---------------------------------------------------------------------------------------------------
-- Quest Widget
---------------------------------------------------------------------------------------------------
local ADDON_NAME, Addon = ...
local ThreatPlates = Addon.ThreatPlates

local Widget = Addon.Widgets:NewWidget("Script")

---------------------------------------------------------------------------------------------------
-- Imported functions and constants
---------------------------------------------------------------------------------------------------

-- Lua APIs
local next, pairs, ipairs = next, pairs, ipairs
local assert, setmetatable = assert, setmetatable
local string_format = string.format

-- WoW APIs
local pcall = pcall
local CreateFrame = CreateFrame
local loadstring, setfenv = loadstring, setfenv

-- ThreatPlates APIs
local L = ThreatPlates.L
local PrintDebugMessage = Addon.PrintDebugMessage

local _G =_G

---------------------------------------------------------------------------------------------------
-- Local variables
---------------------------------------------------------------------------------------------------

Addon.SCRIPT_FUNCTIONS = {
  Standard = {
    IsEnabled = "IsEnabled", OnEnable = "OnEnable", OnDisable = "OnDisable",
    EnabledForStyle = "EnabledForStyle",
    Create = "Create", UpdateFrame = "UpdateFrame", UpdateSettings = "UpdateSettings", UpdateLayout = "UpdateLayout",
    OnUnitAdded = "OnUnitAdded", OnUnitRemoved = "OnUnitRemoved", OnUpdate = "OnUpdate",
    WoWEvent = "Event",
  },
  TargetOnly = {
    IsEnabled = "IsEnabled", OnEnable = "OnEnable", OnDisable = "OnDisable",
    EnabledForStyle = "EnabledForStyle",
    Create = "Create", UpdateFrame = "UpdateFrame", UpdateSettings = "UpdateSettings", UpdateLayout = "UpdateLayout",
    OnTargetUnitAdded = "OnTargetUnitAdded", OnTargetUnitRemoved = "OnTargetUnitRemoved", OnUpdate = "OnUpdate",
    WoWEvent = "Event",
  },
  FocusOnly = {
    IsEnabled = "IsEnabled", OnEnable = "OnEnable", OnDisable = "OnDisable",
    EnabledForStyle = "EnabledForStyle",
    Create = "Create", UpdateFrame = "UpdateFrame", UpdateSettings = "UpdateSettings", UpdateLayout = "UpdateLayout",
    OnFocusUnitAdded = "OnFocusUnitAdded", OnFocusUnitRemoved = "OnFocusUnitRemoved", OnUpdate = "OnUpdate",
    WoWEvent = "Event",
  },
}

Addon.WIDGET_EVENTS = {
  IsEnabled = {
    FunctionExample = [[
-- Example for function IsEnabled:
function()
  -- Return false or nil, to disable the script, e.g., when it should be only active on a certain class
end]]
  },
  OnEnable = {
    FunctionExample = [[
-- Example for function OnEnable:
function()
  --
end]]
  },
  OnDisable = {
    FunctionExample = [[
-- Example for function OnDisable:
function()
  --
end]]
  },
  EnabledForStyle = {
    FunctionExample = [[
-- Example for function EnabledForStyle:
function(style_name, unit)
  -- return not (style == "NameOnly" or style == "NameOnly-Unique" or style == "etotem")
end]]
  },
  Create = {
    FunctionExample = [[
-- Example for function Create:
function(widget_frame)
  -- ...
end]]
  },
  UpdateFrame = {
    FunctionExample = [[
-- Example for function UpdateFrame:
function(widget_frame, unit)
  -- ...
end]]
  },
  UpdateSettings = {
    FunctionExample = [[
-- Example for function UpdateSettings:
function()
  -- ...
end]]
  },
  UpdateLayout = {
    FunctionExample = [[
-- Example for function UpdateLayout:
function()
  -- ...
end]]
  },
  OnUnitAdded = {
    FunctionExample = [[
-- Example for function OnUnitAdded:
function(widget_frame, unit)
  -- ...
end]]
  },
  OnUnitRemoved = {
    FunctionExample = [[
-- Example for function OnUnitRemoved:
function(widget_frame, unit)
  -- ...
end]]
  },
  OnTargetUnitAdded = {
    FunctionExample = [[
-- Example for function OnTargetUnitAdded:
function(tp_frame, unit)
  -- ...
end]]
  },
  OnTargetUnitRemoved = {
    FunctionExample = [[
-- Example for function OnTargetUnitRemoved:
function()
  -- ...
end]]
  },
  OnFocusUnitAdded = {
    FunctionExample = [[
-- Example for function OnFocusUnitAdded:
function(tp_frame, unit)
  -- ...
end]]
  },
  OnFocusUnitRemoved = {
    FunctionExample = [[
-- Example for function OnFocusUnitRemoved:
function()
  -- ...
end]]
  },
  OnUpdate = {
    FunctionExample = [[
-- Example for function OnUpdate:
function(tp_frame)
  -- ...
end]]
  },
  WoWEvent = {
    FunctionExample = [[
-- Example for processing a WoW event:
function(...)
  -- Do some event processing
end]]
  },
}

