/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.support.v7.internal.widget;

import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.Resources;
import android.graphics.Color;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffColorFilter;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.support.v4.util.LruCache;
import android.support.v7.appcompat.R;
import android.util.Log;
import android.util.TypedValue;

/**
 * @hide
 */
public class TintManager {

    private static final String TAG = TintManager.class.getSimpleName();
    private static final boolean DEBUG = false;

    static final PorterDuff.Mode DEFAULT_MODE = PorterDuff.Mode.SRC_IN;

    private static final ColorFilterLruCache COLOR_FILTER_CACHE = new ColorFilterLruCache(6);

    /**
     * Drawables which should be tinted with the value of {@code R.attr.colorControlNormal},
     * using the default mode.
     */
    private static final int[] TINT_COLOR_CONTROL_NORMAL = {
            R.drawable.abc_ic_ab_back_mtrl_am_alpha,
            R.drawable.abc_ic_go_search_api_mtrl_alpha,
            R.drawable.abc_ic_search_api_mtrl_alpha,
            R.drawable.abc_ic_commit_search_api_mtrl_alpha,
            R.drawable.abc_ic_clear_mtrl_alpha,
            R.drawable.abc_ic_menu_share_mtrl_alpha,
            R.drawable.abc_ic_menu_copy_mtrl_am_alpha,
            R.drawable.abc_ic_menu_cut_mtrl_alpha,
            R.drawable.abc_ic_menu_selectall_mtrl_alpha,
            R.drawable.abc_ic_menu_paste_mtrl_am_alpha,
            R.drawable.abc_ic_menu_moreoverflow_mtrl_alpha,
            R.drawable.abc_ic_voice_search_api_mtrl_alpha,
            R.drawable.abc_textfield_search_default_mtrl_alpha,
            R.drawable.abc_textfield_default_mtrl_alpha,
            R.drawable.abc_ab_share_pack_mtrl_alpha
    };

    /**
     * Drawables which should be tinted with the value of {@code R.attr.colorControlActivated},
     * using the default mode.
     */
    private static final int[] TINT_COLOR_CONTROL_ACTIVATED = {
            R.drawable.abc_textfield_activated_mtrl_alpha,
            R.drawable.abc_textfield_search_activated_mtrl_alpha,
            R.drawable.abc_cab_background_top_mtrl_alpha
    };

    /**
     * Drawables which should be tinted with the value of {@code android.R.attr.colorBackground},
     * using the {@link android.graphics.PorterDuff.Mode#MULTIPLY} mode.
     */
    private static final int[] TINT_COLOR_BACKGROUND_MULTIPLY = {
            R.drawable.abc_popup_background_mtrl_mult,
            R.drawable.abc_cab_background_internal_bg,
            R.drawable.abc_menu_hardkey_panel_mtrl_mult
    };

    /**
     * Drawables which should be tinted using a state list containing values of
     * {@code R.attr.colorControlNormal} and {@code R.attr.colorControlActivated}
     */
    private static final int[] TINT_COLOR_CONTROL_STATE_LIST = {
            R.drawable.abc_edit_text_material,
            R.drawable.abc_tab_indicator_material,
            R.drawable.abc_textfield_search_material,
            R.drawable.abc_spinner_mtrl_am_alpha,
            R.drawable.abc_btn_check_material,
            R.drawable.abc_btn_radio_material,
            R.drawable.abc_spinner_textfield_background_material,
            R.drawable.abc_ratingbar_full_material
    };

    /**
     * Drawables which contain other drawables which should be tinted. The child drawable IDs
     * should be defined in one of the arrays above.
     */
    private static final int[] CONTAINERS_WITH_TINT_CHILDREN = {
            R.drawable.abc_cab_background_top_material
    };

    private final Context mContext;
    private final Resources mResources;
    private final TypedValue mTypedValue;

    private ColorStateList mDefaultColorStateList;
    private ColorStateList mSwitchThumbStateList;
    private ColorStateList mSwitchTrackStateList;
    private ColorStateList mButtonStateList;

    /**
     * A helper method to instantiate a {@link TintManager} and then call {@link #getDrawable(int)}.
     * This method should not be used routinely.
     */
    public static Drawable getDrawable(Context context, int resId) {
        if (isInTintList(resId)) {
            return new TintManager(context).getDrawable(resId);
        } else {
            return ContextCompat.getDrawable(context, resId);
        }
    }

    public TintManager(Context context) {
        mContext = context;
        mResources = new TintResources(context.getResources(), this);
        mTypedValue = new TypedValue();
    }

    public Drawable getDrawable(int resId) {
        Drawable drawable = ContextCompat.getDrawable(mContext, resId);

        if (drawable != null) {
            drawable = drawable.mutate();

