local M = require('module'):new()

local map = require('lib/map')

function M:initialize(config)
	self.plugins = nukevim.modules:get('plugins')
	self.keymap = {}
end

function M:register()
	if (self.config.ui.enable) then
		self.plugins:add('folke/which-key.nvim', { branch = "main" }, {
			{ mode = 'n', key = { '?', '?', '?' }, map = ":lua nukevim.modules:get('keymap'):show()<CR>", hidden = true },
			{ mode = 'i', key = { '?', '?', '?' }, map = "<cmd> lua nukevim.modules:get('keymap'):show()<CR>", hidden = true },
			{ mode = 'v', key = { '?', '?', '?' }, map = "<cmd> lua nukevim.modules:get('keymap'):show()<CR>", hidden = true },
		})
	end

	if (self.config.keys ~= nil) then
		for idx, key in ipairs(self.config.keys) do
			self:add(key)
		end
	end
end

function M:show()
	mode = vim.fn.mode()
	buffer = vim.fn.expand('%')
	-- n, i, v/V
	
	show_buffer_keys = false
	for i=1,#self.keymap do
		if (self.keymap[i].buffer ~= nil and self.keymap[i].buffer == buffer) then
			show_buffer_keys = true
			break
		end
	end

	if (show_buffer_keys and false) then

		-- buf = vim.api.nvim_create_buf(false, true)
		-- win = vim.api.nvim_open_win(buf, false, {
		-- 		relative = "editor",
		-- 		height = 6,
		-- 		focusable = false,
		-- 		anchor = "SW",
		-- 		style = "minimal",
		-- 		row = vim.o.lines,
		-- 		col = 0,
		-- 		width = vim.o.columns
		-- 	})
		-- vim.api.nvim_buf_set_option(buf, "filetype", "WhichKey")
		-- vim.api.nvim_buf_set_option(buf, "buftype", "nofile")
		-- vim.api.nvim_win_set_option(win, "winhighlight", "NormalFloat:WhichKeyFloat")
		-- vim.api.nvim_win_set_option(win, "foldmethod", "manual")
		-- -- vim.api.nvim_win_set_option(win, "winblend", true)
		-- vim.cmd([[autocmd! WinClosed <buffer> lua nukevim.modules:get('keymap'):closed()]])

		-- vim.api.nvim_buf_set_lines(buf, 0, -1, false, {
		-- 		"hello, world!",
		-- 		"this is a window"
		-- 	})
	else
		require('which-key').show('', { mode = mode })
	end
end

function M:registerBufferLocal()
	filetype = vim.bo.filetype

	local_binds = {}

	for i=1,#self.keymap do
		if (self.keymap[i].filetype ~= nil and self.keymap[i].filetype == filetype) then
			table.insert(local_binds, self.keymap[i])
		end
	end

	self:registerWithWhichKey(local_binds, { buffer = 0 })

end

function M:map(mode, key, map, options)
	M:add({
		mode = mode,
		key = key,
		map = map,
		options = options or { noremap = true }
	})
end

function M:add(keymap)
	-- todo: validate
	keymap.mode = keymap.mode or nil
	keymap.key = keymap.key or nil
	if (type(keymap.key) == "string") then
		parts = {}
		for part in string.gmatch(keymap.key, '.') do
			table.insert(parts, part)
		end
		keymap.key = parts
	end
	keymap.map = keymap.map or nil
	keymap.options = keymap.options or { noremap = true }
	keymap.label = keymap.label or nil
	keymap.virtual = keymap.virtual or false
	keymap.hidden = keymap.hidden or false
	keymap.group = keymap.group or false
	keymap.with = keymap.with or {}
	keymap.without = keymap.without or {}
	table.insert(self.keymap, keymap)
end

function M:commit()
	if (self.plugins:has('folke/which-key.nvim') and self.config.ui.enable) then
		self:commitWithWhichKey()
	else
		self:commitWithNative()
	end
end

function M:commitWithWhichKey()
	-- Set up whichkey
	whichkey = require('which-key')
	whichkey.setup({
		ignore_missing = true,
		plugins = {
			marks = true,
			registers = true,
			spelling = {
				enabled = true,
				suggestions = 20
			},
			presets = {
				operators = self.config.ui.show_builtin,
				motions = self.config.ui.show_builtin,
				text_objects = self.config.ui.show_builtin,
				windows = self.config.ui.show_builtin,
				nav = self.config.ui.show_builtin,
				z = self.config.ui.show_builtin,
				g = self.config.ui.show_builtin,
			}
		}
	})

	-- Build tree of key binds
	self:registerWithWhichKey(self.keymap)

end

function M:registerWithWhichKey(keys, opts)
	opts = opts or {}
	tree = {}
	node = nil

	for idx, keymap in ipairs(keys) do
		if (keymap.hidden) then
			if (keymap.label ~= nil) then
				keymap.options.desc = keymap.label
			end
			map(keymap.mode, table.concat(keymap.key, ""), keymap.map, keymap.options)
		-- TODO: Hack-y hack.
		elseif (keymap.filetype ~= nil and opts.buffer == nil) then
			-- this only applies to a specific filetype, register() will register
			-- it buffer-local when it's opened
		else
			if (tree[keymap.mode] == nil) then
				tree[keymap.mode] = {}
			end

			node = tree[keymap.mode]

			for i = 1, #keymap.key - 1 do
				if (node[keymap.key[i]] == nil) then
					node[keymap.key[i]] = {}
				end
				node = node[keymap.key[i]]
			end

			last = keymap.key[#keymap.key]
			
			have_all_with = true
			for idx,plugin in ipairs(keymap.with) do
				have_all_with = have_all_with and self.plugins:has(plugin)
			end
			have_any_without = false
			for idx,plugin in ipairs(keymap.without) do
				have_any_without = have_any_without or self.plugins:has(plugin)
			end

			if (have_all_with and not have_any_without) then
				if (keymap.group) then
					node[last] = node[last] or {}
					node[last]['name'] = keymap.label
				elseif (keymap.virtual) then
					node[last] = { keymap.label }
				else
					node[last] = { keymap.map, keymap.label or nil }
					if (keymap.options.noremap) then
						node[last].noremap = true
					end
					if (keymap.options.silent) then
						node[last].silent = true
					end
					if (keymap.options.nowait) then
						node[last].nowait = true
					end
				end
			end

		end
	end

	for mode, node in pairs(tree) do
		local_opts = {}
		for k, v in pairs(opts) do
			local_opts[k] = v
		end
		local_opts['mode'] = mode
		whichkey.register(node, local_opts)
	end

end

function M:commitWithNative()
	for idx, keymap in ipairs(self.keymap) do
		if (keymap.label ~= nil) then
			keymap.options.desc = keymap.label
		end

		if (keymap.virtual ~= true) then

			have_all_with = true
			for plugin in ipairs(keymap.with) do
				have_all_with = have_all_with and self.plugins:has(plugin)
			end
			have_any_without = false
			for plugin in ipairs(keymap.without) do
				have_any_without = have_any_without or self.plugins:has(plugin)
			end

			if (have_all_with and not have_any_without) then
				map(keymap.mode, table.concat(keymap.key, ''), keymap.map, keymap.options)
			end
		end
	end
end

return M