from datetime import datetime, timezone

from fastapi import HTTPException, status
from sqlalchemy.orm import Session

from ..accounts.models import Account
from ..contacts.models import Contact
from ..opportunities.models import Opportunity
from .dto import LeadConvert, LeadCreate, LeadUpdate
from .models import Lead


def get_leads(
    db: Session,
    tenant_id: int,
    company_id: int,
    search: str | None = None,
    lead_status: str | None = None,
) -> list[Lead]:
    query = db.query(Lead).filter(
        Lead.tenant_id == tenant_id,
        Lead.company_id == company_id,
        Lead.deleted_at.is_(None),
    )
    if lead_status:
        query = query.filter(Lead.status == lead_status)
    if search:
        pattern = f"%{search}%"
        query = query.filter(
            Lead.name.ilike(pattern)
            | Lead.company_name.ilike(pattern)
            | Lead.email.ilike(pattern)
        )
    return query.order_by(Lead.created_at.desc()).all()


def get_lead(db: Session, lead_id: int, tenant_id: int, company_id: int) -> Lead:
    lead = (
        db.query(Lead)
        .filter(
            Lead.id == lead_id,
            Lead.tenant_id == tenant_id,
            Lead.company_id == company_id,
            Lead.deleted_at.is_(None),
        )
        .first()
    )
    if not lead:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Prospecto no encontrado")
    return lead


def create_lead(db: Session, payload: LeadCreate, tenant_id: int, company_id: int) -> Lead:
    lead = Lead(**payload.model_dump(), tenant_id=tenant_id, company_id=company_id)
    db.add(lead)
    db.commit()
    db.refresh(lead)
    return lead


def update_lead(db: Session, lead_id: int, payload: LeadUpdate, tenant_id: int, company_id: int) -> Lead:
    lead = get_lead(db, lead_id, tenant_id, company_id)
    for field, value in payload.model_dump(exclude_unset=True).items():
        setattr(lead, field, value)
    db.commit()
    db.refresh(lead)
    return lead


def delete_lead(db: Session, lead_id: int, tenant_id: int, company_id: int) -> None:
    lead = get_lead(db, lead_id, tenant_id, company_id)
    lead.deleted_at = datetime.now(timezone.utc)
    db.commit()


def convert_lead(
    db: Session, lead_id: int, payload: LeadConvert, tenant_id: int, company_id: int
) -> dict:
    """Convierte un prospecto en cuenta (+ contacto y oportunidad opcionales).

    Es idempotente: si el prospecto ya fue convertido, retorna las referencias existentes.
    """
    lead = get_lead(db, lead_id, tenant_id, company_id)
    if lead.status == "converted" and lead.converted_account_id:
        return {
            "lead": lead,
            "account_id": lead.converted_account_id,
            "contact_id": lead.converted_contact_id,
            "opportunity_id": lead.converted_opportunity_id,
        }

    # 1. Cuenta a partir de la empresa (o nombre) del prospecto
    account = Account(
        name=lead.company_name or lead.name,
        email=lead.email,
        phone=lead.phone,
        status="active",
        owner_user_id=lead.owner_user_id,
        tenant_id=tenant_id,
        company_id=company_id,
    )
    db.add(account)
    db.flush()  # necesitamos el id de la cuenta para enlazar contacto/oportunidad

    # 2. Contacto (si el prospecto trae nombre de contacto)
    contact = None
    if lead.contact_name:
        parts = lead.contact_name.split(" ", 1)
        contact = Contact(
            account_id=account.id,
            first_name=parts[0],
            last_name=parts[1] if len(parts) > 1 else None,
            email=lead.email,
            phone=lead.phone,
            is_primary=True,
            owner_user_id=lead.owner_user_id,
            tenant_id=tenant_id,
            company_id=company_id,
        )
        db.add(contact)
        db.flush()

    # 3. Oportunidad (opcional)
    opportunity = None
    if payload.create_opportunity:
        opportunity = Opportunity(
            name=payload.opportunity_name or lead.name,
            account_id=account.id,
            contact_id=contact.id if contact else None,
            pipeline_id=payload.pipeline_id,
            stage_id=payload.stage_id,
            amount=payload.amount if payload.amount is not None else lead.estimated_value,
            source=lead.source,
            status="open",
            owner_user_id=lead.owner_user_id,
            tenant_id=tenant_id,
            company_id=company_id,
        )
        db.add(opportunity)
        db.flush()

    # 4. Marcar el prospecto como convertido y enlazar
    lead.status = "converted"
    lead.converted_account_id = account.id
    lead.converted_contact_id = contact.id if contact else None
    lead.converted_opportunity_id = opportunity.id if opportunity else None

    db.commit()
    db.refresh(lead)
    return {
        "lead": lead,
        "account_id": account.id,
        "contact_id": contact.id if contact else None,
        "opportunity_id": opportunity.id if opportunity else None,
    }