catalog

type Batch struct {
	ID         string
	Datasource string
	StartedBy  string
	// RequestKey names the request that started the batch: a request sent
	// again with the same key gets the same batch.
	RequestKey string
	// Owner is one run of the batch, never reused: a takeover makes a new
	// one.
	Owner      string
	StartedAt  time.Time
	FinishedAt time.Time
	Heartbeat  time.Time
	// Canceled asks the owner to stop.
	Canceled bool
	Items    []BatchItem
}

type BatchItem struct {
	Schema string
	State  string
	Error  string
	// Attempts counts the scans of the schema started; NotBefore is when a
	// pending one that failed may be scanned again.
	Attempts  int
	NotBefore time.Time
}

type BatchStore interface {
	// CreateBatch creates b (its owner beating at b.Heartbeat) unless its
	// datasource has maxOpen unfinished batches (ErrTooManyBatches), checking
	// and creating in one step, so concurrent requests, of any process,
	// cannot pass the bound together. A batch started before with b's
	// RequestKey for the datasource is returned instead, with false.
	CreateBatch(ctx context.Context, b Batch, maxOpen int) (Batch, bool, error)
	Batch(ctx context.Context, id string) (Batch, bool, error)
	// Batches lists the batches of datasource, newest first.
	Batches(ctx context.Context, datasource string, limit int) ([]Batch, error)
	// UnfinishedBatches lists every batch not finished.
	UnfinishedBatches(ctx context.Context) ([]Batch, error)
	// ClaimBatch makes owner the owner of an unfinished batch whose heartbeat
	// is before staleBefore, or already owner's, beating at now; false when
	// another owner holds it.
	ClaimBatch(ctx context.Context, id, owner string, staleBefore, now time.Time) (bool, error)
	// MoveItem moves item (by its schema) to its state, error, attempts and
	// NotBefore when it is in one of from, the owner beating at now; false
	// when it is in none of them. ErrNotOwner, writing nothing, when the
	// batch is finished or not owner's.
	MoveItem(ctx context.Context, id, owner string, now time.Time, item BatchItem, from ...string) (bool, error)
	// FinishBatch ends a batch owner owns at at, canceling its pending and
	// running items in the same step; ErrNotOwner when it does not own it.
	FinishBatch(ctx context.Context, id, owner string, at time.Time) error
	// CancelBatch asks the owner of a batch to stop.
	CancelBatch(ctx context.Context, id string) error
}

type Column struct {
	Name          string `json:"name"`
	Type          string `json:"type"`
	Nullable      bool   `json:"nullable,omitempty"`
	Default       bool   `json:"default,omitempty"`
	Generated     bool   `json:"generated,omitempty"`
	AutoIncrement bool   `json:"autoIncrement,omitempty"`
	Description   string `json:"description,omitempty"`
}

type ForeignKey struct {
	Name       string   `json:"name"`
	Columns    []string `json:"columns"`
	RefSchema  string   `json:"refSchema,omitempty"`
	RefTable   string   `json:"refTable"`
	RefColumns []string `json:"refColumns"`
	OnDelete   string   `json:"onDelete,omitempty"`
	OnUpdate   string   `json:"onUpdate,omitempty"`
}

type Index struct {
	Name    string   `json:"name"`
	Method  string   `json:"method"`
	Parts   []string `json:"parts,omitempty"`
	Unique  bool     `json:"unique,omitempty"`
	Primary bool     `json:"primary,omitempty"`
	Where   string   `json:"where,omitempty"`
}

type Key struct {
	Name       string   `json:"name"`
	Columns    []string `json:"columns"`
	Primary    bool     `json:"primary,omitempty"`
	Deferrable bool     `json:"deferrable,omitempty"`
	Reason     string   `json:"reason,omitempty"`
}

type List struct {
	Schemas []string `json:"schemas"`
	// Current is where unqualified names resolve; empty when unknown.
	Current  string    `json:"current,omitempty"`
	ListedAt time.Time `json:"-"`
}

type MemoryStore struct {
	// contains filtered or unexported fields
}

type Schema struct {
	Name      string    `json:"-"`
	ScannedAt time.Time `json:"-"`
	Default   string    `json:"default,omitempty"`
	FoldCase  bool      `json:"foldCase,omitempty"`
	Tables    []Table   `json:"tables"`
}

type Source struct {
	Datasource string
	Driver     string
	DSN        string
}

type Store interface {
	// CatalogList returns the kept schema list of source; false when none.
	CatalogList(ctx context.Context, source string) (List, bool, error)
	// PutCatalogList replaces the schema list of source.
	PutCatalogList(ctx context.Context, source, datasource string, l List) error
	// CatalogVersions lists the kept schemas of source without their tables.
	CatalogVersions(ctx context.Context, source string) ([]Version, error)
	// CatalogSchemas returns the kept schemas of source among names.
	CatalogSchemas(ctx context.Context, source string, names []string) ([]Schema, error)
	// PutCatalogSchemas replaces the given schemas of source.
	PutCatalogSchemas(ctx context.Context, source, datasource string, schemas []Schema) error
	// PruneCatalog drops what was kept for datasource from sources other
	// than keep, listed or scanned before before.
	PruneCatalog(ctx context.Context, datasource, keep string, before time.Time) error
	// DeleteCatalogSchemas drops the schemas of source among names scanned
	// before before.
	DeleteCatalogSchemas(ctx context.Context, source string, names []string, before time.Time) error
	BatchStore
}

type Table struct {
	Schema      string       `json:"schema,omitempty"`
	Name        string       `json:"name"`
	View        bool         `json:"view,omitempty"`
	Derived     bool         `json:"derived,omitempty"`
	Description string       `json:"description,omitempty"`
	Columns     []Column     `json:"columns"`
	Keys        []Key        `json:"keys,omitempty"`
	Indexes     []Index      `json:"indexes,omitempty"`
	ForeignKeys []ForeignKey `json:"foreignKeys,omitempty"`
	SideEffects bool         `json:"sideEffects,omitempty"`
}

type Version struct {
	Name      string
	ScannedAt time.Time
	Tables    int
}