-- Movable Unit Frames
-- Extended frame support adapted from TokensWorth/ShaguTweaks-mods
-- (MIT, original copyright GryllsAddons).

local _G = ShaguTweaks.GetGlobalEnv()
local T = ShaguTweaks.T
local API = ShaguTweaks.API

local module = ShaguTweaks:register({
  title = T["Movable Unit Frames"],
  description = T["Player, Target, Party, Minimap, Clock, Timer, Buffs, Weapon Buffs and Debuffs can be moved while <Shift> and <Ctrl> are pressed together. Right-click a frame to reset its position."],
  expansions = { ["vanilla"] = true },
  category = T["Unit Frames"],
  enabled = true,
})

module.enable = function(self)
  ShaguTweaks_config = ShaguTweaks_config or {}
  ShaguTweaks_config["MoveUnitframes"] = ShaguTweaks_config["MoveUnitframes"] or {}

  local movedb = ShaguTweaks_config["MoveUnitframes"]

  -- Shared live state lets other modules (notably Enlarged Minimap) respect
  -- manually positioned aura anchors without fighting the mover while dragging.
  ShaguTweaks.MovableUnitFramesState = ShaguTweaks.MovableUnitFramesState or {
    manual = {},
    dragging = {},
  }
  local sharedState = ShaguTweaks.MovableUnitFramesState

  -- Preserve positions created by the former Extras module. The legacy table
  -- is intentionally left untouched so downgrading does not destroy data.
  local legacy = ShaguTweaks_config["MoveUnitframesExtended"]
  if legacy then
    for key, value in pairs(legacy) do
      if movedb[key] == nil then
        movedb[key] = value
      end
    end
  end

  -- Existing saved positions already mean those groups were manually placed.
  -- This also covers positions migrated from the former Extras module.
  sharedState.manual.buffs = movedb["BuffButton0"] ~= nil
  sharedState.manual.debuffs = movedb["BuffButton32"] ~= nil
  sharedState.manual.weapon = movedb["TempEnchant1"] ~= nil
  sharedState.manual.clock = movedb["Clock"] ~= nil
  sharedState.manual.timer = movedb["MinimapTimer"] ~= nil
  sharedState.dragging.buffs = false
  sharedState.dragging.debuffs = false
  sharedState.dragging.weapon = false
  sharedState.dragging.clock = false
  sharedState.dragging.timer = false

  local unlocked = false
  local states = {}
  local defaultPoints = {}
  local grid

  -- Player/Target keep the original ShaguTweaks user-placed behavior.
  -- The formerly-Extended frames use ShaguTweaks_config so their positions
  -- survive reload/relog consistently. defaultPoint is only a fallback for
  -- frames whose live pre-move anchor cannot be recovered (for example a
  -- layout-cache position restored before addons load).
  local targets = {
    {
      name = "PlayerFrame", clamp = true, persist = false,
      defaultPoint = { "TOPLEFT", "UIParent", "TOPLEFT", -19, -4 },
      defaultUnclamped = true,
    },
    {
      name = "TargetFrame", clamp = true, persist = false,
      defaultPoint = { "TOPLEFT", "UIParent", "TOPLEFT", 250, -4 },
      defaultUnclamped = true,
    },
    {
      name = "PartyMemberFrame1", persist = true,
      defaultPoint = { "TOPLEFT", "UIParent", "TOPLEFT", 10, -128 },
    },
    {
      name = "PartyMemberFrame2", persist = true,
      defaultPoint = { "TOPLEFT", "PartyMemberFrame1PetFrame", "BOTTOMLEFT", -23, -10 },
    },
    {
      name = "PartyMemberFrame3", persist = true,
      defaultPoint = { "TOPLEFT", "PartyMemberFrame2PetFrame", "BOTTOMLEFT", -23, -10 },
    },
    {
      name = "PartyMemberFrame4", persist = true,
      defaultPoint = { "TOPLEFT", "PartyMemberFrame3PetFrame", "BOTTOMLEFT", -23, -10 },
    },
    {
      name = "Minimap", moveParent = true, persist = true, clamp = true,
      defaultPoint = { "TOPRIGHT", "UIParent", "TOPRIGHT", 0, 0 },
    },
    {
      name = "MinimapClock", persist = true, clamp = true,
      manualGroup = "clock", suppressMouseDown = true,
      defaultPoint = { "BOTTOM", "MinimapCluster", "BOTTOM", 8, 18 },
    },
    {
      -- MiniMap Clock already owns Ctrl+Shift+RightClick for the timer and
      -- resets both its value and its position, so keep that native handler.
      name = "MinimapTimer", persist = true, clamp = true,
      manualGroup = "timer", nativeReset = true,
      defaultPoint = { "TOP", "MinimapClock", "BOTTOM", 0, 0 },
    },
    {
      name = "BuffButton0", persist = true, manualGroup = "buffs",
      cursorDrag = true, refreshAuras = true,
      defaultPoint = { "TOPRIGHT", "BuffFrame", "TOPRIGHT", 0, 0 },
    },
    {
      -- Turtle WoW dynamically positions the first debuff row, so let its
      -- own BuffButtons_UpdatePositions() rebuild the natural relationship.
      name = "BuffButton32", persist = true, manualGroup = "debuffs",
      cursorDrag = true, auraRowReset = true,
    },
    {
      name = "TempEnchant1", persist = true, manualGroup = "weapon",
      cursorDrag = true, refreshAuras = true,
      defaultPoint = { "TOPRIGHT", "TemporaryEnchantFrame", "TOPRIGHT", 0, 0 },
    },
  }

