local M = {}

--- Get the solarized colors based on the current Vim background setting
---
--- @return table colors   A table containing the solarized colors
function M.get_colors()
  local config = require('solarized.config')
  local colors = {
    solarized = {
      dark = {
        base03 = '#002b36', -- background tone dark (main)
        base02 = '#073642', -- background tone (highlight/menu/LineNr)
        base01 = '#586e75', -- content tone (comment)
        base00 = '#657b83', -- content tone (winseparator)
        base0 = '#839496', -- content tone (foreground)
        base1 = '#93a1a1', -- content tone (statusline/tabline)
        base2 = '#eee8d5', -- background tone light (highlight)
        base3 = '#fdf6e3', -- background tone lighter (main)
        -- accent
        yellow = '#b58900',
        orange = '#cb4b16',
        red = '#dc322f',
        magenta = '#d33682',
        violet = '#6c71c4',
        blue = '#268bd2',
        cyan = '#2aa198',
        green = '#859900',
        -- git
        add = '#859900',
        change = '#b58900',
        delete = '#dc322f',
        -- diagnostic
        info = '#268bd2',
        hint = '#859900',
        warning = '#b58900',
        error = '#dc322f',
      },
      light = {
        base3 = '#002b36', -- background tone darker (main)
        base2 = '#073642', -- background tone dark (highlight)
        base1 = '#586e75', -- content tone (statusline/tabline)
        base0 = '#657b83', -- content tone (foreground)
        base00 = '#839496', -- content tone (winseparator)
        base01 = '#93a1a1', -- content tone (comment)
        base02 = '#eee8d5', -- background tone (highlight/menu/LineNr)
        base03 = '#fdf6e3', -- background tone lighter (main)
        -- accent
        yellow = '#b58900',
        orange = '#cb4b16',
        red = '#dc322f',
        magenta = '#d33682',
        violet = '#6c71c4',
        blue = '#268bd2',
        cyan = '#2aa198',
        green = '#859900',
        -- git
        add = '#859900',
        change = '#b58900',
        delete = '#dc322f',
        -- diagnostic
        info = '#268bd2',
        hint = '#859900',
        warning = '#b58900',
        error = '#dc322f',
      },
    },
    selenized = {
      dark = {
        base03 = '#103c48', -- background tone dark (main)
        base02 = '#184956', -- background tone (highlight/menu/LineNr)
        base01 = '#72898f', -- content tone (comment)
        base00 = '#72898f', -- content tone (winseparator)
        base0 = '#adbcbc', -- content tone (foreground)
        base1 = '#cad8d9', -- content tone (statusline/tabline)
        base2 = '#ece3cc', -- background tone light (highlight)
        base3 = '#fbf3db', -- background tone lighter (main)
        -- accent
        yellow = '#dbb32d',
        orange = '#ed8649',
        red = '#fa5750',
        magenta = '#f275be',
        violet = '#af88eb',
        blue = '#4695f7',
        cyan = '#41c7b9',
        green = '#75b938',
        -- git
        add = '#75b938',
        change = '#dbb32d',
        delete = '#fa5750',
        -- diagnostic
        info = '#4695f7',
        hint = '#75b938',
        warning = '#dbb32d',
        error = '#fa5750',
      },
      light = {
        base3 = '#103c48', -- background tone darker (main)
        base2 = '#2d5b69', -- background tone dark (highlight)
        base1 = '#3a4d53', -- content tone (statusline/tabline)
        base0 = '#53676d', -- content tone (foreground)
        base00 = '#909995', -- content tone (winseparator)
        base01 = '#909995', -- content tone (comment)
        base02 = '#ece3cc', -- background tone (highlight/menu/LineNr)
        base03 = '#fbf3db', -- background tone lighter (main)
        -- accent
        yellow = '#ad8900',
        orange = '#c25d1e',
        red = '#d2212d',
        magenta = '#ca4898',
        violet = '#8762c6',
        blue = '#0072d4',
        cyan = '#009c8f',
        green = '#489100',
        -- git
        add = '#489100',
        change = '#ad8900',
        delete = '#d2212d',
        -- diagnostic
        info = '#0072d4',
        hint = '#489100',
        warning = '#ad8900',
        error = '#d2212d',
      },
    },
  }

  return colors[((config.config or {}).palette or 'solarized')][vim.o.background]
end

--- Filter colors by selecting valid hexadecimal color values.
---
--- @param colors table A table containing color values to be filtered.
--- @return table Filtered colors table, containing only valid hexadecimal color values.
local function filter_colors(colors)
  local filtered_colors = {}

  for color_name, color_value in pairs(colors) do
    if string.match(color_value, '#%x%x%x%x%x%x$') then
      filtered_colors[color_name] = color_value
    elseif string.match(color_value, '#%x%x%x$') then
      color_value = string.sub(color_value, 2, #color_value)
      filtered_colors[color_name] = '#' .. string.rep(color_value, 2)
    end
  end

  return filtered_colors
end

--- Merge custom colors with solarized default colors
---
--- @param colors table A table containing new color values to be added.
--- @param custom_colors table
function M.extend_colors(colors, custom_colors)
  local c = vim.deepcopy(colors)
  custom_colors = filter_colors(custom_colors)

  return vim.tbl_extend('force', c, custom_colors)
end

return M