local DataTableUtils = require("Utils.DataTableUtils")
local ESlateVisibility = import("ESlateVisibility")
local SlateBlueprintLibrary = import("SlateBlueprintLibrary")
local WidgetLayoutLibrary = import("WidgetLayoutLibrary")
local BusyGamePlayLibrary = import("BusyGamePlayLibrary")

--- @class PreCookCenterWidget
--- @field ImgContainer table
--- @field ImgCookMaterial table
local PreCookCenterWidget = {}

function PreCookCenterWidget:ctor()
    self.mouse_tracks = {}
    self.is_pressed = false
end


function PreCookCenterWidget:OnInitialized()
    self.bHasScriptImplementedTick = true

    self.BtnMain.OnReleased:Add(function()
        -- self.bHasScriptImplementedTick = false
        self.is_pressed = false
        print("release")
    end)
    self.BtnMain.OnPressed:Add(function()
        self.mouse_tracks = {}
        self.is_pressed = true
        -- self.bHasScriptImplementedTick = true
        print("pressed")
    end)
    -- self.BtnMain.OnClicked:Add(function()
    --     print("onclicked")
    -- end)

    self.DataTexture = BusyGamePlayLibrary.CreateTextureBuffer(self)
end

function PreCookCenterWidget:Construct()
    -- self.bHasScriptImplementedTick = true
end

function PreCookCenterWidget:Destruct()

end

function PreCookCenterWidget:SetEmpty()
    self.ImgContainer:SetVisibility(ESlateVisibility.Collapsed)
    self.ImgCookMaterial:SetVisibility(ESlateVisibility.Collapsed)
end

function PreCookCenterWidget:AddContainer(pre_cook_contianer_id)
    local row = DataTableUtils.GetDataTableRow("PreCookItemConfig", pre_cook_contianer_id)
    if not row then return end
    self.ImgContainer:SetBrushFromSoftTexture(row.CenterDisplayResource, true)
    self.ImgContainer:SetVisibility(ESlateVisibility.SelfHitTestInvisible)
end

function PreCookCenterWidget:RemoveContainer()
    self.ImgContainer:SetVisibility(ESlateVisibility.Collapsed)
end

function PreCookCenterWidget:AddCookMaterial(pre_cook_material_id)
    local row = DataTableUtils.GetDataTableRow("PreCookItemConfig", pre_cook_material_id)
    if not row then return end
    self.ImgCookMaterial:SetBrushFromSoftTexture(row.CenterDisplayResource, true)
    self.ImgCookMaterial:SetVisibility(ESlateVisibility.SelfHitTestInvisible)
end


local function UpdateOldMouseTrack(old_mouse_tracks, delta_time)
    local new_mouse_tracks = {}
    for _, track in pairs(old_mouse_tracks) do
        track.remain = track.remain - delta_time
        if track.remain > 0 then
            table.insert(new_mouse_tracks, track)
        end
    end
    return new_mouse_tracks
end


local function UpdateCutMaskByTracks(widget, mouse_tracks)
    local FVector2D = import("Vector2D")
    local FWidgetTransform = import("WidgetTransform")
    if #mouse_tracks < 2 then return end

    local translation, scale = FVector2D(), FVector2D()
    local render_transform = FWidgetTransform()
    local first_point, last_point = mouse_tracks[1], mouse_tracks[#mouse_tracks]
    local delta_x = last_point.X - first_point.X
    local delta_y = last_point.Y - first_point.Y
    local mask_length = (delta_x^2 + delta_y^2)^0.5



    translation.X, translation.Y = first_point.X, first_point.Y
    scale.X, scale.Y = mask_length / 512, 1
    render_transform.Scale = scale
    render_transform.Translation = translation
    render_transform.Angle = (math.atan(delta_y, delta_x) / (2 * math.pi)) * 360

    widget:SetRenderTransform(render_transform)
end


--- 从起点到终点画一条线，以这条线为新的x坐标轴，将所有的点坐标映射到新坐标系下
local function TransformCurveToEndpointAxes(points)
    local A = points[1]
    local B = points[#points]

    -- 计算向量AB
    local dx = B.X - A.X
    local dy = B.Y - A.Y
    local len = math.sqrt(dx * dx + dy * dy)
    if len == 0 then
        return {}
        -- error("Start and end points are the same, cannot define X-axis.")
    end

    -- 计算X轴单位向量
    local ux = dx / len
    local uy = dy / len

    -- 计算Y轴单位向量（逆时针旋转90度）
    local vx = -uy
    local vy = ux

    -- 映射所有点到新坐标系
    local new_points = {}
    for i, point in ipairs(points) do
        local apx = point.X - A.X
        local apy = point.Y - A.Y
        local new_x = apx * ux + apy * uy  -- 点积与X轴单位向量
        local new_y = apx * vx + apy * vy  -- 点积与Y轴单位向量
        new_points[i] = {X = new_x, Y = new_y}
    end

    return new_points
end


--- 将曲线的Y坐标规范到(-0.5，0.5)的范围内，供材质使用
local function NormalizeCurveYToHalfRange(points)
    if #points < 2 then return end
    local length = points[#points].X - points[1].X
    for _, point in pairs(points) do
        point.Y = - point.Y / length  -- 临时加个取反
        point.X = point.X / length
    end
    return points
end


function PreCookCenterWidget:Tick(geometry, delta_time)
    local size = SlateBlueprintLibrary.GetLocalSize(geometry)
    local cursor_pos = WidgetLayoutLibrary.GetMousePositionOnViewport(self)
    local left_top = SlateBlueprintLibrary.GetLocalTopLeft(geometry)
    local fixed_x = math.min(math.max(cursor_pos.X - left_top.X, 0), size.X)
    local fixed_y = math.min(math.max(cursor_pos.Y - left_top.Y, 0), size.Y)

    local mouse_tracks = UpdateOldMouseTrack(self.mouse_tracks, delta_time)

    if self.is_pressed then
        table.insert(mouse_tracks, {X=fixed_x, Y=fixed_y, remain=0.5})
    end

    -- 计算样条参数
    if #mouse_tracks > 2 then
        local transformed_tracks = TransformCurveToEndpointAxes(mouse_tracks)
        local normalize_tracks = NormalizeCurveYToHalfRange(transformed_tracks)

        local offsets = {}
        for _, track in pairs(normalize_tracks) do
            table.insert(offsets, track.Y)
        end

        BusyGamePlayLibrary.UpdateTextureBuffer(self.DataTexture, offsets)

        local mi = self.ImgMask:GetDynamicMaterial()
        mi:SetTextureParameterValue("Param", self.DataTexture)
        mi:SetScalarParameterValue("VertexCount", #offsets)
        mi:SetScalarParameterValue("SourceWidth", 512)
        UpdateCutMaskByTracks(self.ImgMask, mouse_tracks)
    end

    self.mouse_tracks = mouse_tracks
end


return Class(nil, nil, PreCookCenterWidget)