From 13ce3d078436f56646640cf99da47a737b21f00c Mon Sep 17 00:00:00 2001
From: Fabio Manganiello <fabio@manganiello.tech>
Date: Thu, 21 Nov 2024 03:21:25 +0100
Subject: [PATCH] Increased `posts.content` size for MySQL.

`TEXT` -> 64kB
`MEDIUMTEXT` -> 16MB

Closes: https://github.com/writefreely/writefreely/issues/987
---
 db/create.go      |  9 +++++++++
 migrations/v16.go | 50 +++++++++++++++++++++++++++++++++++++++++++++++
 schema.sql        |  2 +-
 3 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 migrations/v16.go

diff --git a/db/create.go b/db/create.go
index 1e9e679..164eab8 100644
--- a/db/create.go
+++ b/db/create.go
@@ -57,6 +57,7 @@ const (
 	ColumnTypeChar     ColumnType = iota
 	ColumnTypeVarChar  ColumnType = iota
 	ColumnTypeText     ColumnType = iota
+	ColumnTypeLongText ColumnType = iota
 	ColumnTypeDateTime ColumnType = iota
 )
 
@@ -125,6 +126,14 @@ func (d ColumnType) Format(dialect DialectType, size OptionalInt) (string, error
 		return "DATETIME", nil
 	case ColumnTypeText:
 		return "TEXT", nil
+	case ColumnTypeLongText:
+		{
+			// MySQL TEXT is limited to 64KB, so use MEDIUMTEXT for larger sizes (up to 16MB)
+			if dialect == DialectMySQL {
+				return "MEDIUMTEXT", nil
+			}
+			return "TEXT", nil
+		}
 	}
 	return "", fmt.Errorf("unsupported column type %d for dialect %d and size %v", d, dialect, size)
 }
diff --git a/migrations/v16.go b/migrations/v16.go
new file mode 100644
index 0000000..bf0a730
--- /dev/null
+++ b/migrations/v16.go
@@ -0,0 +1,50 @@
+/*
+ * Copyright © 2019-2024 Musing Studio LLC.
+ *
+ * This file is part of WriteFreely.
+ *
+ * WriteFreely is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, included
+ * in the LICENSE file in this source code package.
+ */
+
+package migrations
+
+import (
+	"context"
+	"database/sql"
+
+	wf_db "github.com/writefreely/writefreely/db"
+)
+
+func increasePostContentSize(db *datastore) error {
+	if db.driverName != driverMySQL {
+		// Only MySQL databases need this migration
+		return nil
+	}
+
+	dialect := wf_db.DialectMySQL
+	return wf_db.RunTransactionWithOptions(context.Background(), db.DB, &sql.TxOptions{}, func(ctx context.Context, tx *sql.Tx) error {
+		builders := []wf_db.SQLBuilder{
+			dialect.AlterTable("posts").
+				ChangeColumn("content",
+					dialect.Column(
+						"column",
+						wf_db.ColumnTypeLongText,
+						wf_db.OptionalInt{
+							Set: false,
+							Value: 0,
+						}).SetNullable(false)),
+		}
+		for _, builder := range builders {
+			query, err := builder.ToSQL()
+			if err != nil {
+				return err
+			}
+			if _, err := tx.ExecContext(ctx, query); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+}
diff --git a/schema.sql b/schema.sql
index b3fae97..c043532 100644
--- a/schema.sql
+++ b/schema.sql
@@ -136,7 +136,7 @@ CREATE TABLE IF NOT EXISTS `posts` (
   `updated` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
   `view_count` int(6) NOT NULL,
   `title` varchar(160) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
-  `content` text CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
+  `content` mediumtext CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
   PRIMARY KEY (`id`),
   UNIQUE KEY `id_slug` (`collection_id`,`slug`),
   UNIQUE KEY `owner_id` (`owner_id`,`id`),