package com.android.systemui.qs;

import static com.android.systemui.util.Utils.useQsMediaPlayer;

import android.content.Context;
import android.content.res.Resources;
import android.provider.Settings;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.TextView;

import androidx.annotation.Nullable;
import androidx.annotation.VisibleForTesting;

import com.android.internal.logging.UiEventLogger;
import com.android.systemui.FontSizeUtils;
import com.android.systemui.flags.Flags;
import com.android.systemui.flags.RefactorFlag;
import com.android.systemui.qs.QSPanel.QSTileLayout;
import com.android.systemui.qs.QSPanelControllerBase.TileRecord;
import com.android.systemui.qs.tileimpl.HeightOverrideable;
import com.android.systemui.qs.tileimpl.QSTileViewImplKt;
import com.android.systemui.res.R;

import java.util.ArrayList;

public class TileLayout extends ViewGroup implements QSTileLayout {

    public static final int NO_MAX_COLUMNS = 100;

    private static final String TAG = "TileLayout";

    protected int mColumns;
    protected int mCellWidth;
    protected int mResourceCellHeightResId = R.dimen.qs_tile_height;
    protected int mResourceCellHeight;
    protected int mEstimatedCellHeight;
    protected int mCellHeight;
    protected int mCellMarginHorizontal;
    protected int mCellMarginVertical;
    protected int mSidePadding;
    protected int mRows = 1;

    protected final ArrayList<TileRecord> mRecords = new ArrayList<>();
    protected boolean mListening;
    protected int mMaxAllowedRows = 3;

    // Prototyping with less rows
    private final boolean mLessRows;
    private int mMinRows = 1;
    private int mMaxColumns = NO_MAX_COLUMNS;
    protected int mResourceColumns;
    private float mSquishinessFraction = 1f;
    protected int mLastTileBottom;
    protected TextView mTempTextView;
    private final Boolean mIsSmallLandscapeLockscreenEnabled =
            RefactorFlag.forView(Flags.LOCKSCREEN_ENABLE_LANDSCAPE).isEnabled();

    public TileLayout(Context context) {
        this(context, null);
    }

    public TileLayout(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        mLessRows = ((Settings.System.getInt(context.getContentResolver(), "qs_less_rows", 0) != 0)
                || useQsMediaPlayer(context));
        mTempTextView = new TextView(context);
        updateResources();
    }

    @Override
    public int getOffsetTop(TileRecord tile) {
        return getTop();
    }

    public void setListening(boolean listening) {
        setListening(listening, null);
    }

    @Override
    public void setListening(boolean listening, @Nullable UiEventLogger uiEventLogger) {
        if (mListening == listening) return;
        mListening = listening;
        for (TileRecord record : mRecords) {
            record.tile.setListening(this, mListening);
        }
    }

    @Override
    public boolean setMinRows(int minRows) {
        if (mMinRows != minRows) {
            mMinRows = minRows;
            updateResources();
            return true;
        }
        return false;
    }

    @VisibleForTesting
    @Override
    public int getMinRows() {
        return mMinRows;
    }

    @Override
    public boolean setMaxColumns(int maxColumns) {
        mMaxColumns = maxColumns;
        return updateColumns();
    }

    @VisibleForTesting
    @Override
    public int getMaxColumns() {
        return mMaxColumns;
    }

    public void addTile(TileRecord tile) {
        mRecords.add(tile);
        tile.tile.setListening(this, mListening);
        addTileView(tile);
    }

    protected void addTileView(TileRecord tile) {
        // Re-using tile views might lead to having out-of-date squishiness. This is fixed by
        // making sure we set the correct squishiness value when added to the layout.
        if (tile.tileView instanceof HeightOverrideable) {
            ((HeightOverrideable) tile.tileView).setSquishinessFraction(mSquishinessFraction);
        }
        addView(tile.tileView);
    }

