require("telescope").load_extension("ui-select")

require("telescope").setup({
	defaults = {
		borderchars = { " ", " ", " ", " ", " ", " ", " ", " " }
	},
	extensions = {
		["ui-select"] = {
			require("telescope.themes").get_dropdown {
				-- even more opts
			}

			-- pseudo code / specification for writing custom displays, like the one
			-- for "codeactions"
			-- specific_opts = {
			--   [kind] = {
			--     make_indexed = function(items) -> indexed_items, width,
			--     make_displayer = function(widths) -> displayer
			--     make_display = function(displayer) -> function(e)
			--     make_ordinal = function(e) -> string
			--   },
			--   -- for example to disable the custom builtin "codeactions" display
			--      do the following
			--   codeactions = false,
			-- }
		}
	}
})

local blend = 50

vim.api.nvim_create_autocmd("FileType", {
	pattern = "TelescopePrompt",
	callback = function(ctx)
		local backdropName = "TelescopeBackdrop"
		local telescopeBufnr = ctx.buf

		-- `Telescope` does not set a zindex, so it uses the default value
		-- of `nvim_open_win`, which is 50: https://neovim.io/doc/user/api.html#nvim_open_win()
		local telescopeZindex = 50

		local backdropBufnr = vim.api.nvim_create_buf(false, true)
		local winnr = vim.api.nvim_open_win(backdropBufnr, false, {
			relative = "editor",
			border = "none",
			row = 0,
			col = 0,
			width = vim.o.columns,
			height = vim.o.lines,
			focusable = false,
			style = "minimal",
			zindex = telescopeZindex - 1, -- ensure it's below the reference window
		})

		vim.api.nvim_set_hl(0, backdropName, { bg = "#000000", default = true })
		vim.wo[winnr].winhighlight = "Normal:" .. backdropName
		vim.wo[winnr].winblend = blend
		vim.bo[backdropBufnr].buftype = "nofile"

		-- close backdrop when the reference buffer is closed
		vim.api.nvim_create_autocmd({ "WinClosed", "BufLeave" }, {
			once = true,
			buffer = telescopeBufnr,
			callback = function()
				if vim.api.nvim_win_is_valid(winnr) then vim.api.nvim_win_close(winnr, true) end
				if vim.api.nvim_buf_is_valid(backdropBufnr) then
					vim.api.nvim_buf_delete(backdropBufnr, { force = true })
				end
			end,
		})
	end,
})

vim.api.nvim_create_autocmd({ "ColorScheme", "VimEnter" }, {
	group = vim.api.nvim_create_augroup('Color', {}),
	pattern = "*",
	callback = function()
		vim.api.nvim_set_hl(0, "TelescopePreviewTitle", { link = "MiniStatuslineModeVisual" })
		vim.api.nvim_set_hl(0, "TelescopePromptTitle", { link = "MiniStatuslineModeCommand" })
		vim.api.nvim_set_hl(0, "TelescopeResultsTitle", { link = "MiniStatuslineModeReplace" })
		vim.api.nvim_set_hl(0, "TelescopePromptNormal", { link = "StatusLine" })
		vim.api.nvim_set_hl(0, "TelescopePromptBorder", { link = "StatusLine" })
		vim.api.nvim_set_hl(0, "TelescopePreviewNormal", { link = "BufferLineHint" })
		vim.api.nvim_set_hl(0, "TelescopePreviewBorder", { link = "BufferLineHint" })
	end
})