package com.gh.common.view;

import android.content.Context;
import android.graphics.Color;
import android.os.Build;
import android.text.Layout;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.TextPaint;
import android.text.style.BackgroundColorSpan;
import android.text.style.ClickableSpan;
import android.util.AttributeSet;
import android.view.View;

import androidx.appcompat.widget.AppCompatTextView;
import androidx.core.content.ContextCompat;

import com.gh.common.util.DisplayUtils;
import com.gh.gamecenter.R;

public class ExpendTextView extends AppCompatTextView {

    private CharSequence mSnapshotText;

    private String mExpendText = "...全文";

    private int mMaxLines = 3; // 由于sdk版本限制(getMaxLines) 这里设置默认值

    private boolean mInitLayout = false;
    private boolean mOpenLayout = false;

    private ExpandCallback mExpandCallback;

    public ExpendTextView(Context context) {
        super(context);
    }

    public ExpendTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
            mMaxLines = getMaxLines();
        }
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        if (mInitLayout && !mOpenLayout && getLineCount() > mMaxLines) {
            mSnapshotText = getText();
            mInitLayout = false;
            showExpendButton();
        }
    }

    public void setExpendText(String text) {
        this.mExpendText = text;
    }

    public void setExpandCallback(ExpandCallback callback) {
        this.mExpandCallback = callback;
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        mInitLayout = true;
        super.setText(text, type);
    }

    private void showExpendButton() {
        Layout layout = getLayout();
        int start = layout.getLineStart(0);
        int lastLineEnd = layout.getLineEnd(mMaxLines - 1);
        int lastLineStart = layout.getLineStart(mMaxLines - 1);
        float lastLineRight = layout.getLineRight(mMaxLines - 1);

        int viewWidth = getWidth() - getPaddingRight() - getPaddingLeft();

        TextPaint paint = getPaint();
        float expendTextWidth = paint.measureText(mExpendText);
        CharSequence content = mSnapshotText.subSequence(start, lastLineEnd);
        if (viewWidth - lastLineRight > expendTextWidth) {
            content = content.toString().trim() + mExpendText;
        } else {
            CharSequence lastText = mSnapshotText.subSequence(lastLineStart, lastLineEnd);
            for (int i = lastText.length() - 1; i > 0; i--) {
                CharSequence sequence = lastText.subSequence(0, i);
                float w = paint.measureText(sequence.toString());
                if (viewWidth - w - DisplayUtils.dip2px(5) > expendTextWidth) {
                    content = mSnapshotText.subSequence(start, lastLineStart + i) + mExpendText;
                    break;
                }
            }
        }
        SpannableStringBuilder msp = new SpannableStringBuilder(mSnapshotText);
        int length = msp.length();
        int startPosition = content.length() - mExpendText.length();
        startPosition = startPosition < 0 ? 0 : startPosition;
        msp.replace(startPosition, length, mExpendText);
        msp.setSpan(new ClickableSpan() {
            @Override
            public void updateDrawState(TextPaint ds) {
                super.updateDrawState(ds);
                ds.setColor(ContextCompat.getColor(getContext(), R.color.theme));
                ds.setUnderlineText(false);
            }

            @Override
            public void onClick(View widget) {
                mOpenLayout = true;
                setMaxLines(Integer.MAX_VALUE);
                setText(mSnapshotText);

                if (mExpandCallback != null) {
                    mExpandCallback.onExpand();
                }
            }
        }, startPosition + 3, msp.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        msp.setSpan(new BackgroundColorSpan(Color.WHITE), startPosition, msp.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

        setText(msp);
        setMovementMethod(CustomLinkMovementMethod.getInstance());
    }


    public void setExpendMaxLines(int maxLines) {
        mMaxLines = maxLines;
        setMaxLines(maxLines);
    }

    public interface ExpandCallback {
        void onExpand();
    }

}