--[[-----------------------------------------------------------------------------
TabGroup Container
Container that uses tabs on top to switch between groups.
-------------------------------------------------------------------------------]]
local Type, Version = "TabGroup", 37
local AceGUI = LibStub and LibStub("AceGUI-3.0", true)
if not AceGUI or (AceGUI:GetWidgetVersion(Type) or 0) >= Version then
    return
end

-- Lua APIs
local pairs, ipairs, assert, type, wipe = pairs, ipairs, assert, type, wipe

-- WoW APIs
local PlaySound = PlaySound
local CreateFrame, UIParent = CreateFrame, UIParent
local _G = _G

-- Global vars/functions that we don't upvalue since they might get hooked, or upgraded
-- List them here for Mikk's FindGlobals script
-- GLOBALS: PanelTemplates_TabResize, PanelTemplates_SetDisabledTabState, PanelTemplates_SelectTab, PanelTemplates_DeselectTab

-- local upvalue storage used by BuildTabs
local widths = {}
local rowwidths = {}
local rowends = {}

--[[-----------------------------------------------------------------------------
Support functions
-------------------------------------------------------------------------------]]
local function UpdateTabLook(frame)
    if frame.disabled then
        PanelTemplates_SetDisabledTabState(frame)
    elseif frame.selected then
        PanelTemplates_SelectTab(frame)
    else
        PanelTemplates_DeselectTab(frame)
    end
end

local function Tab_SetText(frame, text)
    frame:_SetText(text)
    local width = frame.obj.frame.width or frame.obj.frame:GetWidth() or 0
    PanelTemplates_TabResize(frame, 0, nil, nil, width, frame:GetFontString():GetStringWidth())
end

local function Tab_SetSelected(frame, selected)
    frame.selected = selected
    UpdateTabLook(frame)
end

local function Tab_SetDisabled(frame, disabled)
    frame.disabled = disabled
    UpdateTabLook(frame)
end

local function BuildTabsOnUpdate(frame)
    local self = frame.obj
    self:BuildTabs()
    frame:SetScript("OnUpdate", nil)
end

--[[-----------------------------------------------------------------------------
Scripts
-------------------------------------------------------------------------------]]
local function Tab_OnClick(frame)
    if not (frame.selected or frame.disabled) then
        PlaySound(841) -- SOUNDKIT.IG_CHARACTER_INFO_TAB
        frame.obj:SelectTab(frame.value)
    end
end

local function Tab_OnEnter(frame)
    local self = frame.obj
    self:Fire("OnTabEnter", self.tabs[frame.id].value, frame)
end

local function Tab_OnLeave(frame)
    local self = frame.obj
    self:Fire("OnTabLeave", self.tabs[frame.id].value, frame)
end

local function Tab_OnShow(frame)
    _G[frame:GetName() .. "HighlightTexture"]:SetWidth(frame:GetTextWidth() + 30)
end

--[[-----------------------------------------------------------------------------
Methods
-------------------------------------------------------------------------------]]
local methods = {
    ["OnAcquire"] = function(self)
        self:SetTitle()
    end,

    ["OnRelease"] = function(self)
        self.status = nil
        for k in pairs(self.localstatus) do
            self.localstatus[k] = nil
        end
        self.tablist = nil
        for _, tab in pairs(self.tabs) do
            tab:Hide()
        end
    end,

    ["CreateTab"] = function(self, id)
        local tabname = ("AceGUITabGroup%dTab%d"):format(self.num, id)
        local tab = CreateFrame("Button", tabname, self.border, "OptionsFrameTabButtonTemplate")
        tab.obj = self
        tab.id = id

        tab.text = _G[tabname .. "Text"]
        tab.text:ClearAllPoints()
        tab.text:SetPoint("LEFT", 14, -3)
        tab.text:SetPoint("RIGHT", -12, -3)

        tab:SetScript("OnClick", Tab_OnClick)
        tab:SetScript("OnEnter", Tab_OnEnter)
        tab:SetScript("OnLeave", Tab_OnLeave)
        tab:SetScript("OnShow", Tab_OnShow)

        tab._SetText = tab.SetText
        tab.SetText = Tab_SetText
        tab.SetSelected = Tab_SetSelected
        tab.SetDisabled = Tab_SetDisabled

        return tab
    end,

    ["SetTitle"] = function(self, text)
        self.titletext:SetText(text or "")
        if text and text ~= "" then
            self.alignoffset = 25
        else
            self.alignoffset = 18
        end
        self:BuildTabs()
    end,

