"""Foreshadowing-related queries.

Functions take an explicit sqlite3 connection with row_factory=sqlite3.Row
and return plain dicts. No Flask imports.
"""

from datetime import datetime

FORESHADOWING_COLUMNS = (
    "id, novel_id, description, planted_chapter, resolved_chapter, "
    "status, created_at, updated_at"
)

ALLOWED_UPDATE_FIELDS = {
    "description",
    "planted_chapter",
    "resolved_chapter",
    "status",
}


def _rows(cur):
    return [dict(row) for row in cur.fetchall()]


def _now():
    return datetime.now().isoformat(timespec="seconds")


def list_foreshadowing(db, novel_id):
    """All foreshadowing entries of a novel ordered by id."""
    return _rows(
        db.execute(
            f"SELECT {FORESHADOWING_COLUMNS} FROM foreshadowing WHERE novel_id = ? ORDER BY id",
            (novel_id,),
        )
    )


def create_foreshadowing(db, novel_id, description, planted_chapter=None, resolved_chapter=None, status="pending"):
    """Insert a new foreshadowing entry and return its id."""
    now = _now()
    cur = db.execute(
        "INSERT INTO foreshadowing (novel_id, description, planted_chapter, resolved_chapter, status, created_at, updated_at) "
        "VALUES (?, ?, ?, ?, ?, ?, ?)",
        (novel_id, description, planted_chapter, resolved_chapter, status, now, now),
    )
    db.commit()
    return cur.lastrowid


def update_foreshadowing(db, fs_id, **fields):
    """Update allowed foreshadowing fields."""
    updates = {k: v for k, v in fields.items() if k in ALLOWED_UPDATE_FIELDS}
    if not updates:
        return
    updates["updated_at"] = _now()
    assignments = ", ".join(f"{key} = ?" for key in updates)
    db.execute(
        f"UPDATE foreshadowing SET {assignments} WHERE id = ?",
        (*updates.values(), fs_id),
    )
    db.commit()


def list_open_foreshadowing(db, novel_id):
    """Open (pending/planted) foreshadowing entries ordered by id."""
    return _rows(
        db.execute(
            f"SELECT {FORESHADOWING_COLUMNS} FROM foreshadowing "
            "WHERE novel_id = ? AND status IN ('pending', 'planted') ORDER BY id",
            (novel_id,),
        )
    )