package local

import (
	"crypto/rand"
	"encoding/base32"
	"fmt"
	"strings"

	"galaxy/user/internal/domain/common"
	"galaxy/user/internal/domain/entitlement"
	"galaxy/user/internal/domain/policy"
)

var base32NoPadding = base32.StdEncoding.WithPadding(base32.NoPadding)

// IDGenerator creates opaque stable user identifiers and generated initial
// race names.
type IDGenerator struct{}

// NewUserID returns one newly generated opaque user identifier.
func (IDGenerator) NewUserID() (common.UserID, error) {
	token, err := randomToken(10)
	if err != nil {
		return "", fmt.Errorf("generate user id: %w", err)
	}

	userID := common.UserID("user-" + token)
	if err := userID.Validate(); err != nil {
		return "", fmt.Errorf("generate user id: %w", err)
	}

	return userID, nil
}

// NewInitialRaceName returns one generated race name in the `player-<shortid>`
// form.
func (IDGenerator) NewInitialRaceName() (common.RaceName, error) {
	token, err := randomToken(5)
	if err != nil {
		return "", fmt.Errorf("generate initial race name: %w", err)
	}

	raceName := common.RaceName("player-" + token)
	if err := raceName.Validate(); err != nil {
		return "", fmt.Errorf("generate initial race name: %w", err)
	}

	return raceName, nil
}

// NewEntitlementRecordID returns one generated entitlement history record
// identifier.
func (IDGenerator) NewEntitlementRecordID() (entitlement.EntitlementRecordID, error) {
	token, err := randomToken(10)
	if err != nil {
		return "", fmt.Errorf("generate entitlement record id: %w", err)
	}

	recordID := entitlement.EntitlementRecordID("entitlement-" + token)
	if err := recordID.Validate(); err != nil {
		return "", fmt.Errorf("generate entitlement record id: %w", err)
	}

	return recordID, nil
}

// NewSanctionRecordID returns one generated sanction history record
// identifier.
func (IDGenerator) NewSanctionRecordID() (policy.SanctionRecordID, error) {
	token, err := randomToken(10)
	if err != nil {
		return "", fmt.Errorf("generate sanction record id: %w", err)
	}

	recordID := policy.SanctionRecordID("sanction-" + token)
	if err := recordID.Validate(); err != nil {
		return "", fmt.Errorf("generate sanction record id: %w", err)
	}

	return recordID, nil
}

// NewLimitRecordID returns one generated limit history record identifier.
func (IDGenerator) NewLimitRecordID() (policy.LimitRecordID, error) {
	token, err := randomToken(10)
	if err != nil {
		return "", fmt.Errorf("generate limit record id: %w", err)
	}

	recordID := policy.LimitRecordID("limit-" + token)
	if err := recordID.Validate(); err != nil {
		return "", fmt.Errorf("generate limit record id: %w", err)
	}

	return recordID, nil
}

func randomToken(size int) (string, error) {
	buffer := make([]byte, size)
	if _, err := rand.Read(buffer); err != nil {
		return "", err
	}

	return strings.ToLower(base32NoPadding.EncodeToString(buffer)), nil
}