    ["SetStatusTable"] = function(self, status)
        assert(type(status) == "table")
        self.status = status
    end,

    ["SelectTab"] = function(self, value)
        local status = self.status or self.localstatus
        local found
        for i, v in ipairs(self.tabs) do
            if v.value == value then
                v:SetSelected(true)
                found = true
            else
                v:SetSelected(false)
            end
        end
        status.selected = value
        if found then
            self:Fire("OnGroupSelected", value)
        end
    end,

    ["SetTabs"] = function(self, tabs)
        self.tablist = tabs
        self:BuildTabs()
    end,


    ["BuildTabs"] = function(self)
        local hastitle = (self.titletext:GetText() and self.titletext:GetText() ~= "")
        local tablist = self.tablist
        local tabs = self.tabs

        if not tablist then
            return
        end

        local width = self.frame.width or self.frame:GetWidth() or 0

        wipe(widths)
        wipe(rowwidths)
        wipe(rowends)

        --Place Text into tabs and get thier initial width
        for i, v in ipairs(tablist) do
            local tab = tabs[i]
            if not tab then
                tab = self:CreateTab(i)
                tabs[i] = tab
            end

            tab:Show()
            tab:SetText(v.text)
            tab:SetDisabled(v.disabled)
            tab.value = v.value

            widths[i] = tab:GetWidth() - 6 --tabs are anchored 10 pixels from the right side of the previous one to reduce spacing, but add a fixed 4px padding for the text
        end

        for i = (#tablist) + 1, #tabs, 1 do
            tabs[i]:Hide()
        end

        --First pass, find the minimum number of rows needed to hold all tabs and the initial tab layout
        local numtabs = #tablist
        local numrows = 1
        local usedwidth = 0

        for i = 1, #tablist do
            --If this is not the first tab of a row and there isn't room for it
            if usedwidth ~= 0 and (width - usedwidth - widths[i]) < 0 then
                rowwidths[numrows] = usedwidth + 10 --first tab in each row takes up an extra 10px
                rowends[numrows] = i - 1
                numrows = numrows + 1
                usedwidth = 0
            end
            usedwidth = usedwidth + widths[i]
        end
        rowwidths[numrows] = usedwidth + 10 --first tab in each row takes up an extra 10px
        rowends[numrows] = #tablist

        --Fix for single tabs being left on the last row, move a tab from the row above if applicable
        if numrows > 1 then
            --if the last row has only one tab
            if rowends[numrows - 1] == numtabs - 1 then
                --if there are more than 2 tabs in the 2nd last row
                if (numrows == 2 and rowends[numrows - 1] > 2) or (rowends[numrows] - rowends[numrows - 1] > 2) then
                    --move 1 tab from the second last row to the last, if there is enough space
                    if (rowwidths[numrows] + widths[numtabs - 1]) <= width then
                        rowends[numrows - 1] = rowends[numrows - 1] - 1
                        rowwidths[numrows] = rowwidths[numrows] + widths[numtabs - 1]
                        rowwidths[numrows - 1] = rowwidths[numrows - 1] - widths[numtabs - 1]
                    end
                end
            end
        end

        --anchor the rows as defined and resize tabs to fill thier row
        local starttab = 1
        for row, endtab in ipairs(rowends) do
            local first = true
            for tabno = starttab, endtab do
                local tab = tabs[tabno]
                tab:ClearAllPoints()
                if first then
                    tab:SetPoint("TOPLEFT", self.frame, "TOPLEFT", 0, -(hastitle and 14 or 7) - (row - 1) * 20)
                    first = false
                else
                    tab:SetPoint("LEFT", tabs[tabno - 1], "RIGHT", -10, 0)
                end
            end