            if (arrayContains(TINT_COLOR_CONTROL_STATE_LIST, resId)) {
                drawable = new TintDrawableWrapper(drawable, getDefaultColorStateList());
            } else if (resId == R.drawable.abc_switch_track_mtrl_alpha) {
                drawable = new TintDrawableWrapper(drawable, getSwitchTrackColorStateList());
            } else if (resId == R.drawable.abc_switch_thumb_material) {
                drawable = new TintDrawableWrapper(drawable, getSwitchThumbColorStateList(),
                        PorterDuff.Mode.MULTIPLY);
            } else if (resId == R.drawable.abc_btn_default_mtrl_shape) {
                drawable = new TintDrawableWrapper(drawable, getButtonColorStateList());
            } else if (arrayContains(CONTAINERS_WITH_TINT_CHILDREN, resId)) {
                drawable = mResources.getDrawable(resId);
            } else {
                tintDrawable(resId, drawable);
            }
        }
        return drawable;
    }

    void tintDrawable(final int resId, final Drawable drawable) {
        PorterDuff.Mode tintMode = null;
        boolean colorAttrSet = false;
        int colorAttr = 0;
        int alpha = -1;

        if (arrayContains(TINT_COLOR_CONTROL_NORMAL, resId)) {
            colorAttr = R.attr.colorControlNormal;
            colorAttrSet = true;
        } else if (arrayContains(TINT_COLOR_CONTROL_ACTIVATED, resId)) {
            colorAttr = R.attr.colorControlActivated;
            colorAttrSet = true;
        } else if (arrayContains(TINT_COLOR_BACKGROUND_MULTIPLY, resId)) {
            colorAttr = android.R.attr.colorBackground;
            colorAttrSet = true;
            tintMode = PorterDuff.Mode.MULTIPLY;
        } else if (resId == R.drawable.abc_list_divider_mtrl_alpha) {
            colorAttr = android.R.attr.colorForeground;
            colorAttrSet = true;
            alpha = Math.round(0.16f * 255);
        }

        if (colorAttrSet) {
            if (tintMode == null) {
                tintMode = DEFAULT_MODE;
            }
            final int color = getThemeAttrColor(colorAttr);

            // First, lets see if the cache already contains the color filter
            PorterDuffColorFilter filter = COLOR_FILTER_CACHE.get(color, tintMode);

            if (filter == null) {
                // Cache miss, so create a color filter and add it to the cache
                filter = new PorterDuffColorFilter(color, tintMode);
                COLOR_FILTER_CACHE.put(color, tintMode, filter);
            }

            // Finally set the color filter
            drawable.setColorFilter(filter);

            if (alpha != -1) {
                drawable.setAlpha(alpha);
            }

            if (DEBUG) {
                Log.d(TAG, "Tinted Drawable ID: " + mResources.getResourceName(resId) +
                        " with color: #" + Integer.toHexString(color));
            }
        }
    }

    private static boolean arrayContains(int[] array, int value) {
        for (int id : array) {
            if (id == value) {
                return true;
            }
        }
        return false;
    }

    private static boolean isInTintList(int drawableId) {
        return arrayContains(TINT_COLOR_BACKGROUND_MULTIPLY, drawableId) ||
                arrayContains(TINT_COLOR_CONTROL_NORMAL, drawableId) ||
                arrayContains(TINT_COLOR_CONTROL_ACTIVATED, drawableId) ||
                arrayContains(TINT_COLOR_CONTROL_STATE_LIST, drawableId) ||
                arrayContains(CONTAINERS_WITH_TINT_CHILDREN, drawableId);
    }

    private ColorStateList getDefaultColorStateList() {
        if (mDefaultColorStateList == null) {
            /**
             * Generate the default color state list which uses the colorControl attributes.
             * Order is important here. The default enabled state needs to go at the bottom.
             */

            final int colorControlNormal = getThemeAttrColor(R.attr.colorControlNormal);
            final int colorControlActivated = getThemeAttrColor(R.attr.colorControlActivated);

            final int[][] states = new int[7][];
            final int[] colors = new int[7];
            int i = 0;

            // Disabled state
            states[i] = new int[] { -android.R.attr.state_enabled };
            colors[i] = getDisabledThemeAttrColor(R.attr.colorControlNormal);
            i++;

            states[i] = new int[] { android.R.attr.state_focused };
            colors[i] = colorControlActivated;
            i++;

            states[i] = new int[] { android.R.attr.state_activated };
            colors[i] = colorControlActivated;
            i++;

            states[i] = new int[] { android.R.attr.state_pressed };
            colors[i] = colorControlActivated;
            i++;

            states[i] = new int[] { android.R.attr.state_checked };
            colors[i] = colorControlActivated;
            i++;

            states[i] = new int[] { android.R.attr.state_selected };
            colors[i] = colorControlActivated;
            i++;

