include("utils.jl")

function parse_input(filename)
    map(non_empty_lines(filename)) do line
        collect(map(x->parse(Int, x.match), eachmatch(r"[0-9]+", line)))
    end
end

function solution5_1()
    max_x = 0
    max_y = 0
    lines = filter(parse_input("5.data")) do line
        max_x = max(max_x, line[1], line[2])
        max_y = max(max_y, line[2], line[4])
        line[1] == line[3] || line[2] == line[4]
    end
    board = fill(0, max_x + 1 , max_y + 1)
    for line in lines
        if line[1] == line[3]
            if line[2] <= line[4]
                for i in line[2]:line[4]
                    board[line[1] + 1, i + 1] += 1
                end
            else
                for i in line[4]:line[2]
                    board[line[1] + 1, i + 1] += 1
                end
            end
        else
            if line[1] <= line[3]
                for i in line[1]:line[3]
                    board[i + 1, line[2] + 1] += 1
                end
            else
                for i in line[3]:line[1]
                    board[i + 1, line[2] + 1] += 1
                end
            end
        end
    end
    length(filter(>(1), board))
end

function solution5_2()
    max_x = 0
    max_y = 0
    lines = filter(parse_input("5.data")) do line
        max_x = max(max_x, line[1], line[2])
        max_y = max(max_y, line[2], line[4])
        true
    end
    board = fill(0, max_x + 1 , max_y + 1)
    for line in lines
        x = line[1]
        y = line[2]
        board[x + 1, y + 1] += 1
        while x != line[3] || y != line[4]
            x += sign(line[3]-line[1])
            y += sign(line[4]-line[2])
            board[x + 1, y + 1] += 1
        end
    end
    length(filter(>(1), board))
    #    transpose(board)
end

solution5_2()