local api = vim.api

local function get_parameter_label(result)
	local signatures = result.signatures

	local activeSignature = result.activeSignature or 0
	activeSignature = activeSignature + 1
	local signature = signatures[activeSignature]

	if signature == nil or signature.parameters == nil then -- no parameter
		return ""
	end

	local activeParameter = signature.activeParameter or result.activeParameter

	if activeParameter == nil or activeParameter < 0 then
		return ""
	end

	if signature.parameters == nil then
		return ""
	end

	if activeParameter > #signature.parameters then
		activeParameter = 0
	end

	-- local nextParameter = signature.parameters[activeParameter + 1]
	local param = signature.parameters[activeParameter + 1].label
	local param_str
	-- Handle both string and table parameter labels
	if type(param) == "table" then
		local s = param[1]
		local e = param[2]
		param_str = string.sub(signature.label, s, e)
	elseif type(param) == "string" then
		param_str = label
	end

	return param_str
end

---@class opts table
---@field brk_chars string string of characters to break lines at
---@field indent_str string string to indent wrapped lines with
---@param str string string to wrap into lines
---@param maxlen integer maximum length of lines
---@return table table of wrapped lines
local function _wrap_lines(str, maxlen, opts)
	local atoms = {}
	opts = opts or {}
	local brk_chars = opts.brk_chars or ",()"
	local indent_str = opts.indent_str or " "
	local end_char = string.sub(brk_chars, 1, 1)

	str = str .. end_char -- add break char at end of string, so we can match the end of the line
	for w in string.gmatch(str, "[^" .. brk_chars .. "]*" .. "[" .. brk_chars .. "]") do
		table.insert(atoms, w)
	end
	atoms[#atoms] = string.gsub(atoms[#atoms], end_char .. "$", "") -- remove break char at end

	local lines = {}
	lines[1] = ""
	local line_num = 1

	local padding = opts.padding or 2
	local is = ""
	for i, w in ipairs(atoms) do
		if line_num == 1 then
			is = ""
		else
			is = indent_str
		end
		if string.len(lines[line_num]) + string.len(w) + (padding * 2) <= maxlen then
			lines[line_num] = lines[line_num] .. w
		else
			lines[line_num] = string.rep(" ", padding) .. is .. lines[line_num] .. string.rep(" ", padding) --add padding
			line_num = line_num + 1
			lines[line_num] = string.gsub(w, "^%s", "")
		end
		if i == #atoms then
			lines[line_num] = string.rep(" ", padding) .. is .. lines[line_num] .. string.rep(" ", padding) --add padding to last line
		end
	end

	return lines
end

---@param signature_help table
---@param maxlen integer
local function convert_signature_help_to_lines(signature_help, maxlen)
	if not signature_help.signatures then
		return
	end
	local lines = {}
	local active_signature = signature_help.activeSignature or 0
	if active_signature >= #signature_help.signatures or active_signature < 0 then
		active_signature = 0
	end
	local signature = signature_help.signatures[active_signature + 1]
	if not signature then
		return
	end

	vim.list_extend(lines, vim.split(signature.label, "\n", { plain = true, trimempty = true }))

	local wrapped_lines = {}
	for _, ll in ipairs(lines) do
		vim.list_extend(wrapped_lines, _wrap_lines(ll, maxlen))
	end
	return wrapped_lines
end

local function apply_treesitter_highlighting(buf, syntax)
	if not api.nvim_buf_is_valid(buf) then
		return
	end

	if not pcall(require, "nvim-treesitter") then
		return
	end

	-- Store current window and buffer
	local current_win = api.nvim_get_current_win()
	local current_buf = api.nvim_get_current_buf()

	-- Apply treesitter highlighting
	pcall(function()
		require("nvim-treesitter.highlight").attach(buf, syntax)
	end)

	-- Restore focus
	api.nvim_set_current_win(current_win)
	api.nvim_set_current_buf(current_buf)
end

local _make_floating_popup_size = function(contents, opts)
	opts = opts or {}
	local max_width = opts.max_width or 80
	local max_height = opts.max_height or 10
	local line_widths = {}

	local width = 0
	for i, line in ipairs(contents) do
		line_widths[i] = vim.fn.strdisplaywidth(line:gsub("%z", "\n"))
		width = math.max(line_widths[i], width)
	end

	-- local border_width = get_border_size(opts).width
	local border_width = 2 --TODO: do we need to deal with this parametrically?
	local screen_width = api.nvim_win_get_width(0)
	width = math.min(width, screen_width)
	width = math.min(width, max_width)