            // Default enabled state
            states[i] = new int[0];
            colors[i] = colorControlNormal;
            i++;

            mDefaultColorStateList = new ColorStateList(states, colors);
        }
        return mDefaultColorStateList;
    }

    private ColorStateList getSwitchTrackColorStateList() {
        if (mSwitchTrackStateList == null) {
            final int[][] states = new int[3][];
            final int[] colors = new int[3];
            int i = 0;

            // Disabled state
            states[i] = new int[] { -android.R.attr.state_enabled };
            colors[i] = getThemeAttrColor(android.R.attr.colorForeground, 0.1f);
            i++;

            states[i] = new int[] { android.R.attr.state_checked };
            colors[i] = getThemeAttrColor(R.attr.colorControlActivated, 0.3f);
            i++;

            // Default enabled state
            states[i] = new int[0];
            colors[i] = getThemeAttrColor(android.R.attr.colorForeground, 0.3f);
            i++;

            mSwitchTrackStateList = new ColorStateList(states, colors);
        }
        return mSwitchTrackStateList;
    }

    private ColorStateList getSwitchThumbColorStateList() {
        if (mSwitchThumbStateList == null) {
            final int[][] states = new int[3][];
            final int[] colors = new int[3];
            int i = 0;

            // Disabled state
            states[i] = new int[] { -android.R.attr.state_enabled };
            colors[i] = getDisabledThemeAttrColor(R.attr.colorSwitchThumbNormal);
            i++;

            states[i] = new int[] { android.R.attr.state_checked };
            colors[i] = getThemeAttrColor(R.attr.colorControlActivated);
            i++;

            // Default enabled state
            states[i] = new int[0];
            colors[i] = getThemeAttrColor(R.attr.colorSwitchThumbNormal);
            i++;

            mSwitchThumbStateList = new ColorStateList(states, colors);
        }
        return mSwitchThumbStateList;
    }

    private ColorStateList getButtonColorStateList() {
        if (mButtonStateList == null) {
            final int[][] states = new int[4][];
            final int[] colors = new int[4];
            int i = 0;

            // Disabled state
            states[i] = new int[] { -android.R.attr.state_enabled };
            colors[i] = getDisabledThemeAttrColor(R.attr.colorButtonNormal);
            i++;

            states[i] = new int[] { android.R.attr.state_pressed };
            colors[i] = getThemeAttrColor(R.attr.colorControlHighlight);
            i++;

            states[i] = new int[] { android.R.attr.state_focused };
            colors[i] = getThemeAttrColor(R.attr.colorControlHighlight);
            i++;

            // Default enabled state
            states[i] = new int[0];
            colors[i] = getThemeAttrColor(R.attr.colorButtonNormal);
            i++;

            mButtonStateList = new ColorStateList(states, colors);
        }
        return mButtonStateList;
    }

    int getThemeAttrColor(int attr) {
        if (mContext.getTheme().resolveAttribute(attr, mTypedValue, true)) {
            if (mTypedValue.type >= TypedValue.TYPE_FIRST_INT
                    && mTypedValue.type <= TypedValue.TYPE_LAST_INT) {
                return mTypedValue.data;
            } else if (mTypedValue.type == TypedValue.TYPE_STRING) {
                return mResources.getColor(mTypedValue.resourceId);
            }
        }
        return 0;
    }

    int getThemeAttrColor(int attr, float alpha) {
        final int color = getThemeAttrColor(attr);
        final int originalAlpha = Color.alpha(color);

        // Return the color, multiplying the original alpha by the disabled value
        return (color & 0x00ffffff) | (Math.round(originalAlpha * alpha) << 24);
    }

    int getDisabledThemeAttrColor(int attr) {
        // Now retrieve the disabledAlpha value from the theme
        mContext.getTheme().resolveAttribute(android.R.attr.disabledAlpha, mTypedValue, true);
        final float disabledAlpha = mTypedValue.getFloat();

        return getThemeAttrColor(attr, disabledAlpha);
    }

    private static class ColorFilterLruCache extends LruCache<Integer, PorterDuffColorFilter> {

        public ColorFilterLruCache(int maxSize) {
            super(maxSize);
        }

        PorterDuffColorFilter get(int color, PorterDuff.Mode mode) {
            return get(generateCacheKey(color, mode));
        }

        PorterDuffColorFilter put(int color, PorterDuff.Mode mode, PorterDuffColorFilter filter) {
            return put(generateCacheKey(color, mode), filter);
        }

        private static int generateCacheKey(int color, PorterDuff.Mode mode) {
            int hashCode = 1;
            hashCode = 31 * hashCode + color;
            hashCode = 31 * hashCode + mode.hashCode();
            return hashCode;
        }
    }
}