from fastapi import APIRouter, Depends, HTTPException, Query, Response
from sqlalchemy.ext.asyncio import AsyncSession
from typing import Optional
from pydantic import BaseModel
from app.database import get_db
from app.services.quotation import QuotationService
from app.services.pdf_generator import pdf_generator
from app.services import export
from app.api.v1.deps import get_current_user_id
from app.models.quotation import Quotation
from app.models.customer import Customer
from sqlalchemy import select, and_

router = APIRouter()


class InquiryRequest(BaseModel):
    inquiry_text: str
    customer_id: Optional[str] = None


@router.post("/generate-from-inquiry")
async def generate_from_inquiry(
    data: InquiryRequest,
    user_id: str = Depends(get_current_user_id),
    db: AsyncSession = Depends(get_db),
):
    service = QuotationService(db)
    result = await service.generate_from_inquiry(
        user_id=user_id,
        inquiry_text=data.inquiry_text,
        customer_id=data.customer_id,
    )
    return result


@router.post("")
async def create_quotation(
    data: dict,
    user_id: str = Depends(get_current_user_id),
    db: AsyncSession = Depends(get_db),
):
    service = QuotationService(db)
    try:
        quotation = await service.create_quotation(user_id, data)
        return quotation
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))


@router.get("")
async def list_quotations(
    page: int = Query(1, ge=1),
    size: int = Query(20, ge=1, le=100),
    user_id: str = Depends(get_current_user_id),
    db: AsyncSession = Depends(get_db),
):
    service = QuotationService(db)
    return await service.list_quotations(user_id, page, size)


@router.get("/{quotation_id}")
async def get_quotation(
    quotation_id: str,
    user_id: str = Depends(get_current_user_id),
    db: AsyncSession = Depends(get_db),
):
    service = QuotationService(db)
    quotation = await service.get_quotation(user_id, quotation_id)
    if not quotation:
        raise HTTPException(status_code=404, detail="Quotation not found")
    return quotation


@router.patch("/{quotation_id}/status")
async def update_quotation_status(
    quotation_id: str,
    data: dict,
    user_id: str = Depends(get_current_user_id),
    db: AsyncSession = Depends(get_db),
):
    service = QuotationService(db)
    quotation = await service.update_status(user_id, quotation_id, data.get("status", "draft"))
    if not quotation:
        raise HTTPException(status_code=404, detail="Quotation not found")
    return quotation


@router.get("/export/csv")
async def export_quotations(
    user_id: str = Depends(get_current_user_id),
    db: AsyncSession = Depends(get_db),
):
    service = QuotationService(db)
    result = await service.list_quotations(user_id, 1, 9999)
    items = result.get("items", [])
    csv_bytes = export.export_quotations_csv(items)
    return Response(
        content=csv_bytes,
        media_type="text/csv",
        headers={"Content-Disposition": "attachment; filename=quotations.csv"},
    )


@router.get("/{quotation_id}/pdf")
async def export_quotation_pdf(
    quotation_id: str,
    user_id: str = Depends(get_current_user_id),
    db: AsyncSession = Depends(get_db),
):
    service = QuotationService(db)
    quotation = await service.get_quotation(user_id, quotation_id)
    if not quotation:
        raise HTTPException(status_code=404, detail="Quotation not found")

    result = await db.execute(
        select(Customer).where(Customer.id == quotation["customer_id"])
    )
    customer = result.scalar_one_or_none()

    pdf_data = pdf_generator.generate_quotation({
        "quotation_number": f"{quotation_id[:8].upper()}",
        "customer_name": customer.name if customer else "",
        "customer_company": customer.company if customer else "",
        "customer_country": customer.country if customer else "",
        "date": quotation["created_at"][:10] if quotation.get("created_at") else "",
        "valid_until": quotation.get("valid_until", ""),
        "currency": quotation.get("currency", "USD"),
        "items": quotation.get("items", []),
        "subtotal": quotation.get("subtotal", 0),
        "discount": quotation.get("discount", 0),
        "shipping": quotation.get("shipping", 0),
        "total": quotation.get("total", 0),
        "payment_terms": quotation.get("payment_terms", ""),
        "delivery_terms": quotation.get("delivery_terms", ""),
        "lead_time": quotation.get("lead_time", ""),
        "notes": quotation.get("notes", ""),
    })

    if not pdf_data:
        raise HTTPException(status_code=501, detail="PDF generation not available (weasyprint not installed)")

    service = QuotationService(db)
    result = await db.execute(
        select(Quotation).where(
            and_(Quotation.id == quotation_id, Quotation.user_id == user_id)
        )
    )
    q = result.scalar_one_or_none()
    if q:
        pdf_url = f"/quotations/{quotation_id}/pdf"
        q.pdf_url = pdf_url
        await db.flush()

    return Response(
        content=pdf_data,
        media_type="application/pdf",
        headers={
            "Content-Disposition": f'attachment; filename="quotation-{quotation_id[:8]}.pdf"',
        },
    )