PostDetailsActivity.java

package com.codewithharry.firebase;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.ActionBar;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.text.TextUtils;
import android.text.format.DateFormat;
import android.view.Gravity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.PopupMenu;
import android.widget.TextView;
import android.widget.Toast;

import com.codewithharry.firebase.adapters.AdapterComments;
import com.codewithharry.firebase.models.ModelComment;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageReference;
import com.squareup.picasso.Picasso;

import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashMap;
import java.util.Locale;

public class PostDetailsActivity extends AppCompatActivity {

    //to get details of user and post
    String hisUid, myUid, myEmail, myName, myDp,
            postId, pImage, pLikes, hisDp, hisName;

    boolean mProcessComment = false;
    boolean mProcessLike = false;

    //progress dialog
    ProgressDialog pd;

    //views
    ImageView uPictureIv, pImageIv;
    TextView uNameTv, pTimeTiv, pTitleTv, pDescriptionTv, pLikesTv, pCommentsTv;
    ImageButton moreBtn;
    Button likeBtn, shareBtn;
    LinearLayout profileLayout;
    RecyclerView recyclerView;

    ArrayList<ModelComment> commentList;
    AdapterComments adapterComments;

    FirebaseAuth firebaseAuth;

    //add comments views
    EditText commentEt;
    ImageButton sendBtn;
    ImageView cAvatarIv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_post_details);

        //Actionbar and its properties
        ActionBar actionBar = getSupportActionBar();
        actionBar.setTitle("Post Details");
        actionBar.setDisplayShowHomeEnabled(true);
        actionBar.setDisplayHomeAsUpEnabled(true);

        //get id of post using intent
        Intent intent = getIntent();
        postId = intent.getStringExtra("postId");

        //init views
        uPictureIv = findViewById(R.id.uPictureIv);
        pImageIv = findViewById(R.id.pImageIv);
        uNameTv = findViewById(R.id.uNameTv);
        pTimeTiv = findViewById(R.id.pTimeTv);
        pTitleTv = findViewById(R.id.pTitleTv);
        pDescriptionTv = findViewById(R.id.pDescriptionTv);
        pLikesTv = findViewById(R.id.pLikesTv);
        pCommentsTv = findViewById(R.id.pCommentsTv);
        moreBtn = findViewById(R.id.moreBtn);
        likeBtn = findViewById(R.id.likeBtn);
        shareBtn = findViewById(R.id.shareBtn);
        profileLayout = findViewById(R.id.profileLayout);
        recyclerView = findViewById(R.id.recyclerView);

        commentEt = findViewById(R.id.commentEt);
        sendBtn = findViewById(R.id.sendBtn);
        cAvatarIv = findViewById(R.id.cAvtarIv);

        //init FIrebase
        firebaseAuth = FirebaseAuth.getInstance();

        loadPostInfo();

        checkUserStatus();

        loadUserInfo();

        setLikes();

        //set subtitle of action
        actionBar.setSubtitle("Signed in as " + myEmail);
        
        loadComments();
        
        //send comment button click
        sendBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                postComment();
            }
        });

        //like button handler
        likeBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                likePost();
            }
        });

        moreBtn.setOnClickListener(view -> showMoreOptions());
    }

    private void loadComments() {

        //layout for recyclerView
        LinearLayoutManager layoutManager = new LinearLayoutManager(getApplicationContext());
        //set layout to recyclerView
        recyclerView.setLayoutManager(layoutManager);

        //init comments list
        commentList = new ArrayList<>();

        DatabaseReference ref = FirebaseDatabase.getInstance().getReference("Posts").child(postId).child("Comments");
        ref.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                commentList.clear();
                for(DataSnapshot ds: snapshot.getChildren()) {
                    ModelComment modelComment = ds.getValue(ModelComment.class);

                    commentList.add(modelComment);

