from __future__ import annotations

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy import select
from sqlalchemy.orm import Session

from app.api.deps import get_current_user, get_db, require_operations_manager
from app.models.customer import Customer
from app.models.data_quality import DataQualityIssue
from app.models.vehicle import Vehicle
from app.schemas import (
    CurrentUser,
    DataQualityIssueDetailOut,
    DataQualityIssueOut,
    MergeCustomersRequest,
    MergeCustomersResult,
    ScanResultOut,
)
from app.services.data_quality import defer_issue, merge_customers, reject_issue, run_scan

router = APIRouter(prefix="/api/v1/data-quality", tags=["data-quality"])


def _to_out(issue: DataQualityIssue) -> DataQualityIssueOut:
    return DataQualityIssueOut(
        public_ref=issue.public_ref,
        rule_type=issue.rule_type,
        entity_type=issue.entity_type,
        entity_ref=issue.evidence_json.get("entity_ref", ""),
        severity=issue.severity,
        status=issue.status,
        evidence=issue.evidence_json,
        detected_at=issue.detected_at,
        resolved_at=issue.resolved_at,
    )


@router.get("/issues", response_model=list[DataQualityIssueOut])
def list_issues(
    status: str | None = Query(default=None),
    rule_type: str | None = Query(default=None),
    severity: str | None = Query(default=None),
    db: Session = Depends(get_db),
    _user: CurrentUser = Depends(get_current_user),
) -> list[DataQualityIssueOut]:
    stmt = select(DataQualityIssue).order_by(DataQualityIssue.detected_at.desc())
    if status:
        stmt = stmt.where(DataQualityIssue.status == status)
    if rule_type:
        stmt = stmt.where(DataQualityIssue.rule_type == rule_type)
    if severity:
        stmt = stmt.where(DataQualityIssue.severity == severity)
    issues = db.scalars(stmt).all()
    return [_to_out(i) for i in issues]


def _snapshot(entity_type: str, ref: str, db: Session) -> dict | None:
    if entity_type == "customer":
        obj = db.scalar(select(Customer).where(Customer.public_ref == ref))
        if obj is None:
            return None
        return {
            "public_ref": obj.public_ref,
            "first_name": obj.first_name,
            "last_name": obj.last_name,
            "email": obj.email,
            "phone": obj.phone,
            "postal_code": obj.postal_code,
            "city": obj.city,
        }
    obj = db.scalar(select(Vehicle).where(Vehicle.public_ref == ref))
    if obj is None:
        return None
    return {
        "public_ref": obj.public_ref,
        "make": obj.make,
        "model": obj.model,
        "location": obj.location,
        "operational_status": obj.operational_status,
        "odometer_km": obj.odometer_km,
    }


@router.get("/issues/{public_ref}", response_model=DataQualityIssueDetailOut)
def get_issue(
    public_ref: str,
    db: Session = Depends(get_db),
    _user: CurrentUser = Depends(get_current_user),
) -> DataQualityIssueDetailOut:
    issue = db.scalar(select(DataQualityIssue).where(DataQualityIssue.public_ref == public_ref))
    if issue is None:
        raise HTTPException(status_code=404, detail="Data quality issue not found")
    base = _to_out(issue)
    related_refs = issue.evidence_json.get("related_refs", [])
    related_entity_type = (
        "customer" if issue.rule_type == "possible_duplicate_customer" else "vehicle"
    )
    return DataQualityIssueDetailOut(
        **base.model_dump(),
        entity_snapshot=_snapshot(issue.entity_type, base.entity_ref, db),
        related_snapshots=[
            snap
            for ref in related_refs
            if (snap := _snapshot(related_entity_type, ref, db)) is not None
        ],
    )


@router.post("/issues/{public_ref}/defer", response_model=DataQualityIssueOut)
def defer(
    public_ref: str,
    db: Session = Depends(get_db),
    user: CurrentUser = Depends(get_current_user),
) -> DataQualityIssueOut:
    issue = defer_issue(db, public_ref, user)
    return _to_out(issue)


@router.post("/issues/{public_ref}/reject", response_model=DataQualityIssueOut)
def reject(
    public_ref: str,
    db: Session = Depends(get_db),
    user: CurrentUser = Depends(get_current_user),
) -> DataQualityIssueOut:
    issue = reject_issue(db, public_ref, user)
    return _to_out(issue)


@router.post("/issues/{public_ref}/merge-customers", response_model=MergeCustomersResult)
def merge(
    public_ref: str,
    body: MergeCustomersRequest,
    db: Session = Depends(get_db),
    user: CurrentUser = Depends(require_operations_manager),
) -> MergeCustomersResult:
    result = merge_customers(db, public_ref, body.survivor_ref, body.field_overrides, user)
    return MergeCustomersResult(**result)


@router.post("/scan", response_model=ScanResultOut)
def scan(
    db: Session = Depends(get_db),
    _user: CurrentUser = Depends(require_operations_manager),
) -> ScanResultOut:
    result = run_scan(db)
    return ScanResultOut(created=result.created)