package store

import (
	"context"
	"errors"
	"fmt"
	"strings"
	"time"

	"yovision/sense/internal/device"
)

const (
	DriverSQLite   = "sqlite"
	DriverPostgres = "postgres"
)

var (
	ErrQuotaProjectionUnavailable = errors.New("quota projection unavailable")
	ErrQuotaProjectionInvalid     = errors.New("quota projection invalid")
	ErrAreaPolicyUnavailable      = errors.New("area policy unavailable")
	ErrAreaPolicyInvalid          = errors.New("area policy invalid")
	ErrAreaPolicyDenied           = errors.New("area policy denies imaging device")
	ErrReconcileLeaseLost         = errors.New("reconcile lease lost")
	ErrOperationalLeaseLost       = errors.New("operational lease lost")
)

// Repository is the storage boundary used by the Sense process. SQLite stays
// available for M1 development; PostgreSQL implements the M2 production path.
type Repository interface {
	Close() error
	CreateDevice(context.Context, device.Device) error
	SetDesiredState(context.Context, string, device.DesiredState) error
	GetDevice(context.Context, string) (device.Device, error)
	ListDueReconcile(context.Context, time.Time, int) ([]ReconcileCandidate, error)
	ClaimDueReconcile(context.Context, ReconcileClaim) ([]ReconcileCandidate, error)
	RenewReconcileLease(context.Context, string, string, string, time.Time, time.Duration) (bool, error)
	CompleteReconcile(context.Context, string, int64, string, string, time.Time) error
	FailReconcile(context.Context, string, int, time.Time, string, string, string, time.Time) error
	ListEnabledVideoDevices(context.Context, int) ([]device.Device, error)
	MarkReconciled(context.Context, string, int64, time.Time) error
	MarkReconcileFailure(context.Context, string, int, time.Time, string, time.Time) error
	UpdateActualState(context.Context, string, device.ActualState, time.Time) error
	RequestReconcile(context.Context, string, time.Time) error
	ConvergenceSnapshot(context.Context) (ConvergenceSnapshot, error)
}

// ReconcileClaim identifies one short-lived batch claim. Token is unique per
// run and fences a worker whose lease expired and was acquired by another
// process. SQLite accepts the shape but remains explicitly single-process.
type ReconcileClaim struct {
	Owner         string
	Token         string
	Now           time.Time
	LeaseDuration time.Duration
	Limit         int
}

func OpenRepository(ctx context.Context, driver, dsn string) (Repository, error) {
	switch strings.ToLower(strings.TrimSpace(driver)) {
	case "", DriverSQLite:
		return OpenSQLite(ctx, dsn)
	case DriverPostgres:
		return OpenPostgres(ctx, dsn)
	default:
		return nil, fmt.Errorf("unsupported database driver %q", driver)
	}
}

type quotaProjectionError struct {
	kind error
}

func (e *quotaProjectionError) Error() string { return e.kind.Error() }
func (e *quotaProjectionError) Unwrap() error { return e.kind }

func projectionUnavailable() error {
	return &quotaProjectionError{kind: ErrQuotaProjectionUnavailable}
}

func projectionInvalid() error {
	return &quotaProjectionError{kind: ErrQuotaProjectionInvalid}
}

type areaPolicyError struct {
	kind error
}

func (e *areaPolicyError) Error() string { return e.kind.Error() }
func (e *areaPolicyError) Unwrap() error { return e.kind }

func areaPolicyUnavailable() error {
	return &areaPolicyError{kind: ErrAreaPolicyUnavailable}
}

func areaPolicyInvalid() error {
	return &areaPolicyError{kind: ErrAreaPolicyInvalid}
}

func areaPolicyDenied() error {
	return &areaPolicyError{kind: ErrAreaPolicyDenied}
}