cognitive-memory/edges.py

"""EdgesMixin: edge/relationship operations for CognitiveMemoryClient.

This module is part of the client.py mixin refactor. EdgesMixin provides all
edge CRUD and search operations. It relies on helper methods resolved at runtime
via MRO from the composed CognitiveMemoryClient class.
"""

import uuid
import subprocess
from datetime import datetime, timezone
from pathlib import Path
from typing import Optional, List, Dict, Any

from common import (
    VALID_RELATION_TYPES,
    EDGES_DIR_NAME,
    _make_edge_filename,
    serialize_edge_frontmatter,
)


class EdgesMixin:
    """Mixin providing edge/relationship operations for CognitiveMemoryClient."""

    def relate(
        self,
        from_id: str,
        to_id: str,
        rel_type: str,
        strength: float = 0.8,
        context: Optional[str] = None,
        description: Optional[str] = None,
    ) -> str:
        """Create a relationship between two memories with an edge file.

        Returns edge_id string, or empty string if duplicate.
        """
        if rel_type not in VALID_RELATION_TYPES:
            raise ValueError(
                f"Invalid relation type: {rel_type}. Valid: {VALID_RELATION_TYPES}"
            )

        from_path = self._resolve_memory_path(from_id)
        to_path = self._resolve_memory_path(to_id)
        if not from_path or not to_path:
            missing_id = from_id if not from_path else to_id
            raise ValueError(
                f"Memory not found: {missing_id}. "
                f"Note: edges can only connect memories within the same graph."
            )

        # Read source memory
        fm, body = self._read_memory_file(from_path)
        relations = fm.get("relations", [])

        # Check for duplicate
        for r in relations:
            if r.get("target") == to_id and r.get("type") == rel_type:
                return ""  # Already exists

        # Read target memory for title
        to_fm, to_body = self._read_memory_file(to_path)

        # Create edge file
        edge_id = str(uuid.uuid4())
        now = datetime.now(timezone.utc).isoformat()
        from_title = fm.get("title", from_id[:8])
        to_title = to_fm.get("title", to_id[:8])
        clamped_strength = max(0.0, min(1.0, strength))

        edge_data = {
            "id": edge_id,
            "type": rel_type,
            "from_id": from_id,
            "from_title": from_title,
            "to_id": to_id,
            "to_title": to_title,
            "strength": clamped_strength,
            "created": now,
            "updated": now,
        }
        edge_filename = _make_edge_filename(from_title, rel_type, to_title, edge_id)
        edge_path = self.memory_dir / "graph" / EDGES_DIR_NAME / edge_filename
        edge_fm_str = serialize_edge_frontmatter(edge_data)
        edge_body = description.strip() if description else ""
        edge_content = (
            f"{edge_fm_str}\n\n{edge_body}\n" if edge_body else f"{edge_fm_str}\n"
        )
        edge_path.write_text(edge_content, encoding="utf-8")

        # Update source memory frontmatter with edge_id
        new_rel = {
            "target": to_id,
            "type": rel_type,
            "direction": "outgoing",
            "strength": clamped_strength,
            "edge_id": edge_id,
        }
        if context:
            new_rel["context"] = context
        relations.append(new_rel)
        fm["relations"] = relations
        fm["updated"] = now
        self._write_memory_file(from_path, fm, body)

        # Add incoming relation to target with edge_id
        to_relations = to_fm.get("relations", [])
        has_incoming = any(
            r.get("target") == from_id
            and r.get("type") == rel_type
            and r.get("direction") == "incoming"
            for r in to_relations
        )
        if not has_incoming:
            incoming_rel = {
                "target": from_id,
                "type": rel_type,
                "direction": "incoming",
                "strength": clamped_strength,
                "edge_id": edge_id,
            }
            if context:
                incoming_rel["context"] = context
            to_relations.append(incoming_rel)
            to_fm["relations"] = to_relations
            to_fm["updated"] = now
            self._write_memory_file(to_path, to_fm, to_body)

        # Update memory index
        rel_from = str(from_path.relative_to(self.memory_dir))
        rel_to = str(to_path.relative_to(self.memory_dir))
        self._update_index_entry(from_id, fm, rel_from)
        self._update_index_entry(to_id, to_fm, rel_to)

