package manifest

import (
	"strings"
	"time"
)

// ErrorRecord captures structured error metadata at run or stage scope.
type ErrorRecord struct {
	Message string     `json:"message"`
	Code    string     `json:"code,omitempty"`
	At      *time.Time `json:"at,omitempty"`
}

// InputRecord captures one resolved input and optional checksum.
type InputRecord struct {
	Kind      string `json:"kind"`
	Path      string `json:"path"`
	Checksum  string `json:"checksum,omitempty"`
	Source    string `json:"source,omitempty"`
	S3Bucket  string `json:"s3_bucket,omitempty"`
	S3Key     string `json:"s3_key,omitempty"`
	S3Size    int64  `json:"s3_size,omitempty"`
	S3ETag    string `json:"s3_etag,omitempty"`
	SpoolPath string `json:"spool_path,omitempty"`
}

// ArtifactRecord captures one produced artifact and optional remote metadata.
type ArtifactRecord struct {
	Kind      string `json:"kind"`
	LocalPath string `json:"local_path"`
	// ProducerRunID identifies the run that produced this durable artifact.
	ProducerRunID string `json:"producer_run_id,omitempty"`
	RemoteKey     string `json:"remote_key,omitempty"`
	Checksum      string `json:"checksum,omitempty"`
}

// StageRecord tracks lifecycle and provenance for one pipeline stage.
type StageRecord struct {
	Name             string           `json:"name"`
	Status           StageStatus      `json:"status"`
	CreatedAt        time.Time        `json:"created_at"`
	UpdatedAt        time.Time        `json:"updated_at"`
	StartedAt        *time.Time       `json:"started_at,omitempty"`
	CompletedAt      *time.Time       `json:"completed_at,omitempty"`
	Outputs          []ArtifactRecord `json:"outputs,omitempty"`
	Logs             []string         `json:"logs,omitempty"`
	GeneratedConfigs []string         `json:"generated_configs,omitempty"`
	Error            *ErrorRecord     `json:"error,omitempty"`
	Metadata         map[string]any   `json:"metadata,omitempty"`
}

// Manifest is the durable run-state record for a session execution.
type Manifest struct {
	SessionID       string                  `json:"session_id"`
	Campaign        string                  `json:"campaign,omitempty"`
	RunID           string                  `json:"run_id,omitempty"`
	LocalWorkDir    string                  `json:"local_workdir,omitempty"`
	LocalSpoolDir   string                  `json:"local_spool_dir,omitempty"`
	S3Bucket        string                  `json:"s3_bucket,omitempty"`
	S3SessionPrefix string                  `json:"s3_session_prefix,omitempty"`
	S3RunPrefix     string                  `json:"s3_run_prefix,omitempty"`
	PipelineVersion string                  `json:"pipeline_version,omitempty"`
	CreatedAt       time.Time               `json:"created_at"`
	UpdatedAt       time.Time               `json:"updated_at"`
	LastError       *ErrorRecord            `json:"last_error,omitempty"`
	Inputs          []InputRecord           `json:"inputs,omitempty"`
	Artifacts       []ArtifactRecord        `json:"artifacts,omitempty"`
	Stages          map[string]*StageRecord `json:"stages"`
}

// New constructs a new manifest with deterministic timestamps.
func New(sessionID string, now time.Time) *Manifest {
	return &Manifest{
		SessionID: strings.TrimSpace(sessionID),
		CreatedAt: now,
		UpdatedAt: now,
		Stages:    map[string]*StageRecord{},
	}
}

// MarkStageRunning marks a stage as running and updates timestamps.
func (m *Manifest) MarkStageRunning(name string, at time.Time) {
	s := m.ensureStage(name, at)
	s.Status = StatusRunning
	s.StartedAt = timePtr(at)
	s.CompletedAt = nil
	s.Error = nil
	s.UpdatedAt = at
	m.UpdatedAt = at
}

// MarkStageSucceeded marks a stage as succeeded, stores outputs, and updates timestamps.
func (m *Manifest) MarkStageSucceeded(name string, at time.Time, outputs []ArtifactRecord) {
	s := m.ensureStage(name, at)
	s.Status = StatusSucceeded
	s.CompletedAt = timePtr(at)
	s.Error = nil
	s.Outputs = append([]ArtifactRecord(nil), outputs...)
	s.UpdatedAt = at
	m.UpdatedAt = at
}

// MarkStageFailed marks a stage as failed and records error metadata.
func (m *Manifest) MarkStageFailed(name string, at time.Time, message string) {
	s := m.ensureStage(name, at)
	s.Status = StatusFailed
	s.CompletedAt = timePtr(at)
	s.Error = &ErrorRecord{Message: strings.TrimSpace(message), At: timePtr(at)}
	s.UpdatedAt = at
	m.LastError = &ErrorRecord{Message: strings.TrimSpace(message), At: timePtr(at)}
	m.UpdatedAt = at
}

// MarkStageSkipped marks a stage as skipped and records the skip reason.
func (m *Manifest) MarkStageSkipped(name string, at time.Time, reason string) {
	s := m.ensureStage(name, at)
	s.Status = StatusSkipped
	s.CompletedAt = timePtr(at)
	s.Error = &ErrorRecord{Message: strings.TrimSpace(reason), Code: "skipped", At: timePtr(at)}
	s.UpdatedAt = at
	m.UpdatedAt = at
}

// MarkStageStale marks a stage as stale so it is not skipped as idempotently complete.
func (m *Manifest) MarkStageStale(name string, at time.Time, reason string) {
	s := m.ensureStage(name, at)
	s.Status = StatusStale
	s.Error = &ErrorRecord{Message: strings.TrimSpace(reason), Code: "stale", At: timePtr(at)}
	s.UpdatedAt = at
	m.UpdatedAt = at
}

func (m *Manifest) ensureStage(name string, at time.Time) *StageRecord {
	if m.Stages == nil {
		m.Stages = map[string]*StageRecord{}
	}

	stageName := strings.TrimSpace(name)
	s, ok := m.Stages[stageName]
	if !ok || s == nil {
		s = &StageRecord{
			Name:      stageName,
			Status:    StatusPending,
			CreatedAt: at,
			UpdatedAt: at,
		}
		m.Stages[stageName] = s
	}

	if s.Name == "" {
		s.Name = stageName
	}
	if s.CreatedAt.IsZero() {
		s.CreatedAt = at
	}

	return s
}

func timePtr(t time.Time) *time.Time {
	v := t
	return &v
}