using LinearAlgebra

struct Grid{T}
    cols::Int
    rows::Int
    dim::Int
    domainCol::T
    domainRow::T
    deltaCol::T
    deltaRow::T
    concentrations::Ref{Matrix{T}}
    alphaX::Ref{Matrix{T}}
    alphaY::Ref{Matrix{T}}

    # Constructor for 1D-Grid
    function Grid{T}(length::Int) where {T}
        if length <= 3
            throw(ArgumentError("Given grid length too small. Must be greater than 3."))
        end

        new{T}(length, 1, 1, T(length), 0, T(1), 0, Ref(fill(T(0), 1, length)), Ref(fill(T(0), 1, length)), Ref(fill(T(0), 1, length)))
    end

    # Constructor for 2D-Grid
    function Grid{T}(row::Int, col::Int) where {T}
        if row <= 3 || col <= 3
            throw(ArgumentError("Given grid dimensions too small. Must each be greater than 3."))
        end

        new{T}(col, row, 2, T(col), T(row), T(1), T(1), Ref(fill(T(0), row, col)), Ref(fill(T(0), row, col)), Ref(fill(T(0), row, col)))
    end
end

function setConcentrations!(grid::Grid{T}, new_concentrations::Matrix{T}) where {T}
    grid.concentrations[] = new_concentrations
end

function setAlpha!(grid::Grid{T}, alpha::Matrix{T}) where {T}
    if grid.dim != 1
        error("Grid is not one dimensional, you should probably use the 2D setter function!")
    end
    if size(alpha, 1) != 1 || size(alpha, 2) != grid.cols
        error("Given matrix of alpha coefficients mismatch with Grid dimensions!")
    end

    grid.alphaX[] = alpha
end

function setAlpha!(grid::Grid{T}, alphaX::Matrix{T}, alphaY::Matrix{T}) where {T}
    if grid.dim != 2
        error("Grid is not two dimensional, you should probably use the 1D setter function!")
    end
    if size(alphaX) != (grid.rows, grid.cols) || size(alphaY) != (grid.rows, grid.cols)
        error("Given matrices of alpha coefficients mismatch with Grid dimensions!")
    end

    grid.alphaX[] = alphaX
    grid.alphaY[] = alphaY
end