package com.d.lib.ui.view.sort;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.support.annotation.Nullable;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

import com.d.lib.common.util.DimenUtils;
import com.d.lib.ui.view.R;

import java.util.List;

/**
 * SideBar
 * Created by D on 2017/6/6.
 */
public class SideBar extends View {
    public final static int TYPE_NORMAL = 0, TYPE_CENTER = 1;
    private final static String[] DEFAULT_LETTERS = {"↑", "☆", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K",
            "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "#"};
    private final static int DEFAULT_MAX_COUNT = 29;

    private final String[] mDefaultLetters;
    private final int mDefaultMaxCount;
    private String[] mLetters;
    private int mMaxCount;

    private int mWidth;
    private int mHeight;
    private Rect mRect;
    private RectF mRectF;
    private Paint mPaint;
    private Paint mPaintCur;
    private Paint mPaintRect;
    private int mType;
    private int mColorTrans, mColorWhite, mColorBar, mColorRect;
    private int mCount;
    private float mOnepice;
    private int mWidthBar;
    private int mWidthRect;
    private int mRectRadius;
    private float mTextHeight;
    private float mTextLightHeight;
    private boolean mDValid;
    private int mIndex = -1;
    private OnLetterChangedListener mListener;

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

    public SideBar(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public SideBar(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.lib_ui_view_SideBar);
        mType = typedArray.getInt(R.styleable.lib_ui_view_SideBar_lib_ui_view_sidebar_type, TYPE_NORMAL);
        mDefaultMaxCount = typedArray.getInt(R.styleable.lib_ui_view_SideBar_lib_ui_view_sidebar_maxCount, DEFAULT_MAX_COUNT);
        String strLetters = typedArray.getString(R.styleable.lib_ui_view_SideBar_lib_ui_view_sidebar_letters);
        if (TextUtils.isEmpty(strLetters)) {
            mLetters = mDefaultLetters = DEFAULT_LETTERS;
        } else {
            mLetters = mDefaultLetters = strLetters.split(";");
        }
        mMaxCount = Math.max(mDefaultMaxCount, mLetters.length);
        typedArray.recycle();
        init(context);
    }

    private void init(Context context) {
        if (mType == TYPE_CENTER) {
            mLetters = new String[]{};
        }
        mCount = mLetters.length;
        mWidthRect = DimenUtils.dp2px(context, 70);
        mRectRadius = DimenUtils.dp2px(context, 6);
        mColorTrans = Color.parseColor("#00000000");
        mColorWhite = Color.parseColor("#ffffff");
        mColorBar = Color.parseColor("#aaBBBBBB");
        mColorRect = Color.parseColor("#aa7F7F7F");

        mRect = new Rect();
        mRectF = new RectF();
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setTextAlign(Paint.Align.CENTER);
        mPaint.setColor(Color.parseColor("#565656"));

        mPaintCur = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaintCur.setTextAlign(Paint.Align.CENTER);
        mPaintCur.setColor(Color.parseColor("#008577"));

        mPaintRect = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaintRect.setTextAlign(Paint.Align.CENTER);
        mPaintRect.setTextSize(DimenUtils.dp2px(context, 32));
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (mType == TYPE_NORMAL) {
            resetRect(mWidth - mWidthBar, 0, mWidth, mHeight, mIndex == -1 ? mColorTrans : mColorBar);
            canvas.drawRect(mRectF, mPaintRect);

            for (int i = 0; i < mCount; i++) {
                canvas.drawText(mLetters[i], mWidth - mWidthBar / 2, mOnepice * i + mOnepice / 2 + mTextHeight / 2, i == mIndex ? mPaintCur : mPaint);
            }
            if (mIndex >= 0 && mIndex < mCount) {
                resetRect((mWidth - mWidthRect) / 2, (mHeight - mWidthRect) / 2, (mWidth + mWidthRect) / 2, (mHeight + mWidthRect) / 2, mColorRect);
                canvas.drawRoundRect(mRectF, mRectRadius, mRectRadius, mPaintRect);
                mPaintRect.setColor(mColorWhite);
                canvas.drawText(mLetters[mIndex], mWidth / 2, (mHeight + mTextLightHeight) / 2, mPaintRect);
            }
        } else {
            super.onDraw(canvas);
            float offsetY = mHeight * (1 - 1f * mCount / mMaxCount) / 2;
            float endY = offsetY + mOnepice * mCount;

            for (int i = 0; i < mCount; i++) {
                canvas.drawText(mLetters[i], mWidth - mWidthBar / 2, offsetY + mOnepice * i + mOnepice / 2 + mTextHeight / 2, i == mIndex ? mPaintCur : mPaint);
            }
        }
    }

    private void resetRect(int left, int top, int right, int bottom, int color) {
        mRect.set(left, top, right, bottom);
        mRectF.set(mRect);
        mPaintRect.setColor(color);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        mWidth = MeasureSpec.getSize(widthMeasureSpec);
        mHeight = MeasureSpec.getSize(heightMeasureSpec);
        mOnepice = 1f * mHeight / mMaxCount;
        mWidthBar = (int) (mOnepice * 1.182f);
        float textSize = mOnepice * 0.686f;
        mPaint.setTextSize(textSize);
        mPaintCur.setTextSize(textSize);
        mTextHeight = DimenUtils.getTextHeight(mPaint);
        mTextLightHeight = DimenUtils.getTextHeight(mPaintRect);
        setMeasuredDimension(mWidth, mHeight);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        float offsetY = mType == TYPE_CENTER ? mHeight * (1 - 1f * mCount / mMaxCount) / 2 : 0;
        float eX = event.getX();
        float eY = event.getY() - offsetY;
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mDValid = eY >= 0 && eY <= mOnepice * mCount + 1 && eX > mWidth - mWidthBar;
                return mDValid && delegate(adjustIndex(eY));
            case MotionEvent.ACTION_MOVE:
                return delegate(adjustIndex(eY));
            case MotionEvent.ACTION_CANCEL:
            case MotionEvent.ACTION_UP:
                return delegate(-1);
        }
        return super.onTouchEvent(event);
    }

    private int adjustIndex(float eY) {
        eY = Math.max(eY, 0);
        eY = Math.min(eY, mHeight);
        int i = (int) (eY / mOnepice);
        i = Math.max(i, 0);
        i = Math.min(i, mCount - 1);
        return i;
    }

    private boolean delegate(int i) {
        if (mDValid && i != mIndex) {
            mIndex = i;
            if (mIndex != -1 && mListener != null) {
                mListener.onChange(mIndex, mLetters[mIndex]);
            }
            invalidate();
            return true;
        }
        return false;
    }

    public void setType(int type) {
        mType = type;
    }

    public void reset(List<String> datas) {
        if (datas == null) {
            return;
        }
        mLetters = mType == TYPE_CENTER ? datas.toArray(new String[datas.size()])
                : mDefaultLetters;
        mMaxCount = Math.max(mDefaultMaxCount, mLetters.length);
        mCount = mLetters.length;
        requestLayout();
        invalidate();
    }

    public void setOnLetterChangedListener(OnLetterChangedListener listener) {
        this.mListener = listener;
    }

    public interface OnLetterChangedListener {
        void onChange(int index, String c);
    }
}