-- Small XTextEditor plugins should be implemented here


----- XSpellcheckPlugin

DefineClass.XSpellcheckPlugin = {
	__parents = { "XTextEditorPlugin" },
	UnderlineColor = RGB(255, 20, 20),
}

local word_chars = "[_%w\127-\255\39]" -- count any utf8 extented character as a word character
local nonword_chars = "[^_%w\127-\255\39]"
local word_pattern = "(" .. word_chars .. "*)" .. "(" .. nonword_chars .. "*)"
local whitespace = "[\9\32]"
local multiple_whitespace = "[\9\32][\9\32]+"

local MeasureToCharStart = UIL.MeasureToCharStart
local StretchText = UIL.StretchText

function XSpellcheckPlugin:Init()
	LoadDictionary()
end

function XSpellcheckPlugin:OnDrawText(edit, line_idx, text, target_box, font, text_color)
	local y = target_box:maxy() - 4
	local position_in_text = 0
	local substitutions = { {"‘", "'"}, {"’", "'"}, {"“", "\""}, {"”", "\""}, {"–", "-"}, {"—", "-"}, {"…", "."}, {"−", "-"}}
	for i = 1, #substitutions do
		text = text:gsub(substitutions[i][1], substitutions[i][2])
	end
	-- underline whitespace at the begining of the line
	if #text >= 1 and text:sub(1,1):find(whitespace) then
		self:Underline(text, target_box:minx(), y, 1, 2, font)
	end
	-- underline whitespace at the end of the line; lines always end with a space, so the second to last character in the string should be checked
	if #text >= 1 and text:sub(#text - 1,#text - 1):find(whitespace) then
		self:Underline(text, target_box:minx(), y, #text- 1, #text, font)
	end
	local untagged, tag, first, last = string.nexttag(text, 1)
	
	-- Check for unmatched closing tag bracket (>) at the beginning of the text and if found, skip the dictionary checks for the text before it
	local unmatched_closing_tag = false
	local close_tag_idx
	if not tag then
		local open_tag_idx = string.find(untagged, "<")
		close_tag_idx = string.find(untagged, ">")
		
		-- Find the farthest unmatched closing tag bracket (>)
		while open_tag_idx and close_tag_idx do
			local next_close_tag = string.find(untagged, ">", close_tag_idx + 1)
			if next_close_tag and next_close_tag < open_tag_idx then
				close_tag_idx = next_close_tag
			else
				break
			end
		end
		
		unmatched_closing_tag = (close_tag_idx and not open_tag_idx) or (close_tag_idx and open_tag_idx and close_tag_idx < open_tag_idx)
	end
	
	-- try this - if the current position_in_text is < and there's no closing tag until the end skip/break
	for word, non_word in text:gmatch(word_pattern) do
		-- Check for unmatched opening tag bracket (<) at the end of the text and if found, skip the dictionary checks for the text after it
		if string.sub(text, position_in_text, position_in_text) == "<" and not string.find(text, ">", position_in_text + 1) then
			break
		end
		
		local current_word_end_pos = position_in_text + utf8.len(word)
		local new_position_in_text = current_word_end_pos + utf8.len(non_word)
		if tag and position_in_text >= first and current_word_end_pos <= last then
			-- we have reached a word/text enclosed in < and > - don't check it against the dictionary
			if position_in_text < last and new_position_in_text >= last then
				-- find the next word in tags
				untagged, tag, first, last = string.nexttag(text, new_position_in_text)
			end
		-- Enter only if we're outside of the unmatched closing tag (if any)
		elseif not (unmatched_closing_tag and position_in_text <= close_tag_idx) then
			word = word:gsub("^'", ""):gsub("'$", "") -- remove leading and trailing ' characters
			local lowercase_word = word:lower()
			if not WordInDictionary(word, lowercase_word) then
				self:Underline(text, target_box:minx(), y, position_in_text + 1, current_word_end_pos + 1, font)
			end
			local comma_pos = non_word:find("[,;].*")
			local comma, other_chars = non_word:match("([,;])(.*)")
			-- , or ; is underlined only if it is not followed by space and is at the end of line
			-- however, every line ends with a space and if there's a space after the , or ;, it needs to be checked for eol
			if comma and (not other_chars or not other_chars:starts_with("<")) and 
				(not other_chars or other_chars:sub(1, 1) ~= " " or
				 (other_chars:sub(1, 1) == " " and current_word_end_pos + comma_pos ==  text:len()))
			then
				local underline_start = current_word_end_pos + comma_pos
				self:Underline(text, target_box:minx(), y, underline_start, underline_start + 1, font)
			end
			-- . or : is underlined only if it is not followed by space
			local dot_pos = non_word:find("[%.:][^%s]*$")
			local dot_idx = dot_pos and current_word_end_pos + dot_pos
			if dot_idx and dot_idx ~= text:len() then
				local next_char = text:sub(dot_idx + 1, dot_idx + 1)
				if next_char ~= "\"" and next_char ~= "\'" and next_char ~= "." and next_char ~= "<" then
					self:Underline(text, target_box:minx(), y, dot_idx, dot_idx + 1, font)
				end
			end
			-- multiple whitespace handling
			local whitespace_start, whitespace_end = non_word:find(multiple_whitespace)
			if whitespace_start then
				self:Underline(text, target_box:minx(), y, current_word_end_pos + whitespace_start, current_word_end_pos + whitespace_end + 1, font)
			end
		end
		position_in_text = new_position_in_text
	end
end

