Data Lineage Tracker

Overview

Track the origin, transformations, and flow of construction data through systems. Provides audit trails for compliance, helps debug data issues, and ensures data governance.

Business Case

Construction projects require data accountability:

• Audit Compliance: Know where every number came from
• Issue Resolution: Trace data problems to their source
• Change Impact: Understand what downstream systems are affected
• Regulatory Requirements: Maintain data provenance for legal/insurance

Technical Implementation

from dataclasses import dataclass, field
from typing import List, Dict, Any, Optional, Set
from datetime import datetime
from enum import Enum
import json
import hashlib
import uuid

class TransformationType(Enum):
    EXTRACT = "extract"
    TRANSFORM = "transform"
    LOAD = "load"
    AGGREGATE = "aggregate"
    JOIN = "join"
    FILTER = "filter"
    CALCULATE = "calculate"
    MANUAL_EDIT = "manual_edit"
    IMPORT = "import"
    EXPORT = "export"

@dataclass
class DataSource:
    id: str
    name: str
    system: str
    location: str
    owner: str
    created_at: datetime

@dataclass
class TransformationStep:
    id: str
    transformation_type: TransformationType
    description: str
    input_entities: List[str]
    output_entities: List[str]
    logic: str  # SQL, Python, or description
    performed_by: str  # user or system
    performed_at: datetime
    parameters: Dict[str, Any] = field(default_factory=dict)

@dataclass
class DataEntity:
    id: str
    name: str
    source_id: str
    entity_type: str  # table, file, field, record
    created_at: datetime
    version: int = 1
    checksum: Optional[str] = None
    parent_entities: List[str] = field(default_factory=list)
    metadata: Dict[str, Any] = field(default_factory=dict)

@dataclass
class LineageRecord:
    id: str
    entity_id: str
    transformation_id: str
    upstream_entities: List[str]
    downstream_entities: List[str]
    recorded_at: datetime

class ConstructionDataLineageTracker:
    """Track data lineage for construction data flows."""

    def __init__(self, project_id: str):
        self.project_id = project_id
        self.sources: Dict[str, DataSource] = {}
        self.entities: Dict[str, DataEntity] = {}
        self.transformations: Dict[str, TransformationStep] = {}
        self.lineage_records: List[LineageRecord] = []

    def register_source(self, name: str, system: str, location: str, owner: str) -> DataSource:
        """Register a new data source."""
        source = DataSource(
            id=f"SRC-{uuid.uuid4().hex[:8]}",
            name=name,
            system=system,
            location=location,
            owner=owner,
            created_at=datetime.now()
        )
        self.sources[source.id] = source
        return source

    def register_entity(self, name: str, source_id: str, entity_type: str,
                       parent_entities: List[str] = None,
                       metadata: Dict = None) -> DataEntity:
        """Register a data entity (table, file, field)."""
        entity = DataEntity(
            id=f"ENT-{uuid.uuid4().hex[:8]}",
            name=name,
            source_id=source_id,
            entity_type=entity_type,
            created_at=datetime.now(),
            parent_entities=parent_entities or [],
            metadata=metadata or {}
        )
        self.entities[entity.id] = entity
        return entity

    def calculate_checksum(self, data: Any) -> str:
        """Calculate checksum for data verification."""
        if isinstance(data, str):
            content = data
        else:
            content = json.dumps(data, sort_keys=True, default=str)
        return hashlib.sha256(content.encode()).hexdigest()[:16]

    def record_transformation(self,
                             transformation_type: TransformationType,
                             description: str,
                             input_entities: List[str],
                             output_entities: List[str],
                             logic: str,
                             performed_by: str,
                             parameters: Dict = None) -> TransformationStep:
        """Record a data transformation."""
        transformation = TransformationStep(
            id=f"TRF-{uuid.uuid4().hex[:8]}",
            transformation_type=transformation_type,
            description=description,
            input_entities=input_entities,
            output_entities=output_entities,
            logic=logic,
            performed_by=performed_by,
            performed_at=datetime.now(),
            parameters=parameters or {}
        )
        self.transformations[transformation.id] = transformation

        # Create lineage records
        for output_id in output_entities:
            record = LineageRecord(
                id=f"LIN-{uuid.uuid4().hex[:8]}",
                entity_id=output_id,
                transformation_id=transformation.id,
                upstream_entities=input_entities,
                downstream_entities=[],
                recorded_at=datetime.now()
            )
            self.lineage_records.append(record)