  local function Resolve(target)
    local handle = _G[target.name]
    if not handle then return end

    local moveFrame = target.moveParent and handle:GetParent() or handle
    if not moveFrame then return end

    return handle, moveFrame
  end

  local function PositionKey(target, moveFrame)
    if moveFrame.GetName then
      local name = moveFrame:GetName()
      if name then return name end
    end

    return target.name
  end

  local function CapturePoints(frame)
    if not frame or not frame.GetPoint then return end

    local count = frame.GetNumPoints and frame:GetNumPoints() or 1
    local points = {}

    for i = 1, count do
      local point, relativeTo, relativePoint, x, y = frame:GetPoint(i)
      if point then
        table.insert(points, {
          point,
          relativeTo,
          relativePoint,
          x or 0,
          y or 0,
        })
      end
    end

    if table.getn(points) > 0 then return points end
  end

  local function CaptureDefault(target)
    local _, moveFrame = Resolve(target)
    if not moveFrame then return end

    local key = PositionKey(target, moveFrame)
    if target.persist and movedb[key] ~= nil then return end

    -- A user-placed frame may already have been restored by layout-cache before
    -- addon initialization. Do not mistake that old custom position for default.
    if moveFrame.IsUserPlaced and moveFrame:IsUserPlaced() then return end

    defaultPoints[target.name] = CapturePoints(moveFrame)
  end

  local function ApplyCapturedPoints(frame, points)
    if not frame or not points or table.getn(points) == 0 then return false end

    frame:ClearAllPoints()
    for _, point in ipairs(points) do
      frame:SetPoint(point[1], point[2], point[3], point[4], point[5])
    end

    return true
  end

  local function ApplyNamedDefault(target, frame)
    local point = target.defaultPoint
    if not point or not frame then return false end

    local relativeTo = point[2] and _G[point[2]] or nil
    if point[2] and not relativeTo then return false end

    frame:ClearAllPoints()
    frame:SetPoint(point[1], relativeTo, point[3], point[4] or 0, point[5] or 0)
    return true
  end

  local function SetDragging(target, value)
    if target.manualGroup then
      sharedState.dragging[target.manualGroup] = value and true or false
    end
  end

  local function MarkManual(target)
    if target.manualGroup then
      sharedState.manual[target.manualGroup] = true
    end
  end

  local function ClearManual(target)
    if target.manualGroup then
      sharedState.manual[target.manualGroup] = false
      sharedState.dragging[target.manualGroup] = false
    end
  end

  local function SavePosition(target, moveFrame)
    if not target.persist then return end

    if not moveFrame then
      local _, resolved = Resolve(target)
      moveFrame = resolved
    end
    if not moveFrame then return end

    local left = moveFrame:GetLeft()
    local top = moveFrame:GetTop()
    if not left or not top then return end

    movedb[PositionKey(target, moveFrame)] = { left, top }
    MarkManual(target)
  end

  local function RestorePosition(target)
    if not target.persist then return end

    local _, moveFrame = Resolve(target)
    if not moveFrame then return end

    local pos = movedb[PositionKey(target, moveFrame)]
    if not pos or not pos[1] or not pos[2] then return end

    if not target.cursorDrag then
      moveFrame:SetMovable(true)
      if moveFrame.SetUserPlaced then moveFrame:SetUserPlaced(true) end
    end
    moveFrame:ClearAllPoints()
    moveFrame:SetPoint("TOPLEFT", UIParent, "BOTTOMLEFT", pos[1], pos[2])

    if target.name == "Minimap" and ShaguTweaks.ScheduleMinimapClamp then
      ShaguTweaks.ScheduleMinimapClamp()
    end
  end

