"""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) — "
                                          "a calm or gently interesting little note about the given word: what it "
                                          "evokes, where we meet it in everyday life, or why it's pleasant 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.
# ---------------------------------------------------------------------------

_DIRS = [(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1), (1, 0), (1, 1)]

# Size tiers: bigger grid → more words → a longer sit. Built per-request from one
# stored theme+word list, so all three sizes share the day's theme.
WS_TIERS = {"small": {"grid": 8, "count": 6}, "med": {"grid": 11, "count": 9}, "large": {"grid": 14, "count": 13}}

# Curated fallbacks — calm and neutral everyday scenes, not just upbeat. ~13
# words each (4–8 letters, uppercase) so the large tier has enough to place.
_WS_FALLBACKS = [
    ("Around the house", ["TABLE", "CHAIR", "CLOCK", "SHELF", "COUCH", "LAMP", "PILLOW", "WINDOW",
                          "CARPET", "MIRROR", "CANDLE", "KETTLE", "DRAWER"]),
    ("At the beach", ["WAVES", "SHELL", "SANDY", "TIDE", "SHORE", "TOWEL", "BREEZE", "SUNSET",
                      "PEBBLE", "CORAL", "OCEAN", "SAILS", "PIER"]),
    ("In the kitchen", ["BREAD", "SPOON", "PLATE", "KETTLE", "FLOUR", "APRON", "WHISK", "SUGAR",
                        "BUTTER", "RECIPE", "SIMMER", "PANTRY", "TEAPOT"]),
    ("In the garden", ["BLOOM", "PETAL", "ROOTS", "LEAF", "GARDEN", "FLOWER", "SUNNY", "SEEDS",
                       "MEADOW", "SPROUT", "HEDGE", "TROWEL", "VINES"]),
    ("A walk outdoors", ["TRAIL", "MEADOW", "BROOK", "BIRDS", "BREEZE", "PEBBLE", "FOREST", "MAPLE",
                         "ACORN", "STREAM", "BRANCH", "VALLEY", "PATH"]),
    ("Making music", ["PIANO", "DRUMS", "CHOIR", "MELODY", "GUITAR", "VIOLIN", "SINGER", "BALLAD",
                      "RHYTHM", "ENCORE", "TEMPO", "NOTES", "SONG"]),
    ("Quiet calm", ["PEACE", "QUIET", "STILL", "SERENE", "REST", "SOOTHE", "GENTLE", "BREATHE",
                    "CALM", "HUSH", "DRIFT", "EASE", "DREAM"]),
    ("Small joys", ["SMILE", "LAUGH", "CHEER", "HAPPY", "MERRY", "DANCE", "DELIGHT", "GLOW",
                    "PLAY", "GRIN", "BEAM", "GLEE", "WARM"]),
]


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 word search. The theme can be uplifting OR just a "
                                          "pleasant everyday scene (e.g. 'Around the house', 'At the beach', "
                                          "'In the kitchen'). Reply exactly as two lines:\n"
                                          "THEME: <2-4 word theme>\nWORDS: W1, W2, ... W13\n"
                                          "Give 13 single real words, 4-8 letters, UPPERCASE, related to the theme, "
                                          "nothing negative or unpleasant, no phrases."},
            {"role": "user", "content": "Give me one calm 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
    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 theme + word list exists (idempotent). The per-size grid is
    built at request time, so one LLM call serves all three sizes."""
    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 dict.fromkeys(words) if w.isalpha() and 4 <= len(w) <= 8]
    payload = {"theme": theme, "words": words}
    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 _build_grid(words: list[str], size: int, seed: int) -> tuple[list[str], list[str]]:
    """Place words in a size×size grid (date-seeded, deterministic) and fill the
    rest. Returns (rows, placed_words). Every returned word is genuinely placed."""
    rng = random.Random(seed)
    grid: list[list[str | None]] = [[None] * size for _ in range(size)]
    placed = []
    for word in sorted(words, key=len, reverse=True):
        if len(word) > size:
            continue
        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)
                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))
    return ["".join(row) for row in grid], placed


def wordsearch_response(conn: sqlite3.Connection, date: str, size: str = "med") -> dict:
    """Public shape for a size tier: theme + placed words + grid. The grid is meant
    to be seen — the play is finding the words — so there's nothing to hide."""
    if size not in WS_TIERS:
        size = "med"
    p = generate_wordsearch_puzzle(conn, date)  # on-demand (curated fallback) if missing
    tier = WS_TIERS[size]
    usable = [w for w in p["words"] if len(w) <= tier["grid"]][:tier["count"]]
    grid, placed = _build_grid(usable, tier["grid"], _seed(date, "wordsearch", size))
    return {"game": "wordsearch", "date": date, "size": size, "theme": p["theme"],
            "words": placed, "grid": grid}


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