# lagoon

Postgres data layer: the shared GORM connection, per-plugin migrations, model helpers and file attachments.

`import "git.golem15.com/golem15/summercms/modules/lagoon"`

`import "git.golem15.com/golem15/summercms/modules/lagoon/attach"`

## Overview

`lagoon` is the WinterCMS models and migrations counterpart: it opens the one `*sql.DB` pool (pgx stdlib driver) that GORM and the rest of the application share, runs each plugin's gormigrate set in its own history table, and ports the Eloquent model conventions that WinterCMS plugins rely on, such as `$fillable`, `$hidden`, `$jsonable`, encrypted casts and Laravel-style validation rules. Its `attach` subpackage ports WinterCMS's `system_files` attachments, storing originals and lazily generated thumbnails in a gocloud.dev blob bucket. The application binary gets the migrate and key commands from `lagoon.RuntimeCommands`.

## Features

- One shared pool: `lagoon.Open`, `lagoon.Use` and `lagoon.OpenFromApp` return a `*sql.DB` and a `*gorm.DB` built on that same pool; `lagoon.Publish` makes both available on the `backpack.App`.
- Database-ready hooks: `lagoon.OnDatabase` runs a callback with the pool and GORM handle as soon as the database is published, immediately when it already is, otherwise when `lagoon.Publish` runs. Plugins register GORM callbacks through it from Boot, which runs before the `serve` command publishes the database.
- After-commit work: `lagoon.Transaction` runs a function in a transaction and then the callbacks registered with `lagoon.AfterCommit`, in order, only after the commit succeeds; a nested `lagoon.Transaction` is a savepoint whose callbacks are dropped with it when it fails. A single-statement write for which GORM opens its own transaction runs its `lagoon.AfterCommit` callbacks from the `lagoon:after_commit` GORM callback (`lagoon.AfterCommitCallback`) once GORM commits, and never when the write fails. Outside both, including inside a plain GORM `Transaction`, `lagoon.AfterCommit` runs the callback immediately. A panicking callback is logged and never turns a committed write into an error.
- Database check at connect time: `lagoon.CheckLocale` refuses a database whose default collation is not the ICU `pl-PL` locale, so ordering matches the database default without per-query `COLLATE`.
- Per-plugin migrations: `lagoon.Migrate` runs the framework's `system_files` set (`attach.Migrations`), backend admin identity set (`lagoon.BackendAdminMigrations`) and job-queue set (`lagoon.QueueMigrations`: River's schema pinned at `lagoon.RiverSchemaVersion`, then the `lagoon.JobsTable` record table, under the `lagoon.QueueHistoryID` history), then every `pact.HasMigrations` set in plugin activation order, each in its own `summer_migrations_<plugin_id>` history table (`lagoon.HistoryTableName`). `lagoon.RollbackLast` and `lagoon.Status` cover rollback and history.
- Mass assignment: `lagoon.Fill` copies only allow-listed keys onto a model by GORM column name and silently drops the rest, logging each dropped key once outside production. A `json.Number` (from a decoder using `UseNumber`) fills integer, unsigned and float fields. A value that does not fit its column (a fraction, an exponent or an overflow for an integer field, or a value of the wrong type) is a `lagoon.FillTypeError` naming the key, so a caller can answer it as a validation failure on that field. `lagoon.HasFillable` and `lagoon.HasHidden` are the Go forms of `$fillable` and `$hidden`.
- Validation: `lagoon.Validate` accepts Laravel-style rule strings (`required`, `nullable`, `integer`, `numeric`, `between`, `min`, `max`, `in`, `unique`, `boolean`, `email`, `confirmed`, `different`, `mimes`) and returns a field-to-messages map, translated through phrasebook when a translator is given. Unknown rule tokens are an error.
- Safe ordering: `lagoon.OrderBy` appends an ORDER BY only for an allow-listed column and an `asc` or `desc` direction.
- Pagination: `lagoon.Paginate` builds a `lagoon.Page` with `data` and `meta` (`current_page`, `last_page`, `per_page`, `total`).
- Column types: `lagoon.Encrypted` stores AES-256-GCM ciphertext under a key derived from `app.key`, decrypts with previous keys during rotation, and always redacts itself in JSON and string output; `lagoon.Jsonable` stores JSON as TEXT and keeps SQL NULL distinct from an empty value.
- Lifecycle and relations: hook interfaces matching GORM's native method names (`lagoon.HasBeforeCreate`, `lagoon.HasBeforeSave`, `lagoon.HasBeforeDelete`, `lagoon.HasAfterDelete`) plus `lagoon.HasBeforeValidate`; `lagoon.WithSoftDeleteCascade` runs a cascade inside the parent delete; `lagoon.RegisterJoinTable` wires pivot models with business columns.
- Imports from Laravel: `lagoon.DecryptLaravelPayload` decrypts Laravel `encrypted` payloads with the old application key, for one-off data imports.
- Attachments (`attach`): the `attach.File` model for `system_files` rows, WinterCMS-compatible partitioned storage keys (`attach.BlobKey`, `attach.PartitionDirectory`), on-demand thumbnails through `attach.File.Thumb`, static serving with an optional `is_public` gate (`attach.StaticHandlerPublic`), and a two-phase delete that removes blobs only after the database transaction commits (`attach.DeleteForOwner`, `attach.DeleteKeys`).