    @Override
    public void removeTile(TileRecord tile) {
        mRecords.remove(tile);
        tile.tile.setListening(this, false);
        removeView(tile.tileView);
    }

    public void removeAllViews() {
        for (TileRecord record : mRecords) {
            record.tile.setListening(this, false);
        }
        mRecords.clear();
        super.removeAllViews();
    }

    public boolean updateResources() {
        Resources res = getResources();
        int columns = useSmallLandscapeLockscreenResources()
                ? res.getInteger(R.integer.small_land_lockscreen_quick_settings_num_columns)
                : res.getInteger(R.integer.quick_settings_num_columns);
        mResourceColumns = Math.max(1, columns);
        mResourceCellHeight = res.getDimensionPixelSize(mResourceCellHeightResId);
        mCellMarginHorizontal = res.getDimensionPixelSize(R.dimen.qs_tile_margin_horizontal);
        mSidePadding = useSidePadding() ? mCellMarginHorizontal / 2 : 0;
        mCellMarginVertical= res.getDimensionPixelSize(R.dimen.qs_tile_margin_vertical);
        int rows = useSmallLandscapeLockscreenResources()
                ? res.getInteger(R.integer.small_land_lockscreen_quick_settings_max_rows)
                : res.getInteger(R.integer.quick_settings_max_rows);
        mMaxAllowedRows = Math.max(1, rows);
        if (mLessRows) {
            mMaxAllowedRows = Math.max(mMinRows, mMaxAllowedRows - 1);
        }
        // update estimated cell height under current font scaling
        mTempTextView.dispatchConfigurationChanged(mContext.getResources().getConfiguration());
        estimateCellHeight();
        if (updateColumns()) {
            requestLayout();
            return true;
        }
        return false;
    }

    // TODO (b/293252410) remove condition here when flag is launched
    //  Instead update quick_settings_num_columns and quick_settings_max_rows to be the same as
    //  the small_land_lockscreen_quick_settings_num_columns or
    //  small_land_lockscreen_quick_settings_max_rows respectively whenever
    //  is_small_screen_landscape is true.
    //  Then, only use quick_settings_num_columns and quick_settings_max_rows.
    private boolean useSmallLandscapeLockscreenResources() {
        return mIsSmallLandscapeLockscreenEnabled
                && mContext.getResources().getBoolean(R.bool.is_small_screen_landscape);
    }

    protected boolean useSidePadding() {
        return true;
    }

    private boolean updateColumns() {
        int oldColumns = mColumns;
        mColumns = Math.min(mResourceColumns, mMaxColumns);
        return oldColumns != mColumns;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // If called with AT_MOST, it will limit the number of rows. If called with UNSPECIFIED
        // it will show all its tiles. In this case, the tiles have to be entered before the
        // container is measured. Any change in the tiles, should trigger a remeasure.
        final int numTiles = mRecords.size();
        final int width = MeasureSpec.getSize(widthMeasureSpec);
        final int availableWidth = width - getPaddingStart() - getPaddingEnd();
        final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        if (heightMode == MeasureSpec.UNSPECIFIED) {
            mRows = (numTiles + mColumns - 1) / mColumns;
        }
        final int gaps = mColumns - 1;
        mCellWidth =
                (availableWidth - (mCellMarginHorizontal * gaps) - mSidePadding * 2) / mColumns;

        // Measure each QS tile.
        View previousView = this;
        int verticalMeasure = exactly(getCellHeight());
        for (TileRecord record : mRecords) {
            if (record.tileView.getVisibility() == GONE) continue;
            record.tileView.measure(exactly(mCellWidth), verticalMeasure);
            previousView = record.tileView.updateAccessibilityOrder(previousView);
            mCellHeight = record.tileView.getMeasuredHeight();
        }

        int height = (mCellHeight + mCellMarginVertical) * mRows;
        height -= mCellMarginVertical;

        if (height < 0) height = 0;

        setMeasuredDimension(width, height);
    }

    /**
     * Determines the maximum number of rows that can be shown based on height. Clips at a minimum
     * of 1 and a maximum of mMaxAllowedRows.
     *
     * @param allowedHeight The height this view has visually available
     * @param tilesCount Upper limit on the number of tiles to show. to prevent empty rows.
     */
    public boolean updateMaxRows(int allowedHeight, int tilesCount) {
        // Add the cell margin in order to divide easily by the height + the margin below
        final int availableHeight =  allowedHeight + mCellMarginVertical;
        final int previousRows = mRows;
        mRows = availableHeight / (getCellHeight() + mCellMarginVertical);
        if (mRows < mMinRows) {
            mRows = mMinRows;
        } else if (mRows >= mMaxAllowedRows) {
            mRows = mMaxAllowedRows;
        }
        if (mRows > (tilesCount + mColumns - 1) / mColumns) {
            mRows = (tilesCount + mColumns - 1) / mColumns;
        }
        return previousRows != mRows;
    }

