package service

import (
	"strings"
	"time"

	"browser.local/platform/domain"
	"browser.local/platform/validator"
)

func (svc *CoreService) ReportRunLifecycle(report domain.RunLifecycleReport) (domain.RunLifecycleReportResult, error) {
	report = domain.CopyRunLifecycleReport(report)
	if err := validator.ValidateRunLifecycleReport(report); err != nil {
		return domain.RunLifecycleReportResult{}, err
	}
	if _, err := svc.validatedRunSession(report.RunEndpointID, report.SessionToken); err != nil {
		return domain.RunLifecycleReportResult{}, err
	}
	instance, err := svc.store.ServerInstances().Get(report.ServerInstanceID)
	if err != nil {
		return domain.RunLifecycleReportResult{}, err
	}
	if instance.RunEndpointID != report.RunEndpointID {
		return domain.RunLifecycleReportResult{}, validationError("runEndpointId must match server instance")
	}
	if instance.State == domain.ServerInstanceStateDeleted {
		return domain.RunLifecycleReportResult{}, validationError("server instance must not be deleted")
	}

	stamp := svc.now()
	nextState, projected := lifecycleProjectedState(report.Capability, report.State, report.ExecutionResult)
	if lifecycleObservationIsStale(instance, report) {
		projected = false
		nextState = instance.State
	}
	if projected {
		instance.State = nextState
		if report.ManagedProcessID != "" {
			instance.LifecycleProcessID = report.ManagedProcessID
			instance.LifecycleObservationSeq = report.ObservationSeq
			instance.LifecycleObservedAt = report.ObservedAt
			if instance.LifecycleObservedAt.IsZero() {
				instance.LifecycleObservedAt = stamp
			}
		}
		instance.UpdatedAt = stamp
		if err := validator.ValidateServerInstance(instance); err != nil {
			return domain.RunLifecycleReportResult{}, err
		}
		if err := svc.store.ServerInstances().Update(instance); err != nil {
			return domain.RunLifecycleReportResult{}, err
		}
		svc.publishLogProcessState(instance)
	}
	return domain.CopyRunLifecycleReportResult(domain.RunLifecycleReportResult{Accepted: true, RunEndpointID: report.RunEndpointID, ServerInstanceID: report.ServerInstanceID, ProjectedState: nextState, ServerTime: stamp}), nil
}

func lifecycleObservationIsStale(instance domain.ServerInstance, report domain.RunLifecycleReport) bool {
	if report.ManagedProcessID == "" || instance.LifecycleProcessID == "" {
		return false
	}
	if report.ManagedProcessID == instance.LifecycleProcessID {
		return report.ObservationSeq <= instance.LifecycleObservationSeq
	}
	return !report.ObservedAt.IsZero() && !instance.LifecycleObservedAt.IsZero() && report.ObservedAt.Before(instance.LifecycleObservedAt)
}

func (svc *CoreService) projectRemoteAdapterJobResult(job domain.Job, stamp time.Time) error {
	if !strings.HasPrefix(job.Capability, "remote.") || job.ServerInstanceID == "" || !isTerminalJobState(job.State) {
		return nil
	}
	return nil
}

func (svc *CoreService) projectLifecycleJobResult(job domain.Job, stamp time.Time) error {
	if job.Capability == domain.JobCapabilityConfigWrite {
		if job.State != domain.JobStateSucceeded {
			return nil
		}
		instance, err := svc.store.ServerInstances().Get(job.ServerInstanceID)
		if err != nil {
			return err
		}
		instance.ConfigKey = job.TargetKey
		instance.ConfigContent = job.ExecutionInput.Content
		instance.ConfigChecksum = job.ExecutionResult.Checksum
		instance.ConfigVersion = job.ExecutionResult.Version
		instance.ConfigUpdatedAt = stamp
		instance.UpdatedAt = stamp
		if err := validator.ValidateServerInstance(instance); err != nil {
			return err
		}
		if err := svc.store.ServerInstances().Update(instance); err != nil {
			return err
		}
		return nil
	}
	nextState, ok := lifecycleProjectedState(job.Capability, job.State, job.ExecutionResult)
	if !ok || job.ServerInstanceID == "" {
		return nil
	}
	instance, err := svc.store.ServerInstances().Get(job.ServerInstanceID)
	if err != nil {
		return err
	}
	instance.State = nextState
	instance.UpdatedAt = stamp
	if err := validator.ValidateServerInstance(instance); err != nil {
		return err
	}
	if err := svc.store.ServerInstances().Update(instance); err != nil {
		return err
	}
	svc.publishLogProcessState(instance)
	return nil
}

func (svc *CoreService) projectServerDeploymentProgress(job domain.Job, stamp time.Time) error {
	if job.ExecutionInput.Deployment == nil || job.ServerInstanceID == "" {
		return nil
	}
	instance, err := svc.store.ServerInstances().Get(job.ServerInstanceID)
	if err != nil {
		return err
	}
	projection := domain.CopyServerDeploymentProjection(instance.DeploymentProjection)
	projection.State = "running"
	projection.Operation = job.ExecutionInput.LifecycleOperation
	switch job.Progress.Phase {
	case "preflight":
		projection.PreflightState = "running"
	case "scan", "discover", "discovery":
		projection.DiscoveryState = "running"
	case "install", "configure", "mapping":
		projection.MappingState = "running"
	case "start", "health":
		projection.VerificationState = "running"
	}
	projection.UpdatedAt = stamp
	instance.DeploymentProjection = projection
	instance.UpdatedAt = stamp
	return svc.store.ServerInstances().Update(instance)
}

func lifecycleProjectedState(capability string, jobState domain.JobState, result domain.JobExecutionResult) (domain.ServerInstanceState, bool) {
	if capability != domain.LifecycleCapabilityInstall && capability != domain.LifecycleCapabilityStart && capability != domain.LifecycleCapabilityStop && capability != domain.LifecycleCapabilityStatus {
		return "", false
	}
	if capability == domain.LifecycleCapabilityStatus {
		if jobState != domain.JobStateSucceeded {
			return "", false
		}
		return lifecycleStateFromProcessResult(result)
	}
	if jobState == domain.JobStateFailed || jobState == domain.JobStateCancelled {
		return domain.ServerInstanceStateFailed, true
	}
	if jobState != domain.JobStateSucceeded {
		return "", false
	}
	switch capability {
	case domain.LifecycleCapabilityInstall:
		return domain.ServerInstanceStateReady, true
	case domain.LifecycleCapabilityStart:
		return lifecycleStateFromProcessResult(result)
	case domain.LifecycleCapabilityStop:
		if state, ok := lifecycleStateFromProcessResult(result); ok {
			return state, true
		}
		return domain.ServerInstanceStateStopped, true
	default:
		return "", false
	}
}

func lifecycleStateFromProcessResult(result domain.JobExecutionResult) (domain.ServerInstanceState, bool) {
	switch strings.TrimSpace(result.ProcessState) {
	case "running":
		return domain.ServerInstanceStateRunning, true
	case "stopped", "not-started":
		return domain.ServerInstanceStateStopped, true
	case "exited":
		switch strings.TrimSpace(result.ExitClassification) {
		case "requested-stop", "forced-stop", "already-stopped":
			return domain.ServerInstanceStateStopped, true
		default:
			return domain.ServerInstanceStateFailed, true
		}
	default:
		return "", false
	}
}