/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsProtocolProxyService_h__
#define nsProtocolProxyService_h__

#include "nsString.h"
#include "nsCOMPtr.h"
#include "nsTArray.h"
#include "nsIProtocolProxyService2.h"
#include "nsIProtocolProxyFilter.h"
#include "nsIProxyInfo.h"
#include "nsIObserver.h"
#include "nsTHashMap.h"
#include "nsHashKeys.h"
#include "nsITimer.h"
#include "prio.h"
#include "mozilla/Attributes.h"

class nsIPrefBranch;
class nsISystemProxySettings;

namespace mozilla {
namespace net {

using nsFailedProxyTable = nsTHashMap<nsCStringHashKey, uint32_t>;

class nsPACMan;
class nsProxyInfo;
struct nsProtocolInfo;

// CID for the nsProtocolProxyService class
// 091eedd8-8bae-4fe3-ad62-0c87351e640d
#define NS_PROTOCOL_PROXY_SERVICE_IMPL_CID           \
  {                                                  \
    0x091eedd8, 0x8bae, 0x4fe3, {                    \
      0xad, 0x62, 0x0c, 0x87, 0x35, 0x1e, 0x64, 0x0d \
    }                                                \
  }

class nsProtocolProxyService final : public nsIProtocolProxyService2,
                                     public nsIObserver,
                                     public nsITimerCallback,
                                     public nsINamed {
 public:
  NS_DECL_ISUPPORTS
  NS_DECL_NSIPROTOCOLPROXYSERVICE2
  NS_DECL_NSIPROTOCOLPROXYSERVICE
  NS_DECL_NSIOBSERVER
  NS_DECL_NSITIMERCALLBACK
  NS_DECL_NSINAMED

  NS_DECLARE_STATIC_IID_ACCESSOR(NS_PROTOCOL_PROXY_SERVICE_IMPL_CID)

  nsProtocolProxyService();

  nsresult Init();

 public:
  // An instance of this struct is allocated for each registered
  // nsIProtocolProxyFilter and each nsIProtocolProxyChannelFilter.
  class FilterLink {
   public:
    NS_INLINE_DECL_REFCOUNTING(FilterLink)

    uint32_t position;
    nsCOMPtr<nsIProtocolProxyFilter> filter;
    nsCOMPtr<nsIProtocolProxyChannelFilter> channelFilter;

    FilterLink(uint32_t p, nsIProtocolProxyFilter* f);
    FilterLink(uint32_t p, nsIProtocolProxyChannelFilter* cf);

   private:
    ~FilterLink();
  };

 protected:
  friend class nsAsyncResolveRequest;
  friend class TestProtocolProxyService_LoadHostFilters_Test;  // for gtest

  ~nsProtocolProxyService();

  /**
   * This method is called whenever a preference may have changed or
   * to initialize all preferences.
   *
   * @param prefs
   *        This must be a pointer to the root pref branch.
   * @param name
   *        This can be the name of a fully-qualified preference, or it can
   *        be null, in which case all preferences will be initialized.
   */
  void PrefsChanged(nsIPrefBranch* prefBranch, const char* pref);

  /**
   * This method is called to create a nsProxyInfo instance from the given
   * PAC-style proxy string.  It parses up to the end of the string, or to
   * the next ';' character.
   *
   * @param proxy
   *        The PAC-style proxy string to parse.  This must not be null.
   * @param aResolveFlags
   *        The flags passed to Resolve or AsyncResolve that are stored in
   *        proxyInfo.
   * @param result
   *        Upon return this points to a newly allocated nsProxyInfo or null
   *        if the proxy string was invalid.
   *
   * @return A pointer beyond the parsed proxy string (never null).
   */
  const char* ExtractProxyInfo(const char* start, uint32_t aResolveFlags,
                               nsProxyInfo** result);

  /**
   * Load the specified PAC file.
   *
   * @param pacURI
   *        The URI spec of the PAC file to load.
   */
  nsresult ConfigureFromPAC(const nsCString& spec, bool forceReload);

  /**
   * This method builds a list of nsProxyInfo objects from the given PAC-
   * style string.
   *
   * @param pacString
   *        The PAC-style proxy string to parse.  This may be empty.
   * @param aResolveFlags
   *        The flags passed to Resolve or AsyncResolve that are stored in
   *        proxyInfo.
   * @param result
   *        The resulting list of proxy info objects.
   */
  void ProcessPACString(const nsCString& pacString, uint32_t aResolveFlags,
                        nsIProxyInfo** result);