  -- Aura buttons are layout-owned frames on some Vanilla/Turtle UI builds.
  -- Calling StartMoving() on them can fail with "Frame ... is not movable or
  -- resizable" even after SetMovable(true). For those frames, follow the cursor
  -- ourselves and only change their anchor; regular unit frames still use the
  -- native StartMoving path.
  local cursorDrag = CreateFrame("Frame")
  cursorDrag:Hide()

  local function CursorPosition()
    local x, y = GetCursorPosition()
    local scale = UIParent:GetEffectiveScale()
    if not scale or scale <= 0 then scale = 1 end
    return x / scale, y / scale
  end

  local function StartCursorDrag(state, target, moveFrame)
    local left = moveFrame:GetLeft()
    local top = moveFrame:GetTop()
    if not left or not top then return false end

    local x, y = CursorPosition()
    state.cursorStartX = x
    state.cursorStartY = y
    state.frameStartLeft = left
    state.frameStartTop = top

    cursorDrag.state = state
    cursorDrag.target = target
    cursorDrag.moveFrame = moveFrame
    cursorDrag:Show()
    return true
  end

  local function StopCursorDrag(state)
    if cursorDrag.state ~= state then return end

    cursorDrag:Hide()
    cursorDrag.state = nil
    cursorDrag.target = nil
    cursorDrag.moveFrame = nil
  end

  local function ResetTarget(state, target, moveFrame)
    if not moveFrame then
      local _, resolved = Resolve(target)
      moveFrame = resolved
    end
    if not moveFrame then return end

    if target.cursorDrag and state then StopCursorDrag(state) end

    if target.persist then
      movedb[PositionKey(target, moveFrame)] = nil
    end
    ClearManual(target)

    if not target.cursorDrag and moveFrame.SetUserPlaced then
      moveFrame:SetUserPlaced(false)
    end

    local restored = ApplyCapturedPoints(moveFrame, defaultPoints[target.name])

    if not restored and target.auraRowReset then
      moveFrame:ClearAllPoints()
      if BuffButtons_UpdatePositions then
        BuffButtons_UpdatePositions()
        restored = true
      end
    end

    if not restored then
      if target.defaultUnclamped and moveFrame.SetClampedToScreen then
        moveFrame:SetClampedToScreen(false)
      end
      restored = ApplyNamedDefault(target, moveFrame)
    end

    if target.refreshAuras and BuffButtons_UpdatePositions then
      BuffButtons_UpdatePositions()
    end

    if target.name == "Minimap" and ShaguTweaks.ScheduleMinimapClamp then
      ShaguTweaks.ScheduleMinimapClamp()
    end

    if state then
      state.dragged = false
      state.reset = true
      state.suppressRightClick = true
      state.userPlaced = false
    end
  end

  cursorDrag:SetScript("OnUpdate", function()
    local state = this.state
    local target = this.target
    local moveFrame = this.moveFrame
    if not state or not target or not moveFrame then
      this:Hide()
      return
    end

    local x, y = CursorPosition()
    local left = state.frameStartLeft + (x - state.cursorStartX)
    local top = state.frameStartTop + (y - state.cursorStartY)

    moveFrame:ClearAllPoints()
    moveFrame:SetPoint("TOPLEFT", UIParent, "BOTTOMLEFT", left, top)
  end)

  local function CreateGrid()
    if grid then return grid end

    -- Keep the original WorldFrame coordinate space so the cells retain the
    -- same visual size as the old grid. Instead of deriving the yellow center
    -- lines from top-left offsets, build the whole grid symmetrically around
    -- WorldFrame:CENTER. This guarantees the two yellow axes are truly centered
    -- regardless of UI scale / widescreen coordinate quirks.
    grid = CreateFrame("Frame", nil, WorldFrame)
    grid:SetAllPoints(WorldFrame)
    grid:Hide()

