--[[
Copyright (c) 2008, LibTooltip Development Team 

All rights reserved.

Redistribution and use in source and binary forms, with or without 
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice, 
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice, 
      this list of conditions and the following disclaimer in the documentation 
      and/or other materials provided with the distribution.
    * Redistribution of a stand alone version is strictly prohibited without 
      prior written authorization from the Lead of the LibTooltip Development Team. 
    * Neither the name of the LibTooltip Development Team nor the names of its contributors 
      may be used to endorse or promote products derived from this software without 
      specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--]]

assert(LibStub, "LibTooltip-1.0 requires LibStub")
local MAJOR, MINOR = "LibTooltip-1.0", 2
local LibTooltip, oldminor = LibStub:NewLibrary(MAJOR, MINOR)
if not LibTooltip then return end -- No upgrade needed

-- Internal constants to tweak the layout
local TOOLTIP_PADDING = 10
local CELL_MARGIN = 3

local bgFrame = {
	edgeFile = "Interface\\Tooltips\\UI-Tooltip-Border",
	bgFile = "Interface\\Tooltips\\UI-Tooltip-Background",
	tile = true,
	tileSize = 16,
	edgeSize = 16,
	insets = {left = 5, right = 5, top = 5, bottom = 5}
}

------------------------------------------------------------------------------
-- Tables and locals
------------------------------------------------------------------------------

LibTooltip.frameMetatable = LibTooltip.frameMetatable or {__index = CreateFrame("Frame")}

LibTooltip.tipPrototype = LibTooltip.tipPrototype or setmetatable({}, LibTooltip.frameMetatable)
LibTooltip.tipMetatable = LibTooltip.tipMetatable or {__index = LibTooltip.tipPrototype}

LibTooltip.providerPrototype = LibTooltip.providerPrototype or {}
LibTooltip.providerMetatable = LibTooltip.providerMetatable or {__index = LibTooltip.providerPrototype}

LibTooltip.cellPrototype = LibTooltip.cellPrototype or setmetatable({}, LibTooltip.frameMetatable)
LibTooltip.cellMetatable = LibTooltip.cellMetatable or { __index = LibTooltip.cellPrototype }

LibTooltip.activeTooltips = LibTooltip.activeTooltips or {}
LibTooltip.tooltipHeap = LibTooltip.tooltipHeap or {}

LibTooltip.frameHeap = LibTooltip.frameHeap or {}

local tipPrototype = LibTooltip.tipPrototype
local tipMetatable = LibTooltip.tipMetatable

local providerPrototype = LibTooltip.providerPrototype
local providerMetatable = LibTooltip.providerMetatable

local cellPrototype = LibTooltip.cellPrototype
local cellMetatable = LibTooltip.cellMetatable

local activeTooltips = LibTooltip.activeTooltips
local tooltipHeap = LibTooltip.tooltipHeap

local frameHeap = LibTooltip.frameHeap

-- Tooltip private methods
local InitializeTooltip, FinalizeTooltip, ResetTooltipSize, ResizeColspans
local AcquireCell, ReleaseCell

------------------------------------------------------------------------------
-- Public library API
------------------------------------------------------------------------------

function LibTooltip:Acquire(key, ...)
	if key == nil then
		error("attempt to use a nil key", 2)
	end
	local tooltip = activeTooltips[key]
	if not tooltip then
		tooltip = tremove(tooltipHeap) or setmetatable(CreateFrame("Frame", nil, UIParent), tipMetatable)
		InitializeTooltip(tooltip, key)
		activeTooltips[key] = tooltip
	end
	if select('#', ...) > 0 then
	  -- Here we catch any error to properly report it for the calling code
		local ok, msg = pcall(tooltip.SetColumnLayout, tooltip, ...)
		if not ok then error(msg, 2) end 
	end
	return tooltip
end

function LibTooltip:IsAcquired(key)
	if key == nil then
		error("attempt to use a nil key", 2)
	end
	return not not activeTooltips[key]
end