        # Update edge index
        self._update_edge_index(
            edge_id, edge_data, f"graph/{EDGES_DIR_NAME}/{edge_filename}"
        )

        self._git_commit(
            f"relate: {from_id[:8]} --{rel_type}--> {to_id[:8]}",
            [from_path, to_path, edge_path],
        )
        return edge_id

    def edge_get(self, edge_id: str) -> Optional[Dict[str, Any]]:
        """Read full edge file (frontmatter + body)."""
        path = self._resolve_edge_path(edge_id)
        if not path:
            return None
        fm, body = self._read_memory_file(path)
        return {
            "id": fm.get("id", edge_id),
            "type": fm.get("type", ""),
            "from_id": fm.get("from_id", ""),
            "from_title": fm.get("from_title", ""),
            "to_id": fm.get("to_id", ""),
            "to_title": fm.get("to_title", ""),
            "strength": fm.get("strength", 0.8),
            "created": fm.get("created", ""),
            "updated": fm.get("updated", ""),
            "description": body.strip(),
            "path": str(path.relative_to(self.memory_dir)),
        }

    def edge_search(
        self,
        query: Optional[str] = None,
        types: Optional[List[str]] = None,
        from_id: Optional[str] = None,
        to_id: Optional[str] = None,
        limit: int = 20,
    ) -> List[Dict[str, Any]]:
        """Search edges via index."""
        index = self._load_index()
        results = []
        query_lower = query.lower().strip() if query else ""

        # Resolve partial IDs to full UUIDs via prefix match
        if from_id:
            entries = index.get("entries", {})
            resolved = self._resolve_prefix(from_id, entries)
            from_id = resolved or from_id
        if to_id:
            entries = index.get("entries", {})
            resolved = self._resolve_prefix(to_id, entries)
            to_id = resolved or to_id

        for eid, entry in index.get("edges", {}).items():
            if types and entry.get("type") not in types:
                continue
            if from_id and entry.get("from_id") != from_id:
                continue
            if to_id and entry.get("to_id") != to_id:
                continue
            if query_lower:
                searchable = f"{entry.get('from_title', '')} {entry.get('to_title', '')} {entry.get('type', '')}".lower()
                if query_lower not in searchable:
                    continue
            results.append({"id": eid, **entry})

        results.sort(key=lambda x: x.get("created", ""), reverse=True)
        return results[:limit]

    def edge_update(
        self,
        edge_id: str,
        description: Optional[str] = None,
        strength: Optional[float] = None,
    ) -> bool:
        """Update edge body/metadata, sync strength to memory frontmatter."""
        path = self._resolve_edge_path(edge_id)
        if not path:
            return False

        fm, body = self._read_memory_file(path)
        now = datetime.now(timezone.utc).isoformat()

        if description is not None:
            body = description
        if strength is not None:
            fm["strength"] = max(0.0, min(1.0, strength))
        fm["updated"] = now

        # Write edge file
        edge_fm_str = serialize_edge_frontmatter(fm)
        edge_body = body.strip() if body else ""
        edge_content = (
            f"{edge_fm_str}\n\n{edge_body}\n" if edge_body else f"{edge_fm_str}\n"
        )
        path.write_text(edge_content, encoding="utf-8")

        # Sync strength to memory frontmatter if changed
        if strength is not None:
            for mid_key in ("from_id", "to_id"):
                mid = fm.get(mid_key)
                if not mid:
                    continue
                mem_path = self._resolve_memory_path(mid)
                if not mem_path:
                    continue
                mem_fm, mem_body = self._read_memory_file(mem_path)
                for rel in mem_fm.get("relations", []):
                    if rel.get("edge_id") == edge_id:
                        rel["strength"] = fm["strength"]
                mem_fm["updated"] = now
                self._write_memory_file(mem_path, mem_fm, mem_body)

        # Update edge index
        rel_path = str(path.relative_to(self.memory_dir))
        self._update_edge_index(edge_id, fm, rel_path)
        self._git_commit(f"edge-update: {edge_id[:8]}", [path])
        return True

    def edge_delete(self, edge_id: str) -> bool:
        """Remove edge file and clean frontmatter refs from both memories."""
        path = self._resolve_edge_path(edge_id)
        if not path:
            return False

        fm, _ = self._read_memory_file(path)
        now = datetime.now(timezone.utc).isoformat()
        files_to_commit: List[Path] = []

        # Clean edge_id references from both memories
        for mid_key in ("from_id", "to_id"):
            mid = fm.get(mid_key)
            if not mid:
                continue
            mem_path = self._resolve_memory_path(mid)
            if not mem_path:
                continue
            mem_fm, mem_body = self._read_memory_file(mem_path)
            original_rels = mem_fm.get("relations", [])
            mem_fm["relations"] = [
                r for r in original_rels if r.get("edge_id") != edge_id
            ]
            if len(mem_fm["relations"]) != len(original_rels):
                mem_fm["updated"] = now
                self._write_memory_file(mem_path, mem_fm, mem_body)
                rel_p = str(mem_path.relative_to(self.memory_dir))
                self._update_index_entry(mid, mem_fm, rel_p)
                files_to_commit.append(mem_path)

        # Remove edge file
        path.unlink()
        self._remove_edge_index(edge_id)

        # Git stage deletion
        try:
            rel_path = path.relative_to(self.memory_dir)
            subprocess.run(
                ["git", "rm", "--cached", str(rel_path)],
                cwd=str(self.memory_dir),
                capture_output=True,
                timeout=5,
            )
        except Exception:
            pass
        self._git_commit(f"edge-delete: {edge_id[:8]}")
        return True