windui 0.8.3

//! 基础几何与颜色类型。坐标单位默认物理像素（i32）或浮点（f32，用于绘制）。

/// 点（整数像素，用于布局/事件命中）。
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub struct Point {
    pub x: i32,
    pub y: i32,
}

impl Point {
    pub const fn new(x: i32, y: i32) -> Self {
        Self { x, y }
    }
}

/// 尺寸（整数像素）。
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub struct Size {
    pub w: i32,
    pub h: i32,
}

impl Size {
    pub const fn new(w: i32, h: i32) -> Self {
        Self { w, h }
    }
    pub const ZERO: Size = Size { w: 0, h: 0 };
}

/// 矩形：左上角 + 宽高（整数像素）。
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub struct Rect {
    pub x: i32,
    pub y: i32,
    pub w: i32,
    pub h: i32,
}

impl Rect {
    pub const fn new(x: i32, y: i32, w: i32, h: i32) -> Self {
        Self { x, y, w, h }
    }
    pub const fn from_size(s: Size) -> Self {
        Self {
            x: 0,
            y: 0,
            w: s.w,
            h: s.h,
        }
    }
    pub const fn right(&self) -> i32 {
        self.x + self.w
    }
    pub const fn bottom(&self) -> i32 {
        self.y + self.h
    }
    pub const fn size(&self) -> Size {
        Size {
            w: self.w,
            h: self.h,
        }
    }
    pub fn contains(&self, p: Point) -> bool {
        p.x >= self.x && p.x < self.right() && p.y >= self.y && p.y < self.bottom()
    }
    /// 两矩形交集；无交集时返回零宽高矩形。
    pub fn intersect(&self, o: &Rect) -> Rect {
        let x = self.x.max(o.x);
        let y = self.y.max(o.y);
        let r = self.right().min(o.right());
        let b = self.bottom().min(o.bottom());
        Rect::new(x, y, (r - x).max(0), (b - y).max(0))
    }
    pub fn is_empty(&self) -> bool {
        self.w <= 0 || self.h <= 0
    }
    /// 按缩放因子转为物理像素矩形。按边界（右/下）取整，避免四分量独立 round 漂移。
    pub fn scaled(&self, s: f32) -> Rect {
        let x0 = (self.x as f32 * s).round() as i32;
        let y0 = (self.y as f32 * s).round() as i32;
        let x1 = (self.right() as f32 * s).round() as i32;
        let y1 = (self.bottom() as f32 * s).round() as i32;
        Rect::new(x0, y0, x1 - x0, y1 - y0)
    }

    /// 包含两矩形的最小外接矩形（空矩形被忽略）。
    pub fn union(&self, o: &Rect) -> Rect {
        if self.is_empty() {
            return *o;
        }
        if o.is_empty() {
            return *self;
        }
        let x = self.x.min(o.x);
        let y = self.y.min(o.y);
        let r = self.right().max(o.right());
        let b = self.bottom().max(o.bottom());
        Rect::new(x, y, r - x, b - y)
    }

    /// 平移。
    pub fn offset(&self, dx: i32, dy: i32) -> Rect {
        Rect::new(self.x + dx, self.y + dy, self.w, self.h)
    }

    /// 四边各外扩 m 像素（脏区留抗锯齿余量用）。
    pub fn inflate(&self, m: i32) -> Rect {
        Rect::new(self.x - m, self.y - m, self.w + 2 * m, self.h + 2 * m)
    }

    /// 向内收缩四边（用于 padding）。
    pub fn inset(&self, i: Insets) -> Rect {
        Rect::new(
            self.x + i.left,
            self.y + i.top,
            (self.w - i.left - i.right).max(0),
            (self.h - i.top - i.bottom).max(0),
        )
    }
}

/// 四边内边距/外边距。
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub struct Insets {
    pub left: i32,
    pub top: i32,
    pub right: i32,
    pub bottom: i32,
}

impl Insets {
    pub const fn all(v: i32) -> Self {
        Self {
            left: v,
            top: v,
            right: v,
            bottom: v,
        }
    }
    pub const fn symmetric(h: i32, v: i32) -> Self {
        Self {
            left: h,
            top: v,
            right: h,
            bottom: v,
        }
    }
    pub const fn new(left: i32, top: i32, right: i32, bottom: i32) -> Self {
        Self {
            left,
            top,
            right,
            bottom,
        }
    }
    pub const fn horizontal(&self) -> i32 {
        self.left + self.right
    }
    pub const fn vertical(&self) -> i32 {
        self.top + self.bottom
    }
}