function XSpellcheckPlugin:Underline(text, x, y, underline_start, underline_end, font)
	local x_start = MeasureToCharStart(text, font, underline_start)
	local x_end = MeasureToCharStart(text, font, underline_end)			
	UIL.DrawSolidRect(box(x + x_start, y, x + x_end, y + 2), self.UnderlineColor)
end

function XSpellcheckPlugin:OnRightButtonDown(edit, pt)
	local word = edit:GetWordUnderCursor(pt) or ""
	local lowercase_word = word:lower()
	if not WordInDictionary(word, lowercase_word) then
		CreateRealTimeThread(function()
			local title = "Add to dictionary"
			local text = "Do you want to save '"..word.."' to the dictionary?"
			local dialog = StdMessageDialog:new({}, edit.desktop, { question = true, title = title, text = text })
			dialog:Open()
			dialog:SetZOrder(BaseLoadingScreen.ZOrder + 2) -- above the bug report dialog...
			local result, win = dialog:Wait()
			if result == "ok" then
				local new_entry = word:match("%l") and lowercase_word or word
				SpellcheckDict[new_entry] = true
				WriteToDictionary(SpellcheckDict)
			end
		end)
		return "break"
	end
end


----- XExternalTextEditorPlugin

if FirstLoad then
	g_ExternalTextEditorActiveCtrl = false
end

DefineClass.XExternalTextEditorPlugin = {
	__parents = { "XTextEditorPlugin" },
}

function XExternalTextEditorPlugin:Init() 
	g_ExternalTextEditorActiveCtrl = false	
end

function XExternalTextEditorPlugin:Done() 
	if g_ExternalTextEditorActiveCtrl then
		g_ExternalTextEditorActiveCtrl = false
	end
end

function XExternalTextEditorPlugin:OpenEditor(edit)
	g_ExternalTextEditorActiveCtrl = edit
	AsyncCreatePath("AppData/editorplugin/")
	local file_path = "AppData/editorplugin/" .. config.DefaultExternalTextEditorTempFile
	AsyncStringToFile(file_path, edit:GetText())
	local cmd = config.DefaultExternelTextEditorCmd  
					and string.format(config.DefaultExternelTextEditorCmd, ConvertToOSPath(file_path))
					or string.format("\"%s\" %s",config.DefaultExternelTextEditorPath, ConvertToOSPath(file_path))
	os.execute(cmd) 
end

function XExternalTextEditorPlugin:OnShortcut(edit, shortcut, source, ...)
	if shortcut == "Ctrl-E" then
		self:OpenEditor(edit)
		return true
	end
end

function XExternalTextEditorPlugin:OnTextChanged(edit)
	-- update external file
	if g_ExternalTextEditorActiveCtrl == edit then	
		local file_path = "AppData/editorplugin/" .. config.DefaultExternalTextEditorTempFile
		AsyncStringToFile(file_path, edit:GetText())
	end
end

function XExternalTextEditorPlugin.ApplyEdit(file, change)
	if change == "Modified" then
		local err, content = AsyncFileToString(file)
		if not err then
			if g_ExternalTextEditorActiveCtrl then
				g_ExternalTextEditorActiveCtrl:SetText(content)
			end
		end
	end
end


----- XHighlightTextPlugin

DefineClass.XHighlightTextPlugin = {
	__parents = { "XTextEditorPlugin" },
	HighlightColor = RGB(188, 168, 70),
	SingleInstance = false,
	
	highlighted_text = false,
	ignore_case = true,
}

local function find_next(str_lower, str, substr, start_pos)
	local idx = string.find(str_lower, substr, start_pos, true)
	if idx then
		return str:sub(start_pos, idx - 1), str:sub(idx, idx + #substr - 1)
	else
		return str:sub(start_pos)
	end
end

function XHighlightTextPlugin:OnAfterDrawText(edit, line_idx, text, target_box, font, text_color)
	if not self.highlighted_text or self.highlighted_text == "" then return end
	
	local pos = 1
	local text_start = target_box:minx()
	local lower_text = self.ignore_case and text:lower() or text
	local other, word
	repeat
		other, word = find_next(lower_text, text, self.highlighted_text, pos)
		if word then
			local len_word = utf8.len(word)
			local len_other = utf8.len(other)
			local x1 = MeasureToCharStart(text, font, pos + len_other)
			local x2 = MeasureToCharStart(text, font, pos + len_word + len_other)
			local word_box = box(text_start + x1, target_box:miny(), text_start + x2, target_box:maxy())
			StretchText(word, word_box, font, self.HighlightColor)
			pos = pos + len_word + len_other
		end
	until not word
	return true
end