## Usage

Open the shared pool once at boot and publish it, so plugins and handlers reuse the same handles:

```go
sqlDB, gdb, err := lagoon.OpenFromApp(ctx, app)
if err != nil {
	return err
}
if err := lagoon.Publish(app, sqlDB, gdb); err != nil {
	return err
}
```

A model uses the column types and helpers directly:

```go
type Post struct {
	ID       uint                      `gorm:"column:id;primaryKey"`
	Title    string                    `gorm:"column:title"`
	Tags     lagoon.Jsonable[[]string] `gorm:"column:tags"`
	APIToken lagoon.Encrypted          `gorm:"column:api_token"`
}

func (Post) Fillable() []string { return []string{"title"} }

func createPost(ctx context.Context, gdb *gorm.DB, tr *phrasebook.Translator, input map[string]any) (map[string][]string, error) {
	var post Post
	rules := map[string]string{"title": "required|max:255|unique:posts"}
	if errs, err := lagoon.Validate(ctx, gdb, &post, rules, input, tr); err != nil || errs != nil {
		return errs, err
	}
	if err := lagoon.Fill(&post, post.Fillable(), input, false); err != nil {
		return nil, err
	}
	post.APIToken = lagoon.NewEncrypted("change-me")
	return nil, gdb.Create(&post).Error
}
```

A plugin registers its GORM callbacks from Boot through `lagoon.OnDatabase`, so they are installed whenever the database is published, and defers side effects until the write commits:

```go
func (p *Plugin) Boot(app *backpack.App) error {
	return lagoon.OnDatabase(app, func(_ *sql.DB, gdb *gorm.DB) error {
		return gdb.Callback().Create().After("gorm:after_create").Register("acme:post_created", func(db *gorm.DB) {
			if db.Error != nil {
				return
			}
			lagoon.AfterCommit(db.Statement.Context, db, func(ctx context.Context, db *gorm.DB) {
				// runs only once the insert is committed
			})
		})
	})
}

func publish(ctx context.Context, gdb *gorm.DB, post *Post) error {
	return lagoon.Transaction(ctx, gdb, func(ctx context.Context, tx *gorm.DB) error {
		return tx.Create(post).Error // acme:post_created work waits for this commit
	})
}
```

