"""Phase 5 Engineering V1 — The 10 canonical queries.

Each function maps to one or more catalog IDs in
``docs/architecture/engineering-query-catalog.md``. Return values are plain
dicts so API and wiki renderers can consume them without importing dataclasses.

Design principles:
  - All queries filter to status='active' unless the caller asks otherwise
  - All project filters go through ``resolve_project_name`` (canonicalization)
  - Graph traversals are bounded (depth <= 3 for impact, limit 200 for lists)
  - The 3 "killer" queries (gaps) accept project as required — gaps are always
    scoped to one project in V1

These queries are the *useful surface* of the entity graph. Before this module,
the graph was data with no narrative; after this module, the director can ask
real questions about coverage, risk, and evidence.
"""

from __future__ import annotations

from datetime import datetime, timezone

from atocore.engineering.service import (
    Entity,
    _row_to_entity,
    get_entity,
    get_relationships,
)
from atocore.models.database import get_connection
from atocore.projects.registry import resolve_project_name


# ============================================================
# Structure queries (Q-001, Q-004, Q-005, Q-008)
# ============================================================


def system_map(project: str) -> dict:
    """Q-001 + Q-004: return the full subsystem/component tree for a project.

    Shape:
      {
        "project": "p05-interferometer",
        "subsystems": [
          {
            "id": ..., "name": ..., "description": ...,
            "components": [{id, name, description, materials: [...]}],
          },
          ...
        ],
        "orphan_components": [...],   # components with no PART_OF edge
      }
    """
    project = resolve_project_name(project) if project else ""
    out: dict = {"project": project, "subsystems": [], "orphan_components": []}

    with get_connection() as conn:
        # All subsystems in project
        subsys_rows = conn.execute(
            "SELECT * FROM entities WHERE status = 'active' "
            "AND project = ? AND entity_type = 'subsystem' "
            "ORDER BY name",
            (project,),
        ).fetchall()

        # All components in project
        comp_rows = conn.execute(
            "SELECT * FROM entities WHERE status = 'active' "
            "AND project = ? AND entity_type = 'component'",
            (project,),
        ).fetchall()

        # PART_OF edges: component → subsystem
        part_of_rows = conn.execute(
            "SELECT source_entity_id, target_entity_id FROM relationships "
            "WHERE relationship_type = 'part_of'"
        ).fetchall()
        part_of_map: dict[str, str] = {
            r["source_entity_id"]: r["target_entity_id"] for r in part_of_rows
        }

        # uses_material edges for components
        mat_rows = conn.execute(
            "SELECT r.source_entity_id, e.name FROM relationships r "
            "JOIN entities e ON e.id = r.target_entity_id "
            "WHERE r.relationship_type = 'uses_material' AND e.status = 'active'"
        ).fetchall()
        materials_by_comp: dict[str, list[str]] = {}
        for r in mat_rows:
            materials_by_comp.setdefault(r["source_entity_id"], []).append(r["name"])

    # Build: subsystems → their components
    subsys_comps: dict[str, list[dict]] = {s["id"]: [] for s in subsys_rows}
    orphans: list[dict] = []
    for c in comp_rows:
        parent = part_of_map.get(c["id"])
        comp_dict = {
            "id": c["id"],
            "name": c["name"],
            "description": c["description"] or "",
            "materials": materials_by_comp.get(c["id"], []),
        }
        if parent and parent in subsys_comps:
            subsys_comps[parent].append(comp_dict)
        else:
            orphans.append(comp_dict)

    out["subsystems"] = [
        {
            "id": s["id"],
            "name": s["name"],
            "description": s["description"] or "",
            "components": subsys_comps.get(s["id"], []),
        }
        for s in subsys_rows
    ]
    out["orphan_components"] = orphans
    return out


def decisions_affecting(project: str, subsystem_id: str | None = None) -> dict:
    """Q-008: decisions that affect a subsystem (or whole project).

