"""Unified decision service - shared between CLI and HTTP API.

This module provides the core business logic for listing decision operations
(like/dislike). Both the CLI and HTTP API should use these functions.
"""
from models.decision import ListingDecision
from repositories.decision_repository import DecisionRepository

VALID_DECISIONS = {"liked", "disliked", "seen"}
VALID_LISTING_TYPES = {"RENT", "BUY"}


def set_decision(
    repository: DecisionRepository,
    user_id: int,
    listing_id: int,
    listing_type: str,
    decision: str,
    price_at_decision: float | None = None,
) -> ListingDecision:
    """Set or update a decision for a listing.

    price_at_decision is only meaningful for decision="seen"; it lets the
    client resurface a listing whose price has changed since dismissal.
    """
    if decision not in VALID_DECISIONS:
        raise ValueError(
            f"Invalid decision: {decision}. Must be one of {VALID_DECISIONS}"
        )
    if listing_type not in VALID_LISTING_TYPES:
        raise ValueError(
            f"Invalid listing_type: {listing_type}. Must be one of {VALID_LISTING_TYPES}"
        )
    # Only carry the price column when the decision is "seen" — liked/disliked
    # decisions ignore it. This keeps the column null for those rows.
    price = price_at_decision if decision == "seen" else None
    return repository.upsert_decision(
        user_id, listing_id, listing_type, decision, price
    )


def get_user_decisions(
    repository: DecisionRepository,
    user_id: int,
) -> list[ListingDecision]:
    """Get all decisions for a user."""
    return repository.get_decisions_for_user(user_id)


def remove_decision(
    repository: DecisionRepository,
    user_id: int,
    listing_id: int,
    listing_type: str,
) -> bool:
    """Remove a decision (un-like/un-dislike). Returns False if not found."""
    if listing_type not in VALID_LISTING_TYPES:
        raise ValueError(
            f"Invalid listing_type: {listing_type}. Must be one of {VALID_LISTING_TYPES}"
        )
    return repository.delete_decision(user_id, listing_id, listing_type)


def get_disliked_ids(
    repository: DecisionRepository,
    user_id: int,
    listing_type: str,
) -> set[int]:
    """Get all disliked listing IDs for a user and listing type."""
    return repository.get_disliked_listing_ids(user_id, listing_type)


def get_liked_ids(
    repository: DecisionRepository,
    user_id: int,
    listing_type: str,
) -> set[int]:
    """Get all liked listing IDs for a user and listing type."""
    return repository.get_liked_listing_ids(user_id, listing_type)