function LibTooltip:Release(tooltip)
	local key = tooltip and tooltip.key
	if not key or activeTooltips[key] ~= tooltip then return end
	tooltip:Hide()
	FinalizeTooltip(tooltip)
	tinsert(tooltipHeap, tooltip)
	activeTooltips[key] = nil
end

function LibTooltip:IterateTooltips()
	return pairs(activeTooltips)
end

------------------------------------------------------------------------------
-- Frame heap
------------------------------------------------------------------------------

local function AcquireFrame(parent)
	local frame = tremove(frameHeap) or CreateFrame("Frame")
	frame:SetParent(parent)
	return frame
end

local function ReleaseFrame(frame)
	frame:Hide()
	frame:SetParent(nil)
	frame:ClearAllPoints()
	tinsert(frameHeap, frame)
end

------------------------------------------------------------------------------
-- CellProvider and Cell
------------------------------------------------------------------------------

-- Provider prototype

function providerPrototype:AcquireCell(tooltip)
	local cell = tremove(self.heap)
	if not cell then
		cell = setmetatable(CreateFrame("Frame", nil, tooltip), self.cellMetatable)
		if type(cell.InitializeCell) == 'function' then
			cell:InitializeCell()
		end
	end
	self.cells[cell] = true
	return cell
end

function providerPrototype:ReleaseCell(cell)
	if not self.cells[cell] then return end
	if type(cell.ReleaseCell) == 'function' then
		cell:ReleaseCell()
	end
	self.cells[cell] = nil
	tinsert(self.heap, cell)
end

function providerPrototype:GetCellPrototype()
	return self.cellPrototype, self.cellMetatable
end

function providerPrototype:IterateCells()
	return pairs(self.cells)
end

-- Cell provider factory

function LibTooltip:CreateCellProvider(baseProvider)
	local cellBaseMetatable, cellBasePrototype
	if baseProvider and baseProvider.GetCellPrototype then
		cellBasePrototype, cellBaseMetatable = baseProvider:GetCellPrototype()
	else
		cellBaseMetatable = cellMetatable
	end
	local cellPrototype = setmetatable({}, cellBaseMetatable)
	local cellProvider = setmetatable({}, providerMetatable)
	cellProvider.heap = {}
	cellProvider.cells = {}
	cellProvider.cellPrototype = cellPrototype
	cellProvider.cellMetatable = { __index = cellPrototype }
	return cellProvider, cellPrototype, cellBasePrototype
end

------------------------------------------------------------------------------
-- Basic label provider
------------------------------------------------------------------------------

if not LibTooltip.LabelProvider then
	LibTooltip.LabelProvider, LibTooltip.LabelPrototype = LibTooltip:CreateCellProvider()
end

local labelProvider = LibTooltip.LabelProvider
local labelPrototype = LibTooltip.LabelPrototype

function labelPrototype:InitializeCell()
	self.fontString = self:CreateFontString()
	self.fontString:SetAllPoints(self)
  self.fontString:SetFontObject(GameTooltipText)
end

function labelPrototype:SetupCell(tooltip, value, justification, font, ...)
	local fs = self.fontString
	fs:SetFontObject(font or tooltip:GetFont())
	fs:SetJustifyH(justification)
	fs:SetText(tostring(value))
	fs:Show()
	return fs:GetStringWidth(), fs:GetStringHeight()
end

------------------------------------------------------------------------------
-- Helpers
------------------------------------------------------------------------------

local function checkFont(font, level, silent)
	if not font or type(font) ~= 'table' or type(font.IsObjectType) ~= 'function' or not font:IsObjectType("Font") then
		if silent then
			return false
		else
			error("font must be Font instance, not: "..tostring(font), level+1)
		end
	end
	return true
end

local function checkJustification(justification, level, silent)
	if justification ~= "LEFT" and justification ~= "CENTER" and justification ~= "RIGHT" then
		if silent then
			return false 
		else
			error("invalid justification, must one of LEFT, CENTER or RIGHT, not: "..tostring(justification), level+1)
		end
	end
	return true
end