    Walks AFFECTED_BY_DECISION edges. If subsystem_id is given, returns
    decisions linked to that subsystem or any of its components. Otherwise,
    all decisions in the project.
    """
    project = resolve_project_name(project) if project else ""

    target_ids: set[str] = set()
    if subsystem_id:
        target_ids.add(subsystem_id)
        # Include components PART_OF the subsystem
        with get_connection() as conn:
            rows = conn.execute(
                "SELECT source_entity_id FROM relationships "
                "WHERE relationship_type = 'part_of' AND target_entity_id = ?",
                (subsystem_id,),
            ).fetchall()
            for r in rows:
                target_ids.add(r["source_entity_id"])

    with get_connection() as conn:
        if target_ids:
            placeholders = ",".join("?" * len(target_ids))
            rows = conn.execute(
                f"SELECT DISTINCT e.* FROM entities e "
                f"JOIN relationships r ON r.source_entity_id = e.id "
                f"WHERE e.status = 'active' AND e.entity_type = 'decision' "
                f"AND e.project = ? AND r.relationship_type = 'affected_by_decision' "
                f"AND r.target_entity_id IN ({placeholders}) "
                f"ORDER BY e.updated_at DESC",
                (project, *target_ids),
            ).fetchall()
        else:
            rows = conn.execute(
                "SELECT * FROM entities WHERE status = 'active' "
                "AND entity_type = 'decision' AND project = ? "
                "ORDER BY updated_at DESC LIMIT 200",
                (project,),
            ).fetchall()

    decisions = [_entity_dict(_row_to_entity(r)) for r in rows]
    return {
        "project": project,
        "subsystem_id": subsystem_id or "",
        "decisions": decisions,
        "count": len(decisions),
    }


def requirements_for(component_id: str) -> dict:
    """Q-005: requirements that a component satisfies."""
    with get_connection() as conn:
        # Component → SATISFIES → Requirement
        rows = conn.execute(
            "SELECT e.* FROM entities e "
            "JOIN relationships r ON r.target_entity_id = e.id "
            "WHERE r.source_entity_id = ? AND r.relationship_type = 'satisfies' "
            "AND e.entity_type = 'requirement' AND e.status = 'active' "
            "ORDER BY e.name",
            (component_id,),
        ).fetchall()
    requirements = [_entity_dict(_row_to_entity(r)) for r in rows]
    return {
        "component_id": component_id,
        "requirements": requirements,
        "count": len(requirements),
    }


def recent_changes(project: str, since: str | None = None, limit: int = 50) -> dict:
    """Q-013: what changed recently in the project (entity audit log).

    Uses the shared memory_audit table filtered by entity_kind='entity' and
    joins back to entities for the project scope.
    """
    project = resolve_project_name(project) if project else ""
    since = since or "2020-01-01"

    with get_connection() as conn:
        rows = conn.execute(
            "SELECT a.id, a.memory_id AS entity_id, a.action, a.actor, "
            "a.timestamp, a.note, e.entity_type, e.name, e.project "
            "FROM memory_audit a "
            "LEFT JOIN entities e ON e.id = a.memory_id "
            "WHERE a.entity_kind = 'entity' AND a.timestamp >= ? "
            "AND (e.project = ? OR e.project IS NULL) "
            "ORDER BY a.timestamp DESC LIMIT ?",
            (since, project, limit),
        ).fetchall()

    changes = []
    for r in rows:
        changes.append({
            "audit_id": r["id"],
            "entity_id": r["entity_id"],
            "entity_type": r["entity_type"] or "?",
            "entity_name": r["name"] or "(deleted)",
            "action": r["action"],
            "actor": r["actor"] or "api",
            "note": r["note"] or "",
            "timestamp": r["timestamp"],
        })
    return {"project": project, "since": since, "changes": changes, "count": len(changes)}


# ============================================================
# Killer queries (Q-006, Q-009, Q-011) — the "what am I forgetting?" queries
# ============================================================


def orphan_requirements(project: str) -> dict:
    """Q-006: requirements in project with NO inbound SATISFIES edge.

