// SPDX-License-Identifier: MIT

pragma solidity 0.8.19;

import "../interfaces/ITroveManager.sol";
import "../interfaces/ISortedTroves.sol";
import "../interfaces/IFactory.sol";

/*  Helper contract for grabbing Trove data for the front end. Not part of the PropelCore Propel system. */
contract MultiTroveGetter {
	struct CombinedTroveData {
		address owner;
		uint256 debt;
		uint256 interest;
		uint256 coll;
		uint256 stake;
		uint256 pendingCollateral;
		uint256 pendingDebt;
	}

	function getMultipleSortedTroves(ITroveManager troveManager, int _startIdx, uint256 _count) external view returns (CombinedTroveData[] memory _troves) {
		ISortedTroves sortedTroves = ISortedTroves(troveManager.sortedTroves());
		uint256 startIdx;
		bool descend;

		if (_startIdx >= 0) {
			startIdx = uint256(_startIdx);
			descend = true;
		} else {
			startIdx = uint256(-(_startIdx + 1));
			descend = false;
		}

		uint256 sortedTrovesSize = sortedTroves.getSize();
		if (startIdx >= sortedTrovesSize) {
			_troves = new CombinedTroveData[](0);
		} else {
			uint256 maxCount = sortedTrovesSize - startIdx;
			if (_count > maxCount) {
				_count = maxCount;
			}

			if (descend) {
				_troves = _getMultipleSortedTrovesFromHead(troveManager, sortedTroves, startIdx, _count);
			} else {
				_troves = _getMultipleSortedTrovesFromTail(troveManager, sortedTroves, startIdx, _count);
			}
		}
	}

	function _getMultipleSortedTrovesFromHead(ITroveManager troveManager, ISortedTroves sortedTroves, uint256 _startIdx, uint256 _count) internal view returns (CombinedTroveData[] memory _troves) {
		address currentTroveowner = sortedTroves.getFirst();

		for (uint256 idx = 0; idx < _startIdx; ++idx) {
			currentTroveowner = sortedTroves.getNext(currentTroveowner);
		}

		_troves = new CombinedTroveData[](_count);

		for (uint256 idx = 0; idx < _count; ++idx) {
			_troves[idx].owner = currentTroveowner;

			ITroveManager.Trove memory trove = troveManager.getTrove(currentTroveowner);
			_troves[idx].debt = trove.debt;
			_troves[idx].coll = trove.coll;
			_troves[idx].stake = trove.stake;
			(_troves[idx].pendingCollateral, _troves[idx].pendingDebt) = troveManager.getPendingCollAndDebtRewards(currentTroveowner);
			_troves[idx].interest = troveManager.getTroveInterest(currentTroveowner, _troves[idx].debt + _troves[idx].pendingDebt);
			currentTroveowner = sortedTroves.getNext(currentTroveowner);
		}
	}

	function _getMultipleSortedTrovesFromTail(ITroveManager troveManager, ISortedTroves sortedTroves, uint256 _startIdx, uint256 _count) internal view returns (CombinedTroveData[] memory _troves) {
		address currentTroveowner = sortedTroves.getLast();

		for (uint256 idx = 0; idx < _startIdx; ++idx) {
			currentTroveowner = sortedTroves.getPrev(currentTroveowner);
		}

		_troves = new CombinedTroveData[](_count);

		for (uint256 idx = 0; idx < _count; ++idx) {
			_troves[idx].owner = currentTroveowner;
			ITroveManager.Trove memory trove = troveManager.getTrove(currentTroveowner);
			_troves[idx].debt = trove.debt;
			_troves[idx].coll = trove.coll;
			_troves[idx].stake = trove.stake;

			(_troves[idx].pendingCollateral, _troves[idx].pendingDebt) = troveManager.getPendingCollAndDebtRewards(currentTroveowner);

			_troves[idx].interest = troveManager.getTroveInterest(currentTroveowner, _troves[idx].debt + _troves[idx].pendingDebt);

			currentTroveowner = sortedTroves.getPrev(currentTroveowner);
		}
	}
}