    local size = 1
    local step = GetScreenWidth() / 64

    -- Vertical lines: 32 cells to the left and right of the exact center.
    for i = -32, 32 do
      local line = grid:CreateTexture(nil, i == 0 and "BORDER" or "BACKGROUND")

      if i == 0 then
        line:SetTexture(.8, .6, 0)
      else
        line:SetTexture(0, 0, 0, .2)
      end

      line:SetWidth(size)
      line:SetPoint("TOP", grid, "TOP", i * step, 0)
      line:SetPoint("BOTTOM", grid, "BOTTOM", i * step, 0)
    end

    -- Use the exact same step vertically so every cell remains square, as in
    -- the original implementation. Extra off-screen lines are harmless.
    for i = -32, 32 do
      local line = grid:CreateTexture(nil, i == 0 and "BORDER" or "BACKGROUND")

      if i == 0 then
        line:SetTexture(.8, .6, 0)
      else
        line:SetTexture(0, 0, 0, .2)
      end

      line:SetHeight(size)
      line:SetPoint("LEFT", grid, "LEFT", 0, i * step)
      line:SetPoint("RIGHT", grid, "RIGHT", 0, i * step)
    end

    return grid
  end

  local function UnlockTarget(index, target)
    local handle, moveFrame = Resolve(target)
    if not handle or not moveFrame then return end

    states[index] = states[index] or {}
    local state = states[index]
    if state.active then return end

    state.active = true
    state.dragged = false
    state.reset = false
    state.suppressRightClick = false
    state.handle = handle
    state.moveFrame = moveFrame
    state.onDragStart = handle:GetScript("OnDragStart")
    state.onDragStop = handle:GetScript("OnDragStop")
    state.onMouseDown = handle:GetScript("OnMouseDown")
    state.onMouseUp = handle:GetScript("OnMouseUp")
    state.hasClick = handle.RegisterForClicks and true or false
    if state.hasClick then
      state.onClick = handle:GetScript("OnClick")
    else
      state.onClick = nil
    end

    if handle.IsMouseEnabled then
      state.mouseEnabled = handle:IsMouseEnabled() and true or false
    else
      state.mouseEnabled = nil
    end

    if not target.cursorDrag and moveFrame.IsMovable then
      state.movable = moveFrame:IsMovable() and true or false
    else
      state.movable = nil
    end

    if not target.cursorDrag and moveFrame.IsUserPlaced then
      state.userPlaced = moveFrame:IsUserPlaced() and true or false
    else
      state.userPlaced = nil
    end

    if target.clamp and moveFrame.SetClampedToScreen then
      moveFrame:SetClampedToScreen(true)
    end

    -- Aura buttons can reject StartMoving() on some clients. They only need
    -- mouse/drag scripts because cursorDrag handles their position directly.
    if not target.cursorDrag then
      moveFrame:SetMovable(true)
    end
    handle:EnableMouse(true)
    handle:RegisterForDrag("LeftButton")

    -- While Ctrl+Shift mode owns the frame, Ctrl+Shift+RightClick resets only
    -- that frame and swallows its normal right-click action (unit menu, buff
    -- cancel, minimap zoom, etc.). MiniMap Timer keeps its own native reset.
    if not target.nativeReset then
      handle:SetScript("OnMouseDown", function()
        if arg1 == "RightButton" then
          state.suppressRightClick = true
          ResetTarget(state, target, moveFrame)
          return
        end

        state.suppressRightClick = false
        if not target.suppressMouseDown and state.onMouseDown then
          state.onMouseDown()
        end
      end)

      handle:SetScript("OnMouseUp", function()
        if arg1 == "RightButton" and state.suppressRightClick then return end
        if state.onMouseUp then state.onMouseUp() end
      end)

      if state.hasClick then
        handle:SetScript("OnClick", function()
          if arg1 == "RightButton" and state.suppressRightClick then
            state.suppressRightClick = false
            return
          end

          if state.onClick then state.onClick() end
        end)
      end
    end

    handle:SetScript("OnDragStart", function()
      state.dragged = true
      state.reset = false
      MarkManual(target)
      SetDragging(target, true)

      if not target.cursorDrag and moveFrame.SetUserPlaced then
        moveFrame:SetUserPlaced(true)
      end