    These are "something we said must be true" with nothing actually
    satisfying them. The single highest-value query for an engineering
    director: shows what's unclaimed by design.
    """
    project = resolve_project_name(project) if project else ""

    with get_connection() as conn:
        rows = conn.execute(
            "SELECT * FROM entities WHERE status = 'active' "
            "AND project = ? AND entity_type = 'requirement' "
            "AND NOT EXISTS ("
            "  SELECT 1 FROM relationships r "
            "  WHERE r.relationship_type = 'satisfies' "
            "  AND r.target_entity_id = entities.id"
            ") "
            "ORDER BY updated_at DESC",
            (project,),
        ).fetchall()

    orphans = [_entity_dict(_row_to_entity(r)) for r in rows]
    return {
        "project": project,
        "query": "Q-006 orphan requirements",
        "description": "Requirements with no SATISFIES relationship — nothing claims to meet them.",
        "gaps": orphans,
        "count": len(orphans),
    }


def risky_decisions(project: str) -> dict:
    """Q-009: decisions linked to assumptions flagged as unresolved.

    Walks BASED_ON_ASSUMPTION edges. An assumption is "flagged" if its
    properties.flagged=True OR status='superseded' OR status='invalid'.
    """
    project = resolve_project_name(project) if project else ""

    with get_connection() as conn:
        rows = conn.execute(
            "SELECT DISTINCT d.*, a.name AS assumption_name, a.id AS assumption_id, "
            "a.status AS assumption_status, a.properties AS assumption_props "
            "FROM entities d "
            "JOIN relationships r ON r.source_entity_id = d.id "
            "JOIN entities a ON a.id = r.target_entity_id "
            "WHERE d.status = 'active' AND d.entity_type = 'decision' "
            "AND d.project = ? "
            "AND r.relationship_type = 'based_on_assumption' "
            "AND ("
            "  a.status IN ('superseded', 'invalid') OR "
            "  a.properties LIKE '%\"flagged\": true%' OR "
            "  a.properties LIKE '%\"flagged\":true%'"
            ") "
            "ORDER BY d.updated_at DESC",
            (project,),
        ).fetchall()

    risky = []
    for r in rows:
        risky.append({
            "decision_id": r["id"],
            "decision_name": r["name"],
            "decision_description": r["description"] or "",
            "assumption_id": r["assumption_id"],
            "assumption_name": r["assumption_name"],
            "assumption_status": r["assumption_status"],
        })
    return {
        "project": project,
        "query": "Q-009 risky decisions",
        "description": "Decisions based on assumptions that are flagged, superseded, or invalid.",
        "gaps": risky,
        "count": len(risky),
    }


def unsupported_claims(project: str) -> dict:
    """Q-011: validation claims with NO inbound SUPPORTS edge.

    These are asserted claims (e.g., "margin is adequate") with no
    Result entity actually supporting them. High-risk: the engineer
    believes it, but there's no evidence on file.
    """
    project = resolve_project_name(project) if project else ""

    with get_connection() as conn:
        rows = conn.execute(
            "SELECT * FROM entities WHERE status = 'active' "
            "AND project = ? AND entity_type = 'validation_claim' "
            "AND NOT EXISTS ("
            "  SELECT 1 FROM relationships r "
            "  WHERE r.relationship_type = 'supports' "
            "  AND r.target_entity_id = entities.id"
            ") "
            "ORDER BY updated_at DESC",
            (project,),
        ).fetchall()

    claims = [_entity_dict(_row_to_entity(r)) for r in rows]
    return {
        "project": project,
        "query": "Q-011 unsupported claims",
        "description": "Validation claims with no supporting Result — asserted but not evidenced.",
        "gaps": claims,
        "count": len(claims),
    }


def all_gaps(project: str) -> dict:
    """Combined: run Q-006, Q-009, Q-011 for a project in one go."""
    return {
        "project": resolve_project_name(project) if project else "",
        "generated_at": datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ"),
        "orphan_requirements": orphan_requirements(project),
        "risky_decisions": risky_decisions(project),
        "unsupported_claims": unsupported_claims(project),
    }