                    //set up adapter
                    adapterComments = new AdapterComments(getApplicationContext(), commentList);
                    //set adapter
                    recyclerView.setAdapter(adapterComments);
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

    private void showMoreOptions() {
        //creating pop up menu currently having option Delete, we wil add more options later
        PopupMenu popupMenu = null;
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
            popupMenu = new PopupMenu(this, moreBtn, Gravity.END);
        }

        //show delete option in only post(s) of currently signed in user
        if (hisUid.equals(myUid)) {
            //add items in menu
            popupMenu.getMenu().add(Menu.NONE, 0, 0, "Delete");
            popupMenu.getMenu().add(Menu.NONE, 1, 0, "Edit");
        } else {
            moreBtn.setVisibility(View.GONE);
        }

        //item click listener
        popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem menuItem) {
                int id = menuItem.getItemId();
                if (id == 0) {
                    //delete option is clicked
                    beginDelete();
                } else if (id == 1) {
                    //Edit is clicked
                    //start AddPostActivity with key "editPost" and the id of the post clicked
                    Intent intent = new Intent(PostDetailsActivity.this, AddPostActivity.class);
                    intent.putExtra("key", "editPost");
                    intent.putExtra("editPostId", postId);
                    startActivity(intent);
                }
                return false;
            }
        });
        //show menu
        popupMenu.show();
    }

    private void beginDelete() {
        //post can be with or without image

        if (pImage.equals("noImage")) {
            //post is without image
            deleteWithoutImage();
        } else {
            //post is with image
            deleteWithImage();
        }
    }

    private void deleteWithImage() {
        //progress bar
        ProgressDialog pd = new ProgressDialog(this);
        pd.setMessage("Deleting post..");

        /*Steps:
         * Delete image using url
         * Delete from database using post id*/

        StorageReference picRef = FirebaseStorage.getInstance().getReferenceFromUrl(pImage);
        picRef.delete()
                .addOnSuccessListener(new OnSuccessListener<Void>() {
                    @Override
                    public void onSuccess(Void unused) {
                        //image deleted, now delete database
                        Query fquery = FirebaseDatabase.getInstance().getReference("Posts")
                                .orderByChild("pId").equalTo(postId);
                        fquery.addValueEventListener(new ValueEventListener() {
                            @Override
                            public void onDataChange(@NonNull DataSnapshot snapshot) {
                                for (DataSnapshot ds : snapshot.getChildren()) {
                                    ds.getRef().removeValue();
                                    //remove values from firebase where pId matches
                                }
                                //deleted
                                Toast.makeText(PostDetailsActivity.this, "Deleted successfully", Toast.LENGTH_SHORT).show();
                                pd.dismiss();
                            }

                            @Override
                            public void onCancelled(@NonNull DatabaseError error) {

                            }
                        });
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {
                        //failed, can't go further
                        pd.dismiss();
                        Toast.makeText(PostDetailsActivity.this, "" + e.getMessage(), Toast.LENGTH_SHORT).show();
                    }
                });
    }

    private void deleteWithoutImage() {
        ProgressDialog pd = new ProgressDialog(this);
        pd.setMessage("Deleting post..");

        Query fquery = FirebaseDatabase.getInstance().getReference("Posts")
                .orderByChild("pId").equalTo(postId);
        fquery.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                for (DataSnapshot ds : snapshot.getChildren()) {
                    ds.getRef().removeValue();
                    //remove values from firebase where pId matches
                }
                //deleted
                Toast.makeText(PostDetailsActivity.this, "Deleted successfully", Toast.LENGTH_SHORT).show();
                pd.dismiss();
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

