
import static okhttp3.internal.Util.verifyAsIpAddress;

An RFC 6265 Cookie.
This class doesn't support additional attributes on cookies, like Chromium's Priority=HIGH
extension.
/**
 * An <a href="http://tools.ietf.org/html/rfc6265">RFC 6265</a> Cookie.
 *
 * <p>This class doesn't support additional attributes on cookies, like <a
 * href="https://code.google.com/p/chromium/issues/detail?id=232693">Chromium's Priority=HIGH
 * extension</a>.
 */
public final class Cookie {
  private static final Pattern YEAR_PATTERN
      = Pattern.compile("(\\d{2,4})[^\\d]*");
  private static final Pattern MONTH_PATTERN
      = Pattern.compile("(?i)(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec).*");
  private static final Pattern DAY_OF_MONTH_PATTERN
      = Pattern.compile("(\\d{1,2})[^\\d]*");
  private static final Pattern TIME_PATTERN
      = Pattern.compile("(\\d{1,2}):(\\d{1,2}):(\\d{1,2})[^\\d]*");

  private final String name;
  private final String value;
  private final long expiresAt;
  private final String domain;
  private final String path;
  private final boolean secure;
  private final boolean httpOnly;

  private final boolean persistent; // True if 'expires' or 'max-age' is present.
  private final boolean hostOnly; // True unless 'domain' is present.

  private Cookie(String name, String value, long expiresAt, String domain, String path,
      boolean secure, boolean httpOnly, boolean hostOnly, boolean persistent) {
    this.name = name;
    this.value = value;
    this.expiresAt = expiresAt;
    this.domain = domain;
    this.path = path;
    this.secure = secure;
    this.httpOnly = httpOnly;
    this.hostOnly = hostOnly;
    this.persistent = persistent;
  }

  Cookie(Builder builder) {
    if (builder.name == null) throw new NullPointerException("builder.name == null");
    if (builder.value == null) throw new NullPointerException("builder.value == null");
    if (builder.domain == null) throw new NullPointerException("builder.domain == null");

    this.name = builder.name;
    this.value = builder.value;
    this.expiresAt = builder.expiresAt;
    this.domain = builder.domain;
    this.path = builder.path;
    this.secure = builder.secure;
    this.httpOnly = builder.httpOnly;
    this.persistent = builder.persistent;
    this.hostOnly = builder.hostOnly;
  }

  
Returns a non-empty string with this cookie's name. /** Returns a non-empty string with this cookie's name. */
  public String name() {
    return name;
  }

  
Returns a possibly-empty string with this cookie's value. /** Returns a possibly-empty string with this cookie's value. */
  public String value() {
    return value;
  }

  
Returns true if this cookie does not expire at the end of the current session. /** Returns true if this cookie does not expire at the end of the current session. */
  public boolean persistent() {
    return persistent;
  }

  
Returns the time that this cookie expires, in the same format as System.currentTimeMillis(). This is December 31, 9999 if the cookie is not persistent, in which case it will expire at the end of the current session. 
This may return a value less than the current time, in which case the cookie is already
expired. Webservers may return expired cookies as a mechanism to delete previously set cookies
that may or may not themselves be expired.
/**
   * Returns the time that this cookie expires, in the same format as {@link
   * System#currentTimeMillis()}. This is December 31, 9999 if the cookie is {@linkplain
   * #persistent() not persistent}, in which case it will expire at the end of the current session.
   *
   * <p>This may return a value less than the current time, in which case the cookie is already
   * expired. Webservers may return expired cookies as a mechanism to delete previously set cookies
   * that may or may not themselves be expired.
   */
  public long expiresAt() {
    return expiresAt;
  }