# ============================================================
# History + impact (Q-016, Q-017)
# ============================================================


def impact_analysis(entity_id: str, max_depth: int = 3) -> dict:
    """Q-016: transitive outbound reach of an entity.

    Walks outbound edges breadth-first to max_depth. Answers "what would
    be affected if I changed component X?" by finding everything downstream.
    """
    visited: set[str] = {entity_id}
    impacted: list[dict] = []
    frontier = [(entity_id, 0)]

    while frontier:
        current_id, depth = frontier.pop(0)
        if depth >= max_depth:
            continue
        with get_connection() as conn:
            rows = conn.execute(
                "SELECT r.relationship_type, r.target_entity_id, "
                "e.entity_type, e.name, e.status "
                "FROM relationships r "
                "JOIN entities e ON e.id = r.target_entity_id "
                "WHERE r.source_entity_id = ? AND e.status = 'active'",
                (current_id,),
            ).fetchall()
        for r in rows:
            tid = r["target_entity_id"]
            if tid in visited:
                continue
            visited.add(tid)
            impacted.append({
                "entity_id": tid,
                "entity_type": r["entity_type"],
                "name": r["name"],
                "relationship": r["relationship_type"],
                "depth": depth + 1,
            })
            frontier.append((tid, depth + 1))

    root = get_entity(entity_id)
    return {
        "root": _entity_dict(root) if root else None,
        "impacted_count": len(impacted),
        "impacted": impacted,
        "max_depth": max_depth,
    }


def evidence_chain(entity_id: str) -> dict:
    """Q-017: what evidence supports this entity?

    Walks inbound SUPPORTS / EVIDENCED_BY / DESCRIBED_BY edges to surface
    the provenance chain: "this claim is supported by that result, which
    was produced by that analysis model, which was described by that doc."
    """
    provenance_edges = ("supports", "evidenced_by", "described_by",
                        "validated_by", "analyzed_by")
    placeholders = ",".join("?" * len(provenance_edges))

    with get_connection() as conn:
        # Inbound edges of the provenance family
        inbound_rows = conn.execute(
            f"SELECT r.relationship_type, r.source_entity_id, "
            f"e.entity_type, e.name, e.description, e.status "
            f"FROM relationships r "
            f"JOIN entities e ON e.id = r.source_entity_id "
            f"WHERE r.target_entity_id = ? AND e.status = 'active' "
            f"AND r.relationship_type IN ({placeholders})",
            (entity_id, *provenance_edges),
        ).fetchall()

    # Also look at source_refs on the entity itself
    root = get_entity(entity_id)

    chain = []
    for r in inbound_rows:
        chain.append({
            "via": r["relationship_type"],
            "source_id": r["source_entity_id"],
            "source_type": r["entity_type"],
            "source_name": r["name"],
            "source_description": (r["description"] or "")[:200],
        })

    return {
        "root": _entity_dict(root) if root else None,
        "direct_source_refs": root.source_refs if root else [],
        "evidence_chain": chain,
        "count": len(chain),
    }


# ============================================================
# Helpers
# ============================================================


def _entity_dict(e: Entity) -> dict:
    """Flatten an Entity to a public-API dict."""
    return {
        "id": e.id,
        "entity_type": e.entity_type,
        "name": e.name,
        "project": e.project,
        "description": e.description,
        "properties": e.properties,
        "status": e.status,
        "confidence": e.confidence,
        "source_refs": e.source_refs,
        "updated_at": e.updated_at,
    }