"""
FastAPI routes for the Canonical Control Library.

Provides read-only access to independently authored security controls.
All controls are formulated without proprietary nomenclature and anchored
in open-source frameworks (OWASP, NIST, ENISA).

Endpoints:
  GET  /v1/canonical/frameworks                       — All frameworks
  GET  /v1/canonical/frameworks/{framework_id}        — Framework details
  GET  /v1/canonical/frameworks/{framework_id}/controls — Controls of a framework
  GET  /v1/canonical/controls                         — All controls (filterable)
  GET  /v1/canonical/controls/{control_id}            — Single control by control_id
  GET  /v1/canonical/sources                          — Source registry
  GET  /v1/canonical/licenses                         — License matrix
  POST /v1/canonical/controls/{control_id}/similarity-check — Too-close check
"""

from __future__ import annotations

import logging
from typing import Any, Optional

from fastapi import APIRouter, HTTPException, Query
from pydantic import BaseModel
from sqlalchemy import text

from database import SessionLocal
from compliance.services.license_gate import get_license_matrix, get_source_permissions
from compliance.services.similarity_detector import check_similarity

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/v1/canonical", tags=["canonical-controls"])


# =============================================================================
# RESPONSE MODELS
# =============================================================================

class FrameworkResponse(BaseModel):
    id: str
    framework_id: str
    name: str
    version: str
    description: Optional[str] = None
    owner: Optional[str] = None
    policy_version: Optional[str] = None
    release_state: str
    created_at: str
    updated_at: str


class ControlResponse(BaseModel):
    id: str
    framework_id: str
    control_id: str
    title: str
    objective: str
    rationale: str
    scope: dict
    requirements: list
    test_procedure: list
    evidence: list
    severity: str
    risk_score: Optional[float] = None
    implementation_effort: Optional[str] = None
    evidence_confidence: Optional[float] = None
    open_anchors: list
    release_state: str
    tags: list
    created_at: str
    updated_at: str


class SimilarityCheckRequest(BaseModel):
    source_text: str
    candidate_text: str


class SimilarityCheckResponse(BaseModel):
    max_exact_run: int
    token_overlap: float
    ngram_jaccard: float
    embedding_cosine: float
    lcs_ratio: float
    status: str
    details: dict


# =============================================================================
# HELPERS
# =============================================================================

def _row_to_dict(row, columns: list[str]) -> dict[str, Any]:
    """Generic row → dict converter."""
    return {col: (getattr(row, col).isoformat() if hasattr(getattr(row, col, None), 'isoformat') else getattr(row, col)) for col in columns}


# =============================================================================
# FRAMEWORKS
# =============================================================================

@router.get("/frameworks")
async def list_frameworks():
    """List all registered control frameworks."""
    with SessionLocal() as db:
        rows = db.execute(
            text("""
                SELECT id, framework_id, name, version, description,
                       owner, policy_version, release_state,
                       created_at, updated_at
                FROM canonical_control_frameworks
                ORDER BY name
            """)
        ).fetchall()

    return [
        {
            "id": str(r.id),
            "framework_id": r.framework_id,
            "name": r.name,
            "version": r.version,
            "description": r.description,
            "owner": r.owner,
            "policy_version": r.policy_version,
            "release_state": r.release_state,
            "created_at": r.created_at.isoformat() if r.created_at else None,
            "updated_at": r.updated_at.isoformat() if r.updated_at else None,
        }
        for r in rows
    ]


@router.get("/frameworks/{framework_id}")
async def get_framework(framework_id: str):
    """Get a single framework by its framework_id."""
    with SessionLocal() as db:
        row = db.execute(
            text("""
                SELECT id, framework_id, name, version, description,
                       owner, policy_version, release_state,
                       created_at, updated_at
                FROM canonical_control_frameworks
                WHERE framework_id = :fid
            """),
            {"fid": framework_id},
        ).fetchone()

    if not row:
        raise HTTPException(status_code=404, detail="Framework not found")

    return {
        "id": str(row.id),
        "framework_id": row.framework_id,
        "name": row.name,
        "version": row.version,
        "description": row.description,
        "owner": row.owner,
        "policy_version": row.policy_version,
        "release_state": row.release_state,
        "created_at": row.created_at.isoformat() if row.created_at else None,
        "updated_at": row.updated_at.isoformat() if row.updated_at else None,
    }


