openzeppelin-contracts/certora/specs/GovernorCountingSimple.spec

import "GovernorBase.spec"

methods {
    ghost_sum_vote_power_by_id(uint256) returns uint256 envfree
    // castVote(uint256, uint8) returns uint256
    // castVoteBySig(uint256,uint8,uint8,bytes32,bytes32) returns uint256
	
	snapshot(uint256) returns uint64 envfree
    quorum(uint256) returns uint256 envfree
    proposalVotes(uint256) returns (uint256, uint256, uint256) envfree

    getVotes(address, uint256) returns uint256 envfree
    //getVotes(address, uint256) => CONSTANT
}

//////////////////////////////////////////////////////////////////////////////
///////////////////////////////// GHOSTS /////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////

ghost hasVoteGhost(uint256) returns uint256 {
    init_state axiom forall uint256 pId. hasVoteGhost(pId) == 0;
}

hook Sstore _proposalVotes[KEY uint256 pId].hasVoted[KEY address user] bool current_voting_State (bool old_voting_state) STORAGE{
    havoc hasVoteGhost assuming forall uint256 p. ((p == pId && current_voting_State && !old_voting_state) ? (hasVoteGhost@new(p) == hasVoteGhost@old(p) + 1)  :
                                                  (hasVoteGhost@new(p) == hasVoteGhost@old(p)));
}

ghost sum_all_votes_power() returns uint256 {
	init_state axiom sum_all_votes_power() == 0;
}

hook Sstore ghost_sum_vote_power_by_id [KEY uint256 pId] uint256 current_power(uint256 old_power) STORAGE {
	havoc sum_all_votes_power assuming sum_all_votes_power@new() == sum_all_votes_power@old() - old_power + current_power;
}

ghost tracked_weight(uint256) returns uint256 {
	init_state axiom forall uint256 p. tracked_weight(p) == 0;
}
ghost sum_tracked_weight() returns uint256 {
	init_state axiom sum_tracked_weight() == 0;
}

ghost votesAgainst() returns uint256 {
    init_state axiom votesAgainst() == 0;
}

ghost votesFor() returns uint256 {
    init_state axiom votesFor() == 0;
}

ghost votesAbstain() returns uint256 {
    init_state axiom votesAbstain() == 0;
}

hook Sstore _proposalVotes [KEY uint256 pId].againstVotes uint256 votes(uint256 old_votes) STORAGE {
	havoc tracked_weight assuming forall uint256 p.(p == pId => tracked_weight@new(p) == tracked_weight@old(p) - old_votes + votes) &&
	                                            (p != pId => tracked_weight@new(p) == tracked_weight@old(p));
	havoc sum_tracked_weight assuming sum_tracked_weight@new() == sum_tracked_weight@old() - old_votes + votes;
    havoc votesAgainst assuming votesAgainst@new() == votesAgainst@old() - old_votes + votes;
}

hook Sstore _proposalVotes [KEY uint256 pId].forVotes uint256 votes(uint256 old_votes) STORAGE {
	havoc tracked_weight assuming forall uint256 p.(p == pId => tracked_weight@new(p) == tracked_weight@old(p) - old_votes + votes) &&
	                                            (p != pId => tracked_weight@new(p) == tracked_weight@old(p));
	havoc sum_tracked_weight assuming sum_tracked_weight@new() == sum_tracked_weight@old() - old_votes + votes;
    havoc votesFor assuming votesFor@new() == votesFor@old() - old_votes + votes;
}

hook Sstore _proposalVotes [KEY uint256 pId].abstainVotes uint256 votes(uint256 old_votes) STORAGE {
	havoc tracked_weight assuming forall uint256 p.(p == pId => tracked_weight@new(p) == tracked_weight@old(p) - old_votes + votes) &&
	                                            (p != pId => tracked_weight@new(p) == tracked_weight@old(p));
	havoc sum_tracked_weight assuming sum_tracked_weight@new() == sum_tracked_weight@old() - old_votes + votes;
    havoc votesAbstain assuming votesAbstain@new() == votesAbstain@old() - old_votes + votes;
}

/*
ghost totalVotesPossible(uint256) returns uint256 {
	init_state axiom forall uint256 bn. totalVotesPossible(bn) == 0;
}

ghost possibleMaxOfVoters(uint256) returns uint256{
    init_state axiom forall uint256 pId. possibleMaxOfVoters(pId) == 0;
}

hook Sstore _getVotes[KEY address uId][KEY uint256 blockNumber] uint256 voteWeight(uint256 old_voteWeight) STORAGE {
	havoc totalVotesPossible assuming forall uint256 bn.
	                                (bn == blockNumber => totalVotesPossible@new(bn) == totalVotesPossible@old(bn) - old_voteWeight + voteWeight)
	                                && (bn != blockNumber => totalVotesPossible@new(bn) == totalVotesPossible@old(bn));
    //somehow havoc possibleMaxOfVoters based on scheme. Probably can be implemented if previous havoc is possible
}
*/
/*
_proposalVotes[pId].hasVoted[account] -> bool
								^
								|
					go through all accounts,
					if true =>
possibleMaxOfVoters(pId) += getVotes(pId, acount);
*/

