/// <summary>
/// Parse the user input into an InputParserResult object
/// </summary>
/// <param name="input">The string the user has input</param>
/// <param name="maxWidth">The maximum width of the parcel of land</param>
/// <param name="maxHeight">The maximum height of the parcel of land.</param>
/// <returns>An InputParserResult object. This object will either store error information of will contain a 2D array representing the land mass.</returns>
internal static InputParserResult ParseInput(string input, int maxWidth, int maxHeight)
{
// Subtract one from the maximum width and height right away since we're using a 0-based array to track the area
maxWidth -= 1;
maxHeight -= 1;
// In an ideal world this would be evaluated using a regular expression
if (string.IsNullOrEmpty(input))
{
return(new InputParserResult(false, "The entered string was empty"));
}
if (!input.StartsWith("{"))
{
return(new InputParserResult(false, "The input string must start with '{'"));
}
input = input.Remove(0, 1);
if (!input.EndsWith("}"))
{
return(new InputParserResult(false, "The input string must end with '}'"));
}
input = input.Remove(input.Length - 1, 1);
// At this point the resulting string should not contain the curly braces, just the rectangles.
// If the string ends with anything other than a quote then we have invalid input.
if (!input.EndsWith("\""))
{
return(new InputParserResult(false, "The input string contains extra unexpected characters at the end."));
}
string[] rectangleStrings = input.Split(new string[] { ", " }, StringSplitOptions.None);
int[,] landMass = new int[maxWidth + 1, maxHeight + 1];
ArrayHelpers.Fill2DArrayWithRectangleValues(landMass, InputParserResult.FERTILE_INDICATOR, 0, 0, maxWidth, maxHeight);
//foreach (string rectString in rectangleStrings)
for (int i = 0; i < rectangleStrings.Length; i++)
{
string rectString = rectangleStrings[i];
// If any rectangle in the collection does not start with or end with a quote at this point we have invalid input
if (!rectString.StartsWith("\"") || !rectString.EndsWith("\""))
{
return(new InputParserResult(false, "There were invalid delimiters in the rectangle string."));
}
string onlyDigits = rectString.Substring(1, rectString.Length - 2);
// The string should be only digits separated by quotes at this point
string[] digits = onlyDigits.Split(' ');
if (digits.Length != 4)
{
return(new InputParserResult(false, $"There were {digits.Length} sides of the rectangle specified instead of 4."));
}
int[] sides = new int[4];
for (int j = 0; j < digits.Length; j++)
{
if (!int.TryParse(digits[j], out int side))
{
return(new InputParserResult(false, $"{digits[j]} could not be parsed as an integer."));
}
sides[j] = side;
}
int low_x = sides[0];
if (low_x < 0 || low_x > maxWidth)
{
return(new InputParserResult(false, $"{low_x} is not a valid x starting coordinate."));
}
int low_y = sides[1];
if (low_y < 0 || low_y > maxHeight)
{
return(new InputParserResult(false, $"{low_y} is not a valid y starting coordinate."));
}
int up_x = sides[2];
if (up_x > maxWidth || up_x < low_x)
{
return(new InputParserResult(false, $"The resulting width is outside the allowable bounds."));
}
int up_y = sides[3];
if (up_y > maxHeight || up_y < low_y)
{
return(new InputParserResult(false, $"The resulting height is outside the allowable bounds."));
}
// If we've made it this far we have a valid rectangle string with four valid coordinates.
// Take those coordinates and use them to fill in the barren land area based on those coordinates.
ArrayHelpers.Fill2DArrayWithRectangleValues(landMass, InputParserResult.BARREN_INDICATOR, low_x, low_y, up_x, up_y);
}
return(new InputParserResult(true, "This is fine", landMass));
}
