import { HorizontalBox, VerticalBox, ScrollView } from "std-widgets.slint";
import { ZoomControls, ZoomApi } from "zoom-controls.slint";
import { ToolbarIconButton } from "controls.slint";
import { AppTheme, LayoutMetrics } from "../design-system.slint";
import { TypeScale } from "../typography.slint";

component PageNavigation inherits HorizontalBox {
    in property <bool> compact: false;
    in property <bool> busy: false;
    in property <int> page: 0;
    in property <int> pages: 0;
    // A row of its own spreads the arrows to the edges.
    in property <bool> fill: false;
    callback render-page(int, int);
    padding: 0px; spacing: 4px; cross-axis-alignment: center;
    horizontal-stretch: root.fill ? 1 : 0;
    ToolbarIconButton { compact: root.compact; icon-color: AppTheme.secondary; icon: @image-url("../icons/lucide/outline/chevron-left.svg"); tooltip-text: @tr("Previous page"); interactive: !root.busy && root.page > 0; clicked => { root.render-page(root.page - 1, 200); } }
    Text { text: @tr("Page {} of {}", root.page + 1, root.pages); color: AppTheme.secondary; font-size: TypeScale.caption; vertical-alignment: center; horizontal-alignment: center; horizontal-stretch: root.fill ? 1 : 0; }
    ToolbarIconButton { compact: root.compact; icon-color: AppTheme.secondary; icon: @image-url("../icons/lucide/outline/chevron-right.svg"); tooltip-text: @tr("Next page"); interactive: !root.busy && root.page + 1 < root.pages; clicked => { root.render-page(root.page + 1, 200); } }
}

