// Copyright (c) 2026 Xu Shaohua <shaohua@biofan.org>. All rights reserved.
// Use of this source is governed by Apache-2.0 License
// that can be found in the LICENSE file.

use dioxus::prelude::*;

/// This trait is used to override `IconProps`.
///
/// Implements this trait when adding a new real icon.
pub trait IconShape: Clone + PartialEq + 'static {
    /// Returns the SVG child elements (paths, circles, etc.) that define the icon shape.
    ///
    /// # Errors
    ///
    /// Returns `Err` if rendering the child elements fails.
    fn child_elements(&self) -> Element;

    /// Default title text for the SVG element.
    const TITLE: Option<&'static str> = None;

    /// Default width of the SVG element in pixels.
    const WIDTH: Option<&'static str> = None;

    /// Default height of the SVG element in pixels.
    const HEIGHT: Option<&'static str> = None;

    /// Default fill color of the SVG element.
    const FILL: Option<&'static str> = Some("currentColor");

    /// Default stroke color of the SVG element.
    const STROKE: Option<&'static str> = None;

    /// Default stroke width of the SVG element (e.g., "2").
    const STROKE_WIDTH: Option<&'static str> = None;

    /// Default stroke line cap style (e.g., "round", "butt", "square").
    const STROKE_LINE_CAP: Option<&'static str> = None;

    /// Default stroke line join style (e.g., "round", "miter", "bevel").
    const STROKE_LINE_JOIN: Option<&'static str> = None;

    /// Default view box string (e.g., "0 0 24 24").
    const VIEW_BOX: Option<&'static str> = None;

    /// Default XML namespace for the SVG element.
    /// Falls back to `"http://www.w3.org/2000/svg"` if not set.
    const XMLNS: Option<&'static str> = Some("http://www.w3.org/2000/svg");
}

/// Props for the `Icon` component.
///
/// All fields are optional except `icon`. When a field is not provided,
/// the default value from the associated `IconShape` implementation is used.
#[derive(Clone, PartialEq, Props)]
pub struct IconProps<T: IconShape> {
    /// The icon shape implementation that provides SVG child elements.
    pub icon: T,

    /// Optional title text rendered as a `<title>` element inside the SVG for accessibility.
    #[props(default = None)]
    pub title: Option<&'static str>,

    /// Default width of the SVG element in pixels.
    #[props(default = None)]
    pub width: Option<&'static str>,

    /// Default height of the SVG element in pixels.
    #[props(default = None)]
    pub height: Option<&'static str>,

    /// Default fill color of the SVG element.
    #[props(default = None)]
    pub fill: Option<&'static str>,

    /// Default stroke color of the SVG element.
    #[props(default = None)]
    pub stroke: Option<&'static str>,

    /// Default stroke width of the SVG element (e.g., "2").
    #[props(default = None)]
    pub stroke_width: Option<&'static str>,

    /// Default stroke line cap style (e.g., "round", "butt", "square").
    #[props(default = None)]
    pub stroke_line_cap: Option<&'static str>,

    /// Default stroke line join style (e.g., "round", "miter", "bevel").
    #[props(default = None)]
    pub stroke_line_join: Option<&'static str>,

    /// Additional HTML/SVG global attributes to spread onto the `<svg>` element.
    /// Allows passing standard attributes like `id`, `aria-*`, event handlers, etc.
    #[props(extends = GlobalAttributes)]
    pub attributes: Vec<Attribute>,
}

/// # Errors
///
/// Returns `Err` if rendering the icon fails.
#[allow(non_snake_case)]
pub fn Icon<T: IconShape>(props: IconProps<T>) -> Element {
    rsx! {
        svg {
            width: if props.width.is_some() {
                props.width
            } else {
                T::WIDTH
            },
            height: if props.height.is_some() {
                props.height
            } else {
                T::HEIGHT
            },
            fill: if props.fill.is_some() {
                props.fill
            } else {
                T::FILL
            },
            stroke: if props.stroke.is_some() {
                props.stroke
            } else {
                T::STROKE
            },
            stroke_width: if props.stroke_width.is_some() {
                props.stroke_width
            } else {
                T::STROKE_WIDTH
            },
            stroke_linecap: if props.stroke_line_cap.is_some() {
                props.stroke_line_cap
            } else {
                T::STROKE_LINE_CAP
            },
            stroke_linejoin: if props.stroke_line_join.is_some() {
                props.stroke_line_join
            } else {
                T::STROKE_LINE_JOIN
            },
            view_box: T::VIEW_BOX,
            xmlns: T::XMLNS,

            ..props.attributes,

            if let Some(title_text) = props.title {
                title {{ title_text }}
            } else if let Some(title_text) = T::TITLE {
                title {{ title_text }}
            }

            {props.icon.child_elements()}
        }
    }
}
