//! Shared styling primitives for every screen, following the windows-reactor gallery's look:
//! theme brushes (`ThemeRef`), rounded `border` cards, small all-caps section labels, and a
//! centred max-width column per page.

use windows_reactor::*;

pub(crate) fn uniform(v: f64) -> Thickness {
    Thickness::uniform(v)
}

pub(crate) fn edges(left: f64, top: f64, right: f64, bottom: f64) -> Thickness {
    Thickness {
        left,
        top,
        right,
        bottom,
    }
}

/// A rounded, bordered surface in the theme's card colours.
pub(crate) fn card(child: impl Into<Element>) -> Border {
    border(child.into())
        .background(ThemeRef::CardBackground)
        .border_brush(ThemeRef::CardStroke)
        .border_thickness(uniform(1.0))
        .corner_radius(8.0)
        .padding(uniform(16.0))
}

/// Card chrome with no padding — for cards whose interactive regions (tap-to-connect area vs.
/// action buttons) must own their padding so hit areas reach the card edges.
pub(crate) fn card_flush(child: impl Into<Element>) -> Border {
    card(child).padding(uniform(0.0))
}

/// An OPAQUE modal/dialog surface. `card`'s `CardBackground` is a translucent acrylic brush — fine
/// layered on the page, but a floating dialog over a scrim needs a solid fill or the content behind
/// bleeds through (looks "transparent"). `SolidBackground` is the opaque base-layer brush.
pub(crate) fn dialog_surface(child: impl Into<Element>) -> Border {
    border(child.into())
        .background(ThemeRef::SolidBackground)
        .border_brush(ThemeRef::SurfaceStroke)
        .border_thickness(uniform(1.0))
        .corner_radius(8.0)
        .padding(uniform(20.0))
}

/// A fully transparent brush: paints nothing but (unlike a null background) makes the whole
/// element hit-testable, so a tap region catches clicks in its blank space too.
pub(crate) fn hit_test_backstop() -> Color {
    Color {
        a: 0,
        r: 0,
        g: 0,
        b: 0,
    }
}

/// A small all-caps section label above a group of cards.
pub(crate) fn section(label: &str) -> Element {
    text_block(label)
        .font_size(12.0)
        .semibold()
        .foreground(ThemeRef::SecondaryText)
        .margin(edges(2.0, 14.0, 0.0, 2.0))
        .into()
}

/// Wrap a screen's children in a scrollable, centred, max-width column. Alignment stays the
/// default Stretch: with a MaxWidth that still centres the column, but the children get the
/// column's REAL width — an explicit Center would size the column to its content and leave
/// every card at its minimum width no matter how large the window is.
pub(crate) fn page(children: Vec<Element>) -> Element {
    let col = vstack(children)
        .spacing(10.0)
        .max_width(640.0)
        .margin(edges(24.0, 24.0, 24.0, 40.0));
    scroll_view(col).into()
}

/// Like [`page`], but wide and airier — for screens whose cards lay out in a responsive grid
/// and should use the window instead of a narrow settings column.
pub(crate) fn page_wide(children: Vec<Element>) -> Element {
    let col = vstack(children)
        .spacing(14.0)
        .max_width(1120.0)
        .margin(edges(32.0, 28.0, 32.0, 48.0));
    scroll_view(col).into()
}

/// Lay tiles into a `cols`-wide grid of equal-width star columns (rows share the height of
/// their tallest tile, so a grid row always lines up). Shared by the hosts page's host
/// tiles and the library page's posters.
pub(crate) fn tile_grid(tiles: Vec<Element>, cols: usize, gap: f64) -> Element {
    let rows = tiles.len().div_ceil(cols);
    let mut children = Vec::with_capacity(tiles.len());
    for (i, t) in tiles.into_iter().enumerate() {
        children.push(t.grid_row((i / cols) as i32).grid_column((i % cols) as i32));
    }
    grid(children)
        .columns(vec![GridLength::Star(1.0); cols])
        .rows(vec![GridLength::Auto; rows])
        .column_spacing(gap)
        .row_spacing(gap)
        .into()
}