            # Update downstream references for input entities
            for input_id in input_entities:
                for existing_record in self.lineage_records:
                    if existing_record.entity_id == input_id:
                        existing_record.downstream_entities.append(output_id)

        return transformation

    def trace_upstream(self, entity_id: str, depth: int = None) -> List[Dict]:
        """Trace all upstream sources of an entity."""
        visited = set()
        lineage = []

        def trace(eid: str, current_depth: int):
            if eid in visited:
                return
            if depth is not None and current_depth > depth:
                return

            visited.add(eid)

            entity = self.entities.get(eid)
            if not entity:
                return

            # Find transformations that produced this entity
            for record in self.lineage_records:
                if record.entity_id == eid:
                    transformation = self.transformations.get(record.transformation_id)
                    if transformation:
                        lineage.append({
                            'entity': entity.name,
                            'entity_id': eid,
                            'depth': current_depth,
                            'transformation': transformation.description,
                            'transformation_type': transformation.transformation_type.value,
                            'performed_at': transformation.performed_at.isoformat(),
                            'performed_by': transformation.performed_by,
                            'upstream': record.upstream_entities
                        })

                        for upstream_id in record.upstream_entities:
                            trace(upstream_id, current_depth + 1)

        trace(entity_id, 0)
        return sorted(lineage, key=lambda x: x['depth'])

    def trace_downstream(self, entity_id: str, depth: int = None) -> List[Dict]:
        """Trace all downstream dependencies of an entity."""
        visited = set()
        dependencies = []

        def trace(eid: str, current_depth: int):
            if eid in visited:
                return
            if depth is not None and current_depth > depth:
                return

            visited.add(eid)

            entity = self.entities.get(eid)
            if not entity:
                return

            # Find entities that use this entity
            for record in self.lineage_records:
                if eid in record.upstream_entities:
                    transformation = self.transformations.get(record.transformation_id)
                    if transformation:
                        dependencies.append({
                            'entity': self.entities[record.entity_id].name if record.entity_id in self.entities else record.entity_id,
                            'entity_id': record.entity_id,
                            'depth': current_depth,
                            'transformation': transformation.description,
                            'transformation_type': transformation.transformation_type.value
                        })

                        trace(record.entity_id, current_depth + 1)

        trace(entity_id, 0)
        return sorted(dependencies, key=lambda x: x['depth'])

    def get_entity_history(self, entity_id: str) -> List[Dict]:
        """Get complete history of changes to an entity."""
        history = []

        for record in self.lineage_records:
            if record.entity_id == entity_id:
                transformation = self.transformations.get(record.transformation_id)
                if transformation:
                    history.append({
                        'timestamp': transformation.performed_at.isoformat(),
                        'action': transformation.transformation_type.value,
                        'description': transformation.description,
                        'performed_by': transformation.performed_by,
                        'inputs': [
                            self.entities[eid].name if eid in self.entities else eid
                            for eid in record.upstream_entities
                        ]
                    })

        return sorted(history, key=lambda x: x['timestamp'])

    def impact_analysis(self, entity_id: str) -> Dict:
        """Analyze impact of changes to an entity."""
        downstream = self.trace_downstream(entity_id)

        impact = {
            'entity': self.entities[entity_id].name if entity_id in self.entities else entity_id,
            'total_affected': len(downstream),
            'affected_by_depth': {},
            'affected_entities': downstream
        }

        for dep in downstream:
            depth = dep['depth']
            impact['affected_by_depth'][depth] = impact['affected_by_depth'].get(depth, 0) + 1

        return impact

    def validate_lineage(self) -> List[str]:
        """Validate lineage for completeness and consistency."""
        issues = []

        # Check for orphan entities (no source or transformation)
        for eid, entity in self.entities.items():
            has_lineage = any(r.entity_id == eid for r in self.lineage_records)
            if not has_lineage and entity.entity_type != 'source':
                issues.append(f"Entity '{entity.name}' has no lineage record")

        # Check for broken references
        all_entity_ids = set(self.entities.keys())
        for record in self.lineage_records:
            for upstream_id in record.upstream_entities:
                if upstream_id not in all_entity_ids:
                    issues.append(f"Lineage references unknown entity: {upstream_id}")

