//------------------------------------------------------------------------------
/*
    Copyright (c) 2011-2013, OpenCoin, Inc.
*/
//==============================================================================

#ifndef __LEDGERTIMING__
#define __LEDGERTIMING__

// The number of seconds a ledger may remain idle before closing
#   define LEDGER_IDLE_INTERVAL     15

// The number of seconds a validation remains current after its ledger's close time
// This is a safety to protect against very old validations and the time it takes to adjust
// the close time accuracy window
#   define LEDGER_VAL_INTERVAL      300

// The number of seconds before a close time that we consider a validation acceptable
// This protects against extreme clock errors
#   define LEDGER_EARLY_INTERVAL    180

// The number of milliseconds we wait minimum to ensure participation
#   define LEDGER_MIN_CONSENSUS     2000

// The number of milliseconds we wait minimum to ensure others have computed the LCL
#   define LEDGER_MIN_CLOSE         2000

// Initial resolution of ledger close time
#   define LEDGER_TIME_ACCURACY     30

// How often to increase resolution
#   define LEDGER_RES_INCREASE      8

// How often to decrease resolution
#   define LEDGER_RES_DECREASE      1

// How often we check state or change positions (in milliseconds)
#   define LEDGER_GRANULARITY       1000

// The percentage of active trusted validators that must be able to
// keep up with the network or we consider the network overloaded
#   define LEDGER_NET_RATIO         70

// How long we consider a proposal fresh
#   define PROPOSE_FRESHNESS        20

// How often we force generating a new proposal to keep ours fresh
#   define PROPOSE_INTERVAL         12

// Avalanche tuning
#   define AV_INIT_CONSENSUS_PCT    50  // percentage of nodes on our UNL that must vote yes

#   define AV_MID_CONSENSUS_TIME    50  // percentage of previous close time before we advance
#   define AV_MID_CONSENSUS_PCT     65  // percentage of nodes that most vote yes after advancing

#   define AV_LATE_CONSENSUS_TIME   85  // percentage of previous close time before we advance
#   define AV_LATE_CONSENSUS_PCT    70  // percentage of nodes that most vote yes after advancing

#   define AV_STUCK_CONSENSUS_TIME  200
#   define AV_STUCK_CONSENSUS_PCT   95

#   define AV_CT_CONSENSUS_PCT      75

class ContinuousLedgerTiming
{
public:

    static int LedgerTimeResolution[];

    // Returns the number of seconds the ledger was or should be open
    // Call when a consensus is reached and when any transaction is relayed to be added
    static bool shouldClose (
        bool anyTransactions,
        int previousProposers,      int proposersClosed,    int proposerersValidated,
        int previousMSeconds,       int currentMSeconds,    int openMSeconds,
        int idleInterval);

    static bool haveConsensus (
        int previousProposers,      int currentProposers,
        int currentAgree,           int currentClosed,
        int previousAgreeTime,      int currentAgreeTime,
        bool forReal,               bool& failed);

    static int getNextLedgerTimeResolution (int previousResolution, bool previousAgree, int ledgerSeq);
};

#endif