---------------------------------------------------------------------------------------------------
-- (Protected) environ for scripts
---------------------------------------------------------------------------------------------------

local ScriptEnvironmentByStyle = {}
--local CurrentScriptEnvironment

-- Blocked functions and tables for WoW or Lua - thanks to WeakAuras
local BlockedFunctions = {
  -- Lua functions that may allow breaking out of the environment

  -- Block run code inside code
  getfenv = true,
  setfenv = true,
  loadstring = true,
  pcall = true,
  xpcall = true,
  RunScript = true,
  securecall = true,
  DevTools_DumpCommand = true,
  ["getglobal"] = true,
  ["setmetatable"] = true,

  -- Block access to particular frames
  BankFrame	= true,
  TradeFrame = true,
  GuildBankFrame = true,
  MailFrame = true,
  EnumerateFrames = true,

  --Block guild commands
  GuildDisband = true,
  GuildUninvite = true,
  ["C_GuildInfo"] = { -- This should block everything of C_GuildInfo
    ["RemoveFromGuild"] = true,
  },

  -- Block mail, trades, action house, banks
  SendMail = true,
  SetTradeMoney = true,
  AddTradeMoney = true,
  PickupTradeMoney = true,
  PickupPlayerMoney = true,
  AcceptTrade = true,
  SetSendMailMoney = true,
  ["C_AuctionHouse"] 	= true,
  ["C_Bank"] = true,
  ["C_GuildBank"] = true,

  -- Avoid creating macros
  CreateMacro = true,
  EditMacro = true,
  hash_SlashCmdList = true,
  SetBindingMacro = true,

  -- Other things
  ["C_GMTicketInfo"] = true,
}

local BlockedTables = {
  SlashCmdList = true,
}

local OverwrittenFunctionsForScripts = {
  print = function(...) print (...) end,
  PlatesByUnit = Addon.PlatesByUnit,
  PlatesByGUID = Addon.PlatesByGUID,
}


local function WarningForBlockedAccess(key)
  Addon.PrintWarningMessage(string_format(L["Forbidden function or table called from script: %s"], key))
end

local EnvironmentGetGlobal

--local ScriptEnvironment = setmetatable({},
--  {
--    __index = function(t, k)
--      if k == "_G" then
--        return t
--      elseif k == "getglobal" then
--        return EnvironmentGetGlobal
--      elseif k == "ScriptEnvironment" then
--        return CurrentScriptEnvironment
--      elseif BlockedFunctions[k] then
--        return WarningForBlockedAccess
--      elseif BlockedTables[k] then
--        return WarningForBlockedAccess(k)
--      elseif OverwrittenFunctionsForScripts[k] then
--        return OverwrittenFunctionsForScripts[k]
--      else
--        return _G[k]
--      end
--    end,
--    __newindex = function(table, key, value)
--      if _G[key] then
--        Addon.PrintMessage("Warning", string.format(L["The script has overwritten the global '%s', this might affect other scripts ."], key))
--      end
--      rawset(table, key, value)
--    end,
--    __metatable = false,
--  })

