namespace AdventOfCodeLibrary._2022.Day_08
{
    internal class TreeChecker
    {
        internal int VisibleTrees(string[] treeArray)
        {
            int visible = 0;

            // start from the top
            char[] currentHighest = treeArray[0].ToCharArray();

            // from top to bottom
            for (int treeIndex = 1; treeIndex < treeArray.Length - 2; treeIndex++)
            {
                visible += CheckVisibleTrees(ref currentHighest, treeArray[treeIndex].ToCharArray());
            }

            currentHighest = treeArray[^1].ToCharArray();
            // from bottom to top
            for (int treeIndex = treeArray.Length - 1; treeIndex > 1 ; treeIndex--)
            {
                visible += CheckVisibleTrees(ref currentHighest, treeArray[treeIndex].ToCharArray());
            }

            string[] rotatedTreeArray = new string[treeArray[0].Length];
            
            // parse the array so we get array 90 rotated
            for (int horizontalIndex = 0; horizontalIndex < treeArray[0].Length; horizontalIndex++)
            {
                for (int verticalIndex = 0; verticalIndex < treeArray.Length; verticalIndex++)
                {
                    rotatedTreeArray[horizontalIndex] += treeArray[verticalIndex][horizontalIndex];
                }
            }

            currentHighest = rotatedTreeArray[0].ToCharArray();
            // from top to bottom with the rotated array
            for (int treeIndex = 1; treeIndex < rotatedTreeArray.Length - 1; treeIndex++)
            {
                visible += CheckVisibleTrees(ref currentHighest, rotatedTreeArray[treeIndex].ToCharArray());
            }

            currentHighest = rotatedTreeArray[^1].ToCharArray();
            // from bottom to top with the rotated array
            for (int treeIndex = rotatedTreeArray.Length - 1; treeIndex > 1; treeIndex--)
            {
                visible += CheckVisibleTrees(ref currentHighest, rotatedTreeArray[treeIndex].ToCharArray());
            }

            // add the outside trees
            int edgeTrees = (2 * treeArray.Length) + (2 * (treeArray[0].Length - 2));

            // return the result
            return visible + edgeTrees;
        }

        private int CheckVisibleTrees(ref char[] currentHighest, char[] treeLineToCheck)
        {
            int visible = 0;
            for (int treeIndex = 1; treeIndex < treeLineToCheck.Length - 1; treeIndex++)
            {
                int diff = treeLineToCheck[treeIndex] - currentHighest[treeIndex];
                if (diff > 0)
                {
                    visible++;
                    currentHighest[treeIndex] = treeLineToCheck[treeIndex];
                }
            }

            return visible;
        }
    }
}