/// 非预乘 sRGB 颜色（u8 通道）。绘制时再转 tiny-skia 的预乘格式。
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct Color {
    pub r: u8,
    pub g: u8,
    pub b: u8,
    pub a: u8,
}

impl Color {
    pub const fn rgb(r: u8, g: u8, b: u8) -> Self {
        Self { r, g, b, a: 255 }
    }
    pub const fn rgba(r: u8, g: u8, b: u8, a: u8) -> Self {
        Self { r, g, b, a }
    }
    /// 从 0xRRGGBB 构造（不含 alpha）。
    pub const fn hex(v: u32) -> Self {
        Self {
            r: ((v >> 16) & 0xff) as u8,
            g: ((v >> 8) & 0xff) as u8,
            b: (v & 0xff) as u8,
            a: 255,
        }
    }
    pub const TRANSPARENT: Color = Color {
        r: 0,
        g: 0,
        b: 0,
        a: 0,
    };
    pub const WHITE: Color = Color {
        r: 255,
        g: 255,
        b: 255,
        a: 255,
    };
    pub const BLACK: Color = Color {
        r: 0,
        g: 0,
        b: 0,
        a: 255,
    };

    /// 按系数缩放 alpha（保 RGB），用于淡入淡出。`f` 钳到 `[0,1]`。
    pub fn scale_alpha(self, f: f32) -> Color {
        Color {
            a: (self.a as f32 * f.clamp(0.0, 1.0)).round() as u8,
            ..self
        }
    }

    /// 解析 `#RGB` / `#RRGGBB` / `#RRGGBBAA`（# 可省）。失败返回 None。
    pub fn from_hex_str(s: &str) -> Option<Self> {
        let h = s.trim().trim_start_matches('#');
        // 必须为 ASCII：否则按字节切片可能落在多字节字符内部 panic（不可信 TOML 输入）。
        if !h.is_ascii() {
            return None;
        }
        let p = |i: usize| u8::from_str_radix(&h[i..i + 2], 16).ok();
        match h.len() {
            3 => {
                let d = |c: char| c.to_digit(16).map(|v| (v * 17) as u8);
                let mut it = h.chars();
                Some(Self::rgb(d(it.next()?)?, d(it.next()?)?, d(it.next()?)?))
            }
            6 => Some(Self::rgba(p(0)?, p(2)?, p(4)?, 255)),
            8 => Some(Self::rgba(p(0)?, p(2)?, p(4)?, p(6)?)),
            _ => None,
        }
    }
    /// 序列化为 `#RRGGBB`（alpha=255）或 `#RRGGBBAA`。
    pub fn to_hex_string(&self) -> String {
        if self.a == 255 {
            format!("#{:02X}{:02X}{:02X}", self.r, self.g, self.b)
        } else {
            format!("#{:02X}{:02X}{:02X}{:02X}", self.r, self.g, self.b, self.a)
        }
    }

    /// 向白色混合 f（0..=1）：变亮。保留 alpha。
    pub fn lighten(self, f: f32) -> Color {
        self.mix(Color::WHITE, f)
    }
    /// 向黑色混合 f（0..=1）：变暗。保留 alpha。
    pub fn darken(self, f: f32) -> Color {
        self.mix(Color::BLACK, f)
    }
    /// 与 other 按比例 t 混合 RGB（保留 self 的 alpha）。t 钳到 [0,1]。
    fn mix(self, other: Color, t: f32) -> Color {
        let t = t.clamp(0.0, 1.0);
        let m = |a: u8, b: u8| (a as f32 + (b as f32 - a as f32) * t).round() as u8;
        Color {
            r: m(self.r, other.r),
            g: m(self.g, other.g),
            b: m(self.b, other.b),
            a: self.a,
        }
    }
    /// self 作背景时挑选可读前景：感知亮度 > 阈值返回 dark，否则 light。
    pub fn pick_fg(self, dark: Color, light: Color) -> Color {
        let luma = 0.299 * self.r as f32 + 0.587 * self.g as f32 + 0.114 * self.b as f32;
        if luma > 153.0 {
            dark
        } else {
            light
        }
    }
}

