---------------------------------------------------------------------------------
--
-- Prat - A framework for World of Warcraft chat mods
--
-- Copyright (C) 2006-2018  Prat Development Team
--
-- This program is free software; you can redistribute it and/or
-- modify it under the terms of the GNU General Public License
-- as published by the Free Software Foundation; either version 2
-- of the License, or (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program; if not, write to:
--
-- Free Software Foundation, Inc.,
-- 51 Franklin Street, Fifth Floor,
-- Boston, MA  02110-1301, USA.
--
--
-------------------------------------------------------------------------------


--[[ BEGIN STANDARD HEADER ]] --

-- Imports
local _G = _G
local tostring = tostring
local select = select
local type = type
local table = table
local math = math
local string = string

-- Isolate the environment
setfenv(1, select(2, ...))

--[[ END STANDARD HEADER ]] --


CLR = {}

CLR.DEFAULT = "ffffff" -- default to white
CLR.LINK = {
  "|cff", CLR.DEFAULT, "", "|r"
}

CLR.COLOR_NONE = nil

local function get_default_color()
  return 1.0, 1.0, 1.0, 1.0
end

local function get_color(c)
  if type(c.r) == "number" and type(c.g) == "number" and type(c.b) == "number" and type(c.a) == "number" then
    return c.r, c.g, c.b, c.a
  end
  if type(c.r) == "number" and type(c.g) == "number" and type(c.b) == "number" then
    return c.r, c.g, c.b, 1.0
  end
  return get_default_color()
end

local function get_var_color(a1, a2, a3, a4)
  local r, g, b, a

  if type(a1) == "table" then
    r, g, b, a = get_color(a1)
  elseif type(a1) == "number" and type(a2) == "number" and type(a3) == "number" and type(a4) == "number" then
    r, g, b, a = a1, a2, a3, a4
  elseif type(a1) == "number" and type(a2) == "number" and type(a3) == "number" and type(a4) == "nil" then
    r, g, b, a = a1, a2, a3, 1.0
  else
    r, g, b, a = get_default_color()
  end

  return r, g, b, a
end

-- CLR:GetHexColor(color or cr, cg, cb)
local function mult_255(r, g, b, a)
  return r * 255, g * 255, b * 255, a
end

function CLR:GetHexColor(a1, a2, a3, a4)
  return string.format("%02x%02x%02x", mult_255(get_var_color(a1, a2, a3, a4)))
end


function CLR:GetHashColor(text)
  local hash = 17

  for i=1,text:len() do
    hash = hash * 37 * text:byte(i)
  end

  local r = math.floor(math.fmod(hash / 97, 255));
  local g = math.floor(math.fmod(hash / 17, 255));
  local b = math.floor(math.fmod(hash / 227, 255));

  if ((r * 299 + g * 587 + b * 114) / 1000) < 105 then
    r = math.abs(r - 255);
    g = math.abs(g - 255);
    b = math.abs(b - 255);
  end

  return ("%02x%02x%02x"):format(r, g, b)
end

function CLR:Random(text)
  return CLR:Colorize(self:GetHashColor(text), text)
end

function CLR:Colorize(hexColor, text)
  if text == nil or text == "" then
    return ""
  end

  local color = hexColor
  if type(hexColor) == "table" then
    color = self:GetHexColor(hexColor)
  end

  if color == CLR.COLOR_NONE then
    return text
  end

  local link = CLR.LINK

  link[2] = tostring(color or 'ffffff')
  link[3] = text

  return table.concat(link, "")
end

local function desat_chan(c) return ((c or 1.0) * 192 * 0.8 + 63) / 255 end

function CLR:Desaturate(a1, a2, a3, a4)
  local r, g, b, a = get_var_color(a1, a2, a3, a4)

  r = desat_chan(r)
  g = desat_chan(g)
  b = desat_chan(b)

  return r, g, b, a
end


-- Not sure if the follow are used, i got them from either rock or crayon.

function CLR:RGBtoHSL(red, green, blue)
  local hue, saturation, luminance
  local minimum = math.min(red, green, blue)
  local maximum = math.max(red, green, blue)
  local difference = maximum - minimum

  luminance = (maximum + minimum) / 2

  if difference == 0 then --Greyscale
    hue = 0
    saturation = 0
  else --Colour
    if luminance < 0.5 then
      saturation = difference / (maximum + minimum)
    else
      saturation = difference / (2 - maximum - minimum)
    end

    local tmpRed = (((maximum - red) / 6) + (difference / 2)) / difference
    local tmpGreen = (((maximum - green) / 6) + (difference / 2)) / difference
    local tmpBlue = (((maximum - blue) / 6) + (difference / 2)) / difference

    if red == maximum then
      hue = tmpBlue - tmpGreen
    elseif green == maximum then
      hue = (1 / 3) + tmpRed - tmpBlue
    elseif blue == maximum then
      hue = (2 / 3) + tmpGreen - tmpRed
    end

    hue = hue % 1
    if hue < 0 then hue = hue + 1 end
  end

  return hue, saturation, luminance
end

function CLR:HSLtoRGB(hue, saturation, luminance)
  local red, green, blue

  if (S == 0) then
    red, green, blue = luminance, luminance, luminance
  else
    if luminance < 0.5 then
      var2 = luminance * (1 + saturation)
    else
      var2 = (luminance + saturation) - (saturation * luminance)
    end

    var1 = 2 * luminance - var2

    red = self:HueToColor(var1, var2, hue + (1 / 3))
    green = self:HueToColor(var1, var2, hue)
    blue = self:HueToColor(var1, var2, hue - (1 / 3))
  end

  return red, green, blue
end

function CLR:HueToColor(var1, var2, hue)
  hue = hue % 1
  if hue < 0 then hue = hue + 1 end

  if (6 * hue) < 1 then
    return hue + (var2 - var1) * 6 * hue
  elseif (2 * hue) < 1 then
    return var2
  elseif (3 * hue) < 2 then
    return var1 + (var2 - var1) * ((2 / 3) - hue) * 6
  else
    return var1
  end
end