  
Returns true if this cookie's domain should be interpreted as a single host name, or false if it should be interpreted as a pattern. This flag will be false if its Set-Cookie header included a domain attribute. 
For example, suppose the cookie's domain is example.com. If this flag is true it matches only example.com. If this flag is false it matches 
example.com and all subdomains including api.example.com, www.example.com, and beta.api.example.com. /**
   * Returns true if this cookie's domain should be interpreted as a single host name, or false if
   * it should be interpreted as a pattern. This flag will be false if its {@code Set-Cookie} header
   * included a {@code domain} attribute.
   *
   * <p>For example, suppose the cookie's domain is {@code example.com}. If this flag is true it
   * matches <strong>only</strong> {@code example.com}. If this flag is false it matches {@code
   * example.com} and all subdomains including {@code api.example.com}, {@code www.example.com}, and
   * {@code beta.api.example.com}.
   */
  public boolean hostOnly() {
    return hostOnly;
  }

  
Returns the cookie's domain. If hostOnly() returns true this is the only domain that matches this cookie; otherwise it matches this domain and all subdomains. /**
   * Returns the cookie's domain. If {@link #hostOnly()} returns true this is the only domain that
   * matches this cookie; otherwise it matches this domain and all subdomains.
   */
  public String domain() {
    return domain;
  }

  
Returns this cookie's path. This cookie matches URLs prefixed with path segments that match this path's segments. For example, if this path is /foo this cookie matches requests to /foo and /foo/bar, but not / or /football. /**
   * Returns this cookie's path. This cookie matches URLs prefixed with path segments that match
   * this path's segments. For example, if this path is {@code /foo} this cookie matches requests to
   * {@code /foo} and {@code /foo/bar}, but not {@code /} or {@code /football}.
   */
  public String path() {
    return path;
  }

  
Returns true if this cookie should be limited to only HTTP APIs. In web browsers this prevents
the cookie from being accessible to scripts.
/**
   * Returns true if this cookie should be limited to only HTTP APIs. In web browsers this prevents
   * the cookie from being accessible to scripts.
   */
  public boolean httpOnly() {
    return httpOnly;
  }

  
Returns true if this cookie should be limited to only HTTPS requests. /** Returns true if this cookie should be limited to only HTTPS requests. */
  public boolean secure() {
    return secure;
  }

  
Returns true if this cookie should be included on a request to url. In addition to this check callers should also confirm that this cookie has not expired. /**
   * Returns true if this cookie should be included on a request to {@code url}. In addition to this
   * check callers should also confirm that this cookie has not expired.
   */
  public boolean matches(HttpUrl url) {
    boolean domainMatch = hostOnly
        ? url.host().equals(domain)
        : domainMatch(url.host(), domain);
    if (!domainMatch) return false;

    if (!pathMatch(url, path)) return false;

    if (secure && !url.isHttps()) return false;

    return true;
  }

  private static boolean domainMatch(String urlHost, String domain) {
    if (urlHost.equals(domain)) {
      return true; // As in 'example.com' matching 'example.com'.
    }

    if (urlHost.endsWith(domain)
        && urlHost.charAt(urlHost.length() - domain.length() - 1) == '.'
        && !verifyAsIpAddress(urlHost)) {
      return true; // As in 'example.com' matching 'www.example.com'.
    }

    return false;
  }

  private static boolean pathMatch(HttpUrl url, String path) {
    String urlPath = url.encodedPath();

    if (urlPath.equals(path)) {
      return true; // As in '/foo' matching '/foo'.
    }

    if (urlPath.startsWith(path)) {
      if (path.endsWith("/")) return true; // As in '/' matching '/foo'.
      if (urlPath.charAt(path.length()) == '/') return true; // As in '/foo' matching '/foo/bar'.
    }

    return false;
  }

  
Attempt to parse a Set-Cookie HTTP header value setCookie as a cookie. Returns null if setCookie is not a well-formed cookie. /**
   * Attempt to parse a {@code Set-Cookie} HTTP header value {@code setCookie} as a cookie. Returns
   * null if {@code setCookie} is not a well-formed cookie.
   */
  public static @Nullable Cookie parse(HttpUrl url, String setCookie) {
    return parse(System.currentTimeMillis(), url, setCookie);
  }

