#pragma once

#include "Layout.h"

#include <QRectF>
#include <QSizeF>

struct KeyboardMetrics {
    qreal padding = 6;      // around the whole keyboard
    qreal gap = 8;          // between keys, horizontally and vertically
    qreal blockGap = 24;    // between side-by-side blocks (main, navigation, numpad)
};

// The keys on screen: blocks of rows, side by side.
// A block can reserve room (minUnits, minRows) so that swapping its rows, e.g.
// switching layers, moves nothing else; its keys stretch into the room.
struct Block {
    QList<Row> rows;
    bool fillHeight = false; // spans the full height instead of max(rows, minRows) shared rows
    qreal minUnits = 0;      // reserved width
    qsizetype minRows = 0;   // reserved height, in shared rows
    qsizetype fixedRows = 0; // leading rows that keep the shared height when the block stretches
};

// Lays out blocks to fill `size`. Returns one rect per key, block by block in
// row order (spacers included). One key unit has the same width everywhere;
// rows share one height, set by the tallest block that doesn't fill, and
// shorter blocks sit at the bottom. A block given more height than its rows
// need (fillHeight, minRows) grows its rows after fixedRows to take it up.
// In each block, stretch keys grow to make their row as wide as the widest
// one (or minUnits), and remaining shorter rows are centered.
QList<QRectF> computeKeyRects(const QList<Block> &blocks, QSizeF size, KeyboardMetrics metrics = {});
inline QList<QRectF> computeKeyRects(const Layer &layer, QSizeF size, KeyboardMetrics metrics = {})
{
    return computeKeyRects({{layer.rows}}, size, metrics);
}

// Total width of a row in key units, before stretching.
qreal rowUnits(const Row &row);
// Width of all blocks in key units, ignoring gaps.
qreal totalUnits(const QList<Block> &blocks);
// Shared rows of the tallest block that sets the row height (see computeKeyRects).
qsizetype totalRows(const QList<Block> &blocks);