package store

import (
	"context"
	"crypto/sha256"
	"encoding/base64"
	"errors"
	"strconv"
	"time"

	"yovision/sense/internal/device"
)

var (
	ErrETagMismatch          = errors.New("device ETag mismatch")
	ErrIdempotencyConflict   = errors.New("idempotency key body conflict")
	ErrDuplicateSerialNumber = errors.New("duplicate device serial number")
)

type ControlProjectionVersions struct {
	QuotaSourceVersion      *int64     `json:"quota_source_version"`
	AreaPolicySourceVersion *int64     `json:"area_policy_source_version"`
	SyncedAt                *time.Time `json:"synced_at"`
}

// ControlDevice is deliberately safe to serialize. It contains configured
// booleans, never endpoint, credential or profile-token values.
type ControlDevice struct {
	ID                   string                    `json:"id"`
	TenantID             string                    `json:"tenant_id"`
	SiteID               string                    `json:"site_id"`
	SerialNumber         string                    `json:"serial_number"`
	Name                 string                    `json:"name"`
	Modality             device.Modality           `json:"modality"`
	Capabilities         []device.Capability       `json:"capabilities"`
	AreaID               string                    `json:"area_id"`
	DesiredState         device.DesiredState       `json:"desired_state"`
	ActualState          device.ActualState        `json:"actual_state"`
	AdapterStatus        string                    `json:"adapter_status"`
	EndpointConfigured   bool                      `json:"endpoint_configured"`
	CredentialConfigured bool                      `json:"credential_configured"`
	Generation           int64                     `json:"generation"`
	ObservedGeneration   int64                     `json:"observed_generation"`
	Converged            bool                      `json:"converged"`
	FailureCount         int                       `json:"failure_count"`
	NextAttemptAt        *time.Time                `json:"next_attempt_at,omitempty"`
	LastErrorCode        *string                   `json:"last_error_code,omitempty"`
	ProjectionVersions   ControlProjectionVersions `json:"projection_versions"`
	CreatedAt            time.Time                 `json:"created_at"`
	UpdatedAt            time.Time                 `json:"updated_at"`
	ResourceVersion      int64                     `json:"-"`
}

type ControlSiteQuota struct {
	Status                 string
	UsedVideoChannels      int
	MaxVideoChannels       *int
	AvailableVideoChannels *int
	OverLimit              bool
	SourceVersion          *int64
	SyncedAt               *time.Time
}

type ControlListFilter struct {
	Limit         int
	AfterCreated  *time.Time
	AfterDeviceID string
	Modality      *device.Modality
	Capability    *device.Capability
	DesiredState  *device.DesiredState
	ActualState   *device.ActualState
}

type ControlDevicePage struct {
	Items   []ControlDevice
	HasMore bool
	Quota   ControlSiteQuota
}

type IdempotencyScope struct {
	PrincipalID string
	TenantID    string
	SiteID      string
	Operation   string
	Key         string
	RequestHash [sha256.Size]byte
	TraceID     string
}

type ControlCreateRequest struct {
	Scope  IdempotencyScope
	Device device.Device
}

type ControlCreateResult struct {
	Device     ControlDevice
	AcceptedAt time.Time
	TraceID    string
	ETag       string
	Location   string
	Replay     bool
}

type ControlPatch struct {
	Name          *string
	AreaID        *string
	EndpointRef   *string
	CredentialRef *string
	ProfileToken  *string
}

type ControlMutationResult struct {
	Device     ControlDevice
	AcceptedAt time.Time
	TraceID    string
	ETag       string
}

type ControlBatchItem struct {
	DeviceID     string
	ETag         string
	DesiredState device.DesiredState
}

type ControlBatchRequest struct {
	Scope  IdempotencyScope
	Reason string
	Items  []ControlBatchItem
}

type ControlBatchItemResult struct {
	DeviceID   string  `json:"device_id"`
	Status     string  `json:"status"`
	ErrorCode  *string `json:"error_code"`
	Message    *string `json:"message"`
	Generation *int64  `json:"generation"`
}

type ControlBatchOperation struct {
	ID          string                   `json:"id"`
	TenantID    string                   `json:"-"`
	SiteID      string                   `json:"-"`
	Status      string                   `json:"status"`
	SubmittedAt time.Time                `json:"submitted_at"`
	CompletedAt *time.Time               `json:"completed_at"`
	Results     []ControlBatchItemResult `json:"results"`
	TraceID     string                   `json:"trace_id"`
	Replay      bool                     `json:"-"`
}

type ControlRepository interface {
	ListControlDevices(context.Context, string, string, ControlListFilter) (ControlDevicePage, error)
	CreateControlDevice(context.Context, ControlCreateRequest) (ControlCreateResult, error)
	GetControlDevice(context.Context, string, string, string) (ControlDevice, error)
	PatchControlDevice(context.Context, string, string, string, string, ControlPatch) (ControlMutationResult, error)
	SetControlDesiredState(context.Context, string, string, string, string, device.DesiredState) (ControlMutationResult, error)
	BatchSetControlDesiredState(context.Context, ControlBatchRequest) (ControlBatchOperation, error)
	GetControlOperation(context.Context, string, string) (ControlBatchOperation, error)
}

func DeviceETag(deviceID string, resourceVersion int64) string {
	digest := sha256.Sum256([]byte(deviceID + "\x00" + strconv.FormatInt(resourceVersion, 10)))
	return `"` + base64.RawURLEncoding.EncodeToString(digest[:18]) + `"`
}