local ScriptEnvironment =
  {
    __index = function(t, k)
      if k == "_G" then
        return t
      elseif k == "getglobal" then
        return EnvironmentGetGlobal
--      elseif k == "ScriptEnvironment" then
--        return CurrentScriptEnvironment
      elseif BlockedFunctions[k] then
        return WarningForBlockedAccess
      elseif BlockedTables[k] then
        return WarningForBlockedAccess(k)
      elseif OverwrittenFunctionsForScripts[k] then
        return OverwrittenFunctionsForScripts[k]
      else
        return _G[k]
      end
    end,
    __newindex = function(table, key, value)
      if _G[key] then
        Addon.PrintWarningMessage(string_format(L["A script has overwritten the global '%s'. This might affect other scripts ."], key))
      end
      rawset(table, key, value)
    end,
    --__metatable = false,
  }

function EnvironmentGetGlobal(k)
  return ScriptEnvironment[k]
end

--function Addon.ActiveScriptEnvironment(custom_style)
--  local script_environment = ScriptEnvironmentByStyle[custom_style]
--
--  if not script_environment then
--    script_environment = {}
--    ScriptEnvironmentByStyle[custom_style] = script_environment
--  end
--
--  script_environment.Style = custom_style
--
--  CurrentScriptEnvironment = script_environment
--end

local function GetScriptEnvironment(custom_style)
  local script_environment = ScriptEnvironmentByStyle[custom_style]

  if not script_environment then
    script_environment = {
      Environment = {
        Style = custom_style,
      }
    }
    ScriptEnvironmentByStyle[custom_style] = script_environment
  end

  setmetatable(script_environment, ScriptEnvironment)

  return script_environment
end

-- The difference between these two is that script-triggered custom styles are used on all nameplates
-- while custom styles with no script trigger are only used on nameplates that match the custom style's
-- trigger
local ScriptsByCustomStyle = {}
local ScriptsForAllPlates = {}

local InitializedPlatesByStyle = {}
local EnabledForStyle = {}

---------------------------------------------------------------------------------------------------
-- Widget functions for creation and update
---------------------------------------------------------------------------------------------------

-- arg1 can be nil, widget_frame or style, depending on the event processed
local function ProcessEvent(event, widget_frame, unit)
  local func

  --print("ProcessEvent:", event, unit and unit.CustomPlateSettings or "nil")

  -- unit might be nil, e.g., when ProcessEvent is called for Create
  if unit then
    local custom_style = unit.CustomPlateSettings

    if custom_style and ScriptsByCustomStyle[custom_style] then
      if event ~= "OnUnitAdded" or EnabledForStyle[custom_style][unit.unitid] then
        func = ScriptsByCustomStyle[custom_style][event]
        if func then
          --print ("Process Custom Style:", custom_style.Trigger.Type, custom_style.Trigger[custom_style.Trigger.Type].Input, event)
          local call_ok, return_value = pcall(func, widget_frame, unit)
          if not call_ok then
            Addon.PrintErrorMessage(string_format(L["Error in event script '%s' of custom style '%s': %s"], event, Addon.CustomPlateGetHeaderName(custom_style), return_value))
          end
        end
      end
    end
  end

  for custom_style, _ in pairs(ScriptsForAllPlates) do
    if event ~= "OnUnitAdded" or EnabledForStyle[custom_style][unit.unitid] then
      local func = ScriptsForAllPlates[custom_style][event]
      if func then
        --print ("Process Script Trigger:", event, widget_frame, unit)
        local call_ok, return_value = pcall(func, widget_frame, unit)
        if not call_ok then
          Addon.PrintErrorMessage(string_format(L["Error in event script '%s' of custom style '%s': %s"], event, Addon.CustomPlateGetHeaderName(custom_style), return_value))
        end
      end
    end
  end
end

