library BlockNumbDisdIntsLib {
    using SafeMathIntLib for int256;

    //
    // Structures
    // -----------------------------------------------------------------------------------------------------------------
    struct Discount {
        int256 tier;
        int256 value;
    }

    struct Entry {
        uint256 blockNumber;
        int256 nominal;
        Discount[] discounts;
    }

    struct BlockNumbDisdInts {
        Entry[] entries;
    }

    //
    // Functions
    // -----------------------------------------------------------------------------------------------------------------
    function currentNominalValue(BlockNumbDisdInts storage self)
    internal
    view
    returns (int256)
    {
        return nominalValueAt(self, block.number);
    }

    function currentDiscountedValue(BlockNumbDisdInts storage self, int256 tier)
    internal
    view
    returns (int256)
    {
        return discountedValueAt(self, block.number, tier);
    }

    function currentEntry(BlockNumbDisdInts storage self)
    internal
    view
    returns (Entry memory)
    {
        return entryAt(self, block.number);
    }

    function nominalValueAt(BlockNumbDisdInts storage self, uint256 _blockNumber)
    internal
    view
    returns (int256)
    {
        return entryAt(self, _blockNumber).nominal;
    }

    function discountedValueAt(BlockNumbDisdInts storage self, uint256 _blockNumber, int256 tier)
    internal
    view
    returns (int256)
    {
        Entry memory entry = entryAt(self, _blockNumber);
        if (0 < entry.discounts.length) {
            uint256 index = indexByTier(entry.discounts, tier);
            if (0 < index)
                return entry.nominal.mul(
                    ConstantsLib.PARTS_PER().sub(entry.discounts[index - 1].value)
                ).div(
                    ConstantsLib.PARTS_PER()
                );
            else
                return entry.nominal;
        } else
            return entry.nominal;
    }

    function entryAt(BlockNumbDisdInts storage self, uint256 _blockNumber)
    internal
    view
    returns (Entry memory)
    {
        return self.entries[indexByBlockNumber(self, _blockNumber)];
    }

    function addNominalEntry(BlockNumbDisdInts storage self, uint256 blockNumber, int256 nominal)
    internal
    {
        require(
            0 == self.entries.length ||
        blockNumber > self.entries[self.entries.length - 1].blockNumber,
            "Later entry found [BlockNumbDisdIntsLib.sol:101]"
        );

        self.entries.length++;
        Entry storage entry = self.entries[self.entries.length - 1];

        entry.blockNumber = blockNumber;
        entry.nominal = nominal;
    }

    function addDiscountedEntry(BlockNumbDisdInts storage self, uint256 blockNumber, int256 nominal,
        int256[] memory discountTiers, int256[] memory discountValues)
    internal
    {
        require(discountTiers.length == discountValues.length, "Parameter array lengths mismatch [BlockNumbDisdIntsLib.sol:118]");

        addNominalEntry(self, blockNumber, nominal);

        Entry storage entry = self.entries[self.entries.length - 1];
        for (uint256 i = 0; i < discountTiers.length; i++)
            entry.discounts.push(Discount(discountTiers[i], discountValues[i]));
    }

    function count(BlockNumbDisdInts storage self)
    internal
    view
    returns (uint256)
    {
        return self.entries.length;
    }

    function entries(BlockNumbDisdInts storage self)
    internal
    view
    returns (Entry[] memory)
    {
        return self.entries;
    }

    function indexByBlockNumber(BlockNumbDisdInts storage self, uint256 blockNumber)
    internal
    view
    returns (uint256)
    {
        require(0 < self.entries.length, "No entries found [BlockNumbDisdIntsLib.sol:148]");
        for (uint256 i = self.entries.length - 1; i >= 0; i--)
            if (blockNumber >= self.entries[i].blockNumber)
                return i;
        revert();
    }

    /// @dev The index returned here is 1-based
    function indexByTier(Discount[] memory discounts, int256 tier)
    internal
    pure
    returns (uint256)
    {
        require(0 < discounts.length, "No discounts found [BlockNumbDisdIntsLib.sol:161]");
        for (uint256 i = discounts.length; i > 0; i--)
            if (tier >= discounts[i - 1].tier)
                return i;
        return 0;
    }
}
/*
 * Hubii Nahmii
 *
 * Compliant with the Hubii Nahmii specification v0.12.
 *
 * Copyright (C) 2017-2018 Hubii AS
 */
function indexByTier(Discount[] memory discounts, int256 tier)
    internal
    pure
    returns (uint256)
    {
        require(0 < discounts.length, "No discounts found [BlockNumbDisdIntsLib.sol:161]");
        for (uint256 i = discounts.length; i > 0; i--)
            if (tier >= discounts[i - 1].tier)
                return i;
        return 0;
    }
/// @dev The index returned here is 1-based