        # Check for circular dependencies
        for eid in self.entities:
            upstream = set()
            to_check = [eid]
            while to_check:
                current = to_check.pop()
                if current in upstream:
                    issues.append(f"Circular dependency detected involving entity: {self.entities[eid].name}")
                    break
                upstream.add(current)
                for record in self.lineage_records:
                    if record.entity_id == current:
                        to_check.extend(record.upstream_entities)

        return issues

    def generate_lineage_graph(self, entity_id: str) -> str:
        """Generate Mermaid diagram of lineage."""
        lines = ["```mermaid", "graph LR"]

        upstream = self.trace_upstream(entity_id, depth=5)
        downstream = self.trace_downstream(entity_id, depth=5)

        # Add nodes
        added_nodes = set()
        for item in upstream + downstream:
            node_id = item['entity_id'].replace('-', '_')
            if node_id not in added_nodes:
                entity = self.entities.get(item['entity_id'])
                name = entity.name if entity else item['entity_id']
                lines.append(f"    {node_id}[{name}]")
                added_nodes.add(node_id)

        # Add target node
        target_node = entity_id.replace('-', '_')
        if target_node not in added_nodes:
            entity = self.entities.get(entity_id)
            name = entity.name if entity else entity_id
            lines.append(f"    {target_node}[{name}]:::target")

        # Add edges
        for item in upstream:
            for upstream_id in item.get('upstream', []):
                from_node = upstream_id.replace('-', '_')
                to_node = item['entity_id'].replace('-', '_')
                lines.append(f"    {from_node} --> {to_node}")

        for item in downstream:
            from_node = entity_id.replace('-', '_')
            to_node = item['entity_id'].replace('-', '_')
            if to_node != from_node:
                lines.append(f"    {from_node} --> {to_node}")

        lines.append("    classDef target fill:#f96")
        lines.append("```")

        return "\n".join(lines)

    def export_lineage(self) -> Dict:
        """Export complete lineage data."""
        return {
            'project_id': self.project_id,
            'exported_at': datetime.now().isoformat(),
            'sources': {k: {
                'id': v.id,
                'name': v.name,
                'system': v.system,
                'location': v.location,
                'owner': v.owner
            } for k, v in self.sources.items()},
            'entities': {k: {
                'id': v.id,
                'name': v.name,
                'source_id': v.source_id,
                'entity_type': v.entity_type,
                'parent_entities': v.parent_entities
            } for k, v in self.entities.items()},
            'transformations': {k: {
                'id': v.id,
                'type': v.transformation_type.value,
                'description': v.description,
                'input_entities': v.input_entities,
                'output_entities': v.output_entities,
                'performed_by': v.performed_by,
                'performed_at': v.performed_at.isoformat()
            } for k, v in self.transformations.items()},
            'lineage_records': [{
                'id': r.id,
                'entity_id': r.entity_id,
                'transformation_id': r.transformation_id,
                'upstream_entities': r.upstream_entities
            } for r in self.lineage_records]
        }

    def generate_report(self) -> str:
        """Generate lineage report."""
        lines = [f"# Data Lineage Report: {self.project_id}", ""]
        lines.append(f"**Generated:** {datetime.now().strftime('%Y-%m-%d %H:%M')}")
        lines.append(f"**Sources:** {len(self.sources)}")
        lines.append(f"**Entities:** {len(self.entities)}")
        lines.append(f"**Transformations:** {len(self.transformations)}")
        lines.append("")

        # Sources
        lines.append("## Data Sources")
        for source in self.sources.values():
            lines.append(f"- **{source.name}** ({source.system})")
            lines.append(f"  - Location: {source.location}")
            lines.append(f"  - Owner: {source.owner}")
        lines.append("")

        # Validation
        issues = self.validate_lineage()
        if issues:
            lines.append("## Lineage Issues")
            for issue in issues:
                lines.append(f"- ⚠️ {issue}")
            lines.append("")

        # Transformation summary
        lines.append("## Transformation Summary")
        type_counts = {}
        for t in self.transformations.values():
            type_counts[t.transformation_type.value] = type_counts.get(t.transformation_type.value, 0) + 1
        for t_type, count in sorted(type_counts.items()):
            lines.append(f"- {t_type}: {count}")

        return "\n".join(lines)