      if target.cursorDrag then
        if not StartCursorDrag(state, target, moveFrame) then
          state.dragged = false
          SetDragging(target, false)
        end
      else
        moveFrame:StartMoving()
      end
    end)

    handle:SetScript("OnDragStop", function()
      if target.cursorDrag then
        StopCursorDrag(state)
      else
        moveFrame:StopMovingOrSizing()
      end

      if state.dragged then
        SavePosition(target, moveFrame)
      end

      SetDragging(target, false)
    end)
  end

  local function LockTarget(index, target)
    local state = states[index]
    if not state or not state.active then return end

    local handle = state.handle
    local moveFrame = state.moveFrame

    if moveFrame then
      if target.cursorDrag then
        StopCursorDrag(state)
      else
        moveFrame:StopMovingOrSizing()
      end
      SetDragging(target, false)

      if state.dragged then
        SavePosition(target, moveFrame)
      end

      -- MiniMap Timer has its own Ctrl+Shift reset path. Detect its
      -- SetUserPlaced(false) so releasing the modifiers does not undo it.
      if target.nativeReset
        and not state.dragged
        and state.userPlaced
        and moveFrame.IsUserPlaced
        and not moveFrame:IsUserPlaced() then
        state.reset = true
        state.userPlaced = false
      end

      -- Restore UserPlaced while the frame is still temporarily movable.
      -- Some Vanilla/Turtle frames (notably MinimapCluster) reject
      -- SetUserPlaced() after SetMovable(false), which caused repeated
      -- "not movable or resizable" errors when releasing Ctrl+Shift.
      if not target.cursorDrag
        and not state.dragged
        and not state.reset
        and state.userPlaced ~= nil
        and moveFrame.SetUserPlaced then
        moveFrame:SetUserPlaced(state.userPlaced)
      end

      if not target.cursorDrag and state.movable ~= nil then
        moveFrame:SetMovable(state.movable)
      end
    end

    if handle then
      handle:SetScript("OnDragStart", state.onDragStart)
      handle:SetScript("OnDragStop", state.onDragStop)

      if not target.nativeReset then
        handle:SetScript("OnMouseDown", state.onMouseDown)
        handle:SetScript("OnMouseUp", state.onMouseUp)
        if state.hasClick then
          handle:SetScript("OnClick", state.onClick)
        end
      end

      if state.mouseEnabled ~= nil then
        handle:EnableMouse(state.mouseEnabled)
      end
    end

    state.active = false
  end

  local function UnlockAll()
    if unlocked then return end
    unlocked = true

    for i, target in ipairs(targets) do
      UnlockTarget(i, target)
    end

    CreateGrid():Show()
  end

  local function LockAll()
    if not unlocked then return end

    for i, target in ipairs(targets) do
      LockTarget(i, target)
    end

    if grid then grid:Hide() end
    unlocked = false
  end

  local function UpdateLockState()
    if API.IsShiftKeyDown() and API.IsControlKeyDown() then
      UnlockAll()
    else
      LockAll()
    end
  end

  local events = CreateFrame("Frame")
  events:RegisterEvent("PLAYER_ENTERING_WORLD")

  if API.modifierstate then
    events:RegisterEvent("MODIFIER_STATE_CHANGED")
  end

  events:SetScript("OnEvent", function()
    if event == "PLAYER_ENTERING_WORLD" then
      for _, target in ipairs(targets) do
        RestorePosition(target)
      end
    end

    UpdateLockState()
  end)

  -- ClassicAPI supplies MODIFIER_STATE_CHANGED. Only old/fallback clients use
  -- a small throttled key-state check.
  if not API.modifierstate then
    events.elapsed = 0
    events:SetScript("OnUpdate", function()
      this.elapsed = this.elapsed + (arg1 or 0)
      if this.elapsed < .10 then return end
      this.elapsed = 0
      UpdateLockState()
    end)
  end

  -- Capture clean pre-move anchors before this module applies any saved
  -- positions. This preserves compatible addon/Turtle layouts when possible.
  for _, target in ipairs(targets) do
    CaptureDefault(target)

    if target.clamp then
      local _, moveFrame = Resolve(target)
      if moveFrame and moveFrame.SetClampedToScreen then
        moveFrame:SetClampedToScreen(true)
      end
    end

    RestorePosition(target)
  end

  UpdateLockState()
end