"""
FastAPI routes for AI Quality Metrics and Tests.

Endpoints:
  GET/POST   /quality/metrics           — list/create metrics
  PUT/DELETE /quality/metrics/{id}      — update/delete metric
  GET/POST   /quality/tests             — list/create tests
  PUT/DELETE /quality/tests/{id}        — update/delete test
  GET        /quality/stats             — avgScore, metricsAboveThreshold, passed, failed
"""

import logging
from datetime import datetime, timezone
from typing import Optional, Any, Dict

from fastapi import APIRouter, Depends, HTTPException, Query
from pydantic import BaseModel
from sqlalchemy import text
from sqlalchemy.orm import Session

from classroom_engine.database import get_db
from .tenant_utils import get_tenant_id as _get_tenant_id
from .db_utils import row_to_dict as _row_to_dict

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/quality", tags=["quality"])


# =============================================================================
# Pydantic Schemas
# =============================================================================

class MetricCreate(BaseModel):
    name: str
    category: str = "accuracy"
    score: float = 0.0
    threshold: float = 80.0
    trend: str = "stable"
    ai_system: Optional[str] = None
    last_measured: Optional[datetime] = None


class MetricUpdate(BaseModel):
    name: Optional[str] = None
    category: Optional[str] = None
    score: Optional[float] = None
    threshold: Optional[float] = None
    trend: Optional[str] = None
    ai_system: Optional[str] = None
    last_measured: Optional[datetime] = None


class TestCreate(BaseModel):
    name: str
    status: str = "pending"
    duration: Optional[str] = None
    ai_system: Optional[str] = None
    details: Optional[str] = None
    last_run: Optional[datetime] = None


class TestUpdate(BaseModel):
    name: Optional[str] = None
    status: Optional[str] = None
    duration: Optional[str] = None
    ai_system: Optional[str] = None
    details: Optional[str] = None
    last_run: Optional[datetime] = None



# =============================================================================
# Stats
# =============================================================================

@router.get("/stats")
async def get_quality_stats(
    db: Session = Depends(get_db),
    tenant_id: str = Depends(_get_tenant_id),
):
    """Return quality dashboard stats."""

    metrics_row = db.execute(text("""
        SELECT
            COUNT(*)                                            AS total_metrics,
            COALESCE(AVG(score), 0)                             AS avg_score,
            COUNT(*) FILTER (WHERE score >= threshold)          AS metrics_above_threshold
        FROM compliance_quality_metrics
        WHERE tenant_id = :tenant_id
    """), {"tenant_id": tenant_id}).fetchone()

    tests_row = db.execute(text("""
        SELECT
            COUNT(*) FILTER (WHERE status = 'passed')  AS passed,
            COUNT(*) FILTER (WHERE status = 'failed')  AS failed,
            COUNT(*) FILTER (WHERE status = 'warning') AS warning,
            COUNT(*)                                   AS total
        FROM compliance_quality_tests
        WHERE tenant_id = :tenant_id
    """), {"tenant_id": tenant_id}).fetchone()

    return {
        "total_metrics": int(metrics_row.total_metrics or 0),
        "avg_score": round(float(metrics_row.avg_score or 0), 1),
        "metrics_above_threshold": int(metrics_row.metrics_above_threshold or 0),
        "passed": int(tests_row.passed or 0),
        "failed": int(tests_row.failed or 0),
        "warning": int(tests_row.warning or 0),
        "total_tests": int(tests_row.total or 0),
    }


# =============================================================================
# Metrics
# =============================================================================

@router.get("/metrics")
async def list_metrics(
    category: Optional[str] = Query(None),
    ai_system: Optional[str] = Query(None),
    limit: int = Query(100, ge=1, le=500),
    offset: int = Query(0, ge=0),
    db: Session = Depends(get_db),
    tenant_id: str = Depends(_get_tenant_id),
):
    """List quality metrics."""

    where_clauses = ["tenant_id = :tenant_id"]
    params: Dict[str, Any] = {"tenant_id": tenant_id, "limit": limit, "offset": offset}

    if category:
        where_clauses.append("category = :category")
        params["category"] = category
    if ai_system:
        where_clauses.append("ai_system ILIKE :ai_system")
        params["ai_system"] = f"%{ai_system}%"

    where_sql = " AND ".join(where_clauses)

    total_row = db.execute(
        text(f"SELECT COUNT(*) FROM compliance_quality_metrics WHERE {where_sql}"), params
    ).fetchone()
    total = total_row[0] if total_row else 0

    rows = db.execute(
        text(f"""
            SELECT * FROM compliance_quality_metrics
            WHERE {where_sql}
            ORDER BY category, name
            LIMIT :limit OFFSET :offset
        """),
        params,
    ).fetchall()

    return {"metrics": [_row_to_dict(r) for r in rows], "total": total}


@router.post("/metrics", status_code=201)
async def create_metric(
    payload: MetricCreate,
    db: Session = Depends(get_db),
    tenant_id: str = Depends(_get_tenant_id),
):
    """Create a new quality metric."""

    row = db.execute(text("""
        INSERT INTO compliance_quality_metrics
            (tenant_id, name, category, score, threshold, trend, ai_system, last_measured)
        VALUES
            (:tenant_id, :name, :category, :score, :threshold, :trend, :ai_system, :last_measured)
        RETURNING *
    """), {
        "tenant_id": tenant_id,
        "name": payload.name,
        "category": payload.category,
        "score": payload.score,
        "threshold": payload.threshold,
        "trend": payload.trend,
        "ai_system": payload.ai_system,
        "last_measured": payload.last_measured or datetime.now(timezone.utc),
    }).fetchone()
    db.commit()
    return _row_to_dict(row)