  static @Nullable Cookie parse(long currentTimeMillis, HttpUrl url, String setCookie) {
    int pos = 0;
    int limit = setCookie.length();
    int cookiePairEnd = delimiterOffset(setCookie, pos, limit, ';');

    int pairEqualsSign = delimiterOffset(setCookie, pos, cookiePairEnd, '=');
    if (pairEqualsSign == cookiePairEnd) return null;

    String cookieName = trimSubstring(setCookie, pos, pairEqualsSign);
    if (cookieName.isEmpty() || indexOfControlOrNonAscii(cookieName) != -1) return null;

    String cookieValue = trimSubstring(setCookie, pairEqualsSign + 1, cookiePairEnd);
    if (indexOfControlOrNonAscii(cookieValue) != -1) return null;

    long expiresAt = HttpDate.MAX_DATE;
    long deltaSeconds = -1L;
    String domain = null;
    String path = null;
    boolean secureOnly = false;
    boolean httpOnly = false;
    boolean hostOnly = true;
    boolean persistent = false;

    pos = cookiePairEnd + 1;
    while (pos < limit) {
      int attributePairEnd = delimiterOffset(setCookie, pos, limit, ';');

      int attributeEqualsSign = delimiterOffset(setCookie, pos, attributePairEnd, '=');
      String attributeName = trimSubstring(setCookie, pos, attributeEqualsSign);
      String attributeValue = attributeEqualsSign < attributePairEnd
          ? trimSubstring(setCookie, attributeEqualsSign + 1, attributePairEnd)
          : "";

      if (attributeName.equalsIgnoreCase("expires")) {
        try {
          expiresAt = parseExpires(attributeValue, 0, attributeValue.length());
          persistent = true;
        } catch (IllegalArgumentException e) {
          // Ignore this attribute, it isn't recognizable as a date.
        }
      } else if (attributeName.equalsIgnoreCase("max-age")) {
        try {
          deltaSeconds = parseMaxAge(attributeValue);
          persistent = true;
        } catch (NumberFormatException e) {
          // Ignore this attribute, it isn't recognizable as a max age.
        }
      } else if (attributeName.equalsIgnoreCase("domain")) {
        try {
          domain = parseDomain(attributeValue);
          hostOnly = false;
        } catch (IllegalArgumentException e) {
          // Ignore this attribute, it isn't recognizable as a domain.
        }
      } else if (attributeName.equalsIgnoreCase("path")) {
        path = attributeValue;
      } else if (attributeName.equalsIgnoreCase("secure")) {
        secureOnly = true;
      } else if (attributeName.equalsIgnoreCase("httponly")) {
        httpOnly = true;
      }

      pos = attributePairEnd + 1;
    }

    // If 'Max-Age' is present, it takes precedence over 'Expires', regardless of the order the two
    // attributes are declared in the cookie string.
    if (deltaSeconds == Long.MIN_VALUE) {
      expiresAt = Long.MIN_VALUE;
    } else if (deltaSeconds != -1L) {
      long deltaMilliseconds = deltaSeconds <= (Long.MAX_VALUE / 1000)
          ? deltaSeconds * 1000
          : Long.MAX_VALUE;
      expiresAt = currentTimeMillis + deltaMilliseconds;
      if (expiresAt < currentTimeMillis || expiresAt > HttpDate.MAX_DATE) {
        expiresAt = HttpDate.MAX_DATE; // Handle overflow & limit the date range.
      }
    }

    // If the domain is present, it must domain match. Otherwise we have a host-only cookie.
    String urlHost = url.host();
    if (domain == null) {
      domain = urlHost;
    } else if (!domainMatch(urlHost, domain)) {
      return null; // No domain match? This is either incompetence or malice!
    }

