require("utility.misc")

function table.filter(list, predicate)
	local filtered_list = {}

	for _, item in ipairs(list) do
		if predicate(item) then
			table.insert(filtered_list, item)
		end
	end

	return filtered_list
end

local function set_terminal_height(height)
	if not vim.api.nvim_win_is_valid(vim.g.term_win) then
		return
	end

	vim.api.nvim_win_set_height(vim.g.term_win, height)
end

local function get_nerdtree_win_id()
	local nerdtree_win_num = vim.api.nvim_eval("g:NERDTree.GetWinNum()")

	return vim.fn.win_getid(nerdtree_win_num)
end

function _G.check_back_space()
	local col = vim.api.nvim_win_get_cursor(0)[2]

	if col == 0 then
		return true
	end

	return vim.api.nvim_get_current_line():sub(col, col):find("%s") and true
end

function _G.show_documentation()
	if vim.fn.index({"vim", "help"}, vim.bo.filetype) >= 0 then
		vim.cmd("help " .. vim.fn.expand("<cword>"))
	elseif vim.fn["coc#rpc#ready()"] then
		vim.fn.CocActionAsync("doHover")
	else
		vim.cmd(vim.go.keywordprg .. " " .. vim.fn.expand("<cword>"))
	end
end

function _G.toggle_terminal()
    if vim.fn.win_gotoid(vim.g.term_win) == 1 then
		vim.cmd("quit!")
    else
        vim.cmd("botright new")

		vim.api.nvim_win_set_height(vim.fn.win_getid(), vim.g.terminal_height)

		vim.api.nvim_win_set_option(
			vim.fn.win_getid(),
			"winhighlight",
			"Normal:TerminalWindow"
		)


		vim.fn.termopen(vim.env.SHELL, {detach=0})

		vim.g.term_buf = vim.fn.bufnr("")

		vim.o.number = false
		vim.o.relativenumber = false
		vim.o.signcolumn = "no"

        vim.cmd("startinsert!")

        vim.g.term_win = vim.fn.win_getid()

        if vim.fn.exists("g:NERDTree") and vim.api.nvim_eval("g:NERDTree.IsOpen()") then
			local nerdtree_win_id = get_nerdtree_win_id()

			vim.api.nvim_win_call(
				nerdtree_win_id,
				function()
					vim.cmd("wincmd H")
				end
			)

			vim.api.nvim_win_set_width(nerdtree_win_id, vim.g.NERDTreeWinSize)
        end
    end
end

function _G.toggle_nerdtree()
	vim.cmd("NERDTreeToggle")

	vim.api.nvim_win_set_option(
		vim.fn.win_getid(),
		"winhighlight",
		"Normal:NERDTreeWindow"
	)
end

function _G.search_buffers()
	local spec = vim.fn["fzf#vim#with_preview"]({ placeholder = "{1}" })

	local nerdtree_buffer = vim.api.nvim_win_get_buf(get_nerdtree_win_id())

	local buffers = table.filter(
		vim.api.nvim_list_bufs(),
		function(buffer)
			return
				vim.api.nvim_buf_is_loaded(buffer) and
				buffer ~= nerdtree_buffer and
				buffer ~= vim.g.term_buf
		end
	)

	vim.fn["fzf#vim#buffers"]("", buffers, spec, 0)
end

function _G.get_current_file()
    return vim.fn.expand("%")
end

function _G.remove_hidden_windowless_buffers()
	local all_buffers = vim.fn.getbufinfo()

	local buffers = table.filter(all_buffers, function (item)
		local windows = item.windows

		return #windows == 0 and item.hidden
	end)

	for _, buffer in ipairs(buffers) do
		vim.api.nvim_buf_delete(buffer.bufnr, { force = true })
	end
end

function _G.close_current_buffer()
	local curr_win_id = vim.fn.win_getid()

	if curr_win_id == vim.g.term_win or curr_win_id == get_nerdtree_win_id() then
		return
	end

	local current_buf_nr = vim.fn.bufnr()

	local all_buffers = vim.fn.getbufinfo()

	local file_buffers = table.filter(
		all_buffers,
		function(buf_info)
			return buf_info.loaded == 1
				and buf_info.listed == 1
				and buf_info.bufnr ~= current_buf_nr
				and not string.find(buf_info.name, "NERD_tree_")
				and not string.find(buf_info.name, "term://")
		end
	)

	if #file_buffers == 0 then
		vim.cmd("new")
	else
		vim.cmd("buffer " .. file_buffers[1].bufnr)
	end

	vim.api.nvim_buf_delete(current_buf_nr, { force = true })

	set_terminal_height(vim.g.terminal_height)
end