impl serde::Serialize for Color {
    fn serialize<S: serde::Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
        s.serialize_str(&self.to_hex_string())
    }
}

impl<'de> serde::Deserialize<'de> for Color {
    fn deserialize<D: serde::Deserializer<'de>>(d: D) -> Result<Self, D::Error> {
        let s = String::deserialize(d)?;
        Color::from_hex_str(&s).ok_or_else(|| serde::de::Error::custom(format!("无效颜色: {s}")))
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn rect_contains_and_intersect() {
        let r = Rect::new(10, 10, 100, 50);
        assert!(r.contains(Point::new(10, 10)));
        assert!(r.contains(Point::new(109, 59)));
        assert!(!r.contains(Point::new(110, 10)));
        let i = r.intersect(&Rect::new(50, 0, 100, 100));
        assert_eq!(i, Rect::new(50, 10, 60, 50));
    }

    #[test]
    fn rect_inset() {
        let r = Rect::new(0, 0, 100, 100).inset(Insets::all(10));
        assert_eq!(r, Rect::new(10, 10, 80, 80));
    }

    #[test]
    fn color_hex() {
        assert_eq!(Color::hex(0x336699), Color::rgb(0x33, 0x66, 0x99));
    }

    #[test]
    fn color_lighten_darken_bounds() {
        let c = Color::rgb(100, 100, 100);
        assert_eq!(c.lighten(0.0), c, "f=0 不变");
        assert_eq!(c.darken(0.0), c, "f=0 不变");
        assert_eq!(c.lighten(1.0), Color::WHITE, "f=1 趋白");
        assert_eq!(c.darken(1.0), Color::BLACK, "f=1 趋黑");
        assert!(
            c.lighten(0.5).r > c.r && c.darken(0.5).r < c.r,
            "中间值单调"
        );
        assert_eq!(c.lighten(0.5).a, c.a, "保留 alpha");
    }

    #[test]
    fn color_pick_fg_by_luminance() {
        // self 作背景：偏亮选 dark 前景、偏暗选 light 前景。
        assert_eq!(
            Color::rgb(240, 240, 240).pick_fg(Color::BLACK, Color::WHITE),
            Color::BLACK
        );
        assert_eq!(
            Color::rgb(20, 20, 20).pick_fg(Color::BLACK, Color::WHITE),
            Color::WHITE
        );
    }

    #[test]
    fn color_from_hex_str_forms() {
        assert_eq!(
            Color::from_hex_str("#336699"),
            Some(Color::rgb(0x33, 0x66, 0x99))
        );
        assert_eq!(
            Color::from_hex_str("336699"),
            Some(Color::rgb(0x33, 0x66, 0x99))
        );
        assert_eq!(
            Color::from_hex_str("#369"),
            Some(Color::rgb(0x33, 0x66, 0x99))
        );
        assert_eq!(
            Color::from_hex_str("#11223344"),
            Some(Color::rgba(0x11, 0x22, 0x33, 0x44))
        );
    }

    #[test]
    fn color_from_hex_str_rejects_bad_input() {
        // 多字节 UTF-8（字节长 6）不得 panic，返回 None。
        assert_eq!(Color::from_hex_str("€abc"), None);
        assert_eq!(Color::from_hex_str("aébcd"), None);
        assert_eq!(Color::from_hex_str("xyz"), None);
        assert_eq!(Color::from_hex_str("#12"), None);
        assert_eq!(Color::from_hex_str(""), None);
    }

    #[test]
    fn color_hex_string_omits_opaque_alpha() {
        assert_eq!(Color::rgb(0x33, 0x66, 0x99).to_hex_string(), "#336699");
        assert_eq!(
            Color::rgba(0x11, 0x22, 0x33, 0x44).to_hex_string(),
            "#11223344"
        );
    }
}