// Package auditrelay delivers Sense-owned audit facts to Bell without sharing databases.
package auditrelay

import (
	"context"
	"encoding/json"
	"errors"
	"time"
)

const (
	MaxBatchSize  = 100
	MaxBodyBytes  = 1 << 20
	LeaseDuration = 30 * time.Second
)

type Actor struct {
	Type string `json:"type"`
	ID   string `json:"id"`
}

type ProjectionVersions struct {
	QuotaSourceVersion      *int64 `json:"quota_source_version"`
	AreaPolicySourceVersion *int64 `json:"area_policy_source_version"`
}

type Event struct {
	EventID             string             `json:"event_id"`
	EventType           string             `json:"event_type"`
	TenantID            string             `json:"tenant_id"`
	SiteID              string             `json:"site_id"`
	DeviceID            string             `json:"device_id"`
	Actor               Actor              `json:"actor"`
	Reason              *string            `json:"reason"`
	TraceID             *string            `json:"trace_id"`
	AggregateGeneration int64              `json:"aggregate_generation"`
	ProjectionVersions  ProjectionVersions `json:"projection_versions"`
	Data                json.RawMessage    `json:"data"`
	OccurredAt          time.Time          `json:"occurred_at"`
}

type Envelope struct {
	SchemaVersion int   `json:"schema_version"`
	Event         Event `json:"event"`
}

type BatchRequest struct {
	Events []Envelope `json:"events"`
}

type Result struct {
	EventID   string  `json:"event_id"`
	Status    string  `json:"status"`
	ErrorCode *string `json:"error_code,omitempty"`
}

type BatchResponse struct {
	Results []Result `json:"results"`
}

type QueuedEvent struct {
	Envelope
	LeaseToken   int64
	AttemptCount int
}

type Disposition string

const (
	Delivered  Disposition = "delivered"
	DeadLetter Disposition = "dead_letter"
	Retry      Disposition = "retry"
)

type Completion struct {
	EventID     string
	LeaseToken  int64
	Disposition Disposition
	ErrorCode   string
	RetryAfter  time.Duration
}

var ErrLeaseLost = errors.New("audit relay lease lost")

type Repository interface {
	AuditRelayReady(context.Context) error
	ClaimAuditRelayBatch(context.Context, string, int, time.Duration) ([]QueuedEvent, error)
	CompleteAuditRelayBatch(context.Context, string, []Completion) error
}