------------------------------------------------------------------------------
-- Tooltip prototype
------------------------------------------------------------------------------

function InitializeTooltip(self, key)
	-- (Re)set frame settings
	self:SetBackdrop(bgFrame)
	self:SetBackdropColor(0.09, 0.09, 0.09)
	self:SetBackdropBorderColor(1, 1, 1)
	self:SetAlpha(0.9)
	self:SetScale(1.0)	
	self:SetFrameStrata("TOOLTIP")
	self:SetClampedToScreen(false)

	-- Our data
	self.key = key
	self.columns = self.columns or {}
	self.lines = self.lines or {}
	self.colspans = self.colspans or {}

	self.regularFont = GameTooltipText
	self.headerFont = GameTooltipHeaderText
	
	self:SetScript('OnShow', ResizeColspans)

	ResetTooltipSize(self)
end

function tipPrototype:SetColumnLayout(numColumns, ...)
	if type(numColumns) ~= "number" or numColumns < 1  then
		error("number of columns must be a positive number, not: "..tostring(numColumns), 2)
	end
	for i = 1, numColumns do
		local justification = select(i, ...) or "LEFT"
		checkJustification(justification, 2)
		if self.columns[i] then
			self.columns[i].justification = justification
		else
			self:AddColumn(justification)
		end
	end	
end

function tipPrototype:AddColumn(justification)
	justification = justification or "LEFT"
	checkJustification(justification, 2)
	local colNum = #self.columns + 1
	local column = AcquireFrame(self)
	column.justification = justification
	column.width = 0
	column:SetWidth(0)
	column:SetPoint("TOP", self, "TOP", 0, -TOOLTIP_PADDING)
	column:SetPoint("BOTTOM", self, "BOTTOM", 0, TOOLTIP_PADDING)
	if colNum > 1 then
		column:SetPoint("LEFT", self.columns[colNum-1], "RIGHT", CELL_MARGIN, 0)
		self.width = self.width + CELL_MARGIN
		self:SetWidth(self.width)
	else
		column:SetPoint("LEFT", self, "LEFT", TOOLTIP_PADDING, 0)
	end
	column:Show()
	self.columns[colNum] = column
	return colNum
end

function FinalizeTooltip(self)
	self:Clear()
	for i, column in ipairs(self.columns) do
		column:Hide()
		ReleaseFrame(column)
		self.columns[i] = nil
	end
end

function ResetTooltipSize(self)
	self.width = 2*TOOLTIP_PADDING + math.max(0, CELL_MARGIN * (#self.columns - 1))
	self.height = 2*TOOLTIP_PADDING
	self:SetWidth(self.width)
	self:SetHeight(self.height)
end

function tipPrototype:Clear()
	for i, line in ipairs(self.lines) do
		for j, cell in ipairs(line.cells) do
			ReleaseCell(self, cell)
			line.cells[j] = nil
		end
		line:Hide()
		ReleaseFrame(line)
		self.lines[i] = nil
	end
	for i, column in ipairs(self.columns) do
		column.width = 0
		column:SetWidth(0)
	end
	for k in pairs(self.colspans) do
		self.colspans[k] = nil
	end
	ResetTooltipSize(self)
end

function tipPrototype:SetFont(font)
	checkFont(font, 2)
	self.regularFont = font
end

function tipPrototype:GetFont() return self.regularFont end

function tipPrototype:SetHeaderFont(font)
	checkFont(font, 2)
	self.headerFont = font
end

function tipPrototype:GetHeaderFont() return self.headerFont end

local function EnlargeColumn(self, column, width)
	if width > column.width then
		self.width = self.width + width - column.width
		self:SetWidth(self.width)
		column.width = width
		column:SetWidth(width)			
	end
end

function ResizeColspans(self)
	if not self:IsShown() then return end
	local columns = self.columns
	for colRange, width in pairs(self.colspans) do
		local left, right = colRange:match("(%d)%-(%d)")
		left, right = tonumber(left), tonumber(right)
		for col = left, right-1 do 
			width = width - columns[col].width - CELL_MARGIN
		end
		EnlargeColumn(self, columns[right], width)
		self.colspans[colRange] = nil
	end
end