    private void setLikes() {
        final DatabaseReference likesRef = FirebaseDatabase.getInstance().getReference().child("Likes");
        likesRef.addValueEventListener(new ValueEventListener() {
            @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR1)
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                if (snapshot.child(postId).hasChild(myUid)) {
                    //user has liked this post
                    /*To indicate that the post is liked by this(SignedIn) user
                     * Change drawable left icon of like button
                     * Change text of like button fro "Like" to "Liked"*/
                    likeBtn.setCompoundDrawablesRelativeWithIntrinsicBounds(R.drawable.ic_liked, 0, 0, 0);
                    likeBtn.setText("Liked");
                } else {
                    //user has not liked this post
                    /*To indicate that the post is not liked by this(SignedIn) user
                     * Change drawable left icon of like button
                     * Change text of like button fro "Liked" to "Like"*/
                    likeBtn.setCompoundDrawablesRelativeWithIntrinsicBounds(R.drawable.ic_like_black, 0, 0, 0);
                    likeBtn.setText("Like");
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

    private void likePost() {
        //get total number of likes for the post, whose like button is clicked
        //if currently signed in user has not liked it before
        //increase value by 1, otherwise decrease value by 1
        mProcessLike = true;
        //get id of the post clicked
        final DatabaseReference likesRef = FirebaseDatabase.getInstance().getReference().child("Likes");
        final DatabaseReference postsRef = FirebaseDatabase.getInstance().getReference().child("Posts");
        likesRef.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                if (mProcessLike) {
                    if (snapshot.child(postId).hasChild(myUid)) {
                        //already liked, so remove like
                        postsRef.child(postId).child("pLikes").setValue("" + (Integer.parseInt(pLikes) - 1));
                        likesRef.child(postId).child(myUid).removeValue();
                        mProcessLike = false;
                    } else {
                        //not liked, like
                        postsRef.child(postId).child("pLikes").setValue("" + (Integer.parseInt(pLikes) + 1));
                        likesRef.child(postId).child(myUid).setValue("Liked"); //set any value
                        mProcessLike = false;
                    }
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

    private void postComment() {
        pd = new ProgressDialog(this);
        pd.setMessage("Adding comment..");

        //get data from comment edit text
        String comment = commentEt.getText().toString().trim();
        //validate
        if (TextUtils.isEmpty(comment)) {
            //no value is entered
            Toast.makeText(this, "Comment section is empty.", Toast.LENGTH_SHORT).show();
            return;
        }

        String timeStamp = String.valueOf(System.currentTimeMillis());

        //each post will have child comments that will contain comments of that post
        DatabaseReference ref = FirebaseDatabase.getInstance().getReference("Posts").child(postId).child("Comments");

        HashMap<String, Object> hashMap = new HashMap<>();
        //put info in hashMap
        hashMap.put("cId",timeStamp);
        hashMap.put("comment", comment);
        hashMap.put("timeStamp", timeStamp);
        hashMap.put("uid", myUid);
        hashMap.put("uEmail", myEmail);
        hashMap.put("uDp", myDp);
        hashMap.put("uName", myName);

        //put this data in db
        ref.child(timeStamp).setValue(hashMap)
                .addOnSuccessListener(new OnSuccessListener<Void>() {
                    @Override
                    public void onSuccess(Void unused) {
                        //added
                        pd.dismiss();
                        Toast.makeText(PostDetailsActivity.this, "Comment Added..", Toast.LENGTH_SHORT).show();
                        commentEt.setText("");
                        updateCommentCount();
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {
                        //failed, not added
                        pd.dismiss();
                        Toast.makeText(PostDetailsActivity.this, "Failed because "+e.getMessage(), Toast.LENGTH_SHORT).show();
                    }
                });

    }


    private void updateCommentCount() {
        //when ever user adds a comment increase the comment count
        mProcessComment = true;
        DatabaseReference ref = FirebaseDatabase.getInstance().getReference("Posts").child(postId);
        ref.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                if (mProcessComment) {
                    String comments = "" + snapshot.child("pComments").getValue();
                    int newCommentVal = Integer.parseInt(comments) + 1;
                    ref.child("pComments").setValue(""+newCommentVal);
                    mProcessComment = false;
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

    private void loadUserInfo() {
        //get current user info
        Query myRef = FirebaseDatabase.getInstance().getReference("Users");
        myRef.orderByChild("uid").equalTo(myUid).addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                for (DataSnapshot ds : snapshot.getChildren()) {
                    myName = "" + ds.child("name").getValue();
                    myDp = "" + ds.child("image").getValue();