	-- make sure borders are always inside the screen
	if width + border_width > screen_width then
		width = screen_width - border_width
	end

	local height = #contents
	height = 0
	if vim.tbl_isempty(line_widths) then
		for _, line in ipairs(contents) do
			local line_width = vim.fn.strdisplaywidth(line:gsub("%z", "\n"))
			height = height + math.ceil(line_width / max_width)
		end
	else
		for i = 1, #contents do
			height = height + math.max(1, math.ceil(line_widths[i] / max_width))
		end
	end
	if max_height then
		height = math.min(height, max_height)
	end

	return width, height
end

---@param content table window content
---@param opts table window options
---@returns (table) Options
local function _make_floating_popup_options(content, opts)
	local width, height = _make_floating_popup_size(content, opts)

	local offset_y = opts.offset_y or 0
	local offset_x = opts.offset_x or 0

	local anchor_bias = opts.anchor_bias or "auto"
	local relative = opts.relative or "cursor"
	local anchor = ""
	local row, col

	local lines_above = opts.relative == "mouse" and vim.fn.getmousepos().line - 1 or vim.fn.winline() - 1
	local lines_below = vim.fn.winheight(0) - lines_above

	if
		lines_above < height
		or (anchor_bias == "below" and lines_below > height + offset_y)
		or (anchor_bias == "auto" and lines_below > lines_above)
	then
		anchor = anchor .. "N"
		height = math.min(lines_below - offset_y, height)
		row = 1 + offset_y
	else
		anchor = anchor .. "S"
		height = math.min(lines_above - offset_y, height)
		row = 0 - offset_y
	end

	local wincol = opts.relative == "mouse" and vim.fn.getmousepos().column or vim.fn.wincol()

	if wincol + width + offset_x <= vim.o.columns then
		anchor = anchor .. "W"
		col = 0 - wincol
	else
		anchor = anchor .. "E"
		col = 1 - wincol
	end

	offset_x = opts.offset_x or 0

	return {
		anchor = anchor,
		row = row,
		col = col + offset_x,
		width = width,
		height = height,
		focusable = opts.focusable,
		relative = relative,
		style = "minimal",
		border = opts.border or "rounded",
		zindex = opts.zindex or 50,
	}
end

local function create_float_window(content, syntax, opts)
	local npcall = vim.F.npcall
	vim.validate({
		contents = { content, "t" },
		syntax = { syntax, "s", true },
		opts = { opts, "t", true },
	})
	opts = opts or {}

	local bufnr = api.nvim_get_current_buf()
	local existing_float = npcall(api.nvim_buf_get_var, bufnr, "lsp_floating_preview")

	if existing_float and api.nvim_win_is_valid(existing_float) then
		api.nvim_win_close(existing_float, true)
	end

	-- Create the buffer
	local floating_bufnr = api.nvim_create_buf(false, true)

	if syntax then
		vim.bo[floating_bufnr].syntax = syntax
		vim.bo[floating_bufnr].ft = syntax
		vim.treesitter.start(floating_bufnr)
	end
	api.nvim_buf_set_lines(floating_bufnr, 0, -1, true, content)

	local float_options = _make_floating_popup_options(content, opts)
	local floating_winnr = api.nvim_open_win(floating_bufnr, false, float_options)

	vim.wo[floating_winnr].conceallevel = 2
	vim.wo[floating_winnr].foldenable = false
	vim.bo[floating_bufnr].modifiable = false
	vim.bo[floating_bufnr].bufhidden = "wipe"

	api.nvim_buf_set_keymap(
		floating_bufnr,
		"n",
		"q",
		"<cmd>bdelete<cr>",
		{ silent = true, noremap = true, nowait = true }
	)

	-- save focus_id
	api.nvim_buf_set_var(bufnr, "lsp_floating_preview", floating_winnr)

	return floating_bufnr, floating_winnr
end

local function close_float_window(win, buf)
	-- Store current window and buffer
	local current_win = api.nvim_get_current_win()
	local current_buf = api.nvim_get_current_buf()

	if win and api.nvim_win_is_valid(win) then
		pcall(api.nvim_win_close, win, true)
	end
	if buf and api.nvim_buf_is_valid(buf) then
		pcall(api.nvim_buf_delete, buf, { force = true })
	end
	win = nil
	buf = nil

	-- Restore focus
	pcall(api.nvim_set_current_win, current_win)
	pcall(api.nvim_set_current_buf, current_buf)
	-- end
end

return {
	get_parameter_label = get_parameter_label,
	convert_signature_help_to_lines = convert_signature_help_to_lines,
	apply_treesitter_highlighting = apply_treesitter_highlighting,
	create_float_window = create_float_window,
	close_float_window = close_float_window,
}