@router.get("/frameworks/{framework_id}/controls")
async def list_framework_controls(
    framework_id: str,
    severity: Optional[str] = Query(None),
    release_state: Optional[str] = Query(None),
):
    """List controls belonging to a framework."""
    with SessionLocal() as db:
        # Resolve framework UUID
        fw = db.execute(
            text("SELECT id FROM canonical_control_frameworks WHERE framework_id = :fid"),
            {"fid": framework_id},
        ).fetchone()
        if not fw:
            raise HTTPException(status_code=404, detail="Framework not found")

        query = """
            SELECT id, framework_id, control_id, title, objective, rationale,
                   scope, requirements, test_procedure, evidence,
                   severity, risk_score, implementation_effort,
                   evidence_confidence, open_anchors, release_state, tags,
                   created_at, updated_at
            FROM canonical_controls
            WHERE framework_id = :fw_id
        """
        params: dict[str, Any] = {"fw_id": str(fw.id)}

        if severity:
            query += " AND severity = :sev"
            params["sev"] = severity
        if release_state:
            query += " AND release_state = :rs"
            params["rs"] = release_state

        query += " ORDER BY control_id"
        rows = db.execute(text(query), params).fetchall()

    return [_control_row(r) for r in rows]


# =============================================================================
# CONTROLS
# =============================================================================

@router.get("/controls")
async def list_controls(
    severity: Optional[str] = Query(None),
    domain: Optional[str] = Query(None),
    release_state: Optional[str] = Query(None),
):
    """List all canonical controls, with optional filters."""
    query = """
        SELECT id, framework_id, control_id, title, objective, rationale,
               scope, requirements, test_procedure, evidence,
               severity, risk_score, implementation_effort,
               evidence_confidence, open_anchors, release_state, tags,
               created_at, updated_at
        FROM canonical_controls
        WHERE 1=1
    """
    params: dict[str, Any] = {}

    if severity:
        query += " AND severity = :sev"
        params["sev"] = severity
    if domain:
        query += " AND LEFT(control_id, LENGTH(:dom)) = :dom"
        params["dom"] = domain.upper()
    if release_state:
        query += " AND release_state = :rs"
        params["rs"] = release_state

    query += " ORDER BY control_id"

    with SessionLocal() as db:
        rows = db.execute(text(query), params).fetchall()

    return [_control_row(r) for r in rows]


@router.get("/controls/{control_id}")
async def get_control(control_id: str):
    """Get a single canonical control by its control_id (e.g. AUTH-001)."""
    with SessionLocal() as db:
        row = db.execute(
            text("""
                SELECT id, framework_id, control_id, title, objective, rationale,
                       scope, requirements, test_procedure, evidence,
                       severity, risk_score, implementation_effort,
                       evidence_confidence, open_anchors, release_state, tags,
                       created_at, updated_at
                FROM canonical_controls
                WHERE control_id = :cid
            """),
            {"cid": control_id.upper()},
        ).fetchone()

    if not row:
        raise HTTPException(status_code=404, detail="Control not found")

    return _control_row(row)


# =============================================================================
# SIMILARITY CHECK
# =============================================================================

@router.post("/controls/{control_id}/similarity-check")
async def similarity_check(control_id: str, body: SimilarityCheckRequest):
    """Run the too-close detector against a source/candidate text pair."""
    report = await check_similarity(body.source_text, body.candidate_text)
    return {
        "control_id": control_id.upper(),
        "max_exact_run": report.max_exact_run,
        "token_overlap": report.token_overlap,
        "ngram_jaccard": report.ngram_jaccard,
        "embedding_cosine": report.embedding_cosine,
        "lcs_ratio": report.lcs_ratio,
        "status": report.status,
        "details": report.details,
    }


# =============================================================================
# SOURCES & LICENSES
# =============================================================================

@router.get("/sources")
async def list_sources():
    """List all registered sources with permission flags."""
    with SessionLocal() as db:
        return get_source_permissions(db)


@router.get("/licenses")
async def list_licenses():
    """Return the license matrix."""
    with SessionLocal() as db:
        return get_license_matrix(db)


# =============================================================================
# INTERNAL HELPERS
# =============================================================================

def _control_row(r) -> dict:
    return {
        "id": str(r.id),
        "framework_id": str(r.framework_id),
        "control_id": r.control_id,
        "title": r.title,
        "objective": r.objective,
        "rationale": r.rationale,
        "scope": r.scope,
        "requirements": r.requirements,
        "test_procedure": r.test_procedure,
        "evidence": r.evidence,
        "severity": r.severity,
        "risk_score": float(r.risk_score) if r.risk_score is not None else None,
        "implementation_effort": r.implementation_effort,
        "evidence_confidence": float(r.evidence_confidence) if r.evidence_confidence is not None else None,
        "open_anchors": r.open_anchors,
        "release_state": r.release_state,
        "tags": r.tags or [],
        "created_at": r.created_at.isoformat() if r.created_at else None,
        "updated_at": r.updated_at.isoformat() if r.updated_at else None,
    }