export component DocumentPreview inherits Rectangle {
    in property <bool> compact: false;
    in property <bool> busy: false;
    in property <image> source;
    in property <int> page: 0;
    in property <int> pages: 0;
    // Raster resolution can change while its logical page size stays fixed.
    in property <float> raster-zoom: 1;
    in property <int> document-revision: 0;
    callback render-page(int, int);
    private property <bool> fitting: true;
    private property <float> manual-zoom: 1;
    private property <int> revision: 0;
    private property <float> natural-width: root.source.width / max(0.01, root.raster-zoom);
    private property <float> natural-height: root.source.height / max(0.01, root.raster-zoom);
    // The page sits as a sheet on the canvas, inset like the email body.
    private property <length> sheet-gap: root.compact ? 8px : 16px;
    private property <float> zoom: root.fitting ? clamp((canvas.visible-width - 2 * root.sheet-gap) / 1px / max(1, root.natural-width), 0.1, 3) : root.manual-zoom;
    changed document-revision => { root.fitting = true; root.manual-zoom = 1; canvas.content-x = 0px; canvas.content-y = 0px; }
    changed page => { canvas.content-x = 0px; canvas.content-y = 0px; }
    min-width: 0px; min-height: 0px; max-width: 100000px;
    horizontal-stretch: 1; vertical-stretch: 1;
    function command(action: string) {
        if action == "fit" { root.fitting = true; }
        else {
            private-zoom = ZoomApi.resolve(action, root.zoom, 0.1, 3);
            if private-zoom > 0 { root.manual-zoom = clamp(private-zoom, 0.1, 3); root.fitting = false; }
        }
        root.revision += 1;
        canvas.content-x = 0px; canvas.content-y = 0px;
    }
    private property <float> private-zoom: 1;
    private property <length> toolbar-inset: 10px;
    private property <length> page-button-size: root.compact ? LayoutMetrics.touch-target : LayoutMetrics.desktop-icon-button-size;
    // Page navigation shares the zoom row when both fit (four 4px gaps plus
    // some room between the groups), and takes its own row on narrow
    // screens or with longer translations.
    private property <bool> pages-below: root.pages > 0
        && zoom-controls.preferred-width + 2 * root.page-button-size + page-label-probe.preferred-width + 24px
            > root.width - 2 * (LayoutMetrics.divider-width + root.toolbar-inset);
    page-label-probe := Text {
        visible: false; accessible-role: none;
        text: @tr("Page {} of {}", root.page + 1, root.pages); font-size: TypeScale.caption;
    }
    // Framed like the email reader's message card: controls on top, then
    // the document on the page background.
    background: AppTheme.surface;
    border-radius: 8px;
    border-width: LayoutMetrics.divider-width;
    border-color: AppTheme.border-subtle;
    clip: true;
    VerticalBox {
        x: LayoutMetrics.divider-width; y: LayoutMetrics.divider-width;
        width: parent.width - 2 * LayoutMetrics.divider-width; height: parent.height - 2 * LayoutMetrics.divider-width;
        padding: 0px; spacing: 0px; cross-axis-alignment: stretch;
        HorizontalBox {
            padding-top: 4px; padding-bottom: root.pages-below ? 0px : 4px; padding-left: root.toolbar-inset; padding-right: root.toolbar-inset;
            spacing: 4px; cross-axis-alignment: center;
            zoom-controls := ZoomControls { compact: root.compact; zoom: root.zoom; minimum: 0.1; fitting: root.fitting; revision: root.revision; available: root.source.width > 0; command(action) => { root.command(action); } }
            Rectangle { horizontal-stretch: 1; }
            if root.pages > 0 && !root.pages-below : PageNavigation {
                compact: root.compact; busy: root.busy; page: root.page; pages: root.pages;
                render-page(page, zoom) => { root.render-page(page, zoom); }
            }
        }
        if root.pages-below : PageNavigation {
            fill: true;
            padding-left: root.toolbar-inset; padding-right: root.toolbar-inset; padding-bottom: 4px;
            compact: root.compact; busy: root.busy; page: root.page; pages: root.pages;
            render-page(page, zoom) => { root.render-page(page, zoom); }
        }
        Rectangle { height: LayoutMetrics.divider-width; background: AppTheme.border-subtle; }
        Rectangle {
            vertical-stretch: 1;
            background: AppTheme.page-bg;
            canvas := ScrollView {
                width: parent.width; height: parent.height;
                mouse-drag-pan-enabled: true;
                content-width: max(self.visible-width, root.natural-width * root.zoom * 1px + 2 * root.sheet-gap);
                content-height: max(self.visible-height, root.natural-height * root.zoom * 1px + 2 * root.sheet-gap);
                Rectangle {
                    x: max(root.sheet-gap, (canvas.visible-width - self.width) / 2);
                    y: root.sheet-gap;
                    width: root.natural-width * root.zoom * 1px;
                    height: root.natural-height * root.zoom * 1px;
                    Image { width: parent.width; height: parent.height; source: root.source; image-fit: contain; }
                    // The outline lifts the sheet off the canvas.
                    Rectangle { border-width: LayoutMetrics.divider-width; border-color: AppTheme.border; }
                }
            }
        }
    }
}

// Plain-text previews share the document card.
export component TextPreview inherits Rectangle {
    in property <string> text;
    in property <bool> compact: false;
    private property <length> inset: root.compact ? 12px : 16px;
    min-width: 0px; min-height: 0px;
    horizontal-stretch: 1; vertical-stretch: 1;
    background: AppTheme.surface;
    border-radius: 8px;
    border-width: LayoutMetrics.divider-width;
    border-color: AppTheme.border-subtle;
    clip: true;
    scroll := ScrollView {
        x: LayoutMetrics.divider-width; y: LayoutMetrics.divider-width;
        width: parent.width - 2 * LayoutMetrics.divider-width; height: parent.height - 2 * LayoutMetrics.divider-width;
        content-width: self.visible-width;
        content-height: body.height + 2 * root.inset;
        body := Text {
            x: root.inset; y: root.inset;
            width: scroll.visible-width - 2 * root.inset; height: self.preferred-height;
            text: root.text; wrap: word-wrap; color: AppTheme.body; font-size: TypeScale.body;
        }
    }
}