from pathlib import Path

from fastapi import APIRouter, Depends, Form, Request
from fastapi.responses import HTMLResponse, RedirectResponse
from fastapi.templating import Jinja2Templates
from sqlalchemy.orm import Session

from app.db.deps import get_db
from app.models.document_preset import DocumentPreset

router = APIRouter(prefix="/presets", tags=["presets"])

BASE_DIR = Path(__file__).resolve().parent.parent
templates = Jinja2Templates(directory=str(BASE_DIR / "templates"))


def _parse_people_list(value: str) -> list[str]:
    return [part.strip() for part in value.split(",") if part.strip()]


def _format_people_list(value: list | None) -> str:
    if not value:
        return ""
    return ", ".join(str(x).strip() for x in value if str(x).strip())


def _preset_form_values(preset: DocumentPreset | None = None) -> dict:
    if preset is None:
        return {
            "name": "",
            "owner_primary": "",
            "owner_secondary": "",
            "paid_by_person": "",
            "covered_people": "",
            "attendees": "",
            "occasion_note": "",
            "is_shared_expense": False,
            "reimbursement_expected_from": "",
            "reimbursement_paid_by": "",
            "reimbursement_paid_to": "",
            "reimbursement_note": "",
        }

    return {
        "name": preset.name or "",
        "owner_primary": preset.owner_primary or "",
        "owner_secondary": preset.owner_secondary or "",
        "paid_by_person": preset.paid_by_person or "",
        "covered_people": _format_people_list(preset.covered_people),
        "attendees": _format_people_list(preset.attendees),
        "occasion_note": preset.occasion_note or "",
        "is_shared_expense": bool(preset.is_shared_expense),
        "reimbursement_expected_from": _format_people_list(preset.reimbursement_expected_from),
        "reimbursement_paid_by": preset.reimbursement_paid_by or "",
        "reimbursement_paid_to": preset.reimbursement_paid_to or "",
        "reimbursement_note": preset.reimbursement_note or "",
    }


@router.get("/", response_class=HTMLResponse)
def list_presets(request: Request, edit_id: int | None = None, db: Session = Depends(get_db)):
    presets = db.query(DocumentPreset).order_by(DocumentPreset.name.asc()).all()
    editing = None
    if edit_id is not None:
        editing = db.query(DocumentPreset).filter(DocumentPreset.id == edit_id).first()

    return templates.TemplateResponse(
        request=request,
        name="presets/index.html",
        context={
            "request": request,
            "presets": presets,
            "editing": editing,
            "form_values": _preset_form_values(editing),
            "active_page": "presets",
        },
    )


@router.post("/create", response_class=RedirectResponse)
def create_preset(
    name: str = Form(...),
    owner_primary: str = Form(""),
    owner_secondary: str = Form(""),
    paid_by_person: str = Form(""),
    covered_people: str = Form(""),
    attendees: str = Form(""),
    occasion_note: str = Form(""),
    is_shared_expense: str | None = Form(None),
    reimbursement_expected_from: str = Form(""),
    reimbursement_paid_by: str = Form(""),
    reimbursement_paid_to: str = Form(""),
    reimbursement_note: str = Form(""),
    db: Session = Depends(get_db),
):
    preset = DocumentPreset(
        name=name.strip(),
        owner_primary=owner_primary.strip() or None,
        owner_secondary=owner_secondary.strip() or None,
        paid_by_person=paid_by_person.strip() or None,
        covered_people=_parse_people_list(covered_people),
        attendees=_parse_people_list(attendees),
        occasion_note=occasion_note.strip() or None,
        is_shared_expense=bool(is_shared_expense),
        reimbursement_expected_from=_parse_people_list(reimbursement_expected_from),
        reimbursement_paid_by=reimbursement_paid_by.strip() or None,
        reimbursement_paid_to=reimbursement_paid_to.strip() or None,
        reimbursement_note=reimbursement_note.strip() or None,
    )
    db.add(preset)
    db.commit()
    return RedirectResponse(url="/presets/", status_code=303)


@router.post("/{preset_id}/update", response_class=RedirectResponse)
def update_preset(
    preset_id: int,
    name: str = Form(...),
    owner_primary: str = Form(""),
    owner_secondary: str = Form(""),
    paid_by_person: str = Form(""),
    covered_people: str = Form(""),
    attendees: str = Form(""),
    occasion_note: str = Form(""),
    is_shared_expense: str | None = Form(None),
    reimbursement_expected_from: str = Form(""),
    reimbursement_paid_by: str = Form(""),
    reimbursement_paid_to: str = Form(""),
    reimbursement_note: str = Form(""),
    db: Session = Depends(get_db),
):
    preset = db.query(DocumentPreset).filter(DocumentPreset.id == preset_id).first()
    if preset is None:
        return RedirectResponse(url="/presets/", status_code=303)

    preset.name = name.strip()
    preset.owner_primary = owner_primary.strip() or None
    preset.owner_secondary = owner_secondary.strip() or None
    preset.paid_by_person = paid_by_person.strip() or None
    preset.covered_people = _parse_people_list(covered_people)
    preset.attendees = _parse_people_list(attendees)
    preset.occasion_note = occasion_note.strip() or None
    preset.is_shared_expense = bool(is_shared_expense)
    preset.reimbursement_expected_from = _parse_people_list(reimbursement_expected_from)
    preset.reimbursement_paid_by = reimbursement_paid_by.strip() or None
    preset.reimbursement_paid_to = reimbursement_paid_to.strip() or None
    preset.reimbursement_note = reimbursement_note.strip() or None

    db.commit()
    return RedirectResponse(url="/presets/", status_code=303)


@router.post("/{preset_id}/delete", response_class=RedirectResponse)
def delete_preset(preset_id: int, db: Session = Depends(get_db)):
    preset = db.query(DocumentPreset).filter(DocumentPreset.id == preset_id).first()
    if preset is not None:
        db.delete(preset)
        db.commit()
    return RedirectResponse(url="/presets/", status_code=303)