function AcquireCell(self, provider)
	local cell = provider:AcquireCell(self)
	cell:SetParent(self)
	cell:SetFrameLevel(self:GetFrameLevel()+1)	
	return cell
end

function ReleaseCell(self, cell)
	if cell and cell:GetParent() == self then
		cell:Hide()
		cell:SetParent(nil)
		cell:ClearAllPoints()
		cell._provider:ReleaseCell(cell)
	end
end

local function _SetCell(self, lineNum, colNum, value, font, justification, colSpan, provider, ...)
	local line = self.lines[lineNum]
	local cells = line.cells
	
	-- Unset: be quick
	if value == nil then
		local cell = cells[colNum]
		if cell then
			for i = colNum, colNum + cell._colSpan - 1 do
				cells[i] = nil
			end
			ReleaseCell(self, cell)
		end
		return lineNum, colNum
	end

	-- Check previous cell
	local cell
	local prevCell = cells[colNum]
	if prevCell == false then
		error("overlapping cells at column "..colNum, 3)
	elseif prevCell then
		-- There is a cell here
		font = font or prevCell._font
		justification = justification or prevCell._justification
		colSpan = colSpan or prevCell._colSpan
		if provider == nil or prevCell._provider == provider then
			-- Reuse existing cell
			cell = prevCell
			provider = cell._provider
		else
			-- A new cell is required
			ReleaseCell(self, prevCell)
			cells[colNum] = nil
		end
	else
		-- Creating a new cell, use meaning full defaults
		provider = provider or labelProvider
		font = font or self.regularFont
		justification = justification or self.columns[colNum].justification or "LEFT"
		colSpan = colSpan or 1
	end

	local tooltipWidth = #self.columns
	local rightColNum
	if colSpan > 0 then
		rightColNum = colNum + colSpan - 1
		if rightColNum > tooltipWidth then
			error("ColSpan too big, cell extends beyond right-most column", 3)
		end
	else
		-- Zero or negative: count back from right-most columns
		rightColNum = math.max(colNum, tooltipWidth + colSpan)
		-- Update colspan to its effective value
		colSpan = 1 + rightColNum - colNum
	end

	-- Cleanup colspans
	for i = colNum + 1, rightColNum do
		local cell = cells[i]
		if cell == false then
			error("overlapping cells at column "..i, 3)
		elseif cell then
			ReleaseCell(self, cell)
		end
		cells[i] = false
	end

	-- Create the cell and anchor it
	if not cell then
		cell = AcquireCell(self, provider)
		cell:SetPoint("LEFT", self.columns[colNum], "LEFT", 0, 0)
		cell:SetPoint("TOP", line, "TOP", 0, 0)
		cell:SetPoint("BOTTOM", line, "BOTTOM", 0, 0)
		cells[colNum] = cell
	end
	cell:SetPoint("RIGHT", self.columns[rightColNum], "RIGHT", 0, 0)
	
	-- Store the cell settings directly into the cell
	-- That's a bit risky but is is really cheap compared to other ways to do it
	cell._provider, cell._font, cell._justification, cell._colSpan = provider, font, justification, colSpan

	-- Setup the cell content
	local width, height = cell:SetupCell(tooltip, value, justification, font, ...)

