dotfiles/.config/nvim/custom/jonathandarker/lua/jonathandarker/palette.lua

local interpolate = function(source, target, percent)
    local result = "#"
    for _, i in pairs({ 2, 4, 6 }) do
        local sval = tonumber(source:sub(i, i + 1), 16)
        local tval = tonumber(target:sub(i, i + 1), 16)
        local difference = tval - sval
        local delta = math.floor(difference * (percent / 100))
        local value = string.format("%x",
            math.max(math.min(sval + delta, 255), 0))
        if value:len() == 1 then value = "0" .. value end
        result = result .. value
    end
    return result
end

return {
    load = function()
        local loaded = {}
        local output = vim.fn.system([[
            echo BLACK=$JONATHANDARKER_COLOR_00;
            echo RED=$JONATHANDARKER_COLOR_01;
            echo GREEN=$JONATHANDARKER_COLOR_02;
            echo ORANGE=$JONATHANDARKER_COLOR_03;
            echo CYAN=$JONATHANDARKER_COLOR_04;
            echo MAGENTA=$JONATHANDARKER_COLOR_05;
            echo LILAC=$JONATHANDARKER_COLOR_06;
            echo SILVER=$JONATHANDARKER_COLOR_07;
            echo GREY=$JONATHANDARKER_COLOR_08;
            echo BURGUNDY=$JONATHANDARKER_COLOR_09;
            echo CHARTREUSE=$JONATHANDARKER_COLOR_10;
            echo YELLOW=$JONATHANDARKER_COLOR_11;
            echo BLUE=$JONATHANDARKER_COLOR_12;
            echo PLUM=$JONATHANDARKER_COLOR_13;
            echo PERIWINKLE=$JONATHANDARKER_COLOR_14;
            echo WHITE=$JONATHANDARKER_COLOR_15;
            echo BACKGROUND=$JONATHANDARKER_COLOR_BG;
            echo BACKGROUNDALT=$JONATHANDARKER_COLOR_BA;
            echo FOREGROUND=$JONATHANDARKER_COLOR_FG;
            echo FOREGROUNDALT=$JONATHANDARKER_COLOR_FA;
        ]])
        for definition in string.gmatch(output, "[^%s]+=[^%s]+") do
            local name = definition:match("[^%s]+="):sub(1, -2)
            local value = definition:match("=[^%s]+"):sub(2)
            loaded[name] = value
        end
        loaded.SPECIAL_SUBTLE = interpolate(loaded.BACKGROUND,
            loaded.FOREGROUND, 12)
        loaded.SPECIAL_CURSOR = interpolate(loaded.FOREGROUND,
            loaded.BACKGROUND, 10)
        loaded.hset = function(group, config)
            vim.api.nvim_set_hl(0, group, config)
        end
        loaded.link = function(group, target)
            vim.api.nvim_set_hl(0, group, { link = target })
        end
        return loaded
    end
}