use gpui::{FontWeight, Hsla, white};

use crate::prelude::*;

/// Fill style of a [`Badge`].
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum BadgeVariant {
    /// Light tinted background with dark text.
    #[default]
    Soft,
    /// Strong filled background with light text.
    Solid,
    /// Transparent with a colored border.
    Outline,
}

/// Semantic color role of a [`Badge`].
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum BadgeColor {
    #[default]
    Neutral,
    Secondary,
    Primary,
    Success,
    Warning,
    Danger,
}

impl BadgeColor {
    fn shade(self, step: u16) -> Hsla {
        match self {
            BadgeColor::Neutral | BadgeColor::Secondary => palette::neutral(step),
            BadgeColor::Primary => palette::primary(step),
            BadgeColor::Success => palette::success(step),
            BadgeColor::Warning => palette::warning(step),
            BadgeColor::Danger => palette::danger(step),
        }
    }
}

/// A small pill label conveying status or category.
#[derive(IntoElement, RegisterComponent)]
pub struct Badge {
    label: SharedString,
    variant: BadgeVariant,
    color: BadgeColor,
    dot: bool,
}

impl Badge {
    pub fn new(label: impl Into<SharedString>) -> Self {
        Self {
            label: label.into(),
            variant: BadgeVariant::default(),
            color: BadgeColor::default(),
            dot: false,
        }
    }

    pub fn variant(mut self, variant: BadgeVariant) -> Self {
        self.variant = variant;
        self
    }

    pub fn color(mut self, color: BadgeColor) -> Self {
        self.color = color;
        self
    }

    pub fn dot(mut self, dot: bool) -> Self {
        self.dot = dot;
        self
    }
}

impl RenderOnce for Badge {
    fn render(self, _window: &mut Window, cx: &mut App) -> impl IntoElement {
        let mut base = h_flex()
            .items_center()
            .gap(DynamicSpacing::Base04.rems(cx))
            .px(DynamicSpacing::Base08.px(cx))
            .py(DynamicSpacing::Base02.px(cx))
            .rounded_full();

        // shadcn's `secondary` badge is a distinct neutral-solid role
        // (theme `--secondary`/`--secondary-foreground`), not just a
        // lighter/darker shade of `Neutral` — read it from `semantic` so it
        // tracks the active theme instead of aliasing `Neutral`'s static
        // palette shades.
        let is_secondary = self.color == BadgeColor::Secondary;
        let (fill, fill_text, dot_color, outline_border, outline_text) = if is_secondary {
            let bg = semantic::secondary_bg(cx);
            let fg = semantic::secondary_fg(cx);
            (bg, fg, fg, semantic::border(cx), fg)
        } else {
            match self.variant {
                BadgeVariant::Solid => (
                    self.color.shade(600),
                    white(),
                    self.color.shade(500),
                    self.color.shade(300),
                    self.color.shade(700),
                ),
                BadgeVariant::Soft | BadgeVariant::Outline => (
                    self.color.shade(100),
                    self.color.shade(800),
                    self.color.shade(500),
                    self.color.shade(300),
                    self.color.shade(700),
                ),
            }
        };

        base = match self.variant {
            BadgeVariant::Soft | BadgeVariant::Solid => base.bg(fill).text_color(fill_text),
            BadgeVariant::Outline => base
                .border_1()
                .border_color(outline_border)
                .text_color(outline_text),
        };

        let text_color = match self.variant {
            BadgeVariant::Outline => outline_text,
            _ => fill_text,
        };

        base.when(self.dot, |this| {
            this.child(
                div()
                    .size(DynamicSpacing::Base06.px(cx))
                    .rounded_full()
                    .bg(dot_color),
            )
        })
        .child(
            Label::new(self.label)
                .size(LabelSize::XSmall)
                .weight(FontWeight::MEDIUM)
                .color(Color::Custom(text_color)),
        )
    }
}

impl Component for Badge {
    fn scope() -> ComponentScope {
        ComponentScope::Status
    }

    fn description() -> Option<&'static str> {
        Some("A small pill label conveying status or category.")
    }

    fn preview(_window: &mut Window, cx: &mut App) -> Option<AnyElement> {
        let colors = [
            ("Neutral", BadgeColor::Neutral),
            ("Secondary", BadgeColor::Secondary),
            ("Primary", BadgeColor::Primary),
            ("Success", BadgeColor::Success),
            ("Warning", BadgeColor::Warning),
            ("Danger", BadgeColor::Danger),
        ];
        let row = |variant: BadgeVariant, dot: bool| {
            let mut r = h_flex().gap(DynamicSpacing::Base08.rems(cx));
            for (name, color) in colors {
                r = r.child(Badge::new(name).variant(variant).color(color).dot(dot));
            }
            r
        };
        let status_row = || {
            h_flex()
                .gap(DynamicSpacing::Base08.rems(cx))
                .child(
                    Badge::new("Active")
                        .variant(BadgeVariant::Soft)
                        .color(BadgeColor::Success)
                        .dot(true),
                )
                .child(
                    Badge::new("Pending")
                        .variant(BadgeVariant::Soft)
                        .color(BadgeColor::Warning)
                        .dot(true),
                )
                .child(
                    Badge::new("Failed")
                        .variant(BadgeVariant::Solid)
                        .color(BadgeColor::Danger),
                )
                .child(
                    Badge::new("Draft")
                        .variant(BadgeVariant::Outline)
                        .color(BadgeColor::Neutral),
                )
        };

        Some(
            v_flex()
                .gap(DynamicSpacing::Base12.rems(cx))
                .child(row(BadgeVariant::Soft, true))
                .child(row(BadgeVariant::Solid, true))
                .child(row(BadgeVariant::Outline, true))
                .child(row(BadgeVariant::Soft, false))
                .child(row(BadgeVariant::Solid, false))
                .child(row(BadgeVariant::Outline, false))
                .child(status_row())
                .into_any_element(),
        )
    }
}
