"""Daily puzzles for the calm Play hub.

Principle: **the LLM proposes, code disposes.** The LLM only contributes
creative flavor (a one-line "why today's word matters"); the daily answer is
picked deterministically by code from a pre-validated hopeful pool (every word
is guaranteed to be in the guess dictionary, so it's always typeable). Puzzles
are stored per (date, game, variant) so everyone gets the same one and shares
are comparable. Generation never blocks on or trusts the LLM for correctness.
"""

from __future__ import annotations

import base64
import hashlib
import json
import sqlite3
from pathlib import Path

_POOL = json.loads((Path(__file__).parent / "data" / "wordpool.json").read_text())

# Daily Word: 5 letters / 6 guesses · Long Word: 6 letters / 7 guesses.
WORD_VARIANTS = {"5": {"length": 5, "guesses": 6}, "6": {"length": 6, "guesses": 7}}


def _seed(*parts: str) -> int:
    return int(hashlib.sha256(":".join(parts).encode()).hexdigest(), 16)


def _recent_answers(conn: sqlite3.Connection, variant: str, limit: int) -> set[str]:
    rows = conn.execute(
        "SELECT payload_json FROM daily_puzzles WHERE game='word' AND variant=? "
        "ORDER BY puzzle_date DESC LIMIT ?",
        (variant, limit),
    ).fetchall()
    out = set()
    for r in rows:
        try:
            out.add(json.loads(r["payload_json"])["answer"])
        except (ValueError, KeyError, TypeError):
            pass
    return out


def _pick_answer(conn: sqlite3.Connection, date: str, variant: str) -> str:
    pool = _POOL.get(variant, [])
    recent = _recent_answers(conn, variant, max(1, len(pool) // 2))
    start = _seed(date, "word", variant) % len(pool)
    for i in range(len(pool)):
        cand = pool[(start + i) % len(pool)]
        if cand not in recent:
            return cand
    return pool[start]  # pool fully cycled — allow a repeat rather than fail


def _why(client, word: str) -> str | None:
    if client is None:
        return None
    try:
        msg = [
            {"role": "system", "content": "You write one short, warm, plain sentence (no preamble, no quotes) "
                                          "on why a given word is a hopeful or uplifting one to sit with."},
            {"role": "user", "content": f"Word: {word}"},
        ]
        text = (client.chat_text(msg) or "").strip().strip('"').replace("\n", " ")
        return text[:200] or None
    except Exception:  # noqa: BLE001 — flavor only; never block puzzle creation
        return None


def generate_word_puzzle(conn: sqlite3.Connection, date: str, variant: str, client=None) -> dict:
    """Ensure a Daily/Long Word puzzle exists for (date, variant). Idempotent.
    Code picks the answer; the LLM only adds the optional 'why' (with fallback)."""
    if variant not in WORD_VARIANTS:
        variant = "5"
    existing = conn.execute(
        "SELECT payload_json FROM daily_puzzles WHERE puzzle_date=? AND game='word' AND variant=?",
        (date, variant),
    ).fetchone()
    if existing:
        return json.loads(existing["payload_json"])
    answer = _pick_answer(conn, date, variant)
    payload = {
        "answer": answer,
        "why": _why(client, answer),
        "length": WORD_VARIANTS[variant]["length"],
        "guesses": WORD_VARIANTS[variant]["guesses"],
    }
    conn.execute(
        "INSERT OR IGNORE INTO daily_puzzles (puzzle_date, game, variant, payload_json) VALUES (?, 'word', ?, ?)",
        (date, variant, json.dumps(payload)),
    )
    conn.commit()
    row = conn.execute(
        "SELECT payload_json FROM daily_puzzles WHERE puzzle_date=? AND game='word' AND variant=?",
        (date, variant),
    ).fetchone()
    return json.loads(row["payload_json"])


def _b64(s: str | None) -> str | None:
    return base64.b64encode(s.encode()).decode() if s else None


def word_puzzle_response(conn: sqlite3.Connection, date: str, variant: str) -> dict:
    """API shape: answer/why lightly obfuscated (base64) so the day's word isn't
    sitting in plain network view. It's a calm, non-competitive game — not Fort Knox."""
    p = generate_word_puzzle(conn, date, variant)  # create on demand (no LLM) if missing
    return {
        "game": "word",
        "variant": variant,
        "date": date,
        "length": p["length"],
        "guesses": p["guesses"],
        "answer": _b64(p["answer"]),
        "why": _b64(p.get("why")),
    }


def generate_daily_puzzles(conn: sqlite3.Connection, date: str, client=None) -> int:
    """Cycle hook: pre-generate today's word puzzles (with the LLM 'why')."""
    made = 0
    for variant in WORD_VARIANTS:
        before = conn.execute(
            "SELECT 1 FROM daily_puzzles WHERE puzzle_date=? AND game='word' AND variant=?", (date, variant)
        ).fetchone()
        if not before:
            generate_word_puzzle(conn, date, variant, client=client)
            made += 1
    return made