metadata

type AccessEntry struct {
	Timestamp time.Time `json:"timestamp"`
	Principal string    `json:"principal"`
	Action    string    `json:"action"`
	Resource  string    `json:"resource"`
	Success   bool      `json:"success"`
	Details   string    `json:"details,omitempty"`
}

type AccessPolicy struct {
	Version    int         `json:"version"`
	Principals []Principal `json:"principals"`
	Resources  []Resource  `json:"resources"`
	Actions    []string    `json:"actions"`
	Conditions []Condition `json:"conditions"`
	CreatedAt  time.Time   `json:"createdAt"`
	ModifiedAt time.Time   `json:"modifiedAt"`
}

type AuditTrail struct {
	CreatedAt  time.Time     `json:"createdAt"`
	CreatedBy  string        `json:"createdBy"`
	ModifiedAt time.Time     `json:"modifiedAt"`
	ModifiedBy string        `json:"modifiedBy"`
	AccessLog  []AccessEntry `json:"accessLog"`
	Version    int           `json:"version"`
}

type BlockInfo struct {
	ColumnName string `json:"columnName"`
	Offset     int64  `json:"offset"`
	Length     int64  `json:"length"`
	RowCount   int64  `json:"rowCount"`
	Compressed bool   `json:"compressed"`
	Checksum   []byte `json:"checksum"`
	OrigSize   int64  `json:"origSize,omitempty"`
	MimeType   string `json:"mimeType,omitempty"`
}

type Condition struct {
	Type  string      `json:"type"` // "time", "ip", "custom"
	Value interface{} `json:"value"`
}

type EncryptionParams struct {
	Algorithm     string            `json:"algorithm"`     // "AES-256-GCM"
	KeyDerivation string            `json:"keyDerivation"` // "PBKDF2"
	Iterations    int               `json:"iterations"`
	SaltSize      int               `json:"saltSize"`
	ColumnSalts   map[string][]byte `json:"columnSalts"` // Column name -> salt
	MasterSalt    []byte            `json:"masterSalt"`
}

type FileHeader struct {
	Magic    [8]byte `json:"magic"`
	Version  uint32  `json:"version"`
	Flags    uint32  `json:"flags"`
	Reserved uint32  `json:"reserved"`
}

type Metadata struct {
	Header       FileHeader       `json:"header"`
	Schema       *arrow.Schema    `json:"-"` // Serialized separately
	SchemaBytes  []byte           `json:"schemaBytes"`
	Encryption   EncryptionParams `json:"encryption"`
	AccessPolicy *AccessPolicy    `json:"accessPolicy,omitempty"`
	AuditTrail   AuditTrail       `json:"auditTrail"`
	BlockInfo    []BlockInfo      `json:"blockInfo"`
}

type Principal struct {
	Type string `json:"type"` // "user", "role", "service"
	Name string `json:"name"`
}

type Resource struct {
	Type string `json:"type"` // "column", "table", "dataset"
	Name string `json:"name"`
}