-- Dead-simple modal dialogue overlay driven by a narrator (Ink) story.
-- No variables, no saved state: open a book, walk its paragraphs, pick a
-- choice, then a keypress dismisses it. `narrator` is the global set up in
-- main.lua; Dialogable entities (see npc.lua) call Dialogue.open on bump.
Dialogue = {}

local story             -- active narrator story, or nil when the box is closed
local paragraphs = {}   -- text lines currently shown
local choices = {}      -- current choices (empty once we reach an ending)
local selected = 1

function Dialogue.isOpen()
	return story ~= nil
end

-- Run the story forward to the next choice point (or the end), gathering every
-- paragraph printed along the way.
local function advance()
	paragraphs = {}
	while story:can_continue() do
		for _, p in ipairs(story:continue()) do
			table.insert(paragraphs, p.text)
		end
	end
	choices = story:can_choose() and story:get_choices() or {}
	selected = 1
end

function Dialogue.open(book)
	if story then return end          -- already talking: ignore repeat bumps
	story = narrator.init_story(book)
	story:begin()
	advance()
end

function Dialogue.close()
	story, paragraphs, choices, selected = nil, {}, {}, 1
end

function Dialogue.keypressed(key)
	if #choices == 0 then
		-- an ending is on screen: any key dismisses the box
		Dialogue.close()
	elseif key == "up" then
		selected = selected > 1 and selected - 1 or #choices
	elseif key == "down" then
		selected = selected < #choices and selected + 1 or 1
	elseif key == "return" or key == "space" or key == "x" then
		story:choose(selected)
		advance()
	end
end

-- LCD font sized to the current play area, rebuilt only when the size changes,
-- so dialogue text scales with the game like every sprite does.
local dlgFont, dlgFontSize
local function dialogueFont()
	local size = math.max(8, math.floor(height / gridHeight * 0.4))
	if not dlgFont or size ~= dlgFontSize then
		dlgFont = love.graphics.newFont("font/LCD_Solid.ttf", size)
		dlgFontSize = size
	end
	return dlgFont
end

function Dialogue.draw()
	if not story then return end

	local fnt = dialogueFont()
	local fh = fnt:getHeight()
	local pad, lineH = fh * 0.8, fh * 1.3
	local boxH = height * 0.4
	local y0 = height - boxH
	local wrap = width - pad * 2

	-- Dialogue obeys the world's colour rule: only the channels the player has
	-- are rendered. One colour -> that colour; all three -> white (additive), so
	-- a red-only player literally reads the sign in red.
	local has = { red = false, green = false, blue = false }
	for _, c in ipairs(currentRoom.colorsPlayerHas) do has[c] = true end
	local r = has.red and 1 or 0
	local g = has.green and 1 or 0
	local b = has.blue and 1 or 0

	local prevFont = love.graphics.getFont()
	love.graphics.setFont(fnt)

	love.graphics.setColor(0, 0, 0, 0.82)
	love.graphics.rectangle("fill", 0, y0, width, boxH)

	local y = y0 + pad
	love.graphics.setColor(r, g, b, 1)
	for _, text in ipairs(paragraphs) do
		love.graphics.printf(text, pad, y, wrap)
		local _, lines = fnt:getWrap(text, wrap)
		y = y + math.max(1, #lines) * lineH
	end

	y = y + lineH * 0.5
	for i, choice in ipairs(choices) do
		local dim = (i == selected) and 1 or 0.5   -- selected is brighter + "> "
		love.graphics.setColor(r * dim, g * dim, b * dim, 1)
		local line = ((i == selected) and "> " or "  ") .. choice.text
		love.graphics.printf(line, pad, y, wrap)
		local _, lines = fnt:getWrap(line, wrap)
		y = y + math.max(1, #lines) * lineH
	end

	love.graphics.setFont(prevFont)
end