A plugin ships its schema as an ordered gormigrate set; `migrate` runs it after the framework sets:

```go
func (p *Plugin) Migrations() []*gormigrate.Migration {
	return []*gormigrate.Migration{{
		ID: "202601010001_create_posts",
		Migrate: func(tx *gorm.DB) error {
			return tx.Exec(`CREATE TABLE posts (id SERIAL PRIMARY KEY, title TEXT NOT NULL, tags TEXT, api_token TEXT)`).Error
		},
		Rollback: func(tx *gorm.DB) error {
			return tx.Exec(`DROP TABLE IF EXISTS posts`).Error
		},
	}}
}
```

## API reference

| Identifier | Description |
|------------|-------------|
| `lagoon.OpenFromApp` | Opens the shared pool from `database.dsn` and publishes the `app.key` encryption keys. |
| `lagoon.Open` | Opens and pings a DSN, checks the locale and returns the pool plus a GORM handle on it. |
| `lagoon.Use` | Returns a GORM handle on an existing pool after the same checks. |
| `lagoon.Publish` | Stores the pool and GORM handle on the `backpack.App`, then runs the callbacks queued by `lagoon.OnDatabase`. |
| `lagoon.OnDatabase` | Runs a callback with the pool and GORM handle once the database is published. |
| `lagoon.Transaction` | Runs a function in a transaction (a savepoint when nested) and its `lagoon.AfterCommit` callbacks after the commit. |
| `lagoon.AfterCommit` | Registers work to run after the surrounding transaction commits. |
| `lagoon.AfterCommitCallback` | Name of the GORM callback, `lagoon:after_commit`, that runs single-statement after-commit work. |
| `lagoon.DSN` | Reads `database.dsn` from config. |
| `lagoon.CheckLocale` | Fails unless the database default locale is ICU `pl-PL`. |
| `lagoon.Migrate` | Runs framework and plugin migrations in order. |
| `lagoon.RollbackLast` | Rolls back the last migration of one plugin. |
| `lagoon.Status` | Lists applied migration IDs per plugin as `lagoon.StatusRow` values. |
| `lagoon.HistoryTableName` | Returns the gormigrate history table for a plugin ID. |
| `lagoon.BackendAdminMigrations` | Creates the backend user, role and admin token blacklist tables and seeds the system roles. |
| `lagoon.QueueMigrations` | Migrates River's schema to `lagoon.RiverSchemaVersion` and creates the `summer_jobs` job record table. |
| `lagoon.QueueHistoryID` | History id of the job-queue set, `summercms.conga`. |
| `lagoon.JobsTable` | Name of the job record table, `summer_jobs`. |
| `lagoon.RiverSchemaVersion` | The pinned River schema version, 7. |
| `lagoon.RuntimeCommands` | Returns the migrate, migrate:rollback, migrate:status and key:generate commands. |
| `lagoon.KeyGenerateCommand` | Returns the key:generate command on its own. |
| `lagoon.LoadAppKey` | Decodes `app.key` and `app.previous_keys`. |
| `lagoon.PublishEncryptionKeys` | Installs the keys used by `lagoon.Encrypted` columns. |
| `lagoon.Encrypted` | Encrypted text column; `lagoon.Encrypted.Reveal` is the only plaintext accessor. |
| `lagoon.Jsonable` | Generic JSON-as-TEXT column with NULL tracking. |
| `lagoon.Fill` | Allow-listed mass assignment by column name. |
| `lagoon.FillTypeError` | Returned by `lagoon.Fill` when a requested value does not fit its column; `Key` names the column. |
| `lagoon.Validate` | Laravel-style rule validation with a `unique` database check. |
| `lagoon.OrderBy` | Allow-listed ORDER BY. |
| `lagoon.Paginate` | Builds a `lagoon.Page` with `lagoon.PageMeta`. |
| `lagoon.WithSoftDeleteCascade` | Runs a cascade inside the parent delete transaction. |
| `lagoon.RegisterJoinTable` | Registers a custom pivot model for a many-to-many field. |
| `lagoon.DecryptLaravelPayload` | Decrypts a Laravel AES-256-CBC payload for data imports. |
| `attach.File` | The `system_files` row model. |
| `attach.Owner` | Implemented by models that own attachments; returns the stored morph type name. |
| `attach.OpenBucket` | Opens the uploads bucket from config. |
| `attach.Publish` | Stores the bucket on the `backpack.App`. |
| `attach.StaticHandler` | Serves stored files and thumbnails under a URL prefix. |
| `attach.StaticHandlerPublic` | `attach.StaticHandler` plus a 404 for rows that are not public. |
| `attach.DeleteForOwner` | Deletes an owner's attachment rows in a transaction and reports their blob keys. |
| `attach.DeleteKeys` | Deletes blobs, including thumbnails, after the transaction commits. |
| `attach.Migrations` | Creates the `system_files` table. |

