package ocss

import (
	"bytes"
	"encoding/json"
	"fmt"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/bsontype"
	"go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
)

type PriceType int64

const (
	Free PriceType = iota
	Paying
	Unknown
)

var priceTypeToID = map[string]PriceType{
	"FREE":    Free,
	"PAYING":  Paying,
	"UNKNOWN": Unknown,
}

var priceTypeToString = map[PriceType]string{
	Free:    "FREE",
	Paying:  "PAYING",
	Unknown: "UNKNOWN",
}

func (s PriceType) MarshalJSON() ([]byte, error) {
	buffer := bytes.NewBufferString(`"`)
	buffer.WriteString(priceTypeToString[s])
	buffer.WriteString(`"`)
	return buffer.Bytes(), nil
}

func (s PriceType) MarshalBSONValue() (bsontype.Type, []byte, error) {
	return bson.MarshalValue(priceTypeToString[s])
}

func (bs *PriceType) UnmarshalJSON(b []byte) error {
	var j string
	err := json.Unmarshal(b, &j)
	if err != nil {
		return err
	}
	// Note that if the string cannot be found then it will be set to the zero value, 'Created' in this case.
	*bs = priceTypeToID[j]
	return nil
}

func (bs *PriceType) UnmarshalBSONValue(t bsontype.Type, b []byte) error {
	if t == bsontype.Null || len(b) == 0 {
		return nil
	}
	j, _, ok := bsoncore.ReadString(b)
	if !ok {
		return fmt.Errorf("cannot parse status")
	}
	*bs = priceTypeToID[j]
	return nil
}

type Price struct {
	Type     *PriceType `json:"type,omitempty" bson:"type,omitempty"`
	Amount   *float64   `json:"amount,omitempty" bson:"amount,omitempty"`
	Currency *string    `json:"currency,omitempty" bson:"currency,omitempty"`
}