    @Override
    public boolean hasOverlappingRendering() {
        return false;
    }

    protected static int exactly(int size) {
        return MeasureSpec.makeMeasureSpec(size, MeasureSpec.EXACTLY);
    }

    // Estimate the height for the tile with 2 labels (general case) under current font scaling.
    protected void estimateCellHeight() {
        FontSizeUtils.updateFontSize(mTempTextView, R.dimen.qs_tile_text_size);
        int unspecifiedSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        mTempTextView.measure(unspecifiedSpec, unspecifiedSpec);
        int padding = mContext.getResources().getDimensionPixelSize(R.dimen.qs_tile_padding);
        mEstimatedCellHeight = mTempTextView.getMeasuredHeight() * 2 + padding * 2;
    }

    protected int getCellHeight() {
        // Compare estimated height with resource height and return the larger one.
        // If estimated height > resource height, it means the resource height is not enough
        // for the tile content under current font scaling. Therefore, we need to use the estimated
        // height to have a full tile content view.
        // If estimated height <= resource height, we can use the resource height for tile to keep
        // the same UI as original behavior.
        return Math.max(mResourceCellHeight, mEstimatedCellHeight);
    }

    private void layoutTileRecords(int numRecords, boolean forLayout) {
        final boolean isRtl = getLayoutDirection() == LAYOUT_DIRECTION_RTL;
        int row = 0;
        int column = 0;
        mLastTileBottom = 0;

        // Layout each QS tile.
        final int tilesToLayout = Math.min(numRecords, mRows * mColumns);
        for (int i = 0; i < tilesToLayout; i++, column++) {
            // If we reached the last column available to layout a tile, wrap back to the next row.
            if (column == mColumns) {
                column = 0;
                row++;
            }

            final TileRecord record = mRecords.get(i);
            final int top = getRowTop(row);
            final int left = getColumnStart(isRtl ? mColumns - column - 1 : column);
            final int right = left + mCellWidth;
            final int bottom = top + record.tileView.getMeasuredHeight();
            if (forLayout) {
                record.tileView.layout(left, top, right, bottom);
            } else {
                record.tileView.setLeftTopRightBottom(left, top, right, bottom);
            }
            record.tileView.setPosition(i);

            // Set the bottom to the unoverriden squished bottom. This is to avoid fake bottoms that
            // are only used for QQS -> QS expansion animations
            float scale = QSTileViewImplKt.constrainSquishiness(mSquishinessFraction);
            mLastTileBottom = top + (int) (record.tileView.getMeasuredHeight() * scale);
        }
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        layoutTileRecords(mRecords.size(), true /* forLayout */);
    }

    protected int getRowTop(int row) {
        float scale = QSTileViewImplKt.constrainSquishiness(mSquishinessFraction);
        return (int) (row * (mCellHeight * scale + mCellMarginVertical));
    }

    protected int getColumnStart(int column) {
        return getPaddingStart() + mSidePadding
                + column *  (mCellWidth + mCellMarginHorizontal);
    }

    @Override
    public int getNumVisibleTiles() {
        return mRecords.size();
    }

    public boolean isFull() {
        return false;
    }

    /**
     * @return The maximum number of tiles this layout can hold
     */
    public int maxTiles() {
        // Each layout should be able to hold at least one tile. If there's not enough room to
        // show even 1 or there are no tiles, it probably means we are in the middle of setting
        // up.
        return Math.max(mColumns * mRows, 1);
    }

    @Override
    public int getTilesHeight() {
        return mLastTileBottom + getPaddingBottom();
    }

    @Override
    public void setSquishinessFraction(float squishinessFraction) {
        if (Float.compare(mSquishinessFraction, squishinessFraction) == 0) {
            return;
        }
        mSquishinessFraction = squishinessFraction;
        layoutTileRecords(mRecords.size(), false /* forLayout */);

        for (TileRecord record : mRecords) {
            if (record.tileView instanceof HeightOverrideable) {
                ((HeightOverrideable) record.tileView).setSquishinessFraction(mSquishinessFraction);
            }
        }
    }

    public float getSquishinessFraction() {
        return mSquishinessFraction;
    }

    @Override
    public void onInitializeAccessibilityNodeInfoInternal(AccessibilityNodeInfo info) {
        super.onInitializeAccessibilityNodeInfoInternal(info);
        info.setCollectionInfo(
                new AccessibilityNodeInfo.CollectionInfo(mRecords.size(), 1, false));
    }
}