                    //set data
                    try {
                        //if image is received
                        Picasso.get().load(myDp).placeholder(R.drawable.ic_default_image_blue).into(cAvatarIv);
                    } catch (Exception e) {
                        Picasso.get().load(R.drawable.ic_default_image_blue).into(cAvatarIv);
                    }
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });

    }

    private void loadPostInfo() {
        //get post using the id of the post
        DatabaseReference ref = FirebaseDatabase.getInstance().getReference("Posts");
        Query query = ref.orderByChild("pId").equalTo(postId);
        query.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                //keep checking the posts until you get the required post
                for (DataSnapshot ds : snapshot.getChildren()) {
                    //get data
                    String pTitle = "" + ds.child("pTitle").getValue();
                    String pDescr = "" + ds.child("pDescr").getValue();
                    pLikes = "" + ds.child("pLikes").getValue();
                    String pTimeStamp = "" + ds.child("pTime").getValue();
                    pImage = "" + ds.child("pImage").getValue();
                    hisDp = "" + ds.child("uDp").getValue();
                    hisUid = "" + ds.child("uid").getValue();
                    String pEmail = "" + ds.child("uEmail").getValue();
                    String hisName = "" + ds.child("uName").getValue();
                    String commentCount = "" + ds.child("pComments").getValue();

                    //convert timeStamp to dd/mm/yyyy hh:mm am/pm
                    Calendar calendar = Calendar.getInstance(Locale.getDefault());
                    calendar.setTimeInMillis(Long.parseLong(pTimeStamp));
                    String pTime = DateFormat.format("dd/MM/yyyy hh:mm aa", calendar).toString();

                    //set data
                    pTitleTv.setText(pTitle);
                    pDescriptionTv.setText(pDescr);
                    pLikesTv.setText(pLikes + " Likes");
                    pTimeTiv.setText(pTime);
                    pCommentsTv.setText(commentCount + " Comments");

                    uNameTv.setText(hisName);

                    //set image of the user who posted
                    //set post image
                    //if there is no image then hide image view
                    if (pImage.equals("noImage")) {
                        //hide imageview
                        pImageIv.setVisibility(View.GONE);

                    } else {
                        //show imageview
                        pImageIv.setVisibility(View.VISIBLE);

                        try {
                            Picasso.get().load(pImage).into(pImageIv);
                        } catch (Exception e) {

                        }

                    }

                    //set user image in comment part
                    try {
                        Picasso.get().load(hisDp).placeholder(R.drawable.ic_default_image_blue).into(uPictureIv);
                    } catch (Exception e) {
                        Picasso.get().load(R.drawable.ic_default_image_blue).into(cAvatarIv);
                    }
                }

            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

    private void checkUserStatus() {
        //Get current user
        FirebaseUser user = firebaseAuth.getCurrentUser();
        if (user != null) {
            //User is signed in stay here
            myEmail = user.getEmail();
            myUid = user.getUid();
        } else {
            //User not signed in go to main activity
            startActivity(new Intent(this, MainActivity.class));
            finish();
        }

    }

    @Override
    public boolean onSupportNavigateUp() {
        onBackPressed();
        return super.onSupportNavigateUp();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        menu.findItem(R.id.action_add_post).setVisible(false);
        menu.findItem(R.id.action_search).setVisible(false);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        //get item id
        int id = item.getItemId();
        if (id == R.id.action_logout) {
            FirebaseAuth.getInstance().signOut();
            checkUserStatus();
        }
        return super.onOptionsItemSelected(item);
    }

}