local M = {}

---Make a lualine component that is colored only when focused.
---@param base table|string Either a lualine component or a component name.
---@return table component
M.colored_when_focused = function(base)
  local component = {}

  if type(base) == "string" then
    component = require("lualine.components." .. base):extend()
  elseif type(base) == "table" then
    component = base:extend()
  else
    return component
  end

  function component:init(options)
    component.super.init(
      self,
      vim.tbl_deep_extend("keep", options or {}, {
        colored = true,
        colored_when_focused = true,
      })
    )
    self.saved_highlight = self.options.color_highlight
  end

  function component:update_status(is_focused)
    if self.options.colored_when_focused then self.options.colored = is_focused end
    return component.super.update_status(self, is_focused)
  end

  function component:draw(default_highlight, is_focused)
    self.options.color_highlight = self.options.colored and self.saved_highlight or nil
    return component.super.draw(self, default_highlight, is_focused)
  end

  return component
end

---@class LualineIndicatorSpec
---@field icon string The icon to show when the indicator is active.
---@field cond function A function that returns true when the indicator should
---                     be visible, false otherwise.

---Make a lualine indicator that shows an icon when a condition is true.
---@param spec LualineIndicatorSpec
---@return table component
M.indicator = function(spec)
  vim.validate("spec", spec, "table")
  vim.validate("spec.icon", spec.icon, "string")
  vim.validate("spec.cond", spec.cond, "function")

  local component = require("lualine.component"):extend()

  function component:init(options)
    component.super.init(
      self,
      vim.tbl_deep_extend(
        "keep",
        options or {},
        { cond = spec.cond or function() return false end }
      )
    )
  end

  function component:update_status(--[[is_focused]]_) return spec.icon or "?" end

  return component
end

return M