/// A page header: a large bold title on the left, one action button on the right.
pub(crate) fn page_header(title: &str, action: Button) -> Element {
    grid((
        text_block(title)
            .font_size(30.0)
            .bold()
            .grid_column(0)
            .vertical_alignment(VerticalAlignment::Center),
        action
            .grid_column(1)
            .vertical_alignment(VerticalAlignment::Center),
    ))
    .columns([GridLength::Star(1.0), GridLength::Auto])
    .margin(edges(0.0, 0.0, 0.0, 6.0))
    .into()
}

/// A full-screen centred "busy" scene: spinner, headline, secondary detail line, and optional
/// trailing elements (e.g. a Cancel button). Shared by Connecting / RequestAccess / SpeedTest.
pub(crate) fn busy_page(headline: &str, detail: &str, extra: Vec<Element>) -> Element {
    let mut children: Vec<Element> = vec![
        ProgressRing::indeterminate()
            .width(48.0)
            .height(48.0)
            .horizontal_alignment(HorizontalAlignment::Center)
            .into(),
        text_block(headline)
            .font_size(18.0)
            .semibold()
            .wrap()
            .horizontal_alignment(HorizontalAlignment::Center)
            .into(),
        text_block(detail)
            .wrap()
            .foreground(ThemeRef::SecondaryText)
            .horizontal_alignment(HorizontalAlignment::Center)
            .into(),
    ];
    children.extend(extra);
    // max_width + side margins so the text column reads well wide AND wraps instead of
    // clipping narrow.
    vstack(children)
        .spacing(16.0)
        .max_width(520.0)
        .margin(edges(24.0, 0.0, 24.0, 0.0))
        .horizontal_alignment(HorizontalAlignment::Center)
        .vertical_alignment(VerticalAlignment::Center)
        .into()
}

/// A rounded square "monogram" for a host, the first letter on an accent fill — a clean leading
/// visual that avoids depending on an icon font being installed.
pub(crate) fn avatar(name: &str) -> Border {
    let initial = name
        .chars()
        .find(|c| c.is_alphanumeric())
        .map(|c| c.to_uppercase().to_string())
        .unwrap_or_else(|| "?".into());
    border(
        text_block(initial)
            .font_size(17.0)
            .semibold()
            // NOT ThemeRef::AccentText — that's accent-COLOURED text for normal surfaces;
            // on an accent fill it's accent-on-accent (unreadable). This is the on-accent brush.
            .foreground(ThemeRef::custom("TextOnAccentFillColorPrimaryBrush"))
            .horizontal_alignment(HorizontalAlignment::Center)
            .vertical_alignment(VerticalAlignment::Center),
    )
    .background(ThemeRef::Accent)
    .corner_radius(10.0)
    .width(40.0)
    .height(40.0)
}

/// Pill chip colour intent.
#[derive(Clone, Copy)]
pub(crate) enum Pill {
    Info,
    Good,
    Neutral,
}

/// A small rounded status chip (paired/PIN/HDR/etc.) — subtle tinted fills with matching
/// system foregrounds (the InfoBar palette), never solid accent (white-on-bright is unreadable).
pub(crate) fn pill(text: &str, kind: Pill) -> Border {
    let (bg, fg) = match kind {
        Pill::Info => (
            ThemeRef::SystemAttentionBackground,
            ThemeRef::SystemAttention,
        ),
        Pill::Good => (ThemeRef::SystemSuccessBackground, ThemeRef::SystemSuccess),
        Pill::Neutral => (ThemeRef::SubtleFill, ThemeRef::SecondaryText),
    };
    border(text_block(text).font_size(11.0).semibold().foreground(fg))
        .background(bg)
        .border_brush(ThemeRef::CardStroke)
        .border_thickness(uniform(1.0))
        .corner_radius(10.0)
        .padding(edges(9.0, 2.0, 9.0, 2.0))
}

/// A small presence dot (host online/offline).
pub(crate) fn presence_dot(online: bool) -> Border {
    border(vstack(Vec::<Element>::new()))
        .background(if online {
            ThemeRef::SystemSuccess
        } else {
            ThemeRef::SystemNeutral
        })
        .corner_radius(4.0)
        .width(8.0)
        .height(8.0)
}