//////////////////////////////////////////////////////////////////////////////
////////////////////////////// INVARIANTS ////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////


/*
 * sum of all votes casted is equal to the sum of voting power of those who voted, per each proposal
 */
invariant SumOfVotesCastEqualSumOfPowerOfVotedPerProposal(uint256 pId) 
	tracked_weight(pId) == ghost_sum_vote_power_by_id(pId)
		
/*
 * sum of all votes casted is equal to the sum of voting power of those who voted
 */
invariant SumOfVotesCastEqualSumOfPowerOfVoted() 
	sum_tracked_weight() == sum_all_votes_power()
		
/*
* totalVoted >= vote(id)
*/
invariant OneIsNotMoreThanAll(uint256 pId) 
	sum_all_votes_power() >= tracked_weight(pId)


//NEED GHOST FIX	
/*
* totalVotesPossible >= votePower(id)
*/
//invariant possibleTotalVotes(uint256 pId) 
//	tracked_weight(pId) <= totalVotesPossible(snapshot(pId))

/*
* totalVotesPossible >= votePower(id)
*/
// invariant possibleTotalVotes(uint pId)
//invariant trackedVsTotal(uint256 pId) 
//	tracked_weight(pId) <= possibleMaxOfVoters(pId)


/*
rule someOtherRuleToRemoveLater(uint256 num){
    env e; calldataarg args; method f;
    uint256 x = hasVoteGhost(num);
    f(e, args);
    assert(false);
}
*/


rule oneUserVotesInCast(uint256 pId, method f) filtered { f -> ((f.selector == castVote(uint256, uint8).selector) || 
                                                                f.selector == castVoteBySig(uint256, uint8, uint8, bytes32, bytes32).selector) }{
    env e; calldataarg args;
    uint256 ghost_Before = hasVoteGhost(pId);
    f(e, args);
    uint256 ghost_After = hasVoteGhost(pId);
    assert(ghost_After == ghost_Before + 1, "Raised by more than 1");
}


rule noVoteForSomeoneElse(uint256 pId, uint8 support){
    env e;
    uint256 voter = e.msg.sender;
    castVote(e, pId, support);

}


//ok
rule votingWeightMonotonicity(method f){
    uint256 votingWeightBefore = sum_tracked_weight();

    env e; 
    calldataarg args;
    f(e, args);

    uint256 votingWeightAfter = sum_tracked_weight();

    assert votingWeightBefore <= votingWeightAfter, "Voting weight was decreased somehow";
}

// timeouts and strange violations
// https://vaas-stg.certora.com/output/3106/23f63c84c58b06285f4f/?anonymousKey=e5a7dc2e0ce7829cf5af8eb29a4ba231d915704c
rule quorumMonotonicity(method f, uint256 blockNumber){
    uint256 quorumBefore = quorum(blockNumber);

    env e; 
    calldataarg args;
    f(e, args);

    uint256 quorumAfter = quorum(blockNumber);

    assert quorumBefore <= quorumAfter, "Quorum was decreased somehow";
}

// getVotes() returns different results.
// are we assuming that a person with 0 votes can vote? are we assuming that a person may have 0 votes
// it seems like a weight can be 0. At least there is no check for it
// If it can be 0 then < should be changed to <= but it gives less coverage
rule hasVotedCorrelation(uint256 pId, method f, address acc, env e){
    uint256 againstBefore = votesAgainst();
    uint256 forBefore = votesFor();
    uint256 abstainBefore = votesAbstain();
    //againstBefore, forBefore, abstainBefore = proposalVotes(pId);

    bool hasVotedBefore = hasVoted(e, pId, acc);
    uint256 votesBefore = getVotes(acc, pId);
    require votesBefore > 0;

    calldataarg args;
    f(e, args);

    uint256 againstAfter = votesAgainst();
    uint256 forAfter = votesFor();
    uint256 abstainAfter = votesAbstain();
    //againstAfter, forAfter, abstainAfter = proposalVotes(pId);

    uint256 votesAfter = getVotes(acc, pId);
    bool hasVotedAfter = hasVoted(e, pId, acc);

    assert hasVotedBefore != hasVotedAfter => againstBefore < againstAfter || forBefore < forAfter || abstainBefore < abstainAfter, "no correlation";
}