local OnUpdateHandler = CreateFrame("Frame", "ThreatPlatesScriptOnUpdateHandler", UIParent)

local function OnUpdate(widget_frame, elapsed)
  ProcessEvent("OnUpdate")
end

function Widget:IsEnabled()
  local is_enabled = Addon.ActiveScriptTrigger and Addon.db.global.ScriptingIsEnabled

  if is_enabled then
    ProcessEvent("IsEnabled")
  end

  return is_enabled
end

function Widget:OnEnable()
  ProcessEvent("OnEnable")
end

function Widget:OnDisable()
  for _, custom_style in ipairs(Addon.Cache.CustomPlateTriggers.Script) do
    for event, _ in pairs(custom_style.Scripts.Code.Events) do
      --print ("Unregistering:", event)
      self:UnregisterEvent(event)
    end
  end

  ProcessEvent("OnDisable")
end

function Widget:EnabledForStyle(style, unit)
  local func

  --print("ProcessEvent:", "EnabledForStyle", unit and unit.CustomPlateSettings or "nil")

  -- Don't process the event if the custom style is not enabled for this the current style:
  -- OnUnitAdded => widget_frame.Active
  -- Store Ative / EnabledForStyle for each custom style => EnabledForStyleByCustomStyle

  local custom_style = unit.CustomPlateSettings
  if custom_style and ScriptsByCustomStyle[custom_style] then
    func = ScriptsByCustomStyle[custom_style].EnabledForStyle
    if func then
      --print ("Process Custom Style:", custom_style.Trigger.Type, custom_style.Trigger[custom_style.Trigger.Type].Input, "EnabledForStyle")
      local call_ok, return_value = pcall(func, style, unit)
      if call_ok then
        EnabledForStyle[custom_style][unit.unitid] = return_value == true
      else
        Addon.PrintErrorMessage(string_format(L["Error in event script '%s' of custom style '%s': %s"], "EnabledForStyle", Addon.CustomPlateGetHeaderName(custom_style), return_value))
        EnabledForStyle[custom_style][unit.unitid] = false
      end
    else
      EnabledForStyle[custom_style][unit.unitid] = true
    end
  end

  for custom_style, _ in pairs(ScriptsForAllPlates) do
    local func = ScriptsForAllPlates[custom_style].EnabledForStyle
    if func then
      --print ("Process Script Trigger: EnabledForStyle", style, unit)
      local call_ok, return_value = pcall(func, style, unit)
      if call_ok then
        EnabledForStyle[custom_style][unit.unitid] = return_value == true
      else
        Addon.PrintErrorMessage(string_format(L["Error in event script '%s' of custom style '%s': %s"], "EnabledForStyle", Addon.CustomPlateGetHeaderName(custom_style), return_value))
        EnabledForStyle[custom_style][unit.unitid] = false
      end
    else
      EnabledForStyle[custom_style][unit.unitid] = true
    end
  end

  return true
end

function Widget:Create(tp_frame)
  -- Required Widget Code
  local widget_frame = CreateFrame("Frame", nil, tp_frame)

  -- Custom Code
  --------------------------------------
  widget_frame:SetFrameLevel(tp_frame:GetFrameLevel())
  widget_frame:SetAllPoints(tp_frame)
  widget_frame:Hide()

