liecharts 0.1.0-beta

//! 视觉元素模块 - 纯数据描述，与渲染后端解耦

use vello_cpu::kurbo::{BezPath, Point, Rect, Vec2};
use crate::text::TextLayout;

/// 视觉元素枚举 - 纯数据描述，可被任何渲染后端解释
///
/// 设计原则：
/// - 纯数据，不包含任何渲染逻辑
/// - 使用标准几何类型（来自 kurbo）
/// - 支持嵌套组合（Group）
/// - 支持自定义扩展（Custom）
pub enum VisualElement {
    // ---- 基础图形 ----
    Rect {
        rect: Rect,
        style: FillStrokeStyle,
    },
    Circle {
        center: Point,
        radius: f64,
        style: FillStrokeStyle,
    },
    Line {
        start: Point,
        end: Point,
        style: StrokeStyle,
    },
    Polyline {
        points: Vec<Point>,
        style: StrokeStyle,
    },
    Path {
        path: BezPath,
        style: FillStrokeStyle,
    },

    // ---- 渐变路径 ----
    GradientPath {
        path: BezPath,
        gradient: GradientDef,
        stroke: Option<Stroke>,
    },

    // ---- 文本 ----
    TextRun {
        text: String,
        position: Point,  // 锚点位置（配合 align/baseline 确定文本块左上角）
        style: crate::model::TextStyle,  // 字体样式（包含 color, font_size, font_family, font_weight, font_style, align, vertical_align）
        rotation: f64,  // 弧度
        max_width: Option<f64>,
        layout: Option<TextLayout>,  // 预排版结果
    },

    // ---- 变换组合 ----
    Group {
        children: Vec<VisualElement>,
        transform: Option<Transform>,
    },
}

impl Clone for VisualElement {
    fn clone(&self) -> Self {
        match self {
            VisualElement::Rect { rect, style } => VisualElement::Rect {
                rect: *rect,
                style: style.clone(),
            },
            VisualElement::Circle { center, radius, style } => VisualElement::Circle {
                center: *center,
                radius: *radius,
                style: style.clone(),
            },
            VisualElement::Line { start, end, style } => VisualElement::Line {
                start: *start,
                end: *end,
                style: style.clone(),
            },
            VisualElement::Polyline { points, style } => VisualElement::Polyline {
                points: points.clone(),
                style: style.clone(),
            },
            VisualElement::Path { path, style } => VisualElement::Path {
                path: path.clone(),
                style: style.clone(),
            },
            VisualElement::GradientPath { path, gradient, stroke } => VisualElement::GradientPath {
                path: path.clone(),
                gradient: gradient.clone(),
                stroke: stroke.clone(),
            },
            VisualElement::TextRun { text, position, style, rotation, max_width, layout } => VisualElement::TextRun {
                text: text.clone(),
                position: *position,
                style: style.clone(),
                rotation: *rotation,
                max_width: *max_width,
                layout: layout.clone(),
            },
            VisualElement::Group { children, transform } => VisualElement::Group {
                children: children.clone(),
                transform: *transform,
            },
        }
    }
}

impl std::fmt::Debug for VisualElement {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            VisualElement::Rect { rect, style } => f
                .debug_struct("Rect")
                .field("rect", rect)
                .field("style", style)
                .finish(),
            VisualElement::Circle { center, radius, style } => f
                .debug_struct("Circle")
                .field("center", center)
                .field("radius", radius)
                .field("style", style)
                .finish(),
            VisualElement::Line { start, end, style } => f
                .debug_struct("Line")
                .field("start", start)
                .field("end", end)
                .field("style", style)
                .finish(),
            VisualElement::Polyline { points, style } => f
                .debug_struct("Polyline")
                .field("points", points)
                .field("style", style)
                .finish(),
            VisualElement::Path { path: _, style } => f
                .debug_struct("Path")
                .field("path", &"<BezPath>")
                .field("style", style)
                .finish(),
            VisualElement::GradientPath { path: _, gradient, stroke } => f
                .debug_struct("GradientPath")
                .field("path", &"<BezPath>")
                .field("gradient", gradient)
                .field("stroke", stroke)
                .finish(),
            VisualElement::TextRun { text, position, style, rotation, max_width, layout } => f
                .debug_struct("TextRun")
                .field("text", text)
                .field("position", position)
                .field("style", style)
                .field("rotation", rotation)
                .field("max_width", max_width)
                .field("layout", &layout.as_ref().map(|_| "<TextLayout>"))
                .finish(),
            VisualElement::Group { children, transform } => f
                .debug_struct("Group")
                .field("children", children)
                .field("transform", transform)
                .finish(),
        }
    }
}



