package internal

import (
	"context"

	"github.com/shopspring/decimal"
)

// StateVersion is the schema version of the persisted State struct.
const StateVersion = "1"

// State is the platform-agnostic representation of the buy-queue state that is
// written to disk after a successful run and reloaded on the next run.
type State struct {
	Version  string                       `json:"version"`
	Platform string                       `json:"platform"`
	Queues   map[string][]persistedFiller `json:"queues"`
}

// persistedFiller is the on-disk representation of a single Filler. The
// Record-specific data is kept as opaque bytes so the internal package does
// not need to know about any broker package's concrete Record type.
type persistedFiller struct {
	ReaderData []byte          `json:"reader_data"`
	Quantity   decimal.Decimal `json:"quantity"`
	Price      decimal.Decimal `json:"price"`
	Filled     decimal.Decimal `json:"filled"`
}

// RecordEncoder encodes a Record into its broker-specific byte representation.
type RecordEncoder interface {
	MarshalRecord(context.Context, Record) ([]byte, error)
}

// RecordDecoder decodes broker-specific bytes back into a Record.
type RecordDecoder interface {
	UnmarshalRecord(context.Context, []byte) (Record, error)
}

// RecordSerializer composes encoding and decoding of Records. Broker packages
// own the implementation so that lazy/closured Record fields can be re-wired
// on load.
type RecordSerializer interface {
	RecordEncoder
	RecordDecoder
}