--!strict
local Constants = require(script.Parent.Constants)
local Types = require(script.Parent.Types)

local Tokenizer = {}

function Tokenizer.ResolveImage(Name: string): string?
	return Constants.Images[Name]
end

function Tokenizer.Tokenize(Text: string): { Types.Segment }
	local Segments: { Types.Segment } = {}
	local Cursor = 1
	local Length = #Text

	while Cursor <= Length do
		local TokenStart, TokenEnd, Name = string.find(Text, Constants.TokenPattern, Cursor)
		if not TokenStart or not TokenEnd or not Name then
			table.insert(Segments, { Kind = "Text", Value = string.sub(Text, Cursor) })
			break
		end

		if Tokenizer.ResolveImage(Name) then
			if TokenStart > Cursor then
				table.insert(Segments, { Kind = "Text", Value = string.sub(Text, Cursor, TokenStart - 1) })
			end
			table.insert(Segments, { Kind = "Image", Value = Name })
		else
			table.insert(Segments, { Kind = "Text", Value = string.sub(Text, Cursor, TokenEnd) })
		end
		Cursor = TokenEnd + 1
	end

	return Segments
end

function Tokenizer.ContainsImage(Segments: { Types.Segment }): boolean
	for _, Segment in Segments do
		if Segment.Kind == "Image" then
			return true
		end
	end
	return false
end

function Tokenizer.JoinText(Segments: { Types.Segment }): string
	local Pieces: { string } = {}
	for _, Segment in Segments do
		if Segment.Kind == "Text" then
			table.insert(Pieces, Segment.Value)
		end
	end
	return table.concat(Pieces)
end

return Tokenizer