Separate parsers into individual files

1 files changed, 114 insertions, 0 deletions

diff --git a/lua/colorizer/parser/rgb.lua b/lua/colorizer/parser/rgb.lua
new file mode 100644
index 0000000..2786a60
--- /dev/null
+++ b/lua/colorizer/parser/rgb.lua
@@ -0,0 +1,114 @@
+---Helper function to parse argb
+local count = require("colorizer.utils").count
+
+local parser = {}
+local CSS_RGBA_FN_MINIMUM_LENGTH = #"rgba(0,0,0)" - 1
+local CSS_RGB_FN_MINIMUM_LENGTH = #"rgb(0,0,0)" - 1
+---Parse for rgb() rgba() css function and return rgb hex.
+-- For more info: https://developer.mozilla.org/en-US/docs/Web/CSS/color_value/rgb
+---@param line string: Line to parse
+---@param i number: Index of line from where to start parsing
+---@param opts table: Values passed from matchers like prefix
+---@return number|nil: Index of line where the rgb/rgba function ended
+---@return string|nil: rgb hex value
+function parser.rgb_function_parser(line, i, opts)
+  local min_len = CSS_RGBA_FN_MINIMUM_LENGTH
+  local min_commas, min_spaces, min_percent = 2, 2, 3
+  local pattern = "^"
+    .. opts.prefix
+    .. "%(%s*([.%d]+)([%%]?)(%s?)%s*(,?)%s*([.%d]+)([%%]?)(%s?)%s*(,?)%s*([.%d]+)([%%]?)%s*(/?,?)%s*([.%d]*)([%%]?)%s*%)()"
+
+  if opts.prefix == "rgb" then
+    min_len = CSS_RGB_FN_MINIMUM_LENGTH
+  end
+
+  if #line < i + min_len then
+    return
+  end
+
+  local r, unit1, ssep1, csep1, g, unit2, ssep2, csep2, b, unit3, sep3, a, unit_a, match_end =
+    line:sub(i):match(pattern)
+  if not match_end then
+    return
+  end
+
+  if a == "" then
+    a = nil
+  else
+    min_commas = min_commas + 1
+  end
+
+  local units = ("%s%s%s"):format(unit1, unit2, unit3)
+  if units:match "%%" then
+    if not ((count(units, "%%")) == min_percent) then
+      return
+    end
+  end
+
+  local c_seps = ("%s%s%s"):format(csep1, csep2, sep3)
+  local s_seps = ("%s%s"):format(ssep1, ssep2)
+  -- comma separator syntax
+  if c_seps:match "," then
+    if not (count(c_seps, ",") == min_commas) then
+      return
+    end
+    -- space separator syntax with decimal or percentage alpha
+  elseif count(s_seps, "%s") >= min_spaces then
+    if a then
+      if not (c_seps == "/") then
+        return
+      end
+    end
+  else
+    return
+  end
+
+  if not a then
+    a = 1
+  else
+    a = tonumber(a)
+    -- if percentage, then convert to decimal
+    if unit_a == "%" then
+      a = a / 100
+    end
+    -- although alpha doesn't support larger values than 1, css anyways renders it at 1
+    if a > 1 then
+      a = 1
+    end
+  end
+
+  r = tonumber(r)
+  if not r then
+    return
+  end
+  g = tonumber(g)
+  if not g then
+    return
+  end
+  b = tonumber(b)
+  if not b then
+    return
+  end
+
+  if unit1 == "%" then
+    r = r / 100 * 255
+    g = g / 100 * 255
+    b = b / 100 * 255
+  else
+    -- although r,g,b doesn't support larger values than 255, css anyways renders it at 255
+    if r > 255 then
+      r = 255
+    end
+    if g > 255 then
+      g = 255
+    end
+    if b > 255 then
+      b = 255
+    end
+  end
+
+  local rgb_hex = string.format("%02x%02x%02x", r * a, g * a, b * a)
+  return match_end - 1, rgb_hex
+end
+
+return parser.rgb_function_parser