pragma solidity ^0.4.21;

contract SeasonFactory {
    address public owner;
    address[] public seasons;

    event SeasonCreated(uint64 indexed beginTicks, uint64 indexed endTicks, address season);

    function SeasonFactory() public {
        owner = msg.sender;
    }

    function newSeason(uint64 beginTicks, uint64 endTicks) public restricted {
        require(beginTicks < endTicks);
        require(seasons.length == 0 || Season(seasons[seasons.length - 1]).period().endTicks() < beginTicks);

        Season season = new Season(owner, beginTicks, endTicks);
        seasons.push(season);
        emit SeasonCreated(beginTicks, endTicks, season);
    }

    function getSeasonsCount() public view returns(uint) {
        return seasons.length;
    }

    function getSeasonForDate(uint64 ticks) public view returns(address) {
        for (uint i = seasons.length - 1; i >= 0; i--) {
            Season season = Season(seasons[i]);
            if (ticks >= season.period.beginTicks() && ticks <= season.period.endTicks())
                return season;
        }
        return 0;
    }

    modifier restricted {
        require(owner == msg.sender);
        _;
    }
}

contract Season {
    address public owner;
    SharedTypes.DateRange public period;

    function Season(address owner_, uint64 beginTicks, uint64 endTicks) public {
        owner = owner_;
        period = SharedTypes.DateRange(beginTicks, endTicks);
    }
}

library SharedTypes {
    struct DateRange {
        uint64 beginTicks;
        uint64 endTicks;
    }
}