@router.put("/metrics/{metric_id}")
async def update_metric(
    metric_id: str,
    payload: MetricUpdate,
    db: Session = Depends(get_db),
    tenant_id: str = Depends(_get_tenant_id),
):
    """Update a quality metric."""

    updates: Dict[str, Any] = {"id": metric_id, "tenant_id": tenant_id, "updated_at": datetime.now(timezone.utc)}
    set_clauses = ["updated_at = :updated_at"]

    for field, value in payload.model_dump(exclude_unset=True).items():
        updates[field] = value
        set_clauses.append(f"{field} = :{field}")

    if len(set_clauses) == 1:
        raise HTTPException(status_code=400, detail="No fields to update")

    row = db.execute(text(f"""
        UPDATE compliance_quality_metrics
        SET {', '.join(set_clauses)}
        WHERE id = :id AND tenant_id = :tenant_id
        RETURNING *
    """), updates).fetchone()
    db.commit()

    if not row:
        raise HTTPException(status_code=404, detail="Metric not found")
    return _row_to_dict(row)


@router.delete("/metrics/{metric_id}", status_code=204)
async def delete_metric(
    metric_id: str,
    db: Session = Depends(get_db),
    tenant_id: str = Depends(_get_tenant_id),
):
    result = db.execute(text("""
        DELETE FROM compliance_quality_metrics
        WHERE id = :id AND tenant_id = :tenant_id
    """), {"id": metric_id, "tenant_id": tenant_id})
    db.commit()
    if result.rowcount == 0:
        raise HTTPException(status_code=404, detail="Metric not found")


# =============================================================================
# Tests
# =============================================================================

@router.get("/tests")
async def list_tests(
    status: Optional[str] = Query(None),
    ai_system: Optional[str] = Query(None),
    limit: int = Query(100, ge=1, le=500),
    offset: int = Query(0, ge=0),
    db: Session = Depends(get_db),
    tenant_id: str = Depends(_get_tenant_id),
):
    """List quality tests."""

    where_clauses = ["tenant_id = :tenant_id"]
    params: Dict[str, Any] = {"tenant_id": tenant_id, "limit": limit, "offset": offset}

    if status:
        where_clauses.append("status = :status")
        params["status"] = status
    if ai_system:
        where_clauses.append("ai_system ILIKE :ai_system")
        params["ai_system"] = f"%{ai_system}%"

    where_sql = " AND ".join(where_clauses)

    total_row = db.execute(
        text(f"SELECT COUNT(*) FROM compliance_quality_tests WHERE {where_sql}"), params
    ).fetchone()
    total = total_row[0] if total_row else 0

    rows = db.execute(
        text(f"""
            SELECT * FROM compliance_quality_tests
            WHERE {where_sql}
            ORDER BY last_run DESC NULLS LAST, created_at DESC
            LIMIT :limit OFFSET :offset
        """),
        params,
    ).fetchall()

    return {"tests": [_row_to_dict(r) for r in rows], "total": total}


@router.post("/tests", status_code=201)
async def create_test(
    payload: TestCreate,
    db: Session = Depends(get_db),
    tenant_id: str = Depends(_get_tenant_id),
):
    """Create a new quality test entry."""

    row = db.execute(text("""
        INSERT INTO compliance_quality_tests
            (tenant_id, name, status, duration, ai_system, details, last_run)
        VALUES
            (:tenant_id, :name, :status, :duration, :ai_system, :details, :last_run)
        RETURNING *
    """), {
        "tenant_id": tenant_id,
        "name": payload.name,
        "status": payload.status,
        "duration": payload.duration,
        "ai_system": payload.ai_system,
        "details": payload.details,
        "last_run": payload.last_run or datetime.now(timezone.utc),
    }).fetchone()
    db.commit()
    return _row_to_dict(row)


@router.put("/tests/{test_id}")
async def update_test(
    test_id: str,
    payload: TestUpdate,
    db: Session = Depends(get_db),
    tenant_id: str = Depends(_get_tenant_id),
):
    """Update a quality test."""

    updates: Dict[str, Any] = {"id": test_id, "tenant_id": tenant_id, "updated_at": datetime.now(timezone.utc)}
    set_clauses = ["updated_at = :updated_at"]

    for field, value in payload.model_dump(exclude_unset=True).items():
        updates[field] = value
        set_clauses.append(f"{field} = :{field}")

    if len(set_clauses) == 1:
        raise HTTPException(status_code=400, detail="No fields to update")

    row = db.execute(text(f"""
        UPDATE compliance_quality_tests
        SET {', '.join(set_clauses)}
        WHERE id = :id AND tenant_id = :tenant_id
        RETURNING *
    """), updates).fetchone()
    db.commit()

    if not row:
        raise HTTPException(status_code=404, detail="Test not found")
    return _row_to_dict(row)


@router.delete("/tests/{test_id}", status_code=204)
async def delete_test(
    test_id: str,
    db: Session = Depends(get_db),
    tenant_id: str = Depends(_get_tenant_id),
):
    result = db.execute(text("""
        DELETE FROM compliance_quality_tests
        WHERE id = :id AND tenant_id = :tenant_id
    """), {"id": test_id, "tenant_id": tenant_id})
    db.commit()
    if result.rowcount == 0:
        raise HTTPException(status_code=404, detail="Test not found")