  ProcessEvent("Create", widget_frame)
  --------------------------------------
  -- End Custom Code

  return widget_frame
end

local function InitializeNonScriptTriggerScripts(widget_frame, unit)
  -- If this is a trigger-based script (not script-trigger), the nameplate might not
  -- yet have been initialized with Create
  local custom_style = unit.CustomPlateSettings
  if custom_style then
    local custom_style_init = InitializedPlatesByStyle[custom_style] or {}
    InitializedPlatesByStyle[custom_style] = custom_style_init

    if not custom_style_init[widget_frame] then
      ProcessEvent("Create", widget_frame)
      custom_style_init[widget_frame] = true
    end
  end
end

function Widget:OnUnitAdded(widget_frame, unit)
  InitializeNonScriptTriggerScripts(widget_frame, unit)
  ProcessEvent("OnUnitAdded", widget_frame, unit)

  if unit.isTarget then
    ProcessEvent("OnTargetUnitAdded", widget_frame, unit)
  end

  if unit.IsFocus then
    ProcessEvent("OnFocusUnitAdded", widget_frame, unit)
  end

  --widget_frame:Show()
  widget_frame:SetShown(unit.CustomPlateSettings or next(ScriptsForAllPlates))
end

function Widget:OnUnitRemoved(widget_frame, unit)
  ProcessEvent("OnUnitRemoved", widget_frame, unit)

  if unit.isTarget then
    ProcessEvent("OnTargetUnitRemoved", widget_frame, unit)
  end

  if unit.IsFocus then
    ProcessEvent("OnFocusUnitRemoved", widget_frame, unit)
  end

  --widget_frame:SetShown(unit.CustomPlateSettings or next(ScriptsForAllPlates))
end

function Widget:UpdateFrame(widget_frame, unit)
  ProcessEvent("UpdateFrame", widget_frame, unit)
end

function Widget:UpdateLayout(widget_frame)
  ProcessEvent("UpdateLayout", widget_frame)
end

local ScriptsForWoWEvents = {}

local function HandleWoWEvent(event, ...)
  local custom_styles = ScriptsForWoWEvents[event]
  if custom_styles then
    for custom_style, func in pairs(custom_styles) do
      local call_ok, error_message = pcall(func, ...)
      if not call_ok then
        Addon.PrintErrorMessage(string_format(L["Error in event script '%s' of custom style '%s': %s"], event, Addon.CustomPlateGetHeaderName(custom_style), error_message))
      end
    end
  end
end

-- Load settings from the configuration which are shared across all aura widgets
-- used (for each widget) in UpdateWidgetConfig
function Widget:UpdateSettings()
  self.CustomStyles = Addon.db.profile.uniqueSettings

  ScriptsForAllPlates = {}
  ScriptsByCustomStyle = {}
  ScriptsForWoWEvents = {}
  EnabledForStyle = {}

  if not self:IsEnabled() then return end

  local on_update_script_used = false

  for i, custom_style in ipairs(Addon.Cache.CustomPlateTriggers.Script) do
    --PrintDebugMessage("Reloading Script Style:", i, "=>", Addon.CustomPlateGetHeaderName(custom_style))
    EnabledForStyle[custom_style] = EnabledForStyle[custom_style] or {}

    -- Register scripting events
    for event, script in pairs(custom_style.Scripts.Code.Functions) do
      --PrintDebugMessage("=> Event:", event)
      -- Don't add OnUnitAdded for target/focus-based scripts
      if script and script ~= "" and Addon.SCRIPT_FUNCTIONS[custom_style.Scripts.Type][event] then
        local func = Addon.LoadScript(script, custom_style, event)
        if func then
          if custom_style.Trigger.Type == "Script" then
            ScriptsForAllPlates[custom_style] = ScriptsForAllPlates[custom_style] or {}
            ScriptsForAllPlates[custom_style][event] = func
          else
            ScriptsByCustomStyle[custom_style] = ScriptsByCustomStyle[custom_style] or {}
            ScriptsByCustomStyle[custom_style][event] = func
          end

          on_update_script_used = on_update_script_used or event == "OnUpdate"
        end
      end
    end