    // If the domain is a suffix of the url host, it must not be a public suffix.
    if (urlHost.length() != domain.length()
        && PublicSuffixDatabase.get().getEffectiveTldPlusOne(domain) == null) {
      return null;
    }

    // If the path is absent or didn't start with '/', use the default path. It's a string like
    // '/foo/bar' for a URL like 'http://example.com/foo/bar/baz'. It always starts with '/'.
    if (path == null || !path.startsWith("/")) {
      String encodedPath = url.encodedPath();
      int lastSlash = encodedPath.lastIndexOf('/');
      path = lastSlash != 0 ? encodedPath.substring(0, lastSlash) : "/";
    }

    return new Cookie(cookieName, cookieValue, expiresAt, domain, path, secureOnly, httpOnly,
        hostOnly, persistent);
  }

  
Parse a date as specified in RFC 6265, section 5.1.1. /** Parse a date as specified in RFC 6265, section 5.1.1. */
  private static long parseExpires(String s, int pos, int limit) {
    pos = dateCharacterOffset(s, pos, limit, false);

    int hour = -1;
    int minute = -1;
    int second = -1;
    int dayOfMonth = -1;
    int month = -1;
    int year = -1;
    Matcher matcher = TIME_PATTERN.matcher(s);

    while (pos < limit) {
      int end = dateCharacterOffset(s, pos + 1, limit, true);
      matcher.region(pos, end);

      if (hour == -1 && matcher.usePattern(TIME_PATTERN).matches()) {
        hour = Integer.parseInt(matcher.group(1));
        minute = Integer.parseInt(matcher.group(2));
        second = Integer.parseInt(matcher.group(3));
      } else if (dayOfMonth == -1 && matcher.usePattern(DAY_OF_MONTH_PATTERN).matches()) {
        dayOfMonth = Integer.parseInt(matcher.group(1));
      } else if (month == -1 && matcher.usePattern(MONTH_PATTERN).matches()) {
        String monthString = matcher.group(1).toLowerCase(Locale.US);
        month = MONTH_PATTERN.pattern().indexOf(monthString) / 4; // Sneaky! jan=1, dec=12.
      } else if (year == -1 && matcher.usePattern(YEAR_PATTERN).matches()) {
        year = Integer.parseInt(matcher.group(1));
      }

      pos = dateCharacterOffset(s, end + 1, limit, false);
    }

    // Convert two-digit years into four-digit years. 99 becomes 1999, 15 becomes 2015.
    if (year >= 70 && year <= 99) year += 1900;
    if (year >= 0 && year <= 69) year += 2000;

    // If any partial is omitted or out of range, return -1. The date is impossible. Note that leap
    // seconds are not supported by this syntax.
    if (year < 1601) throw new IllegalArgumentException();
    if (month == -1) throw new IllegalArgumentException();
    if (dayOfMonth < 1 || dayOfMonth > 31) throw new IllegalArgumentException();
    if (hour < 0 || hour > 23) throw new IllegalArgumentException();
    if (minute < 0 || minute > 59) throw new IllegalArgumentException();
    if (second < 0 || second > 59) throw new IllegalArgumentException();

    Calendar calendar = new GregorianCalendar(UTC);
    calendar.setLenient(false);
    calendar.set(Calendar.YEAR, year);
    calendar.set(Calendar.MONTH, month - 1);
    calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
    calendar.set(Calendar.HOUR_OF_DAY, hour);
    calendar.set(Calendar.MINUTE, minute);
    calendar.set(Calendar.SECOND, second);
    calendar.set(Calendar.MILLISECOND, 0);
    return calendar.getTimeInMillis();
  }