## Configuration

Keys are read from the compass config; the `SUMMER_` environment overlay maps a double underscore to a dot, for example `SUMMER_DATABASE__DSN` to `database.dsn`.

| Key | Default | Controls |
|-----|---------|----------|
| `database.dsn` | none (required) | Postgres connection string used by `lagoon.OpenFromApp` and every database command. |
| `app.key` | none (required) | Base64 encoding of 32 random bytes; the source of the `lagoon.Encrypted` column key. Generate one with `key:generate`. |
| `app.previous_keys` | empty | List of earlier base64 keys still accepted when decrypting, for key rotation. |
| `storage.uploads.bucket_url` | none (required by `attach.OpenBucket`) | Uploads bucket URL, `file://` or `mem://`. |
| `storage.uploads.public_path_prefix` | `/storage/uploads` | URL prefix used when building public file and thumbnail URLs. |

```yaml
database:
  dsn: postgres://acme:<secret>@127.0.0.1:5432/acme?sslmode=disable
app:
  key: <base64 key from key:generate>
storage:
  uploads:
    bucket_url: file:///var/lib/acme/uploads
```

## CLI commands

`lagoon.RuntimeCommands` adds these commands to the application binary. All of them except key:generate open the database through `lagoon.OpenFromApp`, so they need `database.dsn` and `app.key`.

| Command | Flags | Description |
|---------|-------|-------------|
| `migrate` | none | Runs the framework migrations, then each plugin's migrations in dependency order. |
| `migrate:rollback` | `--plugin <id>` | Rolls back the last migration of the given plugin; without the flag, of the last activated plugin that has migrations. |
| `migrate:status` | none | Prints a table of plugin, history table and applied migration IDs. |
| `key:generate` | none | Prints a fresh base64 32-byte key for `app.key`; writes nothing. |

## Dependencies

- SummerCMS modules: [backpack](../backpack/README.md), [bonfire](../bonfire/README.md), [compass](../compass/README.md), [pact](../pact/README.md), [party](../party/README.md), [phrasebook](../phrasebook/README.md) (validation messages).
- Third-party: `gorm.io/gorm`, `gorm.io/driver/postgres`, `github.com/jackc/pgx/v5` (stdlib driver), `github.com/go-gormigrate/gormigrate/v2`, `github.com/go-playground/validator/v10`, `github.com/riverqueue/river` (its `rivermigrate` and `riverdriver/riverdatabasesql` packages, for the River schema in `lagoon.QueueMigrations`).
- Third-party, `attach` only: `gocloud.dev/blob` (file and memory drivers), `github.com/disintegration/imaging` (thumbnails).
- Standard library: `database/sql`, `crypto/aes`, `crypto/cipher`, `crypto/hkdf`, `log/slog`, `image`, among others.

## Testing

```sh
go test ./modules/lagoon/...
```

The database tests in `lagoon` and `lagoon/attach` start a `postgres:16-alpine` container, initialised with the ICU `pl-PL` locale, through testcontainers-go, so they need a running Docker daemon. They are skipped by `go test -short ./modules/lagoon/...`, which runs only the unit tests.