  /**
   * This method generates a string valued identifier for the given
   * nsProxyInfo object.
   *
   * @param pi
   *        The nsProxyInfo object from which to generate the key.
   * @param result
   *        Upon return, this parameter holds the generated key.
   */
  void GetProxyKey(nsProxyInfo* pi, nsCString& key);

  /**
   * @return Seconds since start of session.
   */
  uint32_t SecondsSinceSessionStart();

  /**
   * This method removes the specified proxy from the disabled list.
   *
   * @param pi
   *        The nsProxyInfo object identifying the proxy to enable.
   */
  void EnableProxy(nsProxyInfo* pi);

  /**
   * This method adds the specified proxy to the disabled list.
   *
   * @param pi
   *        The nsProxyInfo object identifying the proxy to disable.
   */
  void DisableProxy(nsProxyInfo* pi);

  /**
   * This method tests to see if the given proxy is disabled.
   *
   * @param pi
   *        The nsProxyInfo object identifying the proxy to test.
   *
   * @return True if the specified proxy is disabled.
   */
  bool IsProxyDisabled(nsProxyInfo* pi);

  /**
   * This method queries the protocol handler for the given scheme to check
   * for the protocol flags and default port.
   *
   * @param uri
   *        The URI to query.
   * @param info
   *        Holds information about the protocol upon return.  Pass address
   *        of structure when you call this method.  This parameter must not
   *        be null.
   */
  nsresult GetProtocolInfo(nsIURI* uri, nsProtocolInfo* info);

  /**
   * This method is an internal version nsIProtocolProxyService::newProxyInfo
   * that expects a string literal for the type.
   *
   * @param type
   *        The proxy type.
   * @param host
   *        The proxy host name (UTF-8 ok).
   * @param port
   *        The proxy port number.
   * @param username
   *        The username for the proxy (ASCII). May be "", but not null.
   * @param password
   *        The password for the proxy (ASCII). May be "", but not null.
   * @param flags
   *        The proxy flags (nsIProxyInfo::flags).
   * @param timeout
   *        The failover timeout for this proxy.
   * @param next
   *        The next proxy to try if this one fails.
   * @param aResolveFlags
   *        The flags passed to resolve (from nsIProtocolProxyService).
   * @param result
   *        The resulting nsIProxyInfo object.
   */
  nsresult NewProxyInfo_Internal(const char* type, const nsACString& host,
                                 int32_t port, const nsACString& username,
                                 const nsACString& password,
                                 const nsACString& aProxyAuthorizationHeader,
                                 const nsACString& aConnectionIsolationKey,
                                 uint32_t flags, uint32_t timeout,
                                 nsIProxyInfo* aFailoverProxy,
                                 uint32_t aResolveFlags, nsIProxyInfo** result);

  /**
   * This method is an internal version of Resolve that does not query PAC.
   * It performs all of the built-in processing, and reports back to the
   * caller with either the proxy info result or a flag to instruct the
   * caller to use PAC instead.
   *
   * @param channel
   *        The channel to test.
   * @param info
   *        Information about the URI's protocol.
   * @param flags
   *        The flags passed to either the resolve or the asyncResolve method.
   * @param usePAC
   *        If this flag is set upon return, then PAC should be queried to
   *        resolve the proxy info.
   * @param result
   *        The resulting proxy info or null.
   */
  nsresult Resolve_Internal(nsIChannel* channel, const nsProtocolInfo& info,
                            uint32_t flags, bool* usePAC,
                            nsIProxyInfo** result);

  /**
   * Shallow copy of the current list of registered filters so that
   * we can safely let them asynchronously process a single proxy
   * resolution request.
   */
  void CopyFilters(nsTArray<RefPtr<FilterLink>>& aCopy);

  /**
   * This method applies the provided filter to the given proxy info
   * list, and expects |callback| be called on (synchronously or
   * asynchronously) to provide the updated proxyinfo list.
   */
  bool ApplyFilter(FilterLink const* filterLink, nsIChannel* channel,
                   const nsProtocolInfo& info, nsCOMPtr<nsIProxyInfo> list,
                   nsIProxyProtocolFilterResult* callback);

  /**
   * This method prunes out disabled and disallowed proxies from a given
   * proxy info list.
   *
   * @param info
   *        Information about the URI's protocol.
   * @param proxyInfo
   *        The proxy info list to be modified.  This is an inout param.
   */
  void PruneProxyInfo(const nsProtocolInfo& info, nsIProxyInfo** list);

