preset

type MetaTable struct {
	Key, Value string
	Platform   string
	Keys       map[string]*detect.Hint       // known keys
	Probe      []string                      // keys worth reading directly if the sample misses them
	HintFor    func(key string) *detect.Hint // pattern-based hints
	Label      func(key string) string       // maps raw keys to names, e.g. Magento attribute IDs
	// Families are keys known to share a prefix, such as Ultimate Member's
	// per-user caches. They are grouped and probed by prefix.
	Families []detect.FamilyRule
	// Settings marks a table that holds one row per key, such as
	// wp_options, even when it lost its unique index.
	Settings bool
	// Primary marks the tables of the main site and the shared ones; a
	// scan spends its budgets on them first.
	Primary bool
	// Labels marks a translation table found without a preset: its keys
	// name UI strings, so only their values are judged.
	Labels bool
	// Guard marks a key/value table found without a preset by a shape data
	// tables can have too. Its keys must read as identifiers or labels; a
	// table keyed by people's names is judged as a plain table instead.
	Guard bool
}

type Querier interface {
	QueryContext(ctx context.Context, query string, args ...any) (*sql.Rows, error)
	QueryRowContext(ctx context.Context, query string, args ...any) *sql.Row
}

type Result struct {
	Platforms     []model.Platform
	Columns       map[string]map[string]*detect.Hint // table → lower-case column → hint
	Meta          map[string]*MetaTable
	Actions       map[string]TableAction
	Relationships []model.Relationship
	Prefixes      []string
	SideEffects   []model.SideEffect
	RowSubjects   []RowSubject
	Warnings      []string
}

type RowSubject struct {
	Table, Column string
	// Where selects the rows. It is a constant written in the preset,
	// never text from the database.
	Where string
	// IndexColumn must lead an index, so the rows are found without a
	// full scan; without one the subject is skipped.
	IndexColumn string
	Hint        *detect.Hint
}

type TableAction struct {
	Action string // "truncate"
	Reason string
}