	-- Enforce cell size
	cell:SetWidth(width)
	cell:SetHeight(height)
	cell:Show()

	if colSpan > 1 then
		-- Postpone width changes until the tooltip is shown
		local colRange = colNum.."-"..rightColNum
		self.colspans[colRange] = math.max(self.colspans[colRange] or 0, width)
	else
		-- Enlarge the column and tooltip if need be
		EnlargeColumn(self, self.columns[colNum], width)
	end

	-- Enlarge the line and tooltip if need be
	if height > line.height then
		self.height = self.height + height - line.height
		self:SetHeight(self.height)
		line.height = height
		line:SetHeight(height)
	end
	
	if rightColNum < tooltipWidth then
		return lineNum, rightColNum+1
	else
		return lineNum, nil
	end
end

local function CreateLine(self, font, ...)
	local line = AcquireFrame(self)
	local lineNum = #self.lines + 1
	line:SetPoint('LEFT', self, 'LEFT', TOOLTIP_PADDING, 0)
	line:SetPoint('RIGHT', self, 'RIGHT', -TOOLTIP_PADDING, 0)
	if lineNum > 1 then
		line:SetPoint('TOP', self.lines[lineNum-1], 'BOTTOM', 0, -CELL_MARGIN)
		self.height = self.height + CELL_MARGIN
		self:SetHeight(self.height)
	else
		line:SetPoint('TOP', self, 'TOP', 0, -TOOLTIP_PADDING)
	end
	self.lines[lineNum] = line
	line.cells = line.cells or {}
	line.height = 0
	line:SetHeight(0)
	line:Show()
	
	local colNum = 1
	for i = 1, #self.columns do
		local value = select(i, ...)
		if value ~= nil then
			lineNum, colNum = _SetCell(self, lineNum, i, value, font, nil, 1, labelProvider)
		end
	end
	return lineNum, colNum
end

function tipPrototype:AddLine(...)
	local lineNum, colNum = CreateLine(self, self.regularFont, ...)
	ResizeColspans(self)
	return lineNum, colNum
end

function tipPrototype:AddHeader(...)
	local lineNum, colNum = CreateLine(self, self.headerFont, ...)
	ResizeColspans(self)
	return lineNum, colNum
end

function tipPrototype:SetCell(lineNum, colNum, value, ...)
	-- Mandatory argument checking
	if type(lineNum) ~= "number" then
		error("line number must be a number, not: "..tostring(lineNum), 2)
	elseif lineNum < 1 or lineNum > #self.lines then
		error("line number out of range: "..tostring(lineNum), 2)
	elseif type(colNum) ~= "number" then
		error("column number must be a number, not: "..tostring(colNum), 2)
	elseif colNum < 1 or colNum > #self.columns then
		error("column number out of range: "..tostring(colNum), 2)
	end

	-- Variable argument checking
	local font, justification, colSpan, provider
	local i, arg = 1, ...
	if arg == nil or checkFont(arg, 2, true) then
		i, font, arg = 2, ...
	end
	if arg == nil or checkJustification(arg, 2, true) then
		i, justification, arg = i+1, select(i, ...)
	end
	if arg == nil or type(arg) == 'number' then
		i, colSpan, arg = i+1, select(i, ...)
	end
	if arg == nil or type(arg) == 'table' and type(arg.AcquireCell) == 'function' then
		i, provider = i+1, arg
	end

	lineNum, colNum = _SetCell(self, lineNum, colNum, value, font, justification, colSpan, provider, select(i, ...))
	ResizeColspans(self)
	return lineNum, colNum
end

function tipPrototype:GetLineCount() return #self.lines end

function tipPrototype:GetColumnCount() return #self.columns end

------------------------------------------------------------------------------
-- "Smart" Anchoring (work in progress)
------------------------------------------------------------------------------
local function GetTipAnchor(frame)
	local x,y = frame:GetCenter()
	if not x or not y then return "TOPLEFT", "BOTTOMLEFT" end
	local hhalf = (x > UIParent:GetWidth()*2/3) and "RIGHT" or (x < UIParent:GetWidth()/3) and "LEFT" or ""
	local vhalf = (y > UIParent:GetHeight()/2) and "TOP" or "BOTTOM"
	return vhalf..hhalf, frame, (vhalf == "TOP" and "BOTTOM" or "TOP")..hhalf
end

function tipPrototype:SmartAnchorTo(frame)
	if not frame then
		error("Invalid frame provided.", 2)
	end
	self:ClearAllPoints()
	self:SetClampedToScreen(true)
	self:SetPoint(GetTipAnchor(frame))
end