  /**
   * This method is a simple wrapper around PruneProxyInfo that takes the
   * proxy info list inout param as a nsCOMPtr.
   */
  void PruneProxyInfo(const nsProtocolInfo& info,
                      nsCOMPtr<nsIProxyInfo>& proxyInfo) {
    nsIProxyInfo* pi = nullptr;
    proxyInfo.swap(pi);
    PruneProxyInfo(info, &pi);
    proxyInfo.swap(pi);
  }

  /**
   * This method populates mHostFiltersArray from the given string.
   *
   * @param hostFilters
   *        A "no-proxy-for" exclusion list.
   */
  void LoadHostFilters(const nsACString& aFilters);

  /**
   * This method checks the given URI against mHostFiltersArray.
   *
   * @param uri
   *        The URI to test.
   * @param defaultPort
   *        The default port for the given URI.
   *
   * @return True if the URI can use the specified proxy.
   */
  bool CanUseProxy(nsIURI* uri, int32_t defaultPort);

  /**
   * Disable Prefetch in the DNS service if a proxy is in use.
   *
   * @param aProxy
   *        The proxy information
   */
  void MaybeDisableDNSPrefetch(nsIProxyInfo* aProxy);

 private:
  nsresult SetupPACThread(
      nsISerialEventTarget* mainThreadEventTarget = nullptr);
  nsresult ResetPACThread();
  nsresult ReloadNetworkPAC();

  nsresult AsyncConfigureFromPAC(bool aForceReload, bool aResetPACThread);
  nsresult OnAsyncGetPACURI(bool aForceReload, bool aResetPACThread,
                            nsresult aResult, const nsACString& aUri);

 public:
  // The Sun Forte compiler and others implement older versions of the
  // C++ standard's rules on access and nested classes.  These structs
  // need to be public in order to deal with those compilers.

  struct HostInfoIP {
    uint16_t family;
    uint16_t mask_len;
    PRIPv6Addr addr;  // possibly IPv4-mapped address
  };

  struct HostInfoName {
    char* host;
    uint32_t host_len;
  };

 protected:
  // simplified array of filters defined by this struct
  struct HostInfo {
    bool is_ipaddr{false};
    int32_t port{0};
    // other members intentionally uninitialized
    union {
      HostInfoIP ip;
      HostInfoName name;
    };

    HostInfo() = default;
    ~HostInfo() {
      if (!is_ipaddr && name.host) {
        free(name.host);
      }
    }
  };

 private:
  // Private methods to insert and remove FilterLinks from the FilterLink chain.
  nsresult InsertFilterLink(RefPtr<FilterLink>&& link);
  nsresult RemoveFilterLink(nsISupports* givenObject);

 protected:
  // Indicates if local hosts (plain hostnames, no dots) should use the proxy
  bool mFilterLocalHosts{false};

  // Holds an array of HostInfo objects
  nsTArray<UniquePtr<HostInfo>> mHostFiltersArray;

  // Filters, always sorted by the position.
  nsTArray<RefPtr<FilterLink>> mFilters;

  nsTArray<nsCOMPtr<nsIProxyConfigChangedCallback>>
      mProxyConfigChangedCallbacks;

  uint32_t mProxyConfig{PROXYCONFIG_DIRECT};

  nsCString mHTTPProxyHost;
  int32_t mHTTPProxyPort{-1};

  nsCString mHTTPSProxyHost;
  int32_t mHTTPSProxyPort{-1};

  // mSOCKSProxyTarget could be a host, a domain socket path,
  // or a named-pipe name.
  nsCString mSOCKSProxyTarget;
  int32_t mSOCKSProxyPort{-1};
  int32_t mSOCKSProxyVersion{4};
  bool mSOCKSProxyRemoteDNS{false};
  bool mProxyOverTLS{true};
  bool mWPADOverDHCPEnabled{false};

  RefPtr<nsPACMan> mPACMan;  // non-null if we are using PAC
  nsCOMPtr<nsISystemProxySettings> mSystemProxySettings;

  PRTime mSessionStart;
  nsFailedProxyTable mFailedProxies;
  // 30 minute default
  int32_t mFailedProxyTimeout{30 * 60};

 private:
  nsresult AsyncResolveInternal(nsIChannel* channel, uint32_t flags,
                                nsIProtocolProxyCallback* callback,
                                nsICancelable** result, bool isSyncOK,
                                nsISerialEventTarget* mainThreadEventTarget);
  bool mIsShutdown{false};
  nsCOMPtr<nsITimer> mReloadPACTimer;
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsProtocolProxyService,
                              NS_PROTOCOL_PROXY_SERVICE_IMPL_CID)

}  // namespace net
}  // namespace mozilla

#endif  // !nsProtocolProxyService_h__