local M = {}

---@alias ColorSpec string RGB Hex string
---@alias ColorTable table<string, ColorSpec>
---@alias KansoColorsSpec { palette: ColorTable, theme: ColorTable }
---@alias KansoColors { palette: PaletteColors, theme: ThemeColors }

--- default config
---@class KansoConfig
M.config = {
	bold = true,
	undercurl = true,
	commentStyle = { italic = true },
	functionStyle = {},
	keywordStyle = { italic = true },
	statementStyle = {},
	typeStyle = {},
	transparent = false,
	dimInactive = false,
	terminalColors = true,
	disableItalics = false,
	colors = { theme = { zen = {}, pearl = {}, ink = {}, all = {} }, palette = {} },
	---@type fun(colors: KansoColorsSpec): table<string, table>
	overrides = function()
		return {}
	end,
	---@type { dark: string, light: string }
	background = { dark = "ink", light = "pearl" },
	theme = "ink",
	compile = false,
}

local function check_config(config)
	local err
	return not err
end

--- update global configuration with user settings
---@param config? KansoConfig user configuration
function M.setup(config)
	if check_config(config) then
		M.config = vim.tbl_deep_extend("force", M.config, config or {})
	else
		vim.notify("Kanso: Errors found while loading user config. Using default config.", vim.log.levels.ERROR)
	end
end

--- load the colorscheme
---@param theme? string
function M.load(theme)
	local utils = require("kanso.utils")

	theme = theme or M.config.background[vim.o.background] or M.config.theme
	M._CURRENT_THEME = theme

	if vim.g.colors_name then
		vim.cmd("hi clear")
	end

	vim.g.colors_name = "kanso"
	vim.o.termguicolors = true

	if M.config.compile then
		if utils.load_compiled(theme) then
			return
		end

		M.compile()
		utils.load_compiled(theme)
	else
		local colors = require("kanso.colors").setup({ theme = theme, colors = M.config.colors })
		local highlights = require("kanso.highlights").setup(colors, M.config)
		require("kanso.highlights").highlight(highlights, M.config.terminalColors and colors.theme.term or {})
	end
end

function M.compile()
	for theme, _ in pairs(require("kanso.themes")) do
		local colors = require("kanso.colors").setup({ theme = theme, colors = M.config.colors })
		local highlights = require("kanso.highlights").setup(colors, M.config)
		require("kanso.utils").compile(theme, highlights, M.config.terminalColors and colors.theme.term or {})
	end
end

vim.api.nvim_create_user_command("KansoCompile", function()
	for mod, _ in pairs(package.loaded) do
		if mod:match("^kanso%.") then
			package.loaded[mod] = nil
		end
	end
	M.compile()
	vim.notify("Kanso: compiled successfully!", vim.log.levels.INFO)
	M.load(M._CURRENT_THEME)
	vim.api.nvim_exec_autocmds("ColorScheme", { modeline = false })
end, {})

return M