From 22f49dfea2b49edc42b4bda1d1c1b0973e306ee4 Mon Sep 17 00:00:00 2001
From: flashburst <82953782+flashburst@users.noreply.github.com>
Date: Mon, 17 Apr 2023 13:21:24 +0530
Subject: [PATCH 1/2] Added log like function

---
 sql/nft/website/functions/log_like.sql | 58 ++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 sql/nft/website/functions/log_like.sql

diff --git a/sql/nft/website/functions/log_like.sql b/sql/nft/website/functions/log_like.sql
new file mode 100644
index 0000000..76a2215
--- /dev/null
+++ b/sql/nft/website/functions/log_like.sql
@@ -0,0 +1,58 @@
+CREATE OR REPLACE FUNCTION log_like
+(
+  _account                               address,
+  _token_id                             uint256
+)
+RETURNS uint256
+AS
+$$
+  DECLARE _previous               boolean;
+  DECLARE _current                boolean;
+  DECLARE _last_liked_at          TIMESTAMP WITH TIME ZONE;
+  DECLARE _last_unliked_at        TIMESTAMP WITH TIME ZONE;
+  DECLARE _liked_at               TIMESTAMP WITH TIME ZONE;
+  DECLARE _token_likes           uint256;
+BEGIN
+  IF NOT EXISTS(SELECT 1 FROM nfts WHERE token_id = _token_id) THEN
+    RAISE EXCEPTION 'Invalid token id';
+  END IF;
+
+  SELECT likes.liked                    INTO _previous
+  WHERE likes.liked_by                  = _account
+  AND likes.token_id                    = _token_id;
+
+  IF(_previous = false) THEN
+    _current                            := true;
+    _last_liked_at                      := NOW();
+  ELSIF(_previous = true) THEN
+    _current                            := false;
+    _last_unliked_at                    := NOW();
+  ELSE
+    _current                            := true;
+    _last_liked_at                      := NOW();
+  END IF;
+
+  UPDATE likes
+  SET
+    liked                               = _current,
+    last_liked_at                       = _last_liked_at,
+    last_unliked_at                     = _last_unliked_at
+  WHERE likes.liked_by                  = _account
+  AND likes.token_id                    = _token_id;
+
+  IF(_current = true) THEN
+    UPDATE nfts
+    SET likes = nfts.likes + 1
+    WHERE token_id = _token_id
+    RETURNING nfts.likes                INTO _token_likes;
+  ELSE
+    UPDATE nfts
+    SET likes = nfts.likes - 1
+    WHERE token_id = _token_id
+    RETURNING nfts.likes                INTO _token_likes;
+  END IF;
+
+  RETURN _token_likes;
+END
+$$
+LANGUAGE plpgsql;
\ No newline at end of file

From 30e9602624babb044c235e47e2e5aea77b097b3f Mon Sep 17 00:00:00 2001
From: flashburst <82953782+flashburst@users.noreply.github.com>
Date: Mon, 17 Apr 2023 15:45:58 +0530
Subject: [PATCH 2/2] Refactored to remove if-else for updating table

---
 sql/nft/website/functions/log_like.sql | 55 ++++++++------------------
 1 file changed, 17 insertions(+), 38 deletions(-)

diff --git a/sql/nft/website/functions/log_like.sql b/sql/nft/website/functions/log_like.sql
index 76a2215..1220bb2 100644
--- a/sql/nft/website/functions/log_like.sql
+++ b/sql/nft/website/functions/log_like.sql
@@ -1,56 +1,35 @@
 CREATE OR REPLACE FUNCTION log_like
 (
-  _account                               address,
-  _token_id                             uint256
+  _account                                address,
+  _token_id                               uint256
 )
 RETURNS uint256
 AS
 $$
-  DECLARE _previous               boolean;
-  DECLARE _current                boolean;
-  DECLARE _last_liked_at          TIMESTAMP WITH TIME ZONE;
-  DECLARE _last_unliked_at        TIMESTAMP WITH TIME ZONE;
-  DECLARE _liked_at               TIMESTAMP WITH TIME ZONE;
-  DECLARE _token_likes           uint256;
+  DECLARE _previous                       boolean;
+  DECLARE _token_likes                    uint256;
 BEGIN
   IF NOT EXISTS(SELECT 1 FROM nfts WHERE token_id = _token_id) THEN
     RAISE EXCEPTION 'Invalid token id';
   END IF;
 
-  SELECT likes.liked                    INTO _previous
-  WHERE likes.liked_by                  = _account
-  AND likes.token_id                    = _token_id;
-
-  IF(_previous = false) THEN
-    _current                            := true;
-    _last_liked_at                      := NOW();
-  ELSIF(_previous = true) THEN
-    _current                            := false;
-    _last_unliked_at                    := NOW();
-  ELSE
-    _current                            := true;
-    _last_liked_at                      := NOW();
-  END IF;
+  SELECT likes.liked                      INTO _previous
+  WHERE likes.liked_by                    = _account
+  AND likes.token_id                      = _token_id
+  LIMIT 1;
 
   UPDATE likes
   SET
-    liked                               = _current,
-    last_liked_at                       = _last_liked_at,
-    last_unliked_at                     = _last_unliked_at
-  WHERE likes.liked_by                  = _account
-  AND likes.token_id                    = _token_id;
+    last_unliked_at                       = CASE WHEN liked = true  THEN NOW() ELSE last_unliked_at END,
+    last_liked_at                         = CASE WHEN liked = false THEN NOW() ELSE last_liked_at   END,
+    liked                                 = !liked
+  WHERE likes.liked_by                    = _account
+  AND likes.token_id                      = _token_id;
 
-  IF(_current = true) THEN
-    UPDATE nfts
-    SET likes = nfts.likes + 1
-    WHERE token_id = _token_id
-    RETURNING nfts.likes                INTO _token_likes;
-  ELSE
-    UPDATE nfts
-    SET likes = nfts.likes - 1
-    WHERE token_id = _token_id
-    RETURNING nfts.likes                INTO _token_likes;
-  END IF;
+  UPDATE nfts
+  SET likes                               = likes + (CASE WHEN _previous = true THEN -1 ELSE 1 END)
+  WHERE token_id                          = _token_id
+  RETURNING nfts.likes                    INTO _token_likes;
 
   RETURN _token_likes;
 END