From 5bc16977744ce5bafe3d589a665a8362872613c0 Mon Sep 17 00:00:00 2001
From: Thomas Miceli <tho.miceli@gmail.com>
Date: Tue, 18 Apr 2023 02:33:19 +0200
Subject: [PATCH] Migration system & fix ssh key table constraint

---
 internal/models/db.go        |  2 +
 internal/models/migration.go | 96 ++++++++++++++++++++++++++++++++++++
 internal/models/user.go      |  2 +-
 3 files changed, 99 insertions(+), 1 deletion(-)
 create mode 100644 internal/models/migration.go

diff --git a/internal/models/db.go b/internal/models/db.go
index 4b54b5a..fc4890b 100644
--- a/internal/models/db.go
+++ b/internal/models/db.go
@@ -23,6 +23,8 @@ func Setup(dbpath string) error {
 		return err
 	}
 
+	ApplyMigrations(db)
+
 	// Default admin setting values
 	return initAdminSettings(map[string]string{
 		SettingDisableSignup: "0",
diff --git a/internal/models/migration.go b/internal/models/migration.go
new file mode 100644
index 0000000..d4d7629
--- /dev/null
+++ b/internal/models/migration.go
@@ -0,0 +1,96 @@
+package models
+
+import (
+	"fmt"
+	"github.com/rs/zerolog/log"
+	"gorm.io/gorm"
+)
+
+type MigrationVersion struct {
+	ID      uint `gorm:"primaryKey"`
+	Version uint
+}
+
+func ApplyMigrations(db *gorm.DB) error {
+	// Create migration table if it doesn't exist
+	if err := db.AutoMigrate(&MigrationVersion{}); err != nil {
+		log.Fatal().Err(err).Msg("Error creating migration version table")
+		return err
+	}
+
+	// Get the current migration version
+	var currentVersion MigrationVersion
+	db.First(&currentVersion)
+
+	// Define migrations
+	migrations := []struct {
+		Version uint
+		Func    func(*gorm.DB) error
+	}{
+		{1, v1_modifyConstraintToSSHKeys},
+		// Add more migrations here as needed
+	}
+
+	// Apply migrations
+	for _, m := range migrations {
+		if m.Version > currentVersion.Version {
+			tx := db.Begin()
+			if err := tx.Error; err != nil {
+				log.Fatal().Err(err).Msg("Error starting transaction")
+				return err
+			}
+
+			if err := m.Func(db); err != nil {
+				log.Fatal().Err(err).Msg(fmt.Sprintf("Error applying migration %d:", m.Version))
+				tx.Rollback()
+				return err
+			} else {
+				if err = tx.Commit().Error; err != nil {
+					log.Fatal().Err(err).Msg(fmt.Sprintf("Error committing migration %d:", m.Version))
+					return err
+				}
+				currentVersion.Version = m.Version
+				db.Save(&currentVersion)
+				log.Info().Msg(fmt.Sprintf("Migration %d applied successfully", m.Version))
+			}
+		}
+	}
+
+	return nil
+}
+
+// Modify the constraint on the ssh_keys table to use ON DELETE CASCADE
+func v1_modifyConstraintToSSHKeys(db *gorm.DB) error {
+	createSQL := `
+	CREATE TABLE ssh_keys_temp (
+		id integer primary key,
+		title text,
+		content text,
+		sha text,
+		created_at integer,
+		last_used_at integer,
+		user_id integer
+		constraint fk_users_ssh_keys references users(id) on update cascade on delete cascade
+	);
+	`
+
+	if err := db.Exec(createSQL).Error; err != nil {
+		return err
+	}
+
+	// Copy data from the old table to the new table
+	copySQL := `INSERT INTO ssh_keys_temp SELECT * FROM ssh_keys;`
+	if err := db.Exec(copySQL).Error; err != nil {
+		return err
+	}
+
+	// Drop the old table
+	dropSQL := `DROP TABLE ssh_keys;`
+	if err := db.Exec(dropSQL).Error; err != nil {
+		return err
+	}
+
+	// Rename the new table to the original table name
+	renameSQL := `ALTER TABLE ssh_keys_temp RENAME TO ssh_keys;`
+	return db.Exec(renameSQL).Error
+}
diff --git a/internal/models/user.go b/internal/models/user.go
index 961e54b..9b0cabe 100644
--- a/internal/models/user.go
+++ b/internal/models/user.go
@@ -16,7 +16,7 @@ type User struct {
 	GiteaID   string
 
 	Gists   []Gist   `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;foreignKey:UserID"`
-	SSHKeys []SSHKey `gorm:"foreignKey:UserID"`
+	SSHKeys []SSHKey `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;foreignKey:UserID"`
 	Liked   []Gist   `gorm:"many2many:likes;constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
 }