    -- Register WoW events
    for event, script in pairs(custom_style.Scripts.Code.Events) do
      --PrintDebugMessage("=> WoW Event:", event)
      if script and script ~= "" then
        local func = Addon.LoadScript(script, custom_style, event)
        if func then
          ScriptsForWoWEvents[event] = ScriptsForWoWEvents[event] or {}
          ScriptsForWoWEvents[event][custom_style] = func
          if not pcall(self.RegisterEvent, self, event, HandleWoWEvent) then
            Addon.PrintErrorMessage(string_format(L["Attempt to register script for unknown WoW event '%s'"], event))
          end
        end
      end
    end
  end

  for custom_style, funcs_by_event in pairs(ScriptsForAllPlates) do
    --PrintDebugMessage("All Plates:", Addon.CustomPlateGetHeaderName(custom_style))

    -- Only load enabled scripts
    local script_is_enabled = true
    local func = funcs_by_event.IsEnabled
    if func then
      local call_ok, return_value = pcall(func)
      if call_ok then
        script_is_enabled = return_value
      else
        Addon.PrintErrorMessage(string_format(L["Error in event script '%s' of custom style '%s': %s"], "IsEnabled", Addon.CustomPlateGetHeaderName(custom_style), return_value))
        script_is_enabled = false
      end
    end

    --PrintDebugMessage("  =>", (script_is_enabled and "Enabled") or "Disabled")

    if script_is_enabled then
      local func = funcs_by_event.UpdateSettings
      if func then
        local call_ok, return_value = pcall(func)
        if not call_ok then
          Addon.PrintErrorMessage(string_format(L["Error in event script '%s' of custom style '%s': %s"], "UpdateSettings", Addon.CustomPlateGetHeaderName(custom_style), return_value))
        end
      end
    else
      ScriptsForAllPlates[custom_style] = nil
    end
  end

  for custom_style, funcs_by_event in pairs(ScriptsByCustomStyle) do
    --PrintDebugMessage ("By Custom Style Plates:", Addon.CustomPlateGetHeaderName(custom_style))

    -- Only load enabled scripts
    local script_is_enabled = true
    local func = funcs_by_event.IsEnabled
    if func then
      local call_ok, return_value = pcall(func)
      if call_ok then
        script_is_enabled = return_value
      else
        Addon.PrintErrorMessage(string_format(L["Error in event script '%s' of custom style '%s': %s"], "IsEnabled", Addon.CustomPlateGetHeaderName(custom_style), return_value))
        script_is_enabled = false
      end
    end

    --PrintDebugMessage("  =>", (script_is_enabled and "Enabled") or "Disabled")

    local func = funcs_by_event.UpdateSettings
    if func then
      local call_ok, error_message = pcall(func)
      if not call_ok then
        Addon.PrintErrorMessage(string_format(L["Error in event script '%s' of custom style '%s': %s"], "UpdateSettings", Addon.CustomPlateGetHeaderName(custom_style), return_value))
      end
    end
  end

  if on_update_script_used then
    --PrintDebugMessage("Enabling OnUpdate handling.")
    OnUpdateHandler:SetScript("OnUpdate", OnUpdate)
  else
    --PrintDebugMessage("Disabling OnUpdate handling.")
    OnUpdateHandler:SetScript("OnUpdate", nil)
  end
end

local ScriptFunctionCache = {}

function Addon.LoadScript(script_code, custom_style, event)
  --PrintDebugMessage("Loading Script:", event)

  local script_func = ScriptFunctionCache[script_code]
  if script_func then
    return script_func
  else
    --local info_header = "--[==[ Error in event script '" .. event .. "' of custom style '" .. (Addon.CustomPlateGetHeaderName(custom_style)) .. "' ]==] "
    local loaded_func, error_message = loadstring("return " .. script_code)
    if not loaded_func then
      Addon.PrintErrorMessage(string_format(L["Syntax error in event script '%s' of custom style '%s': %s"], event, Addon.CustomPlateGetHeaderName(custom_style), error_message))
    else
      setfenv(loaded_func, GetScriptEnvironment(custom_style))

      local call_ok, func = pcall(assert(loaded_func))
      if call_ok then
        ScriptFunctionCache[script_code] = func
        return func
      end
    end
  end
end