/// 2D 变换
#[derive(Clone, Copy, Debug, Default)]
pub struct Transform {
    pub translate: Vec2,
    pub rotate: f64,  // 弧度
    pub scale: Vec2,
}

impl Transform {
    pub fn new() -> Self {
        Self::default()
    }

    pub fn with_translation(x: f64, y: f64) -> Self {
        Self {
            translate: Vec2::new(x, y),
            ..Default::default()
        }
    }

    pub fn with_rotation(angle: f64) -> Self {
        Self {
            rotate: angle,
            ..Default::default()
        }
    }

    pub fn with_scale(x: f64, y: f64) -> Self {
        Self {
            scale: Vec2::new(x, y),
            ..Default::default()
        }
    }
}

/// 颜色
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct Color {
    pub r: u8,
    pub g: u8,
    pub b: u8,
    pub a: u8,
}

impl Color {
    pub const fn new(r: u8, g: u8, b: u8) -> Self {
        Self { r, g, b, a: 255 }
    }

    pub const fn with_alpha(r: u8, g: u8, b: u8, a: u8) -> Self {
        Self { r, g, b, a }
    }

    pub fn set_alpha(&self, alpha: f64) -> Self {
        Self {
            r: self.r,
            g: self.g,
            b: self.b,
            a: (alpha.clamp(0.0, 1.0) * 255.0) as u8,
        }
    }

    /// 从十六进制字符串解析颜色
    pub fn from_hex(hex: &str) -> Option<Self> {
        let hex = hex.trim_start_matches('#');
        match hex.len() {
            6 => {
                let r = u8::from_str_radix(&hex[0..2], 16).ok()?;
                let g = u8::from_str_radix(&hex[2..4], 16).ok()?;
                let b = u8::from_str_radix(&hex[4..6], 16).ok()?;
                Some(Self::new(r, g, b))
            }
            8 => {
                let r = u8::from_str_radix(&hex[0..2], 16).ok()?;
                let g = u8::from_str_radix(&hex[2..4], 16).ok()?;
                let b = u8::from_str_radix(&hex[4..6], 16).ok()?;
                let a = u8::from_str_radix(&hex[6..8], 16).ok()?;
                Some(Self::with_alpha(r, g, b, a))
            }
            _ => None,
        }
    }
}

impl Default for Color {
    fn default() -> Self {
        Self::new(0, 0, 0)
    }
}

/// 渐变定义
#[derive(Clone, Debug)]
pub struct GradientDef {
    /// 渐变停止点列表 (offset 0.0~1.0, color)
    pub stops: Vec<(f64, Color)>,
}

impl GradientDef {
    pub fn new(stops: Vec<(f64, Color)>) -> Self {
        Self { stops }
    }
}

/// 描边样式
#[derive(Clone, Debug)]
pub struct Stroke {
    pub color: Color,
    pub width: f64,
}

impl Stroke {
    pub fn new(color: Color, width: f64) -> Self {
        Self { color, width }
    }
}

impl Default for Stroke {
    fn default() -> Self {
        Self {
            color: Color::new(0, 0, 0),
            width: 1.0,
        }
    }
}

/// 描边样式（简化版，用于 Line/Polyline）
#[derive(Clone, Debug)]
pub struct StrokeStyle {
    pub color: Color,
    pub width: f64,
}

impl StrokeStyle {
    pub fn new(color: Color, width: f64) -> Self {
        Self { color, width }
    }
}

impl Default for StrokeStyle {
    fn default() -> Self {
        Self {
            color: Color::new(0, 0, 0),
            width: 1.0,
        }
    }
}

/// 填充和描边组合样式
#[derive(Clone, Debug, Default)]
pub struct FillStrokeStyle {
    pub fill: Option<Color>,
    pub stroke: Option<Stroke>,
}

impl FillStrokeStyle {
    pub fn new() -> Self {
        Self::default()
    }

    pub fn with_fill(mut self, color: Color) -> Self {
        self.fill = Some(color);
        self
    }

    pub fn with_stroke(mut self, color: Color, width: f64) -> Self {
        self.stroke = Some(Stroke::new(color, width));
        self
    }
}

/// 文本对齐方式
#[derive(Clone, Copy, Debug, PartialEq, Default)]
pub enum TextAlign {
    #[default]
    Left,
    Center,
    Right,
}


/// 文本基线方式
#[derive(Clone, Copy, Debug, PartialEq)]
#[derive(Default)]
pub enum TextBaseline {
    Top,
    Middle,
    Bottom,
    #[default]
    Alphabetic,
}


// 文本样式已移除：改用 model::TextStyle + TextRun 的 align/baseline/rotation 字段