            -- equal padding for each tab to fill the available width,
            -- if the used space is above 75% already
            -- the 18 pixel is the typical width of a scrollbar, so we can have a tab group inside a scrolling frame,
            -- and not have the tabs jump around funny when switching between tabs that need scrolling and those that don't
            local padding = 0
            if not (numrows == 1 and rowwidths[1] < width * 0.75 - 18) then
                padding = (width - rowwidths[row]) / (endtab - starttab + 1)
            end

            for i = starttab, endtab do
                PanelTemplates_TabResize(tabs[i], padding + 4, nil, nil, width, tabs[i]:GetFontString():GetStringWidth())
            end
            starttab = endtab + 1
        end

        self.borderoffset = (hastitle and 17 or 10) + ((numrows) * 20)
        self.border:SetPoint("TOPLEFT", 1, -self.borderoffset)
    end,

    ["OnWidthSet"] = function(self, width)
        local content = self.content
        local contentwidth = width - 60
        if contentwidth < 0 then
            contentwidth = 0
        end
        content:SetWidth(contentwidth)
        content.width = contentwidth
        self:BuildTabs(self)
        self.frame:SetScript("OnUpdate", BuildTabsOnUpdate)
    end,

    ["OnHeightSet"] = function(self, height)
        local content = self.content
        local contentheight = height - (self.borderoffset + 23)
        if contentheight < 0 then
            contentheight = 0
        end
        content:SetHeight(contentheight)
        content.height = contentheight
    end,

    ["LayoutFinished"] = function(self, width, height)
        if self.noAutoHeight then
            return
        end
        self:SetHeight((height or 0) + (self.borderoffset + 23))
    end
}

--[[-----------------------------------------------------------------------------
Constructor
-------------------------------------------------------------------------------]]
local PaneBackdrop = {
    bgFile = "Interface\\ChatFrame\\ChatFrameBackground",
    edgeFile = "Interface\\Tooltips\\UI-Tooltip-Border",
    tile = true, tileSize = 16, edgeSize = 16,
    insets = { left = 3, right = 3, top = 5, bottom = 3 }
}

local function Constructor()
    local num = AceGUI:GetNextWidgetNum(Type)
    local frame = CreateFrame("Frame", nil, UIParent)
    frame:SetHeight(100)
    frame:SetWidth(100)
    frame:SetFrameStrata("FULLSCREEN_DIALOG")

    local titletext = frame:CreateFontString(nil, "OVERLAY", "GameFontNormal")
    titletext:SetPoint("TOPLEFT", 14, 0)
    titletext:SetPoint("TOPRIGHT", -14, 0)
    titletext:SetJustifyH("LEFT")
    titletext:SetHeight(18)
    titletext:SetText("")

    local border = CreateFrame("Frame", nil, frame, BackdropTemplateMixin and "BackdropTemplate" or nil)
    border:SetPoint("TOPLEFT", 1, -27)
    border:SetPoint("BOTTOMRIGHT", -1, 3)
    border:SetBackdrop(PaneBackdrop)
    border:SetBackdropColor(0.1, 0.1, 0.1, 0.5)
    border:SetBackdropBorderColor(0.4, 0.4, 0.4)

    local content = CreateFrame("Frame", nil, border)
    content:SetPoint("TOPLEFT", 10, -7)
    content:SetPoint("BOTTOMRIGHT", -10, 7)

    local widget = {
        num = num,
        frame = frame,
        localstatus = {},
        alignoffset = 18,
        titletext = titletext,
        border = border,
        borderoffset = 27,
        tabs = {},
        content = content,
        type = Type
    }
    for method, func in pairs(methods) do
        widget[method] = func
    end

    return AceGUI:RegisterAsContainer(widget)
end

AceGUI:RegisterWidgetType(Type, Constructor, Version)