  
Returns the index of the next date character in input, or if invert the index of the next non-date character in input. /**
   * Returns the index of the next date character in {@code input}, or if {@code invert} the index
   * of the next non-date character in {@code input}.
   */
  private static int dateCharacterOffset(String input, int pos, int limit, boolean invert) {
    for (int i = pos; i < limit; i++) {
      int c = input.charAt(i);
      boolean dateCharacter = (c < ' ' && c != '\t') || (c >= '\u007f')
          || (c >= '0' && c <= '9')
          || (c >= 'a' && c <= 'z')
          || (c >= 'A' && c <= 'Z')
          || (c == ':');
      if (dateCharacter == !invert) return i;
    }
    return limit;
  }

  
Returns the positive value if attributeValue is positive, or Long.MIN_VALUE if it is either 0 or negative. If the value is positive but out of range, this returns Long.MAX_VALUE. 
Throws:
NumberFormatException – if s is not an integer of any precision./**
   * Returns the positive value if {@code attributeValue} is positive, or {@link Long#MIN_VALUE} if
   * it is either 0 or negative. If the value is positive but out of range, this returns {@link
   * Long#MAX_VALUE}.
   *
   * @throws NumberFormatException if {@code s} is not an integer of any precision.
   */
  private static long parseMaxAge(String s) {
    try {
      long parsed = Long.parseLong(s);
      return parsed <= 0L ? Long.MIN_VALUE : parsed;
    } catch (NumberFormatException e) {
      // Check if the value is an integer (positive or negative) that's too big for a long.
      if (s.matches("-?\\d+")) {
        return s.startsWith("-") ? Long.MIN_VALUE : Long.MAX_VALUE;
      }
      throw e;
    }
  }

  
Returns a domain string like example.com for an input domain like EXAMPLE.COM or .example.com. /**
   * Returns a domain string like {@code example.com} for an input domain like {@code EXAMPLE.COM}
   * or {@code .example.com}.
   */
  private static String parseDomain(String s) {
    if (s.endsWith(".")) {
      throw new IllegalArgumentException();
    }
    if (s.startsWith(".")) {
      s = s.substring(1);
    }
    String canonicalDomain = canonicalizeHost(s);
    if (canonicalDomain == null) {
      throw new IllegalArgumentException();
    }
    return canonicalDomain;
  }

  
Returns all of the cookies from a set of HTTP response headers. /** Returns all of the cookies from a set of HTTP response headers. */
  public static List<Cookie> parseAll(HttpUrl url, Headers headers) {
    List<String> cookieStrings = headers.values("Set-Cookie");
    List<Cookie> cookies = null;

    for (int i = 0, size = cookieStrings.size(); i < size; i++) {
      Cookie cookie = Cookie.parse(url, cookieStrings.get(i));
      if (cookie == null) continue;
      if (cookies == null) cookies = new ArrayList<>();
      cookies.add(cookie);
    }

    return cookies != null
        ? Collections.unmodifiableList(cookies)
        : Collections.<Cookie>emptyList();
  }

  
Builds a cookie. The name, value, and domain values must all be set before calling build. /**
   * Builds a cookie. The {@linkplain #name() name}, {@linkplain #value() value}, and {@linkplain
   * #domain() domain} values must all be set before calling {@link #build}.
   */
  public static final class Builder {
    @Nullable String name;
    @Nullable String value;
    long expiresAt = HttpDate.MAX_DATE;
    @Nullable String domain;
    String path = "/";
    boolean secure;
    boolean httpOnly;
    boolean persistent;
    boolean hostOnly;

    public Builder name(String name) {
      if (name == null) throw new NullPointerException("name == null");
      if (!name.trim().equals(name)) throw new IllegalArgumentException("name is not trimmed");
      this.name = name;
      return this;
    }

    public Builder value(String value) {
      if (value == null) throw new NullPointerException("value == null");
      if (!value.trim().equals(value)) throw new IllegalArgumentException("value is not trimmed");
      this.value = value;
      return this;
    }

    public Builder expiresAt(long expiresAt) {
      if (expiresAt <= 0) expiresAt = Long.MIN_VALUE;
      if (expiresAt > HttpDate.MAX_DATE) expiresAt = HttpDate.MAX_DATE;
      this.expiresAt = expiresAt;
      this.persistent = true;
      return this;
    }

