"""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 hashlib
import json
import random
import re
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 word_puzzle_response(conn: sqlite3.Connection, date: str, variant: str) -> dict:
    """Public puzzle shape — deliberately holds NO answer. Guesses are adjudicated
    server-side (see adjudicate_word_guess), so the day's word never sits in the
    network response for a curious user to read."""
    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"],
    }


def _color(guess: str, answer: str) -> list[str]:
    """Two-pass Wordle colouring: greens first, then presents limited by counts."""
    res = ["absent"] * len(answer)
    counts: dict[str, int] = {}
    for ch in answer:
        counts[ch] = counts.get(ch, 0) + 1
    for i, ch in enumerate(guess):
        if i < len(answer) and ch == answer[i]:
            res[i] = "correct"; counts[ch] -= 1
    for i, ch in enumerate(guess):
        if res[i] == "correct":
            continue
        if counts.get(ch, 0) > 0:
            res[i] = "present"; counts[ch] -= 1
    return res


def adjudicate_word_guess(conn: sqlite3.Connection, date: str, variant: str, guess: str, n: int) -> dict:
    """Colour a guess against the day's answer server-side. The answer (and 'why')
    are revealed ONLY once solved or the guesses are spent — never up front."""
    if variant not in WORD_VARIANTS:
        variant = "5"
    p = generate_word_puzzle(conn, date, variant)
    length, maxg, answer = p["length"], p["guesses"], p["answer"]
    guess = (guess or "").strip().lower()
    if len(guess) != length or not guess.isalpha():
        return {"error": "bad guess"}
    solved = guess == answer
    reveal = solved or n >= maxg
    return {
        "colors": _color(guess, answer),
        "solved": solved,
        "answer": answer if reveal else None,
        "why": p.get("why") if reveal else None,
    }


# ---------------------------------------------------------------------------
# Word Search — LLM proposes a theme + words, code validates and PLACES them in
# the grid (so it's always solvable). No answer to hide: the grid and word list
# are inherently visible; the play is finding them.
# ---------------------------------------------------------------------------

WORDSEARCH_SIZE = 10
WORDSEARCH_COUNT = 8
_DIRS = [(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1), (1, 0), (1, 1)]

# Curated fallbacks (all uppercase alpha, 4–8 letters) used if the LLM is thin.
_WS_FALLBACKS = [
    ("Kindness", ["KIND", "CARE", "GIVE", "SHARE", "GENTLE", "WARMTH", "THANKS", "FRIEND"]),
    ("In the garden", ["BLOOM", "PETAL", "ROOTS", "LEAF", "GARDEN", "FLOWER", "SUNNY", "SEEDS"]),
    ("Quiet calm", ["PEACE", "QUIET", "STILL", "SERENE", "REST", "SOOTHE", "GENTLE", "BREATHE"]),
    ("Bright skies", ["SUNNY", "CLOUD", "BREEZE", "LIGHT", "SHINE", "RAINBOW", "WARMTH", "DAWN"]),
    ("Small joys", ["SMILE", "LAUGH", "CHEER", "HAPPY", "MERRY", "DANCE", "DELIGHT", "GLOW"]),
]


def _ws_propose(client) -> tuple[str, list[str]] | None:
    """LLM proposes a theme + words; code disposes (alpha / length / dedup)."""
    if client is None:
        return None
    try:
        msg = [
            {"role": "system", "content": "You set up a calm, hopeful word search. Reply exactly as two lines:\n"
                                          "THEME: <2-4 word theme>\nWORDS: W1, W2, W3, W4, W5, W6, W7, W8\n"
                                          "Each word a single real word, 4-8 letters, UPPERCASE, related to the theme, no phrases."},
            {"role": "user", "content": "Give me one gentle, uplifting theme."},
        ]
        text = client.chat_text(msg) or ""
        theme, words = None, []
        for line in text.splitlines():
            s = line.strip()
            if s.upper().startswith("THEME:"):
                theme = s.split(":", 1)[1].strip()[:40]
            elif s.upper().startswith("WORDS:"):
                words = [w.strip().upper() for w in re.split(r"[,\s]+", s.split(":", 1)[1]) if w.strip()]
        words = [w for w in dict.fromkeys(words) if w.isalpha() and 4 <= len(w) <= 8]
        if theme and len(words) >= 6:
            return theme, words[:WORDSEARCH_COUNT]
    except Exception:  # noqa: BLE001 — fall back to a curated theme
        pass
    return None


def generate_wordsearch_puzzle(conn: sqlite3.Connection, date: str, client=None) -> dict:
    """Ensure today's word search exists. Idempotent. Code places every word, so
    the puzzle is guaranteed solvable; only placed words are returned."""
    existing = conn.execute(
        "SELECT payload_json FROM daily_puzzles WHERE puzzle_date=? AND game='wordsearch' AND variant=''", (date,)
    ).fetchone()
    if existing:
        return json.loads(existing["payload_json"])
    rng = random.Random(_seed(date, "wordsearch"))
    proposed = _ws_propose(client)
    theme, words = proposed if proposed else _WS_FALLBACKS[rng.randrange(len(_WS_FALLBACKS))]
    words = [w.upper() for w in words]

    size = WORDSEARCH_SIZE
    grid: list[list[str | None]] = [[None] * size for _ in range(size)]
    placed = []
    for word in sorted(words, key=len, reverse=True):
        for _ in range(400):
            dr, dc = rng.choice(_DIRS)
            r0, c0 = rng.randrange(size), rng.randrange(size)
            cells = [(r0 + dr * i, c0 + dc * i) for i in range(len(word))]
            if any(not (0 <= r < size and 0 <= c < size) for r, c in cells):
                continue
            if all(grid[r][c] in (None, word[i]) for i, (r, c) in enumerate(cells)):
                for i, (r, c) in enumerate(cells):
                    grid[r][c] = word[i]
                placed.append({"word": word, "cells": cells})
                break
    for r in range(size):
        for c in range(size):
            if grid[r][c] is None:
                grid[r][c] = chr(65 + rng.randrange(26))
    payload = {
        "theme": theme,
        "words": sorted((p["word"] for p in placed), key=len, reverse=True),
        "grid": ["".join(row) for row in grid],
        "size": size,
        "placements": placed,  # stored, not sent to the client
    }
    conn.execute(
        "INSERT OR IGNORE INTO daily_puzzles (puzzle_date, game, variant, payload_json) VALUES (?, 'wordsearch', '', ?)",
        (date, json.dumps(payload)),
    )
    conn.commit()
    row = conn.execute(
        "SELECT payload_json FROM daily_puzzles WHERE puzzle_date=? AND game='wordsearch' AND variant=''", (date,)
    ).fetchone()
    return json.loads(row["payload_json"])


def wordsearch_response(conn: sqlite3.Connection, date: str) -> dict:
    """Public shape: theme + word list + grid. The grid is meant to be seen — the
    play is finding the words — so there's nothing to hide here (no placements)."""
    p = generate_wordsearch_puzzle(conn, date)  # on-demand (curated fallback) if missing
    return {"game": "wordsearch", "date": date, "theme": p["theme"],
            "words": p["words"], "grid": p["grid"], "size": p["size"]}


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