"""Saved portfolio definitions, persisted to portfolios.json next to the app.

A portfolio is fully defined by its symbol/weight spec, rebalance scheme
and cost. Tax rates and the analysis period are global (sidebar), not part
of the saved definition.
"""

from __future__ import annotations

import json
from dataclasses import asdict, dataclass
from pathlib import Path

FILE = Path(__file__).parent / "portfolios.json"


@dataclass
class Portfolio:
    name: str
    spec: str              # "sym1:0.5, sym2:0.5" (parsed by portfolio.parse_weights)
    scheme: str | None     # rebalance freq alias ("1W", "1ME", "QE", "YE") or None
    cost_bps: float = 0.0


def load_all() -> list[Portfolio]:
    if not FILE.exists():
        return []
    try:
        return [Portfolio(**d) for d in json.loads(FILE.read_text())]
    except Exception:
        return []


def save(p: Portfolio) -> None:
    all_p = {q.name: q for q in load_all()}
    all_p[p.name] = p
    FILE.write_text(json.dumps([asdict(q) for q in all_p.values()], indent=2))


def delete(name: str) -> None:
    all_p = [q for q in load_all() if q.name != name]
    FILE.write_text(json.dumps([asdict(q) for q in all_p], indent=2))