    
Set the domain pattern for this cookie. The cookie will match domain and all of its subdomains. /**
     * Set the domain pattern for this cookie. The cookie will match {@code domain} and all of its
     * subdomains.
     */
    public Builder domain(String domain) {
      return domain(domain, false);
    }

    
Set the host-only domain for this cookie. The cookie will match domain but none of its subdomains. /**
     * Set the host-only domain for this cookie. The cookie will match {@code domain} but none of
     * its subdomains.
     */
    public Builder hostOnlyDomain(String domain) {
      return domain(domain, true);
    }

    private Builder domain(String domain, boolean hostOnly) {
      if (domain == null) throw new NullPointerException("domain == null");
      String canonicalDomain = Util.canonicalizeHost(domain);
      if (canonicalDomain == null) {
        throw new IllegalArgumentException("unexpected domain: " + domain);
      }
      this.domain = canonicalDomain;
      this.hostOnly = hostOnly;
      return this;
    }

    public Builder path(String path) {
      if (!path.startsWith("/")) throw new IllegalArgumentException("path must start with '/'");
      this.path = path;
      return this;
    }

    public Builder secure() {
      this.secure = true;
      return this;
    }

    public Builder httpOnly() {
      this.httpOnly = true;
      return this;
    }

    public Cookie build() {
      return new Cookie(this);
    }
  }

  @Override public String toString() {
    return toString(false);
  }

  
Params:
forObsoleteRfc2965 – true to include a leading . on the domain pattern. This is necessary for example.com to match www.example.com under RFC 2965. This extra dot is ignored by more recent specifications./**
   * @param forObsoleteRfc2965 true to include a leading {@code .} on the domain pattern. This is
   *     necessary for {@code example.com} to match {@code www.example.com} under RFC 2965. This
   *     extra dot is ignored by more recent specifications.
   */
  String toString(boolean forObsoleteRfc2965) {
    StringBuilder result = new StringBuilder();
    result.append(name);
    result.append('=');
    result.append(value);

    if (persistent) {
      if (expiresAt == Long.MIN_VALUE) {
        result.append("; max-age=0");
      } else {
        result.append("; expires=").append(HttpDate.format(new Date(expiresAt)));
      }
    }

    if (!hostOnly) {
      result.append("; domain=");
      if (forObsoleteRfc2965) {
        result.append(".");
      }
      result.append(domain);
    }

    result.append("; path=").append(path);

    if (secure) {
      result.append("; secure");
    }

    if (httpOnly) {
      result.append("; httponly");
    }

    return result.toString();
  }

  @Override public boolean equals(@Nullable Object other) {
    if (!(other instanceof Cookie)) return false;
    Cookie that = (Cookie) other;
    return that.name.equals(name)
        && that.value.equals(value)
        && that.domain.equals(domain)
        && that.path.equals(path)
        && that.expiresAt == expiresAt
        && that.secure == secure
        && that.httpOnly == httpOnly
        && that.persistent == persistent
        && that.hostOnly == hostOnly;
  }

  @Override public int hashCode() {
    int hash = 17;
    hash = 31 * hash + name.hashCode();
    hash = 31 * hash + value.hashCode();
    hash = 31 * hash + domain.hashCode();
    hash = 31 * hash + path.hashCode();
    hash = 31 * hash + (int) (expiresAt ^ (expiresAt >>> 32));
    hash = 31 * hash + (secure ? 0 : 1);
    hash = 31 * hash + (httpOnly ? 0 : 1);
    hash = 31 * hash + (persistent ? 0 : 1);
    hash = 31 * hash + (hostOnly ? 0 : 1);
    return hash;
  }
}